Citation
Intelligibility of speech processed through the cochlea of fetal sheep in utero

Material Information

Title:
Intelligibility of speech processed through the cochlea of fetal sheep in utero
Creator:
Huang, Xinyan, 1964-
Publication Date:
Language:
English
Physical Description:
xii, 190 leaves : ill. ; 29 cm.

Subjects

Subjects / Keywords:
Auditory perception ( jstor )
Consonants ( jstor )
Fetus ( jstor )
Infants ( jstor )
Inner ear ( jstor )
Mutual intelligibility ( jstor )
Recordings ( jstor )
Sound ( jstor )
Uterus ( jstor )
Vowels ( jstor )
Cochlea ( lcsh )
Communication Sciences and Disorders thesis, Ph. D ( lcsh )
Dissertations, Academic -- Communication Sciences and Disorders -- UF ( lcsh )
Language acquisition -- Fetuses ( lcsh )
Sheep -- Fetuses ( lcsh )
Sheep -- Physiology ( lcsh )
Genre:
bibliography ( marcgt )
non-fiction ( marcgt )

Notes

Thesis:
Thesis (Ph. D.)--University of Florida, 1999.
Bibliography:
Includes bibliographical references (leaves 178-189).
General Note:
Typescript.
General Note:
Vita.
Statement of Responsibility:
by Xinyan Huang.

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
Copyright [name of dissertation author]. Permission granted to the University of Florida to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Resource Identifier:
030474611 ( ALEPH )
43413630 ( OCLC )

Downloads

This item has the following downloads:


Full Text










INTELLIGIBILITY OF SPEECH PROCESSED THROUGH
THE COCHLEA OF FETAL SHEEP IN UTERO













By

XINYAN HUANG


A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY

UNIVERSITY OF FLORIDA

























Dedicated to my wife, Min Feng














ACKNOWLEDGMENTS


First and foremost, I would like to express my sincerest appreciation and gratitude

to my committee chairman and mentor, Dr. Kenneth Gerhardt, for his constant guidance,

support, encouragement, and invaluable contribution to my professional and personal

development. I would like to respectfully thank Dr. Robert Abrams for the constant

support and encouragement he gave me regarding science, academics, and American

culture.

Secondly, my thanks go to my committee members, Dr. Scott Griffiths, Dr.

Francis Joseph Kemker, and Dr. Kyle Rarey, for their thoughtful suggestions and support.

I would like to thank the faculty and staff in the Department of Communication Sciences

and Disorders and in the Perinatology Research Laboratory for their valuable help during

this study. I especially thank Mr. Rodney Housen for his computer programming

assistance.

Finally, I wish to express my deepest appreciation and thanks to my wife.

Without her love, patience, understanding, and continued support, this endeavor would

have not been possible. My love and appreciation are imparted to my parents whose

inspiration has kept me in constant pursuit of my dreams.















TABLE OF CONTENTS
page


ACKNOW LEDGM ENTS .......................................... ............................... iii

L IST O F T A B L E S ...................................................................... .............................. vi

LIST O F FIG U RES ....................................................................... ....................... ix

A B ST R A C T .................................................................................... ............................ xi

CHAPTERS

1 IN T R O D U C TIO N .................................................................... ........................ ......

2 REVIEW OF LITERATURE ............................ .........................6

Fetal H hearing ........................................................................... .......................... 6
Development of the Auditory System ........................ .........................6
Development of the Place Principle .................... .........................9
Central Auditory System ...........................................................13
Fetal Behavioral Response to Sound ...................................... ........................14
Fetal Sound Enviroment .................... .....................................16
Intrauterine Background Noise ................................... ......................16
Sound Transmission into the Uterus ............................ ........................19
Fetal Sound Isolation ..................................................... .......................... 21
Route of Sound Transmission into the Fetal Inner Ear ........................................23
Model of Fetal Hearing .................................................................................25
Intelligibility of Speech Sounds Recorded within the Uterus .............................27
Fetal Auditory Experiences and Learning ......................... ...........................31
Prenatal Effects of Sound Experience .......................... ........................ 31
Postnatal Effects of Prenatal Sound Experience ................................................ 35
Speech Perception .................................................................................................44
Speech Perception in Infancy .................... .. ................................44
Characteristic of Speech ...................... ....................................45
Intelligibility of Speech ..................... ...................................... 48

3 MATERIALS AND METHODS ................................... .......................56

Surgery ........................................................................................................................56

iv









Recording Speech Stimuli ................................... ...................................... 58
Perceptual Testing ................................................................ ...........................62
Subjects ............................................................................ ............................. 62
Speech Stim uli .................................................................. 62
Procedures .................................... ... .. ... ................. 64
Data Analyses ................................ .......... ....................65
Statistical A analyses .................................................... .. ........................... 65
Information Analyses ........................................ .... ................. .. 67
Acoustic Analyses .....................................................68

4 RESULTS AND DISCUSSION ....................... .. ............................. 70

Intelligibility ........................................ ............................ .. ..70
Consonant Feature Transmission ................................. ............. ...........94
Acoustic Analyses of Vowel Transmission ............................................. ...........117

5 SUMMARY AND CONCLUSIONS ........................................ .. ....153

APPENDICES

A SUBJECT RESPONSE SHEET .......................... ............. .............158

B RAW DATA FROM SUBJECT RESPONSE FORMS ........................................161

C RAW DATA FROM ACOUSTIC ANALYSES OF VOWELS .............................. 169

R EFEREN CES ........................................................... ............... .................... ..............178

BIOGRAPHICAL SKETCH .................................. ...... ......................190














LIST OF TABLES


Table pge

3-1 Perceptual tests ................................................................ ..........................63

4-1 VCV stimulus intelligibility scores ............................ .........................76

4-2 CVC stimulus intelligibility scores .................................. ....................77

4-3 ANOVA summary table for VCV stimuli .......................... ......................78

4-4 Post hoc multiple comparisons (Newman-Keuls test) for VCV stimuli ...............79

4-5 ANOVA summary table for CVC stimuli .......................... ......................80

4-6 Post hoc multiple comparisons (Newman-Keuls test) for CVC stimuli ...............81

4-7 Consonant confusion matrix for male talker, recorded in air at 105 dB SPL .......95

4-8 Consonant confusion matrix for male talker, recorded in air at 95 dB SPL .........96

4-9 Consonant confusion matrix for male talker, recorded in the uterus at 105 dB
SPL ........................................................................................................................97

4-10 Consonant confusion matrix for male talker, recorded in the uterus at 95 dB
S P L .................................................................................. ................................98

4-11 Consonant confusion matrix for male talker, recorded from CM-ex utero at 105
dB S P L ............................................................................ ................................99

4-12 Consonant confusion matrix for male talker, recorded from CM-ex utero at 95 dB
SPL ...................................................................................................................... 100

4-13 Consonant confusion matrix for male talker, recorded from CM-in utero at 105
dB S P L ....................................................................... ..................................10 1

4-14 Consonant confusion matrix for male talker, recorded from CM-in utero at 95 dB
S P L ................................................................................. ..............................102

vi










4-15 Consonant confusion matrix for female talker, recorded in air at 105 dB SPL ..103

4-16 Consonant confusion matrix for female talker, recorded in air at 95 dB SPL ....104

4-17 Consonant confusion matrix for female talker, recorded in the uterus at 105 dB
S P L ................................................................................. .. ............................10 5

4-18 Consonant confusion matrix for female talker, recorded in the uterus at 95 dB
S P L ................................................................................. ...............................10 6

4-19 Consonant confusion matrix for female talker, recorded from CM-ex utero at 105
dB S P L ......................................................................... ................................. 107

4-20 Consonant confusion matrix for female talker, recorded from CM-ex utero at 95
dB SPL ...................................................................... ...............108

4-21 Consonant confusion matrix for female talker, recorded from CM-in utero at 105
dB SPL .......................................................................... ...............................109

4-22 Consonant confusion matrix for female talker, recorded from CM-in utero at 95
dB SP L .......................................................................... ................................110

4-23 Conditional percentage of voicing, manner, and place information received (of
bits sent) for each talker, recording location, and stimulus level condition for the
nonsense syllables (VCV) ................................... ...........................112

4-24 Average fundamental frequencies (F0) and first three formant frequencies (FI, F2,
F3) for five vowels produced by each talker and recorded in air ......................128

4-25 Mean and standard deviation (S.D.) of relative intensity levels (dB) of
fundamental frequency (F0) and first three formant frequencies (F,, F2, F,) for
vowel /i/ produced by each talker at different recording sites in the 105 dB
condition .................................................... .............................................129

4-26 Mean and standard deviation (S.D.) of relative intensity levels (dB) of
fundamental frequency (F0) and first three formant frequencies (F,, F2, F3) for
vowel /I/ produced by each talker at different recording sites in the 105 dB
condition ....................................................... ..........................................135

4-27 Mean and standard deviation (S.D.) of relative intensity levels (dB) of
fundamental frequency (F0) and first three formant frequencies (Fi, F2, F3) for
vowel /e/ produced by each talker at different recording sites in the 105 dB
condition ............................................................................... ..................138

vii









4-28 Mean and standard deviation (S.D.) of relative intensity levels (dB) of
fundamental frequency (Fo) and first three formant frequencies (F,, F2, F3) for
vowel /a/ produced by each talker at different recording sites in the 105 dB
condition ............................................................................. ..................143

4-29 Mean and standard deviation (S.D.) of relative intensity levels (dB) of
fundamental frequency (Fo) and first three formant frequencies (F1, F2, F) for
vowel /A/ produced by each talker at different recording sites in the 105 dB
condition .................................................... ............... ..........................146

4-30 Summary of acoustic analyses of vowels .....................................................150














LIST OF FIGURES


Figure p

3-1 Schematic drawing showing the animal and the setup of devices for stimulus
generation, stimulus measurement, and recording in air, in the uterus, and from
the fetal inner ear cochlearr microphonic) ......................... ......................59

3-2 Examples of CMs evoked by airborne pure tones at 0.5 and 2.0 kHz ..................61

3-3 The frequency responses of two types of earphones .............................................66

4-1 Mean percent intelligibility of VCV nonsense stimuli spoken by a male and a
female talker recorded in air, in the uterus, from the fetal CM ex utero, and from
fetal CM in utero at two airborne stimulus levels ............................................... 72

4-2 Mean percent intelligibility of CVC words spoken by a male and a female talker
recorded in air, in the uterus, from the fetal CM ex utero, and from fetal CM in
utero at two airborne stimulus levels ............................ ...............................74

4-3 Mean percent intelligibility of VCV nonsense stimuli spoken by a male and a
female talker recorded in air, in the uterus, from the fetal CM ex utero, and from
fetal CM in utero when combining two airborne stimulus levels .......................84

4-4 Mean percent intelligibility of CVC words spoken by a male and a female talker
recorded in air, in the uterus, from the fetal CM ex utero, and from fetal CM in
utero when combining two airborne stimulus levels ..........................................87

4-5 Conditional percentage of voicing, manner and place information received for a
male (M) and a female (F) talker; in air (A), in the uterus (U), from the fetal CM
ex utero (X), and from the fetal CM in utero (I); at 105 dB (H) and 95 dB (L)
SPL .......................................................... ......................................... 114

4-6 Spectrographic recordings of "Mark the word lash" at different recording
conditions ...................................................................... .. ........................ 119

4-7 Mean of intensity levels (dB relative) of fundamental frequency (F0) and first
three formant frequencies (F,, F2, and F3) for vowel /i/ produced by both talkers
recorded at different locations at 105 dB SPL ............................................131

ix









4-8 Mean of intensity levels (dB relative) of fundamental frequency (F0) and first
three formant frequencies (FI, F2, and F3) for vowel /I/ produced by both talkers
recorded at different locations at 105 dB SPL ..................................................137

4-9 Mean of intensity levels (dB relative) of fundamental frequency (Fo) and first
three formant frequencies (F,, F2, and F3) for vowel /s/ produced by both talkers
recorded at different locations at 105 dB SPL .................................................140

4-10 Mean of intensity levels (dB relative) of fundamental frequency (F0) and first
three formant frequencies (F,, F,, and F3) for vowel /x/ produced by both talkers
recorded at different locations at 105 dB SPL ...................................................145

4-11 Mean of intensity levels (dB relative) of fundamental frequency (F0) and first
three formant frequencies (F,, F2, and F,) for vowel /A/ produced by both talkers
recorded at different locations at 105 dB SPL ................................................. 148














Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy

INTELLIGIBILITY OF SPEECH PROCESSED THROUGH
THE COCHLEA OF FETAL SHEEP IN UTERO

By

Xinyan Huang

August 1999

Chairman: Kenneth J. Gerhardt
Major Department: Communication Sciences and Disorders

The intelligibility of speech stimuli recorded from the fetal sheep inner ear

cochlearr microphonic, CM) in utero was determined perceptually using a group of

untrained judges. A fetus was prepared for acute recordings during a surgical procedure.

Two separate lists, one of meaningful and one of nonmeaningful speech, were spoken by a

male and a female talker, delivered through a loudspeaker to the side of a pregnant ewe,

and recorded with an air microphone, a hydrophone placed inside the uterus, and an

electrode secured to the round window of the fetus in utero. Perceptual test audio compact

discs (CDs) generated from these recordings were played to 139 judges.

The intelligibility of the phonemes recorded in air was significantly greater than the

intelligibility of these stimuli when recorded from within the uterus. The intelligibility of

the phonemes recorded from CM ex utero was significantly greater than from CM in utero.

Overall, male and female talker intelligibility scores recorded within the uterus averaged

xi








91% and 85%, respectively. When recorded from the fetal CM in utero, intelligibility

scores averaged 45% and 42% for the male and female talkers, respectively.

An analysis of the transmission of consonant feature information revealed that

"voicing" is better transmitted into the uterus and into the fetal inner ear in utero than

"manner" or "place." Voicing information for the male, as well as manner and place

information, was better preserved in the fetal inner ear in utero than for the female.

Spectral analyses of vowels showed that the fundamental frequency (F0) and the first

three formants (F,, F2, and F,) were well preserved in the uterus recordings for both talkers,

but only F0, F|, and F, (< 2000 Hz) were perceived in the fetal inner ear in utero. Only the

lower frequency contents of vowels were present in fetal inner ear recordings.

This study demonstrated the presence of external speech signals in the fetal inner

ear in utero and described the type of phonetic information that was detected at the fetal

inner ear in utero.














CHAPTER 1
INTRODUCTION



There is overwhelming evidence that the human fetus detects and responds to

sound in utero (Querleu et al., 1989; Hepper, 1992; Lecanuet and Schaal, 1996). Studies

in pregnant humans (Walker, Grimwade and Wood, 1971; Querleu et al., 1988a; Richards

et al., 1992) and sheep (Armitage, Baldwin and Vince, 1980; Vince et al., 1982, 1985;

Gerhardt, Abrams and Oliver, 1990) have shown the existence of a rich diversity of

sound in the fetal environment, heavily dominated by the mother's voice and other

internal noises and permeated by varied rhythmic and tonal sounds from the external

environment. The human fetus has a well-developed hearing mechanism by the sixth

month of gestation (Rubel, 1985a; Pujol and Uziel, 1988; Pujol, Lavigne-Rebillard and

Uziel, 1990). During the last trimester, sound exposure may have a pronounced effect on

fetal behavior and central nervous system maturation. Speech perception and voice

recognition by the newborn may result directly from its prenatal experience (Fifer and

Moon, 1988, 1995).

Linguistic theorists have proposed two alternative hypotheses regarding language

development that infants upon birth are equipped with either a generalized auditory

mechanism or a specialized speech-specific mechanism designed for perception of

speech. Some theorists hold that human infants are born with a "speech module," a

mechanism designed specifically for processing the complex and intricate acoustic








signals needed by humans to communicate with one another (Liberman, 1982; Fodor,

1983; Liberman and Mattingly, 1985; Wilkins and Wakefield, 1995; Fowler, 1996). An

alternative theory of the neonate's initial state suggests that infants enter the world

without specialized mechanisms dedicated to speech and language, but rather respond to

speech using general sensory, motor, and cognitive abilities (Aslin, 1987; Kuhl, 1987,

1992; Jusczyk 1996; Ohala, 1996; Fitch, Miller and Tallal, 1997). Which theory, if

either, applies to the human fetus is not known. What is known is that the fetus is

beginning the dynamic process of acquiring the necessary skills for speech and language

acquisition during prenatal life in utero (Querleu et al., 1989; Lecanuet, Granier-Deferre

and Busnel, 1991; Lecanuet and Schaal, 1996).

The maternal voice is a naturally occurring and salient stimulus in utero that

occurs during a crucial time period of fetal ontogeny (Querleu et al., 1988a; Benzaquen et

al., 1990; Richards et al., 1992) in which several psychobiological systems, including the

auditory system, are developing. The immediate effects of exposure to the mother's

voice on the fetus may provide a way of tracking auditory system development, as well as

measuring fetal ability to process sensory information (Fifer and Moon, 1988, 1994,

1995). Fetal auditory discrimination has also led to the hypothesis that prenatal

experience with auditory stimulation is the precursor to postnatal linguistic development

(Cooper and Aslin, 1989; Querleu et al., 1989; Ruben, 1992; Abrams, Gerhardt and

Antonelli, 1998).

DeCasper and his colleagues (DeCasper and Fifer, 1980; DeCasper and Prescott,

1984) demonstrated that newborn infants preferred their mother's voice over that of other

talkers. While this preference was assumed to be the product of in utero exposure to the








mother's voice and suggested that the fetus detected maternal vocalizations and retained

memories of her speech patterns, it is not known what speech information actually

reaches the fetal inner ear nor the extent to which the auditory system responds to

externally generated speech. Querleu et al. (1988b) and more recently Griffiths et al.

(1994) reported on the intelligibility of speech recorded with a hydrophone in the human

(Querleu et al., 1988b) and sheep (Griffiths et al., 1994) uterus. In both studies, the

recordings were played back to juries of normal listeners and speech intelligibility was

calculated from their responses. The intelligibility of in utero recordings of speech was

poorer than that of air recordings because the acoustic signature of human speech is

modified by the abdominal wall, uterus, and amniotic fluids as it passes from air to the

fetal head. The attenuation properties of the abdomen and uterus can be modeled as a

low-pass filter with a high frequency cutoff at 250 Hz and a rejection rate of

approximately 6 dB/octave (Gerhardt, Abrams and Oliver, 1990).

While the results of these studies reflect the perceptibility of the speech energies

present in the amniotic fluid, they do not specify what speech energy might be present at

the level of fetal inner ear. Measures of acoustic transmission to the fetal inner ear are

quite limited at present (Gerhardt et al., 1992). Much work needs to be completed before

conclusions can be drawn regarding what speech energies reach and are able to be

perceived by the fetus.

The present experiment was designed to evaluate the intelligibility of speech

produced through a loudspeaker and recorded with an electrode secured to the fetal sheep

round window. The electrode recorded a bioelectric potential called the cochlear

microphonic (CM). The CM is generated at the level of the hair cells and mimics the







4
input in amplitude and frequency (Gulick, Gescheider and Frisina, 1989). Recordings of

the CM represent the time displacement patterns of the basilar membrane and reflect the

initial response of the auditory periphery. The hypothesis is that speech is further

degraded as it passes into the inner ear. Sheep were used in this study not only because

sound attenuation characteristics of the abdominal contents of pregnant sheep are similar

to those of pregnant women (Armitage, Baldwin and Vince, 1980; Querleu et al., 1988a;

Gerhardt, Abrams and Oliver, 1990; Richards et al., 1992), but also because of the

precocious hearing and the similarity of auditory sensitivity to humans. Sheep's hearing

is only slightly poorer than that of humans for frequencies below about 8000 Hz

(Wollack, 1963). The objective of this study was to determine what speech information

was transmitted into the uterus and presented within the inner ear of the sheep fetus in

utero.

The following hypotheses were tested:

I. The intelligibility of monosyllabic words and nonsense syllables will be reduced when

recorded in the uterus compared to air.

2. The intelligibility of monosyllabic words and nonsense syllables will be reduced when

recorded from the fetal inner ear in utero compared to uterus.

3. The intelligibility of a male talker will be greater than the intelligibility of a female

talker when recorded in the uterus and from the fetal inner ear in utero.

4. Transmission into the uterus and fetal inner ear will be greater for voicing

information than for manner and place information.







5
5. The transmission of voicing, manner, and place information will be better for males

than for females when recorded in the uterus and from the inner ear of the fetus in

utero.

6. Acoustic energy in the second and third formants of vowels measured in air for both

male and female talkers will be reduced when recorded in the uterus, and will be

reduced to the noise floor when recorded from the fetal inner ear in utero.














CHAPTER 2
REVIEW OF LITERATURE



The human, unlike most mammalian species, is born with highly developed

auditory sensitivity. By the 20th week of gestation, the structures of the peripheral

auditory system, including the outer, middle, and inner ear, are anatomically like that of

an adult, thus enabling the fetus to detect sounds during the last trimester of pregnancy

(Rubel, 1985a; Pujol and Uziel, 1988; Pujol, Lavigne-Rebillard and Uziel, 1990).

Responsiveness of the fetus to auditory stimuli begins during the 24th week of gestation

(Birnholz and Benacerraf, 1983; Shahidullah and Hepper 1993). Maturation of auditory

processing capabilities takes place through prenatal and perinatal periods. An

appreciation of the process of auditory development is important not only for an

understanding of the normal auditory system, but also for an understanding of the impact

of prenatal sound experience on the postnatal development, from structural, functional to

behavioral development (Lecanuet and Schaal, 1996).



Fetal Hearing



Development of the Auditory System

The earliest embryological signs of the human auditory apparatus are thickenings

of the ectoderm on the sides of the head, bilaterally, called the auditory placodes. About








the 23rd day of gestational age (GA), each placode begins to invaginate to form the

auditory pit, which then splits off from the overlying ectoderm to form an otocyst at the

30th day. At about 4 to 5 weeks, the otocyst divides into two parts, the vestibular portion

and the cochlea. During the 8th through 11th week, the two and a half coils of the

cochlea are attained. Complete maturation of sensory and supporting cells in the cochlea

does not occur until the 20th week when the cochlea reaches adult size (Northern and

Downs, 1991; Peck, 1994). Cytodifferentiation occurs during the 9th to 10th weeks

within the cochlear duct, where there is a thickening of epithelium. From the 3rd to the

5th month, the thickening epithelium differentiates into the distinct receptor and

supporting cells of the organ of Corti.

Comparing with that found in other mammals when the first responses to sound

can be evoked, the human cochlea has achieved a functional stage by 20 weeks of

gestation (Pujol and Uziel, 1988). At this time, the cochlea may have high thresholds and

very poor discriminative properties. It is thus not possible to detect signs of cochlear

activity using behavioral or electrophysiological methods, which explains why the first

responses to acoustic stimulation can only be recorded a few weeks later (Starr et al.

1977; Bimholz and Benacerraf, 1983).

Rubel (1984) indicated that no single event triggers the onset of cochlear function.

Many simultaneous and synchronous events contribute to the maturation of mechanical

and neural properties. These events include thinning of the basilar membrane, formation

of the inner spiral sulcus, maturation of the pillar cells, freeing of the inferior margin of

the tectorial membrane, opening of the tunnel of Corti, formation of Nuel's spaces,







8
differentiation of the hair cells, establishment of mature cilia structure, and the maturation

of synapses (Pujol and Hilding, 1973).

These final maturational events do not occur simultaneously throughout the length

of the cochlea. There are two general developmental gradients in the differentiation and

maturation of cochlea hair cells and their neural connections. The first is the classic basal

to apical gradient, that at each maturation stage the mid-basal region develops first and

spreads in both directions, with the apex maturating last. The second gradient is from

inner hair cells (IHCs) to outer hair cells (OHCs); IHCs differentiate and develop first

(Pujol and Uziel, 1988; Pujol, Lavigne-Rebillard and Lenoir, 1998). This does not

necessarily imply that IHCs are the first to achieve all adult characteristics. For example,

the completion of the ciliogenesis process occurs first at OHCs. Generally, synapse

formation on IHCs occurs early and undergoes only minor modifications thereafter. The

OHCs are initially surrounded by afferent terminals, which are gradually replaced by

numerous efferents. Then the large calyciform efferent terminals form, typical of the

mature cochlea.

Based on cat studies, the functional development of the auditory system is divided

into three stages (Walsh and McGee, 1990). During the first stage, which is through the

cats' first postnatal week and corresponds to the second trimester of human gestation,

auditory responses can be elicited, but hearing thresholds are very high and well outside

of the range of naturally occurring acoustic events. Response sensitivity does not

significantly improve during this stage and the responsive frequency range is limited to

low-frequency and mid-frequency sounds. During the second stage, in cats through the

third postnatal week and in humans probably through the final trimester, rapid maturation








of auditory function takes place. Thresholds decrease substantially, the adult frequency

response range is attained, and response duration is perceived. These changes are

attributable in large part to cochlear maturation, and to a lesser extent to maturation of the

central auditory system. During the final developmental stage, the remaining

components within the auditory system mature slowly and myelination is complete. The

adult characteristics for the cat are acquired during the second month after birth.

However, further maturation of the human auditory system occurs after birth and

continues for the next few years.



Development of the Place Principle

Young mammals do not respond initially to all of the frequencies to which they

respond as adults. Generally, initial responses are elicited by low- or mid-frequency

sounds. As development proceeds, responsiveness to both lower and higher frequencies

increases. Responsiveness to the highest frequencies develops last (Rubel, 1978; Rubel,

1985a). However, cochlear differentiation occurs first in basal or mid-basal high-

frequency regions, then spreads in both directions. The last part of the cochlea to

undergo differentiation is the apical, low-frequency region (Rubel, 1978). A similar

differentiation gradient also occurs in eighth-nerve ganglion cells and cochlear nuclei;

regions receiving input from the basal, high-frequency region of the cochlea mature prior

to the development of apical projection areas (Romand and Romand, 1982; Rubel, Smith

and Miller, 1976; Schweitzer and Cant, 1984).

A paradox of cochlear development was pointed out by Rubel in 1978. During

the early stages of hearing, the base or mid-basal region of the cochlea and the basal








representation areas of the central nervous system are the first to respond to sound.

However, these areas are initially most sensitive to relatively low-frequency sound, even

though this region of the cochlea has been tuned to being respond to high-frequency

sound. With maturation of both mechanical and neural properties of the cochlea, the

place code gradually shifts toward the apex until mature organization is achieved.

In an effort to understand more fully the mechanisms underlining this apparent

paradox, Rubel and Ryals (1983) studied the position of hair cell damage produced by

high-intensity pure tones of three different frequencies on three age groups of young

chicks. The results showed that the position of maximum damage produced by each

frequency shifted systematically toward the apex as a function of age. This experiment

was carried out during the late stages of hearing development in the chick, corresponding

to the perinatal or immediate postnatal periods in humans. On a related study, Lippe and

Rubel (1983) evaluated the relationship between the location of neurons of the brainstem

in chicks (nucleus magnocellularis and nucleus laminaris) and the frequency to which

they were most sensitive. In both nuclei of the brainstem, embryonic neurons were most

sensitive to tones 1-1.5 octaves below the frequencies that activate the same neurons one

to two weeks after hatching. These two experiments provided support for the model of

cochlear development offered by Rubel in 1978.

Later investigations, again in chicks, revealed some inconsistencies in the theory

developed by Rubel (1978). The discrepancy between these studies may be attributed to

developmental changes in middle-ear transfer function, the changes of the physical size

of the basilar papilla, and temperature effects on frequency tuning (Riibsamen and Lippe,

1998). Currently, there are two alternative hypotheses for the development of the








cochlear frequency map in chicks. One theory suggests that frequency representation

does not change developmentally. Another theory proposes that frequency representation

shifts developmentally but that the shift is restricted to regions along the papilla that code

mid- and high-frequency sounds, while low-frequency sounds are always represented at

the apical location. Responses to mid-frequency sounds occur progressively more

apically as the base becomes responsive to high-frequency sounds (Riibsamen and Lippe,

1998).

Dallos and his colleagues (Harris and Dallos, 1984; Yancey and Dallos, 1985;

Arijmand, Harris and Dallos, 1988) studied the developmental change of the place code

in gerbils. They reported that the cutoff frequency of the cochlear microphonic (CM) and

the summating potential in the mid-basal turn (15 kHz location) increased about 1.5 to 2

octaves between the onset of sound evoked response on the 12th postnatal day when

frequency representation becomes adultlike on the 21st postnatal days. But, the cutoff

frequency of the CM at a second turn location (2.5 kHz) remains stable during

development.

More direct evidence was provided by the finding that the characteristic

frequencies of spiral ganglion neurons at a constant basal cochlear location increased up

to 1.5 octaves between the second and third postnatal weeks (Echteler, Arjmand and

Dallos, 1989). It has been uniformly reported that tonotopic organization in the mid- and

high-frequency regions of the cochlea and central auditory nuclei changes during

development. However, tonotopy in the cochlear apex and its central projection sites

appeared to be developmentally stable (Rtbsamen and Lippe, 1998). As a result of this

new information, two updated explanations for the place code have been proposed. First,








the shifts in frequency code are attributed to maturational changes in the passive

mechanical properties of the cochlea (Lippe and Rubel, 1985). Second, Romand (1987)

proposed that the shifts in frequency organization should be attributed to maturational

changes in cochlear active processes mediated by the outer hair cells. Both factors were

examined by comparing tone-evoked distortion product otoacoustic emissions before and

after an injection of furosemide in gerbils between 14 days old and adult (Mills, Norton

and Rubel, 1994; Mills and Rubel, 1996). Results showed that increase in the passive

base cutoff frequency rather than maturational changes in active processes accounts for

the place code shift.

Currently, a revised model of the place code shift hypothesis for mammals, based

on the evidence from developmental studies of central and peripheral frequency maps, is

suggested. The entire length of the basilar membrane is capable of supporting a

traveling wave at or very soon after the onset of hearing. Frequency representation in the

cochlear apex is developmentally stable. From the very onset of hearing, the apex

responds to its correct (adult) frequency, although the sensitivity and sharpness of tuning

are reduced. In contrast, the more basal regions of the cochlea, mid- and high-frequency

regions, undergo a shift in frequency organization such that each location becomes

responsive to progressively higher frequencies in older animals. Shifts in the cochlear

map result largely from maturational changes in the mechanical properties of the cochlear

partition. The active mechanism also contributes to the shift in frequency organization

(Riibsamen and Lippe, 1998).








Central Auditory System

The development of the central auditory system and its relation to the maturation

of the auditory periphery has been studied in animal models (Rubel, 1985a). Normal

growth of central auditory neural elements requires an intact peripheral mechanism.

However, initial stages of development of the auditory centers in the central nervous

system are independent of peripheral regulation. The proliferation and migration of

neurons in the central auditory system do not depend on the cochlea. The major

pathways are established prior to or simultaneously with the development of peripheral

function. Marty (1962) showed that in newborn kittens, the cortical evoked responses

were elicited by electrical stimulation of the auditory nerve. The cochlea is immature at

this time, and it is not possible to reliably evoke cortical responses to sound.

Following the establishment of functional connections between the periphery and

the central nervous system, the continued maturation of neurons is highly dependent on

the functional integrity of their afferents. Rubel and his colleges (Rubel, Smith and

Miller, 1976; Jackson, Hackett and Rubel, 1982) revealed that in chicks after the time

when functional connections normally are established between the eighth nerve and the

cochlear nucleus cells, the absence of peripheral innervation caused rapid and severe

degeneration of the neurons. Abrams et al. (1987) demonstrated the impairment of

glucose utilization in the auditory as well as nonauditory portions of the brain after

cochlear ablation in fetal sheep.








Fetal Behavioral Response to Sound

The human fetal auditory system is functional by the start of the third trimester

(Bimholz and Benacerraf, 1983). Although direct measurement of fetal hearing cannot

be made by electrophysiological methods, indirect methods have been applied to measure

fetal behavioral responses to sound stimuli. The most common approaches used to

measure responsiveness to sound include the monitoring of fetal heart rate (Johansson,

Wedenberg and Westen, 1964), fetal movement (Shahidullah and Hepper, 1994) and

reflexive responses such as the auropalpebral reflex (Bimholz and Benacerraf, 1983).

Fetal movements in response to sound and to vibroacoustic stimulation or to both relate

closely to the development of fetal audition (Gelman et. al, 1982; Hepper and

Shahidullah, 1994a).

In 1983, Birnholz and Benacerraf measured fetal responsiveness to an electronic

artificial larynx (EAL) applied directly to the maternal abdomen. The auropalpebral

reflex (blink-startle response) of the 236 fetuses tested from 16 to 32 weeks of gestation

was monitored by ultrasonography. Reflexive eye movements were first elicited in some

fetuses between 24 and 25 weeks of gestational age, and responses increased in frequency

after 26 weeks. Consistent responses to EAL were observed after 28 weeks of

pregnancy.

Shahidullah and Hepper (1993) examined the response of fetuses to a 110 dB SPL

broadband air-borne stimulus (80-2000 Hz) at 15, 20 and 25 weeks of gestation. Using a

response, which consists of a movement within 4.5 seconds of the onset of the stimulus,

the investigators found that fetuses heard the noise at 25 weeks of gestation, but not

earlier. However, when the stimulus was changed from a single pulse to a series of ten








pulses with two-second duration and ten-second inter-stimulus interval, a response was

observed at 20 weeks of pregnancy. Thus, very early diffuse motor responses of slow

latency were appeared as early as 20 weeks of gestation; by 25 weeks the response had

become an immediate auditory startle response.

The auditory system of the fetus does not just begin to function uniformly across

frequency. While the adult range of audibility is from 20 Hz to 20,000 Hz with greatest

sensitivity in the 300 to 3000 Hz range, the fetus hears a much more limited range.

Hepper and Shahidullah (1994b) examined the range of frequencies and intensity levels

required to elicit human fetal movements as assessed with ultrasonography. Out of 450

fetuses involved in the study, only one demonstrated a response to a 500 Hz tone at 19

weeks gestational age. The range of frequencies to which the fetus responded expanded

first to low frequencies, 100 Hz and 250 Hz, and then to high frequencies, 1000 Hz and

3000 Hz. By 27 weeks, 96% of the fetuses responded to tones at 100, 250 and 500 Hz,

while none responded to frequencies at 1000 and 3000 Hz. It was not until weeks 29

(1000 Hz) and 31 (3000 Hz) that the fetuses responded to these tones. Between 33 and

35 weeks, the fetuses responded 100% of the time to presentations of 1000 and 3000 Hz.

As gestation progressed from 19 to 37 weeks, the fetuses exhibited responsiveness to

frequencies over a progressively wider frequency range. During this period, there was a

significant decrease (20-30 dB) in the intensity level of stimulus required to elicit a

response for all frequencies. This finding suggests that fetal hearing to pure tones

becomes more sensitive as gestation proceeds.

The ability to discriminate frequency is fundamental for the interpretation of

auditory information and for the development of speech perception and speech








production. Adults can detect changes of less than 2 Hz when the primary tone is

between 100 Hz and 1000 Hz (Yost, 1994). The development of frequency

discrimination in the human fetus was studied by Shahidullah and Hepper (1994) through

the method habituation/dishabituation measurement. Ultrasound imaging was used to

monitor fetal response to 250 and 500 Hz tones at 27 and 35 weeks gestation (N=48).

They found that 35-week-old fetuses were capable of distinguishing between the two

pure tones. However, fetuses at 27 weeks were not as likely to demonstrate this same

discrimination.

Shahidullah and Hepper (1994b) also evaluated the abilities of 36 fetuses to

differentiate between speech sounds. Fetuses at 27 and 35 weeks of age were exposed to

a pair of pre-recorded syllables presented at 110 dB SPL through an earphone placed on

the maternal abdomen. Half of the fetuses received /baba/ as their habituating stimuli and

/bibi/ as their dishabituating stimulus and vice versa. Although all fetuses habituated,

fewer stimuli were required for habituation for the 35-week-old fetuses than the 27-week-

olds, and a greater number of the 35-week-old fetuses (17 of 18) demonstrated

dishabituation compared to the younger ones (3 of 18). Thus, fetuses at thirty-five weeks

possess the ability to discriminate among different phonemes.



Fetal Sound Environment



Intrauterine Background Noise

The fetal sound environment is composed of a variety of internally generated

noises, as well as many sounds originating from the environment of its mother. The once








held belief that the fetus develops in an environment devoid of external stimulation

(Grimwarde, Walker and Wood, 1970) has been replaced by the fact that the fetus grows

in the uterus filled with rich and diversified sounds originated inside and outside the

mother (Gerhardt, 1989; Querleu et al., 1989).

The acoustic characteristics of internal noises and of external sounds that transmit

into the uterus have been described in the human from various recording sites including

inside the vagina (Bench, 1968), inside the cervix (Grimwarde, Walker and Wood, 1970),

and inside the uterus following amniotomy (Querleu et al., 1988b; Benzaquen et al.,

1990; Richards et al., 1992). These intrauterine sounds in humans were very similar to

those recorded in pregnant sheep, via a chronically implanted hydrophone on the fetal

head inside the uterus with an intact amniotic sac (Vince et al., 1982, 1985; Gerhardt,

Abrams and Oliver, 1990).

Sounds generated inside the mother and present in the uterus are associated with

maternal respiration (Vince et al., 1982; Gerhardt, Abrams and Oliver, 1990), maternal

heartbeats (Walker, Grimwarde, and Wood, 1971; Querleu et al., 1988a), maternal

intestinal activity (Vince et al., 1982; Gerhardt, Abrams and Oliver, 1990; Benzaquen et

al., 1990), maternal physical movements (Vince et al., 1982; Gerhardt, Abrams and

Oliver, 1990), and with placental and fetal circulation (Querleu et al., 1988a). These

sounds provide a background or "noise floor" above which maternal vocalizations and

externally generated sounds emerge (Vince et al., 1982, 1985; Querleu et al., 1988b;

Gerhardt, Abrams and Oliver, 1990; Benzaquen et al., 1990; Richards et al., 1992).

In 1968, Bench measured the intrauterine noise floor at 72 dB SPL in a pregnant

woman during labor. Three years later, Walker et al. (1971) reported an average intensity







18
of the background noise at 85 dB SPL (sound pressure level), with a peak at 95 dB SPL,

which was associate with maternal heartbeats. However, the accuracy of these early

studies was questioned by further studies using a hydrophone instead of a rubber-covered

microphone previously used to measure the intrauterine sound level.

The use of a hydrophone represented an important technological improvement

and provided more accurate data than was previously collected with air microphones.

Studies in pregnant sheep (Vince et al., 1982; Gerhardt, Abrams and Oliver, 1990) and

human (Querleu et al., 1988a; Benzaquen et al., 1990; Richards et al., 1992) showed that

there is a quiet background with a muffled quality to sounds inside the uterus.

Intrauterine sounds are predominately low frequency (< 100 Hz) and reach 90 dB SPL

(Querleu, Renard and Crepin, 1981; Vince et al., 1982; Gerhardt et al., 1990). Spectral

levels decrease as frequency increases, and are as low as 40 dB for higher frequencies

(Benzaquen et al., 1990; Gagnon, Benzaquen and Hunse, 1992). Gagnon et al.

positioned a hydrophone in a pocket of fluid by the human fetal neck and measured

sound pressure levels of 85 dB SPL at 12.5 Hz, decreasing to 60 dB for 100 Hz and less

than 40 dB for 200 Hz and above. When measured in dBA, the human intrauterine sound

level was only 28 dBA (Querleu et al., 1988a). Thus, for both humans and sheep, the

noise floor tends to be dominated by low-frequency energy less than 100 Hz and can

reach levels as high as 90 dB SPL.

Recently, Abrams et al. (1998) explored the origin of the intrauterine background

noise in sheep under well-controlled laboratory conditions. The intrauterine noise level

was measured before and after death of the ewe and fetus, and the average reduction in

sound level postmortem approached 10-15 dB for frequencies below 100 Hz. The result








showed that sounds originating in the ewe and fetus contribute significantly to the low

frequency (< 100 Hz) component of the background noise.



Sound Transmission into the Uterus

Specifications of the amplitudes and frequency distributions of external sounds

transmitted into the uterus have been well described in humans (Querleu et al., 1988a;

Richards et al., 1992) and sheep (Armitage, Baldwin and Vince, 1980; Vince et al., 1982,

1985; Gerhardt, Abrams and Oliver, 1990). The attenuation of sound by the maternal

abdominal wall, uterus and amniotic fluid is low in the low frequencies and increases in

the high frequencies. In pregnant women, studied by Querleu et al. (1981), the

attenuation is 2 dB at 250 Hz, 14 dB at 500 Hz, 20 dB at 1000 Hz and 26 dB at 2000 Hz.

For high frequencies ranging from 3800 to above 18000 Hz, the attenuation is 20 to 40

dB (Querleu et al., 1988a). More recent results from Richards et al. (1992) showed that

there was an average of 3.7 dB enhancement at 125 Hz, with progressively increasing

attenuation up to 10.0 dB at 4000 Hz. Similar conclusions came from studies in sheep

(Armitage, Baldwin and Vince, 1980; Vince et al., 1982, 1985; Gerhardt, Abrams and

Oliver, 1990).

For frequencies below 250 Hz the reduction in sound pressure level through

maternal tissue and fluids was less than 5 dB. Some enhancement of low-frequency

sound pressures has been reported in both humans (Querleu et al., 1981; Richards et al.,

1992) and sheep (Vince et al., 1982, 1985; Gerhardt, Abrams and Oliver, 1990). That is,

the sound pressure in the amnion was greater than the sound pressure in air. Above 250

Hz, attenuation increased at a rate of about 6 dB per octave up to approximately 4000 Hz,








where the average attenuation was 20 to 25 dB. However, at 8000 Hz transmission loss

was 15 dB (Gerhardt, Abrams and Oliver, 1990). These general findings have been

refined and extended by Peters et al. (1993a, 1993b) who evaluated the transfer of

airborne sounds across the abdominal wall of sheep as a function of frequency and

intraabdominal location.

Peters et al. (1993a) studied the transmission of airborne sound into the abdomen

of sheep over a wide frequency range (50-20,000 Hz). They found that mean attenuation

varied from a high of 28 dB to a low of-3 dB. The greatest attenuation occurred for the

frequencies between 5,000 and 12,500 Hz. Surprisingly, sound attenuation varied

inversely as a function of stimulus level for low frequencies (50-125 Hz) and for high

frequencies (7,000-20,000 Hz). At higher stimulus levels (110 dB SPL in air),

attenuation was greater than the attenuation at lower stimulus levels (90 dB SPL). Thus,

the 90 dB stimulus was more efficient than the 110 dB. In the middle frequency range

(200-4,000 Hz), no effect of stimulus level was found.

In another study by Peters et al. (1993b), a hydrophone was positioned at each of

45 locations in a 20 x 20 x 20 array in the abdomen of five non-pregnant sheep post

mortem. Isoattenuation contours within the abdomen were obtained. The sound pressure

at different locations within the three-dimensional space of the sheep was highly variable.

Low-frequency bands (< 250 Hz) of noise revealed strong enhancement of sound

pressure by up to 12 dB in the ventral part of the abdomen. For mid-frequencies (250-

2000 Hz), attenuation reached as high as 20 dB. Attenuation for high frequencies (>

3150 Hz) were somewhat less than for mid-frequencies and reached an upper limit of

approximately 16 dB.








Over the frequency range from 250 to 4000 Hz, the abdomen can be characterized

as a low-pass filter with high-frequency energy rejected at a rate of approximately 6

dB/octave (Gerhardt, Abrams and Oliver, 1990). Thus, external stimuli are shaped by the

tissues and fluids of pregnancy before reaching the fetal head.



Fetal Sound Isolation

It is known how much sound pressure is present at the fetal head. Now there is

information about how much sound actually reaches the fetal inner ear (Gerhardt, et al.

1992). For the fetus in utero, external airborne sound energy must pass from the air

medium to the fluid medium of the amnion before reaching the fetal inner ear. As sound

energy changes medium, it is reduced because of the impedance difference at the air-

tissue interface. The two quantities, pressure and particle velocity, are related and are

dependent on the acoustic impedance of the medium. The acoustic impedance of water is

much higher than that of air, for a given pressure disturbance, the particle velocity is

much less by a factor of approximately 3600 (10 log3600 = 35.5 dB) (Hawkins and

Myrberg, 1983). Thus, equal pressure in air and fluid differ in sound energy by

approximately 35 dB. One would assume that the sound pressure level required to

produce a physiological response from the fetus would be approximately 35 dB greater

than the sound pressure level in air necessary to produce the same response from the

newborn (Gerhardt, 1990; Gerhardt, et al. 1992). Factors that determine how much ex

utero sound reaches the inner ear of the fetus include the sound pressure attenuation

through maternal tissue and fluid and the transformation of this pressure into basilar

membrane displacement.








Gerhardt et al. (1992) studied the extent to which the fetal sheep in utero is

isolated from sounds produced outside the mother. Inferences regarding sound

transmission to the inner ear were made from cochlear microphonic (CM) input-output

functions to stimuli with different frequency content. The CM, an alternating current

generated by the hair cells of the inner ear, mimics the input signal in frequency and

amplitude over a fairly wide range. As the signal amplitude increases, so does the

amplitude of the CM. Cochlear microphonics recorded from the round window are

sensitive indices of transmission characteristics of the middle ear. Thus, changes in the

condition of the middle ear influence the amplitude of the CM. By comparing the sound

pressure levels necessary to produce equal CM amplitude from the fetus in utero, and

later, from the newborn lamb in the same sound field, estimates of fetal sound isolation

can be made.

Cochlear microphonic input-output functions were recorded from in utero fetuses

in response to one-third octave band noises from 125 to 2000 Hz and then again from the

same animals after birth. The magnitude of fetal sound isolation was dependent upon

stimulus frequency. For 125 Hz, sound isolation ranged from 6 to 17 dB, whereas for

2000 Hz fetal sound isolation ranged from 27 to 56 dB. The averages for each stimulus

frequency were 11.1 dB for 125 Hz, 19.8 dB for 250 Hz, 35.3 dB for 500 Hz, 38.2 dB for

1000 Hz and 45.0 dB for 2000 Hz. Thus, for lower frequencies (< 500 Hz) the fetal

auditory system appears to be sensitive to pressure variations produced by the stimulus

originated from outside the mother.








Route of Sound Transmission into the Fetal Inner Ear

Another factor that influences how airborne stimuli affects the fetus is related to

the transmission of sound pressure from the fluid at the fetal head into the inner ear.

Transmission is governed by the route that pressure variations take to reach the inner ear.

The route of sound transmission postnatally is through the outer and middle ear system.

Normal auditory function requires an air-filled middle ear cavity, an intact tympanic

membrane, and functional hair cells and neural mechanism. In order to stimulate the hair

cells of the inner ear, the movement of the stapes footplate in and out of the oval window

creates hydraulic motion of the cochlear fluids, which causes basilar membrane

displacement. However, in the fetus this route is likely to be rendered less efficient

because the mechanical properties of the middle ear are highly dampened. The fetal

middle ear and external ear canal are filled with amniotic fluid, which decreases the

mechanical advantage of the middle ear. In addition, sound pressure may be present with

the same phase at the oval window and round window. The lack of a phase difference, as

well as the lack of a middle ear amplifier, may substantially decrease basilar membrane

displacement and therefore cause a decrease in hearing sensitivity.

Two hypotheses have been proposed that describe the route that exogenous

sounds take to reach the fetal cochlea. It has been suggested that acoustic stimuli in the

fetal environment pass easily through the fluid-filled external auditory canal and middle

ear system to the inner ear (Rubel, 1985b; Querleu et al., 1989). The impedance of inner

ear fluids is similar to that of amniotic fluid, thus, little acoustic energy is lost due to an

impedance mismatch (Querleu et al., 1989).








Hearing via bone conduction is a second alternative. Researchers have shown

that the contribution of the external auditory meatus to auditory sensitivity in underwater

divers is negligible (Hollien and Feinstein, 1975). By comparing the ability of a diver to

hear under different conditions while in water, bone conduction has been shown to be

much more effective in transmitting underwater sound energy. Similarly, fetal hearing

occurs in a fluid environment and sound transmission may be through bone conduction as

well.

Gerhardt, et al. (1996) compared the effectiveness of the two routes of sound

transmission (outer and middle ear vs. bone conduction) by recording CM amplitudes

from fetus sheep in utero in response to airborne sounds. CM input-output functions

were obtained from the fetus in utero during three different conditions: uncovered fetal

head, covered entire fetal head, and covered fetal head with exposed pinna and ear canal.

Results showed that when the fetal head was covered with sound attenuating

material, even though the pinna and ear canal remain uncovered, sound levels necessary

to evoke a response were greater than those necessary to evoke the same response from

the fetus with its head uncovered. This fact revealed that acoustic energy in amniotic

fluid reaches the fetal inner ear through a bone conduction route. External sounds

transmitted into uterus stimulate the inner ear by vibrating fetal skull directly, which in

turn results in the basilar membrane displacement. Thus, more sound energy is necessary

to vibrate the skull to stimulate hair cell by bone conduction than by air conduction.








Model of Fetal Hearing

Gerhardt and Abrams (1996) proposed a model of fetal hearing that considers

what sounds are present in the environment of the fetus and to what extent these sounds

can be detected. The model includes information regarding intrauterine background

noise, sound transmission through the tissues and fluids associated with pregnancy and

sound transmission through the fetal skull into the inner ear.

For the fetus to detect a signal from outside the mother, extrinsic sounds have to

exceed the ambient sound level in utero. The internal noise floor of the mother is

dominated by low-frequency energy produced by respiration, intestinal function,

cardiovascular system, and maternal movements. Spectral levels decrease as frequency

increases, and are 60 dB for 100 Hz and lower than 40 dB for 200 Hz and above.

Presumably, the ability of the fetus to detect exogenous sounds will be dependent in part

on the spectrum level of the noise floor because of masking effects. As expected, high-

frequency sound pressures would be reduced by about 20 dB. The attenuation of low-

frequency sounds by the abdominal wall, uterus and fluids surrounding the fetal head is

quite small and in some cases enhancement of sound pressure of about 5 dB has been

noted. Between 250 and 4000 Hz, sound pressure levels drop at a rate of 6 dB/octave.

At 4000 Hz, maximum attenuation is approximately 20 dB. At frequencies higher than

4000 Hz, the attenuation is reduced to less than 20 dB.

Sound pressures at the fetal head create compressive forces through bone

conduction that result in displacements of the basilar membrane thereby producing a CM.

For 125 and 250 Hz, an airborne signal would be reduced by 10-20 dB in its passage to

the fetal inner ear over what would be expected to reach the inner ear of the organism in







26
air. For 500 through 2000 Hz, the signal would be reduced by 40-45 dB. For frequencies

in this range, the fetus is indeed buffered from sounds in the environment surrounding its

mother probably because of limited function of the ossicular chain. However, for low-

frequency sounds, the fetus is not well isolated. Low-frequency stimuli reach the inner

ear of the fetus with far greater amplitudes than high-frequency stimuli. Interestedly, the

development of the inner ear is such that low-frequency stimuli are detected before high-

frequency stimuli. If the development of normal function is dependent on external

stimulation, then the developmental pattern of the auditory system provides a mechanism

to ensure each neuronal regions receive adequate stimulation from the environment

(Rubel, 1984).

The fetus in utero will detect speech, but probably only the low-frequency

components less than 500 Hz, and only when the airborne signal exceeds about 60 dB

SPL. If it is less than that, the signal could be masked by internal noises. It is predicted

that the human fetus could detect speech at conversational levels (65-75 dB SPL), but

would not be able to discriminate many of the speech sounds with high-frequency

components. Likewise, if music was played to the mother at comfortable listening levels,

the temporal characteristics of music, rhythms, could be sensed by the fetus, but the high-

frequency overtones would not be of sufficient amplitude to be detected (Abrams et al.,

1998). Simply put, the fetus would be stimulated by music with the "bass" register

turned up and the "treble" register turned down. This information may relate to in utero

development of speech and language, to musical preferences and to subsequent cognitive

development.








Intelligibility of Speech Sounds Recorded within the Uterus

Speech produced during normal conversation is approximately 70 dB SPL and is

comprised of acoustic energy primarily between 200 and 3000 Hz. The average

fundamental frequency of an adult is 125 Hz for male's voice, and is 220 Hz for female's

voice. Speech becomes unintelligible when the background noise in the speech-

frequency range exceeds the level of the message by approximately 10 dB.

There are many factors that determine how well a fetus will hear sounds from

outside its mother. These factors include: the frequency content and level of the internal

noise floor; the attenuation of external signals provided by the tissues and fluids

surrounding the fetal head; sound transmission into the fetal inner ear; and the sensitivity

of the auditory system at the time of sound stimulation.

As a result of experimental work, the characteristics of the intrauterine sound

environment are now fairly well understood. Studies in sheep (Vince et al., 1982, 1985;

Gerhardt, Abrams and Oliver, 1990) and in humans (Querleu et al., 1988a; Benzaquen et

al., 1990; Richards et al., 1992) have shown that the mother's voice and speech sounds

from outside the mother transmit easily into the uterus with little attenuation, and form

part of the intrauterine sound environment. Vince et al. (1982, 1985) implanted a

hydrophone inside the amniotic sac of pregnant ewes, and obtained long-term recordings.

They showed that the sound of maternal vocalizations forms a prominent part of the

intrauterine sound environment, and is louder inside the uterus than outside. Gerhardt et

al. (1990) also noted that when listening to the internal recordings from sheep,

conversations were recognized between experimenters with normal vocal effort 3 feet

from the ewe. Speech was muffled and intelligibility was poor, however, pitch,








intonation, and rhythm were quite clear. These findings are in accordance with data

provided by human studies. Querleu et al. (1988b) presented various human voices

through a loudspeaker to pregnant women and recorded the speech with a hydrophone in

the uterus. The voice included mother talking directly, the mother's voice recorded on

tape and playback, and the recorded voices of other women and men. All types of

recorded voices (presented at 60 dBA) emerged above the basal noise floor (28 dBA) by

+8 to +12 dB. The mother's voice recorded directly was 24 dB greater than the noise

floor. The intensity of the maternal voice transmitted to the uterine cavity was greater

than that of outside voices. Moreover, it was also transmitted to fetus more often than

any other voices. In 1990, Benzaquen et al. reported that maternal vocalization was

easily recorded in utero in ten pregnant women tested in the study. The sound spectrum

produced by pronouncing the words of "99" was characterized by peak intensity of 70 to

75 dB SPL at 200 to 250 Hz and was approximately 20 dB above the intrauterine

background noise at those frequencies.

Richards et al. (1992) studied the transmission of speech into the uterus.

Intrauterine sound pressure levels of the mother's voice were enhanced by an average of

5.2 dB in the low-frequency range, whereas external male and female voices were

attenuated by 2.1 and 3.2 dB, respectively. However, these studies only provided the

information about the existence of speech sound in the intrauterine sound environment.

The understandability of speech recorded from within the uterus is another critical issue

for our understanding of early speech and language development. Fetal identification of

its mother's voice and its ability to form memories of early exposure to speech are in part

dependent on the intelligibility of the speech message.








Currently, two published studies address the perceptibility of speech recorded

from inside the uterus. Querleu et al. (1988b) recorded the voices of five pregnant

women and voices of other male and female talkers with a modified microphone

positioned by the head of the fetus. Six listeners were able to recognize about 30% of the

3120 French phonemes. No significant difference was noted between the male and

female voice, and the mother's voice was not better perceived although more intense.

The recognition of vowels was correlated with their second formant. The intonation

patterns, which frequencies were ranging from 100 to 1000 Hz, were perfectly well

discriminated compared to linguistic meaning.

In a more recent study conducted by Griffiths et al. (1994), a panel of over 100

untrained individuals judged the intelligibility of speech recorded in utero from a

pregnant ewe. Two separate word lists, one d' mcai ni rul and one of non-meaningful

speech stimuli were delivered to the side of the ewe through a loudspeaker and were

simultaneously recorded with an air microphone located 15 cm from the flank and with a

hydrophone previously sutured to the neck of the fetus. Perceptual test tapes generated

from these recordings were played to 102 judges. Intelligibility was influenced by three

factors: transducer site (maternal flank or in utero); gender of the talker (male or female);

and intensity level (65, 75 or 85 dB). For recordings made at the maternal flank, there

was no significant difference between male and female talkers. Intelligibility scores

increased with increased stimulus level for talkers and at both recording sites. However,

intelligibility scores were significantly lower for females than for males when the

recordings were made in utero.








An analysis of the feature information from recordings inside and outside the

uterus showed that voicing information is better transmitted in utero than place or manner

information. "Voicing" refers to the presence or absence of vocal fold vibrations (e.g., /s/

vs. /z/), "place" of articulation refers to the location of the major air-flow constriction

during production (e.g., bilabial vs. alveolar), and manner" refers to the way the speech

sound is produced (e.g., plosive vs. glide).

Miller and Nicely (1955) reported that low-pass filtering of speech signals

resulted in a greater loss of manner and place information than of voicing information.

They concluded that the higher frequency information in the speech signal is critical for

accurate identification of manner and place of articulation. The findings of Griffiths et al.

(1994) are consistent with those of Miller and Nicely (1955) in that transmission into the

uterus can be modeled as a low-pass filter. The poorer in utero reception of place and

manner information is associated with the greater high frequency attenuation.

Voicing information from the male talker, which is carried by low-frequency

energy, was largely preserved in utero. The judges evaluated the male talker's voice

equally well regardless of transducer site. Speech of the female talker carried less well

into the uterus. The fundamental frequency of the female talker was higher than that of

the male talker. Thus, it is understandable that voicing information from the male would

carry better into the uterus than that from the female.

Male and female talker intelligibility scores averaged approximately 55% and

34%, respectively, when recorded from within the uterus. Although these results reflect

the perceptibility of the speech energies present in the amniotic fluid, they do not specify

what speech energy might be present at the fetal inner ear. Measures of acoustic








transmission to the fetal inner ear are quite limited at present. Much work needs to be

completed before conclusions can be drawn regarding what speech energies reach and are

able to be perceived by the fetus.



Fetal Auditory Experiences and Learning

During the last trimester, the human fetus, with a well-developed hearing

mechanism, is exposed to a large variety of simple and complex sounds. Prolonged

exposure, for several weeks or even months, to external and maternal sounds may have

several consequences to the fetus at structural, functional, and behavioral levels. Prenatal

activation of the auditory system may contribute to normal development of peripheral

structures and central connections, as well as maintenance of anatomic and functional

integrity during prenatal maturation. On a more general level, fetal auditory stimulation

may contribute to the formation of auditory perceptual abilities, and to the organization of

the newborn's preferences for a particular acoustical signal (Lecanuet and Schaal, 1996).



Prenatal Effects of Sound Experience

Human fetal responsiveness to intense acoustical stimulation has been studied

only in the past two decades. Fetuses are not only responsive to intense stimulation, they

also display differential auditory responses as a function of the characteristics of the

stimulus. When acoustic or vibroacoustic stimuli are above 110 dB SPL, fetuses display

heart rate accelerations and motor-startle movement responses. Below 100 dB SPL, no

reliable movement responses can be recorded, but fetuses display small, transient heart-

rate decelerations rather than heart-rate accelerations (Lecanuet, Granier-Deferre and








Busnel, 1989, 1995). The heart-rate acceleration changes to auditory stimulation are

typically associated with so-called "startling" or defensive response, while deceleration

changes are "orienting" or attentive response (Berg and Berg, 1987).

Experiments have shown that repetition at a short interval (every 3-4 seconds) of

a 92 to 95 dB SPL acoustic stimulus led to the disappearance of a cardiac deceleration

response that had been induced by the first presentation of the stimulus, indicating an

habituation (Lecanuet et al., 1992). Habituation is defined as the decrement in response

after repeated presentation of a stimulus. Habituation is essential for the efficient

functioning and survival of the organism, enabling it to ignore familiar stimuli and attend

to new stimuli. Habituation represents one of the simplest yet most essential learning

processes the individual possesses, and underlies much of our functioning and

development (Hepper, 1992). Using a classical habituation / dishabituation procedure,

Kisilevsky and Muir (1991) obtained a significant decrement of both fetal cardiac

acceleration and movement responses to a complex noise (at 110 dB SPL), followed by a

recovery of these responses when triggered by a novel vibroacoustic stimulus. The

fetuses were between 37 and 42 weeks gestation during the experiment. Habituation in

utero relates not only to the reception of the sensory message, but also its integration at

lower levels of the central nervous system. Therefore, the fetus in utero is capable of

learning (Querleu et al., 1989).

Lecanuet et al. (1989, 1993) studied the auditory discriminative capacities of the

near-term fetus by using habituation/dishabituation of heart-rate deceleration responses.

In one study (Lecanuet, Granier-Deferre and Busnel, 1989), fetuses at 35 to 38 weeks

gestation displayed a transit heart-rate deceleration response when they were exposed to







33
the repeated presentation (every 3.5 second) of a pair of French syllables: /ba/ and /bi/ or

/bi/ and /ba/, spoken by a female talker at 95 dB SPL. Reversing the order of the paired

syllables after 16 presentations also reliably induced the same type of response. This was

observed in 15/19 fetuses in the BABI/BIBA condition and in 10/14 fetuses in the

BIBA/BABI condition. Response recovery suggested that fetuses discriminated between

the two stimuli. The discrimination that occurred may have been performed on the basis

of a perceptual difference in loudness (intensity) between the /ba/ and /bi/, since the

equalization of these syllables was presented with SPL, not hearing level. This intensity

adjustment makes /bi/ louder than /ba/ for audit listeners. Similarly, Shahidullah and

Hepper (1994) found that fetuses at 35 weeks gestation had the ability to discriminate

between /baba/ and /bibi/.

In another experiment (Lecanuet et al., 1993), the ability of near-term fetuses to

discriminate different speakers producing the same sentence was studied. The heart-rate

responses of fetuses between 36 to 39 weeks gestation were recorded before, during and

after stimulation to the sentence 'Dick a du bon the' (Dick has some good tea). The

sentence was spoken by either a male talker (minimum fundamental frequency F = 83

Hz) or a female talker (minimum Fo= 165 Hz) and delivered through a loudspeaker 20

cm above the mother's abdomen at the same level (90-95 dB SPL). The fetuses were

exposed to the first voice presentation (male or female) and followed by the other voice

or the same voice (control condition) after fetal heart-rate response returned to baseline.

The results demonstrated that in the first 10 s after presentation of the initial voice, the

voice (male or female) induced a high and similar proportion of heart rate deceleration

changes (77% to the male voice, 66% to the female voice) compared to a group of non-








stimulated subjects (9% of deceleration and 46% of acceleration). Within the first 10 s

following the voice change, 69% of the fetuses exposed to the other voice displayed a

heart-rate deceleration response, whereas 43% of the fetuses in the control condition

displayed heart-rate acceleration change. The authors pointed out that near-term fetuses

might perceive a difference between the voice characteristics of two speakers, at least

when they are highly contrasted for Fo and timbre. The results cannot be generalized for

all male and female voices or for all speakers since voices with extremely low Fo were

used in the study (Lecanuet, Granier-Deferre and Busnel, 1995; Lecanuet, 1996).

Hepper et al. (1993) studied the ability of fetuses to discriminate between a

strange female's voice and the mother's voice by measurement of the number of fetal

movements during a 2-minute speech presentation. The results showed that fetuses at 36

weeks gestation did not discriminate between their mother's voice and that of a stranger,

when tape recordings were played to them via an air-coupled loudspeaker placed on the

abdomen. However, the fetuses were able to discriminate between their mother's voice

recorded on tape and played to them over the loudspeaker and the mother's voice

produced naturally; less movements were noted in response to the mother's direct

speaking voice when compared to a tape recording of her voice. According to the

authors, discrimination may be due to the presence of internally transmitted components

of speech which the fetus perceives when the mother is speaking, but that are not present

when the tape recording of the mother's voice is played.

The possibility of prenatal recognition of a familiar child's rhyme was studied by

DeCasper et al. (1994). Seventeen pregnant women recited a child's rhyme aloud three

times a day from their 33rd to 37th week of pregnancy. Fetal heart-rate response was








used to assess differential fetal responsiveness to the target rhyme versus a novel rhyme.

During the 37th week of gestation, each fetus was stimulated to one rhyme for 30 seconds

through a loudspeaker placed over the mother's abdomen. The first rhyme was followed

by 75 s of silence and then the other rhyme was presented for 30 s. Stimulus level for

both rhymes was set at 80-82 dB SPL. Care was taken during fetal testing to keep the

mother unaware of which rhyme was being presented so that she could not inadvertently

cue her fetus. The results showed that fetal heart rates significantly decreased from

prestimulus levels when the target rhyme was presented and significantly increased over

prestimulus levels when the novel rhyme was presented, regardless of presentation order.

This differential heart-rate change implied that the fetus discriminated the two rhymes.

Moreover, since these rhymes were counterbalanced across fetuses, the different patterns

of heart-rate responds could not be attributed to any unique acoustic attributes of one

rhyme.

There is now a growing body of data showing that fetuses perceive acoustical

stimuli. Near-term fetuses can discriminate between two complex stimuli (such as

syllables), between two speech passages, and they are able to learn. Such a competence

may be partly a consequence of fetal familiarization to speech sounds.



Postnatal Effects of Prenatal Sound Experience

Prenatal auditory experience may result in general and / or specific learning

effects that are evidenced in postnatal life. Stimuli familiar to the fetus may selectively

soothe the baby after birth or may elicit orienting responses during quiet states. Familiar

stimuli are more alerting than unfamiliar ones. It is well documented that prenatal








auditory experience plays a major role in the development of human newborn auditory

preferences and capabilities (Fifer, 1987; Leanuet, 1996).

It has been shown that maternal heartbeat (Salk, 1962) and recordings of

intrauterine noises (Rosner and Doherty, 1979) can calm a restless baby and serves as a

potent reinforcer during operant conditioning nonnutritive sucking procedures (DeCasper

and Sigafoos, 1983). Indeed, intrauterine cardiac rhythms are potent reinforces for 2- to

3-day-old newborns, a finding that suggests that prenatal auditory experience affects

postnatal behavior.

Nonnutritive sucking procedures made it possible to objectify newbom's

discriminative abilities and to test the newborn's preference for a given stimulus. The

human voice, especially that of its mother, is likely to have increased salience for the

fetus relative to other auditory stimuli. Mother's voice in the fetal sound environment

differs from other sounds in its intensity, variability, and other multimodal characteristics.

Mother's voice has been reported to be the most intense acoustic signal measured in the

amniotic environment (Querleu et al., 1988a; Benzaquen et al., 1990; Richards et al.,

1992). The nature of the maternal voice may promote greater fetal responsiveness to

mother's voice than any other prenatal sound. The earliest evidence for differential

responsiveness to maternal voice came from work with older infants (Mills and Meluish,

1974). The experiments demonstrated a differential sensitivity to the maternal voice in

20- to 30-day-old infants. The amount of time spent sucking and number of sucks per

minute were increased after a brief presentation of his/her mother's voice. In a later

study using 1-month-old infants (Mehler et al., 1978), sucks were reinforced with either a

mother's or a stranger's voice, intonated or monotone. A significant increase in sucking







37
was only observed when mother's voice was normally intonated. The role of intonation

in recognition of the mother's voice was suggested. Although these procedures clearly

demonstrate that infants respond differentially to their mother's normal voice, the

differences in responding do not necessarily indicate a preference for her voice (Fifer,

1987).

The study by DeCasper and Fifer (1980), using two different nonnutritive sucking

procedures, was the first to provide direct experimental evidence that neonates prefer

their mother's voice. Using a temporal discrimination procedure, 2- to 3-day-old infants

were observed for a 5-minute baseline period in which nonrewarded sucks on a

nonnutritive nipple were recorded. The median time of the interburst intervals (IBIs) was

calculated and used to set the contingency for the testing. For 5 of the 10 infants tested,

sucking bursts that ended IBIs shorter than the baseline median IBI (mIBI) turned on a

tape recording of the infant's mother reading a children's story. Whereas sucking bursts

that ended IBIs equal to or longer than the mlBI turned on a tape recording of another

infant's mother reading the same story. For the other five infants, the IBI/story

contingency was reversed. The results showed that 8 of the 10 infants shifted their

overall medians significantly in the direction necessary to turn on the recording of its

mother's voice. Also, the infants turned on the recording of their mother's voice more

often and for a longer total period of time than the unfamiliar female voice.

In the second procedure, which involved a signal discrimination paradigm, the

presence or absence of a 4-s 400 Hz tone signaled the availability of the different voices,

and the voices remained on for the duration of the sucking burst. For 8 of the 16 infants

tested, sucking on the nipple during the tone resulted in the cessation of the tone and








turned on a recording of their own mother's voice reading a children's story, whereas

sucking during silence turned on a recording of another woman reading the same story.

For the other eight infants, the signal/story contingency was reversed. Again, evidence of

newborns' preference for their own mother's voice was obtained. Infants showed a

significantly greater probability of sucking during the signal (tone or silence) that led to

the presentation of the maternal voice recording.

Since it is possible that preference for the mother's voice could be generated very

fast by the newborn's initial postnatal contact with the mother, several subsequent studies

have attempted to rule out the effect of postnatal auditory experience. Fifer (1987) failed

to find any evidence that preference in newborns for maternal voice was related to either

postnatal age (1- vs. 3-day-olds) or method of feeding (bottle-fed vs. breast-fed).

Another study showed that 2-day-old newborns did not prefer its father's voice to that of

another male's voice, even though these newborns had 4 to 10 hours of postnatal contact

with their fathers (DeCasper and Prescott, 1984). This study also determined that the

absence of a preference for the paternal voice was not due to the inability of newborns to

discriminate between pairs of male voices. Furthermore, the authors compared the

preference between an airborne version of those mother's voice and their "intrauterine",

low-pass filtered version. Using tone/silence discriminative responding procedures, 2- to

3-day-old infants were given a choice of hearing their mother's voice (or other female's

voice) either unfiltered or low-pass filtered at 1000 Hz (Spence and DeCasper, 1987).

Infants showed no preference for either the unfiltered or low-pass filtered version of their

mother's voice, whereas infants preferred the unfiltered version of the nonmatemal voice

to the filtered nonmaternal voice. According to the authors, since there is apparently little








prenatal experience with the low-frequency features of other female voices, but

considerable postnatal experience with their full spectral characteristics, the newborns

preferred the more familiar version of the female stranger's voice. In contrast, both the

filtered and unfiltered versions of maternal voice contained the necessary low-frequency

features for maternal voice recognition, so the infants showed no preference.

Finally, Fifer and Moon (1989), using a modified version of the "intrauterine"

mother's voice mixed or not mixed with maternal cardiovascular sounds, found that 2-

day-old newborns preferred a low-pass filtered version of the maternal voice to an

unfiltered version when 500 Hz was the cutoff frequency. Therefore, it is possible that

the infants in the previous study (Spence and DeCasper, 1987) did not show a preference

for the filtered maternal voice because it was more similar to their postnatal rather than

their prenatal experience with the maternal voice. Newborns' prenatal familiarity with

maternal voice may explain the findings by Hepper et al. (1993). Using an analysis of

fetal movements, Hepper et al. demonstrated that 2- to 4-day-old newborns discriminated

normal speech from "motherese" speech of their mothers' voice, but not between normal

intonated and one of "motherese" of a strange female's voice. Newborns, however,

discriminated the maternal voice from a strange female voice.

Taken together, these results suggest that prenatal auditory experience determines

at least some of the infant's early auditory preferences. This prenatal effect was

demonstrated more directly by the study conducted by DeCasper and Spence (1986).

Sixteen pregnant women recited one of the three children's stories aloud twice each day

during the final 6 weeks of their pregnancies. After birth, the newborns (average age of

55.8 hours) were tested using the nonnutritive IBI contingent sucking procedure. For







40
eight of the infants in the prenatal group, sucking bursts following IBIs < mIBI turned on

a recording of a woman (either the infant's own mother or the mother of another infant)

reading the story that the infant's mother had read while pregnant. Sucking bursts which

followed IBIs > mIBI turned on a recording of that same woman reading a novel story.

For the other eight infants in the prenatal group, the IBI/story contingency was reversed.

Additionally, a control group (12 infants) was tested under the same conditions except

that these infants had no experience with any of three stories. The results showed that

regardless of which story the mothers had recited while pregnant and regardless of the

IBI/story contingency, the newborns in the prenatal group were more likely to suck after

IBIs required to turn on the familiar story, the one they had heard prenatally, whereas

infants in the control group showed no systematic change in their sucking pattern from

baseline. Moreover, these preferences for one of three stories were not dependent on the

specific voice of the storyteller. This result showed that the induction of a preference for

a story (speech passage) generalized from maternal to nonmateral voice. It implies that

the newborn retains two different kinds of acoustic information from prenatal experience:

information about specific characteristics of the mother's voice (perhaps fundamental

frequency) and more general characteristics that are not necessarily mother-specific, such

as intonation contours and / or temporal characteristics.

These studies provide strong evidence that the late-term human fetus is able to

process some aspects of vocal stimulation presented by the mother and retain some of

that information for at least several days after birth. It remains unclear, however, which

specific aspects of prenatal auditory stimulation were responsible for postnatal auditory

preferences.








Because external low-frequency sound is transmitted into the uterus with little

attenuation and because high-frequency sound is attenuated, the fetus can only detect the

low-frequency components of passage presented by the mother. It appears that these

newborns could not merely depend on segmental information (phonetic components of

speech, i.e., the specific consonants and vowels making up the words), which they

experienced prenatally, as the basis for their postnatal recognition, since segmental

information is carried by those frequencies that appear to be most attenuated in utero

(frequencies above 1000 Hz). In contrast, the suprasegmental information (intonation,

frequency variation, stress, and rhythm) contained in the maternal voice and in the stories

recited by the mother is available to the fetus with very little attenuation. The hypothesis

about the role of suprasegmental information in fetal auditory perception has been

investigated (Cooper and Aslin, 1989).

In an effort to test whether prenatally available suprasegmental information would

be sufficient to induce a postnatal preference, the authors had 13 pregnant women sing

the lyrics of the tune to "Mary HadA Little Lamb" using the syllable "la" instead of the

actual words of the melody (Cooper and Aslin, 1989). Each woman sang the melody 5

minutes daily starting on the 14th day prior to her due date. The newborns of these

mothers were tested between 34 and 72 hours after birth (mean age = 52 hours old) using

the IBI procedure. For the seven infants in the prenatal group, sucking bursts that ended

IBIs < mIBI turned on a recording of "Mary HadA Little Lamb" sung by a professional

female singer (using "la" instead of the words), whereas sucking bursts that ended IBIs 2

mlBI turned on a recording of the same singer singing "Love Somebody", also with "la"

instead of the words. These two melodies were sung in the same key and contained the







42
same absolute notes, but the notes occurred in different orders to yield different melodic

contours. For the other six infants in the prenatal group, the IBI/melody contingency was

reversed. In addition, a control group of eight newborns was tested under the identical

condition except that they had no prior experience with either melody. The results

showed that the newborns in the prenatal group produced more of the IBIs to turn on their

familiar melody compared to their baseline performance, while the newborns in the

control group did not, regardless of condition. This study demonstrated that the

suprasegmental characteristics of a prenatally experienced melody were sufficient to

induce a postnatal preference for that melody.

Further supporting evidence for the salience of suprasegmental information in

fetal perception comes from the demonstration that newborns discriminated and preferred

their native language to a foreign language (Mehler et al., 1988; Moon, Cooper and Fifer,

1993). Using the /a/ or /i/ signal discrimination procedure (Moon and Fifer, 1990), Moon

et al. (1993) demonstrated that 2-day-old newborns whose mothers were monolingual

speakers of Spanish or English, preferred their mother's language to the other one.

Demonstration of a preference for the native language at such an early age favors an

interpretation of the study by Mehler et al. (1988) in terms of a prenatal familiarization.

In the latter studies, using a noncontingent habituation / dishabituation of high-amplitude

sucking procedure, Mehler et al. (1988) demonstrated that 4-day-old native French

newborns could discriminate a recording of a woman speaking Russian from the same

woman speaking French, but did not iillIlerentii.ll, respond to English from Italian

recordings. Also, 4-day-olds of non-French parents did not respond differentially to

either Russian or French recordings. Thus, very young infants seem to require some








experience with a language in order to respond differentially to languages. This

interpretation is strengthened by additional data (Mehler et al., 1988) showing that native

English 2-month-olds also did not respond differentially to Russian or French, but easily

discriminated English from Italian. Thus, it was not merely the young age of the

newborns that resulted in their failure to respond differentially to nonnative languages.

Prenatal maternal speech is one likely source of native language experience for the

newborns.

Finally, Mehler et al. (1988) demonstrated that native French 4-day-old newborns

and native English 2-month-olds could still discriminate French from Russian and

English from Italian, respectively, even when all of the these recordings were low-pass

filtered at 400 Hz, which effectively removed most segmental information and

maintained their intonational and temporal structures. It is more likely that prenatal

auditory experience with the suprasegmental features of maternal speech influences the

ability of newborns to discriminated their native language from other nonnative language,

although it certainly is possible that newborns rely on both segmental and suprasegmental

information when discriminating their native language from a foreign language.

There is now clear evidence that from the earliest days of postnatal life the human

infant is actively engaged in processing sounds, particularly those containing acoustic

attributes of the infant's native language. The infant's prenatal experience with maternal

speech may, in large part, determine the early postnatal perceptual salience of a specific

mother's speech and native speech.








Speech Perception


Speech Perception in Infancy

There are two characterizations of infants' "initial state" regarding speech

perception. One argues that infants enter the world equipped with specialized speech-

specific mechanisms evolved for the perception of speech, and that infants are born with

a "speech module" to decode the complex and intricate speech signals (Foder, 1983;

Mehler and Dupoux, 1994). The other holds that infants begin life without specialized

mechanisms dedicated to speech, and that infants' initial responsiveness to speech can be

attributed to their more general sensory and cognitive abilities (Aslin, 1987; Kuhl, 1987;

Jusczyk, 1996).

In fact, the capacity of newborns to distinguish minimal speech contrasts is

remarkable (Aslin, Pisoni and Jusczyk, 1983; Aslin, 1987; Kuhl, 1987; Mehler and

Dupoux, 1994). Eimas et al. (1971) were the first to demonstrate that human infants, as

young as one month old, can discriminate subtle acoustic properties in a categorical

manner that differentiate for English-speaking adults the stop-consonant-vowel syllables

/ba/ from /pa/, which are different in voice onset time (VOT). In their study, computer-

generated (synthetic) speech differing only VOT was presented in pairs to infants for

testing with the high-amplitude sucking procedure. Only one of these VOT pairs spanned

the boundary between English-speaking adults' phonemic categories for /ba/ and /pa/.

This between-category VOT pair was discriminated by the infants, whereas several other

within-category pairs were not discriminated, even though the VOT difference between

each pair was identical (20 second). Since then, there is growing body of evidence that

nearly all speech contrasts (phonetic contrasts) used in any of the world's natural








languages can be discriminated by 6 months of age (Aslin, Pisoni and Jusczyk, 1983;

Aslin, 1987; Kuhl, 1987; Jusczyk, 1996). There are also indications that during the early

stages, the mechanisms that underlie speech processing by infants may be a part of more

general auditory processing capacities (Aslin, Pisoni and Jusczyk, 1983; Aslin, 1987;

Kuhl, 1987; Jusczyk, 1996). Prior to 6 months of age, infants are performing their

analysis of speech sounds solely on the basis of acoustic differences. These acoustic

differences are sufficient to permit categorical perception, just as similar acoustic

mechanisms presumably support the processing of nonspeech contrasts by infants

(Jusczyk et al., 1983) and the processing of speech contrasts by nonhumans (Kuhl and

Miller, 1975, 1978).



Characteristic of Speech

Speech signals have numerous distinctive acoustic properties or attributes that are

used in the earliest stages of perceptual analysis. The average intensity of normal speech,

measured at a distance of 30 centimeter from the speaker's lips, is about 66 dB intensity

level (IL), and individual variation between speakers is about 5 dB (Dunn and White,

1940). If the pauses (silent intervals) are excluded, the experimental data indicated that

these levels would be increased 3 dB (Fletcher, 1953). Loud speech may reach 86 dB IL,

while soft speech may be as low as 46 dB. In the course of ordinary conversation, the

dynamic range of speech is about 35-40 dB (Fletcher, 1953). In a more recent study (Cox

and Moore, 1988), the mean sound pressure level at 1 meter for a male talker speaking

with normal vocal effort was 61 dB and for a female talker was 59 dB. The average

spectra were similar in the range from 400 to 5000 Hz between male and female talkers.








Interestingly, the comparison of long-term average speech spectra over 12 languages

showed that the spectrum was similar for all languages although there were many small

differences (Byrne, et al., 1994). The average value of sound pressure level at 20

centimeter for males was 71.8 dB SPL, while that for females was 71.5 dB SPL. For

one-third octave bands of speech, the maximum short-term r.m.s. level was 10 dB above

the maximum long-term r.m.s. level, and was consistent across languages and frequency.

Most of the energy of speech derives from vowels. Vowels are usually more

intense and relatively longer in duration than consonants. The average difference in

intensity between vowels and consonants is about 12 dB. In English, the intensity

difference between the weakest consonants /0/ and the strongest vowel lo/ is about 28 dB

(Fletcher, 1953). The frequency range of speech extends from 80 Hz to several thousand

Hertz, while the frequencies important to the speech signal are within the 100 to 5000 Hz

range (Borden and Harris, 1984). The human voice is composed of many frequencies.

The lowest frequency is the fundamental frequency of the voice, driven by the vibration

of the vocal folds. The fundamental frequency is constantly changing during articulation,

and varies considerably from one person to another. The fundamental frequency of a

low-pitched male voice is about 90 Hz, while a woman with a high-pitched voice may

speak at a fundamental frequency of about 300 Hz. On average, the average female voice

corresponds to middle C or 256 Hz, whereas the male voice is about an octave lower

(Fletcher, 1953).

The energy in vowels is concentrated mainly in the harmonic sounds of the

fundamental frequency, which for each vowel is divided into several typical frequency

regions, called formants, whose center frequency depends on the shape of the vocal tract








(resonance of the vocal tract). In addition to the fundamental frequency (Fo), four

formants are usually recognized; the lowest two formants (F1 and F2) are stronger than

the other two and occur at frequencies typical for each vowel. The lowest three formants

are the most important for correct recognition of English vowels. The frequency range of

these formants fits fairly well within the 300-3500 Hz range, which is the standard

bandwidth used in the telephone industry (Borden and Harris, 1984; Kent, 1997). If the

fundamental frequency is raised by an octave, the formant values increase by only 17

percent (Peterson and Barney, 1952).

The consonants differ essentially from the vowels in that they usually have no

distinct formant composition; they are composed of mostly high-frequency noise

components. In most consonants, however, energy is concentrated mainly in

characteristic frequency regions. Thus, consonant sounds have components that are

higher in frequency and lower in intensity than vowel sounds. The intensity tends to be

scattered continuously over the frequency region characteristic of each consonant sound

(French and Steinberg, 1947; Borden and Harris, 1984; Kent, 1997).

In contrast to acoustic phonetics that identifies speech sounds in terms of acoustic

parameters (frequency composition, relative intensity, and duration changes), traditional

phonetics describes speech sounds in terms of the way they are produced. The main

divisions are voicing, place and manner. "Voicing" is related to vocal fold vibration, e.g.,

voiced or voiceless. "Place" is related to the location of the major airflow constriction of

the vocal tract during articulation, e.g., bilabial, labio-dental, lingui-dental, alveolar,

palatal or velar. "Manner" is related to the degree of nasal, oral, or pharyngeal cavity








construction, e.g., vowels, stops plosivess), nasals, fricates, affricates, liquids or glides.

Thus, /b/ in the word "best" is a voiced bilabial stop (plosive) (Borden and Harris, 1984).



Intelligibility of Speech

The ability to understand speech is the most important measurable aspect of

human auditory function. Speech can be detected as a signal as soon as the most intense

point of its spectrum exceeds the ear's pure tone threshold at the frequency concerned.

This intensity is called the speech detection threshold or threshold of detectability (Egan,

1948; Schill, 1985). At this intensity level, a listener is just able to detect the presence of

speech sounds about 50% of the time. When the intensity is increased by some 8 dB, the

subjects begin to understand some words and can repeat half of the speech material

presented; this is the speech reception threshold or threshold of perceptibility (Egan,

1948; Hawkins and Stevens, 1950; Schill, 1985). The speech reception threshold of

spondee words (two syllables), which is considerably lower than one-syllable words, is at

about 20 dB SPL (Davis, 1948; Penord, 1985). However, only after the average intensity

of speech has reached between 30 to 33 dB SPL, are 50 percent of monosyllabic words

understood (Kryter, 1946; French and Steinberg, 1947; Davis, 1948; Egan, 1948).

Speech intelligibility or speech discrimination, expressed in terms of percentage correct,

is used to describe how much speech sound can be understood. The factors affecting

speech intelligibility are numerous. These include physical factors related to the speech

stimuli such as level of presentation, frequency composition, distortion, and signal to

noise ratio.








French and Steinberg (1947) used nonsense monosyllables of the consonant-

vowel-consonant (CVC) type as word material in their studies, and examined

intelligibility after low-pass and high-pass filtering. They found that when intensity was

increased, discrimination improved up to a certain limit, after which it remained largely

constant even if intensity was further increased. Optimal intensity with different filter

settings proved to be approximately the same, within a range of 10 dB. The optimal

intensity was 75 dB SPL. At this level, when all frequencies above 1000 Hz were passed

through the filter, 90% of CVC syllables were recognized correctly. However, when only

the frequencies below 1000 Hz were presented, correct identification of the CVC

syllables declined to 27%. The French and Steinberg study clearly demonstrated the

importance of the high frequencies for correct identification of CVC syllables.

Furthermore, when intelligibility scores were plotted as a function of cutoff-frequency of

at optimal intensity levels, the low-pass and high-pass curves intersected at 1900 Hz,

where the intelligibility score was 68%. It was said that the crossover point divided the

frequency scale into two equivalent parts; the frequencies above the cross were as

important as the frequencies below the crossover frequency.

The type of speech material distinctly affects the intelligibility of filtered speech

(Hirsh, Reynolds and Joseph, 1954). The speech materials in their study included

nonsense syllables, monosyllabic words (Central Institute for the Deaf Auditory Test W-

22), disyllabic words spondeess, iambs and trochees) and polysyllabic words. The input

speech level for all filter conditions was 95 dB SPL. They found that nonsense

monosyllables and monosyllable words suffered most in intelligibility during frequency

filtering. When the cutoff frequency (high-pass filter) was less than 3200 Hz, the








intelligibility did not decrease significantly. But iritliibhltll decreased rapidly as the

cutoff frequency increased above 3200 Hz. Under low-pass filter conditions, it was only

when all the frequencies above 800 Hz were eliminated that the intelligibility decreased

noticeably from its maximum, and then it dropped rapidly as the more extreme filter

conditions were reached. The functional curves for the different speech materials

remained nearly constant under both high-pass and low-pass filtering. The fewer

syllables there were in a meaningful word the lower its intelligibility. Nonsense

monosyllables were the least intelligible of all. Intelligibility of nonsense syllables and

monosyllable words is severely affected by frequency distortion. However, as word

length increases, intelligibility is retained. For nonsense syllables, the low-pass and high-

pass functional curves intersected at 1700 Hz, where the intelligibility score was 75%.

The higher crossover frequency (1900 Hz) with lower intelligibility score (68%) in the

French and Steinberg (1947) curves may be due to the high rejection rate of the filters.

Hirsh et al. (1954) also studied noise-masking effects on the intelligibility of different

types of speech materials. The intelligibility of easy speech material increased more

rapidly as a function of signal-to-noise (S/N) ratio than did the irnlcll'b HIII.. of more

difficult material. At a given S/N ratio, noise levels significantly affect intelligibility. In

general, intelligibility at a noise level of 70 dB was higher than that at other noise levels.

The results also showed that the intelligibility of polysyllabic, disyllabic and

monosyllabic words in noise was higher when they appeared in sentences than when they

appeared as discrete items on a list. Differences among the inilligil-l of the different

types of words were much smaller when the words appeared in sentences. Sentence

context had the greatest benefit on understanding monosyllabic words.








Pollack (1948) increased the difficulty of the test method for studying the effect

of low-pass and high-pass filtering by adding continuous spectrum white noise at 81.5 dB

SPL as a constant background noise. The test material consisted of monosyllabic,

phonetically balanced words. The overall speech level was about 68 dB SPL at a

distance of 1 meter from the talker. In general, the results indicated that speech

intelligibility increased as the intensity level of the speech signal and the frequency range

were increased. Owing to the background noise, +10 dB orthotelephonic gain (ratio of

the sound intensity at the listener's ear produced by the test system to the orthotelephonic

reference system, about 75 dB SPL) gave only 30 percent discrimination even to

unfiltered speech. With low-pass and high-pass filtering, the intelligibility improved

continuously with increasing intensity, up to a +50 dB orthotelephonic gain with different

filter settings, even though the rise of the curves between orthotelephonic gain of +30 and

+50 dB was fairly slight. The introduction of background noise resulted in shifting

optimal intensity from +10 dB orthotelephonic gain (French and Steinberg, 1947) to the

+30 to +50 dB level.

The Pollack (1948) study also demonstrated that the contribution to the

intelligibility of the higher speech frequencies alone was small. When a high-pass filter

with a 2375 Hz cutoff was used, intelligibility was only 5% at maximal gain. However,

these same frequencies made an appreciable difference in intelligibility when the low

frequency sounds were also passed at the same time. When the cutoff frequency of low-

pass filter was extended from 2500 Hz to 3950 Hz, the intelligibility was improved from

70% to 90%. It was suggested that the contribution to intelligibility of a given band of

speech frequencies was not independent of the contribution being made at the same time








by other bands of frequencies. There was an interaction among the contributions of the

various bands. Similarly, the contribution to intelligibility of very low speech

frequencies was also small. No words were recognized when the frequencies below 425

Hz alone were heard. However, when high-pass cutoff frequency was decreased from

580 Hz to 350 Hz, the intelligibility was improved from 85% to 93%.

A study of the effects of noise and frequency filtering on the perceptual

confusions of English consonants revealed that noise and low-pass filtering ensured more

homogeneous and well-defined results, whereas the mistakes from high-pass filtering

were more indefinite (Miller and Nicely, 1955). Nonsense consonant-vowel (CV)

syllables were used as the test material. The 16 consonants were spoken initially before

the vowel /a!. The results showed that voicing and nasality (manner of articulation) were

much less affected by a random masking noise than were the other features. Affrication

and duration (manner of articulation) were somewhat superior to place but far inferior to

voicing and nasality. Voicing and nasality were discriminable at S/N ratio as poor as -12

dB whereas the place of articulation was hard to distinguish at S/N ratio less than 6 dB,

an 18 dB difference in efficiency. After low-pass filtering (cutoff frequency ranged from

5000 Hz to 300 Hz), voicing and nasality features were well preserved compared with

affrication and place information although affrication was superior to place of

articulation. These results showed the considerable similarity between masking by

broadband noise and filtering by low-pass filters. The authors explained that the uniform

noise spectrum masked high frequencies more than low frequencies since the high-

frequency components of speech were relative weaker than low-frequency components,

so it was in effect a kind of low-pass filter. However, high-pass filtering (cutoff








frequency ranged from 1000 Hz to 4500 Hz) produced a totally different pattern. All

features deteriorated in about the same way as the low frequencies were removed. Thus,

low-pass filters affected linguistic features differentially, leaving the phonemes audible

but similar in predictable ways, whereas high-pass filters removed most of the acoustic

power in the consonants, leaving them inaudible and producing quite random confusions.

Audibility was the problem for high-pass filtering and confusibility was the problem for

low-pass filtering. In addition, the crossover point of the high-pass and low-pass function

curves was 1550 Hz, and it became 1250 Hz when plotted by the relative amount of

information transmitted instead of the intelligibility score. The downward shift of

crossover point in frequency indicated that relative to the intelligibility, the low-pass

information was greater and the high-pass information was smaller in consonant

recognition.

Wang and her colleagues studied perceptual features of consonant confusions in

noise (Wang and Bilger, 1973), and following filtering distortion of speech (Wang, Reed

and Bilger, 1978), by sequential information analysis (SINFA), which sequentially

identifies features with a high proportion of transmitted information contributing to

consonant perception. Nonsense syllables were used as test materials in their studies.

The stimuli represented all phonologically permissible consonant-vowel (CV) and vowel-

consonant (VC) syllables, which were formed by combing one of 25 consonants with the

vowels /i/, /a/ or/u/. Wang and Bilger (1973) demonstrated that articulatory and

phonological features could account for a large proportion of transmitted information.

The particular features, which resulted in high levels of performance, varied significantly

from one syllable set to another and in some cases varied within syllable sets as a








function of listening conditions. Voice and nasal features were well perceived both in

noise and in quiet, and they were identified as perceptually important in every syllable set

where they were distinctive. The feature round (/w/ and /h'/) was also well perceived

both in noise and in quiet. Other features, such as frication and place, appeared to have

different perceptual importance depending upon the listening condition. Under filtering

conditions, there were differential effects of high-pass and low-pass filtering on feature

recognition (Wang, Reed and Bilger, 1978). Low-pass filtering (cutoff frequency ranged

from 5600 Hz to 500 Hz) produced systematic changes in the importance of different

features, whereas high-pass filtering (cutoff frequency ranged from 355 Hz to 4000 Hz)

produced less consistent changes in features recognition. When the low-pass cutoff was

lowered from 2800 to 1400 Hz, sibilance (/s/, /z/, /S/, /tS/, /Z/ and /dZ/) (manner of

articulation) quickly lost its perceptibility. The high-pass filtering had little effect on the

recognition of sibilance. The high crossover point of the functions at 2800 Hz indicated

that cues for sibilant sound lay in the high-frequency region of the spectrum, above 2000

Hz. High (/k/, /g/, /S/, /tS/, /Z/, /dZ/, /I1/, /w/ and /j/) and anterior (/p/, /t/, /b/, /d/, /f/, /s/,

/v/, /z/, /m/, /n/, /1/, /0/ and //) features (place of articulation) also dropped noticeably

when the cutoff of low-pass filter was lowered to 1400 Hz. For CV syllables, the

crossover point, approximately 1700 Hz, was lower than that for VC syllables, about

2400 Hz. Thus, the cues for high / anterior features were partly dependent on the position

of the consonant within the syllables. However, voice and nasality became increasingly

important as the low-pass cutoff was lowered, while they were adversely affected by

high-pass filtering. The characteristics of consonant confusions following filtering were

quite similar to that noted by Miller and Nicely (1955).








The patterns of consonant confusions generated by subjects with sensorineural

hearing loss were like those generated by normal hearing subjects in response to the

appropriate filtering distortion of speech (Bilger and Wang, 1976; Wang, Reed and

Bilger, 1978). For example, severe low-pass filtering produced consonant confusions

comparable to those of listeners with high-frequency hearing loss. Severe high-pass

filtering gave a result comparable to that of patients with flat or rising hearing loss.

In 1994, Griffiths et al. investigated the intelligibility of speech stimuli recorded

within the uterus of a pregnant sheep. The results showed that the intelligibility of the

phonemes recorded in the air was significantly greater than the intelligibility of phonemes

recorded in utero. A male talker's voice was more intelligible than a female talker's

voice when the recordings were made in utero. Furthermore, an analysis of the feature

information transmission from recordings inside and outside the uterus revealed that

voicing information is better transmitted in utero than place or manner information. The

findings are quite similar to those of studies conducted by Miller and Nicely (1955) and

Wang et al. (1978) in that transmission into the uterus can be modeled as a low-pass

filter. While the results of Griffiths et al. (1994) study only reflect the perceptibility of the

speech energies present in the amniotic fluid, they do not specify what speech energy might

be present at the level of fetal inner ear. Measurements of acoustic transmission to the fetal

inner ear are quite limited at present. The purpose of current study was to evaluate the

intelligibility of externally generated speech utterances transmitted to and recorded at the

fetal sheep inner ear in utero.














CHAPTER 3
MATERIALS AND METHODS



The overall aims of this project were to determine the intelligibility of speech

information that was transmitted into the uterus and present within the inner ear of the sheep

fetus in utero. Cues inherent in the speech of both the mother and external talkers may be

perceived by the fetus, thus forming the basis for language acquisition. This study was

intended to provide evidence of fetal inner ear physiological responses to externally

generated speech and to address the hypotheses included in Chapter 1. The study had two

distinct components. The first involved recording speech produced through a loudspeaker

with an air microphone, a hydrophone placed in the uterus of a pregnant sheep and an

electrode secured to the round window of the fetus in utero cochlearr microphonic, CM).

The second portion of the study involved playing the recordings to a jury of normal hearing

adults so speech intelligibility could be evaluated.



Surgery

Eight time-mated pregnant ewes carrying fetuses at gestational ages from 130-140

days were prepared for surgery (term is 145 days). From this group, speech stimuli

recorded from only one animal were used in this study. Recordings from this animal were

judged by the experimenter to have the best fidelity. Speech signals produced from a








loudspeaker were recorded with an air microphone, a hydrophone placed in the uterus of

pregnant sheep and an electrode secured to the round window of the fetus. The Animal Use

Protocol in this study was approved by the Institutional Animal Care and Use Committee

(IACUC) of the University of Florida.

In preparation for measurements of fetal cochlear microphonic (CM), ewes were

fasted, anesthetized and maintained on a mixture of oxygen and halothane (1.5-2%) during

surgery and subsequent experimentation. The ewe was placed in the supine position and

the fetal head was delivered through a midline hysterotomy. An incision was made over the

fetal right bulla posterior and inferior to the pinna. The incision was located at the

attachment of the cartilaginous portion of the canal to the lateral surface of the skull and

was made parallel to the posterior border of the mandibular ramus. The bulla was exposed

and a small hole was opened through the bulla. The round window was located with an

operating microscope. An electrode was made from insulated stranded stainless steel wire

(Cooner Wire Company, Chatesworth, CA) with the insulation removed from one end. The

uninsulated end was rolled into a 2-mm diameter ball and placed inside the round window

niche (positive electrode). After verifying the impedance of the round window electrode (<

10 kO), the bulla was refilled with amniotic fluid and sealed over with methylmethacrylate.

Additional Cooner wire electrodes were sutured to tissue overlying the bulla (negative

electrode) and to tissue at a remote site (ground electrode). The skin over the bulla was

sutured and the electrodes were carefully secured to the fetus with silk thread. The fetus

was returned to the uterus and the uterus and abdomen were closed with clamps. Electrode








wires passed through the incisions and were connected to a biological amplifier (Grass

Instruments Co., model P511K, Quincy, MA).



Recording Speech Stimuli

The anesthetized ewe was placed supine on a stretcher and transported to a sound-

treated booth (Industrial Acoustics Co., model GDC-IL, Bronx, NY). Speech stimuli for

producing fetal CM were prerecorded on cassette tape and consisted of Vowel-Consonant-

Vowel (VCV) nonsense syllables and Consonant-Vowel-Consonant (CVC) monosyllable

words spoken by a male and a female talker. The center of a loudspeaker was one meter

from the ewe and was adjusted to the same height as the center of the lateral wall of the

ewe's abdomen. A calibrated air microphone (Briiel and Kjael, type 4165, Marlborough,

MA) was positioned over the maternal abdomen at a distance of 10 cm. A miniature

hydrophone (Briiel and Kjael, model 8103), calibrated with a pistonphone (Briiel and Kjael,

model 4223), was inserted in the uterus and connected to a charge amplifier (Brilel and

Kjael, type 2635). The output from the tape player (Harman Kardon, model TD 392,

Woodbury, NY) was routed through a power amplifier (Peavey DECA/1200, Peavey

Electronics Corp., Meridian, MS) that activated the loudspeaker (Peavey HDH-2). The

cochlear potentials, CMs recorded from the fetal inner ear in response to the speech stimuli,

were amplified (Grass Instruments Co., model P511K, Quincy, MA) and high-pass filtered

at 100 Hz (Kron-Hite Corp., model 3550, Avon, MA, 24 dB/octave). Figure 3-1 showed

the schematic drawing of recording system set-up.

Because the CM is produced during acoustic stimulation, the potential can be

contaminated with electromagnetic artifact emanating from the loudspeaker and associated








































Figure 3-1. Schematic drawing showing the aminal and the setup of devices for stimulus generation, stimulus
measurement, and recording in air, in the uterus, and from the fetal inner ear cochlearr microphonic).








wires. The electrical interference produces a voltage output from the biological amplifier

that mimics the true biologic potential. Because electromagnetic energy travels at the speed

of light, whereas acoustic energy travels at the speed of sound (344 m/s), uncontaminated

CM occurred approximately 3 ms after the onset of the stimulus. If this onset delay was not

present in the recording, then measurements were repeated after appropriate equipment

adjustment and / or grounding. The presence of an onset delay confirmed that the recorded

waveform was bioelectric rather than electromagnetic (Gerhardt et al., 1992).

Before recording speech stimuli, CMs (Figure 3-2) were verified by using tone-

bursts (0.5, 1.0 and 2.0 kHz). An evoked potential averaging computer (Tucker-Davis

Technologies, Gainesville, FL) delivered stimuli to the loudspeaker. Tone bursts were

delivered to the ewe's flank at intensity levels that were capable of producing CM

responses. Twenty stimuli were delivered and averaged for each CM response. Stimulus

duration (10 or 20 ms), sweep time (20 or 50 ms) and filtering (100-3,000 Hz or 100-10,000

Hz) varied with stimulus frequency (0.5, 1.0 and 2.0 kHz). The rate of stimulation was 5/s

and the rise/fall time was 0.2 ms.

The speech stimuli were delivered to the flank of pregnant ewes at two intensity

levels (105 and 95 dB SPL). First, the signals were simultaneously detected with a

microphone located over the abdomen and electrodes placed on the fetal round window in

utero. The outputs from the microphone and inner ear (CM) were recorded on two separate

channels of a DAT tape recorder (SONY Corporation, type ZA5ES, Japan). Then, the same

speech stimuli were repeated and recorded with a hydrophone placed in the uterus and

electrodes placed on the fetal round window ex utero. The fetal external canal and middle

ear cavity were cleared of fluids during ex utero measurement. At the completion of all










500 Hz 70 dB



500 Hz 60 dB


500 Hz 50 dB



2000 Hz -70 dB


2000 Hz 60 dB


Figure 3-2. CM responses obtained from a fetal sheep. Examples of CMs evoked by airborne pure tones at 0.5 and
2.0 kHz and at stimulus levels indicated under each waveform. The apparent onset latency represents the acoustic travel-time
from the loudspeaker to the fetal inner.


---~-----








measurements, the ewe and fetus were euthanized as prescribed by the IACUC of the

University of Florida.



Perceptual Testing



Subjects

A total of 155 undergraduate students from the Department of Communication

Sciences and Disorders at University of Florida volunteered to participate in this study.

From this group, responses from 139 students who judged the intelligibility of speech

stimuli were used. Sixteen students were excluded from the study for the following

reasons: eight judges used unreadable symbols; four judges were normative American

English speakers; and four judges reported hearing loss. The descriptive information of the

perceptual tests is presented in Table 3-1.

All of the judges had taken or were taking an undergraduate course in phonetics,

although as a group they would not be considered experienced phoneticians. All testing

was completed in a single 45-minute session. The protocol for the perceptual testing was

approved by the University of Florida Institutional Review Board (UFIRB Project # 1998-

563).



Speech Stimuli

Two sets of stimuli were used, vowel-consonant-vowel (VCV) nonsense syllables

and consonant-vowel-consonant (CVC) words spoken by male and female talkers and

words based on the Griffiths word lists (1967). Each stimulus item was presented in a








Table 3-1. Perceptual tests.


Perceptual audio CD

A

B

C

D

E

F


Contents

VCV

CVC

CVC

CVC

CVC

CVC


Number ofjudges

33

19

21

20

21

25








carrier phrase, "Mark the word ." The 14 nonsense syllables (C=/p, t, k, b, d, g, f, v, s,

z, m, n, S, tS/) spoken by both a male and a female talker were preceded and followed by

the vowel /a/ (e.g. /aga/). The mean fundamental frequencies were 120 and 225 Hz for the

male and female talkers, respectively. Sixty-four items were recorded at each of 16

conditions among gender of talker (male and female), stimulus levels (105 and 95 dB SPL),

and recording locations (air, uterus, CM ex utero, and CM in utero).



Procedures

The word list, spoken by both male and female talkers, were played through the

loudspeaker via a cassette tape recorder at two different airborne levels measured at the

maternal flank: 105 and 95 dB SPL (dB re: 20 jiPa). The outputs from the air microphone,

the hydrophone, and the fetus inner ear (CM) ex utero and in utero were recorded on DAT

tapes. One set of recordings with the best quality sound from one fetus was chosen for

constructing perceptual tapes. First, speech stimuli were digitized and reproduced via a

computer program (Cool Edit, Syntrillium Software Corporation, Phoenix, AZ) with 44.1-

kHz sampling rate and 16-bit resolution. The amplitudes of the speech stimuli were

adjusted to the same relative voltage levels. Second, each syllable item with a carrier phrase

was saved as an individual file. Then a computer program was used to randomize and

counter-balance the speech stimuli among gender of talker (male and female), stimulus

levels (105 and 95 dB SPL), and recording locations (air, uterus, CM ex utero, and CM in

utero). Finally, six different perceptual audio compact discs (CDs) were created. One

contained randomized recordings of 224 nonsense items (14 nonsense syllables recorded








under 16 conditions). The five other CDs contained recordings of 800 monosyllabic words,

each version consisted of 160 words (10 words recorded under 16 conditions, the same

word occurred no more than 4 times in each version). A 5-second silence interval separated

each test item.

The recordings were used to conduct a perceptual test of speech intelligibility. The

test required groups of judges to listen to the utterances in the carrier phrase and mark on

paper what they heard. The judges' responses provided the basis for determining

intelligibility scores (percent correct) associated with the VCV nonsense items and the CVC

words.

For the 14 VCV nonsense items, the judges filled in a blank in a /a a / frame with

the vowel set to la/. For example, if a judge heard "Mark the word /apa/," he or she would

have to write a "p" in the blank to be correct.

For the 50 CVC words, each judge selected his or her response from a closed set of

six monosyllable words that differed in either the initial or final consonant. For example,

one stimulus item was "Mark the word bat" and the response list included "batch, bash, bat,

bass, back, badge." To be correct, the judge would have to mark the word "bat."

Each version of perceptual audio CDs were played to a group of judges comprising

20-30 normal hearing young adults. All testing were conducted in a specially designed

listening laboratory which accommodated up to 25 people at one time. The perceptual

audio CD were played over earphones (HS-95 and HS-56, SONY) to the judges at an

output level set to be comfortably loud (approximately 70 dB SPL). Figure 3-3 showed the

frequency responses of two types of earphones used in the perceptual tests. Each listening




















O 90


o so-... "


70






50



63 125 250 500 1k 2k 4k 8k A L

FREQUENCY (Hz)



Figure 3-3. The frequency responses of two types of earphones: SONY HS-95 (dot line) and HS-56 (solid line)
used for the perceptual tests.
C.








test was preceded by a brief practice session using a version of perceptual audio CD

different from the real testing CD to ensure that subjects understood the perceptual tests.



Data Analyses



Statistical Analyses

Intelligibility, consonant confusion matrices and spectral analyses of recorded

speech signals were assessed. The speech intelligibility scores (percent correct) were

derived from the judges' responses to the perceptual audio CDs for the VCV nonsense

syllables and CVC words by gender, intensity level, and recording location. Multifactor

analysis of variance (ANOVA) was performed on the data of the VCV nonsense syllables

and CVC words separately. The independent variables included three factors: gender of the

talker (male and female), sound pressure level of the airborne stimulus (105 and 95 dB), and

location of recording (air, uterus, CM from ex utero fetus, and CM from in utero fetus).

The dependent variables were percentage of correct identification of nonsense syllables and

monosyllabic words (perceptual scores). In order to meet the variance assumptions for

statistical analysis, the pr cr .nt niell I h. ih', data, which are binomial variables (Thomton

and Raffin, 1978), were transformed using an arcsine function (2xarcsinx4(%/100)) to

normalize the variance prior to further analysis (Winer, Brown and Michels, 1991).








Information Analyses

Data were presented in the form of a 14 x 14-item confusion matrix for each

condition. A total of 16 matrices for VCV nonsense syllables were collected. Sequential

Information Analysis (SINFA; Wang, 1976) of perceptual pattern was performed. SINFA

is applied to the error matrices in order to evaluate the amount of feature information

received. SINFA allows for the partitioning of the contingent information transmitted and

received for particular features of the stimuli (e.g., voicing, manner, and place). From these

results a relative measure of performance may be calculated (the ratio of the bits of

information received to the bits sent, with the effects of other features held constant). The

data from all 16 conditions were analyzed using SINFA.



Acoustic Analyses

Acoustic analyses of five vowels (/i/, /I/, /E/, /as/, /A/) selected from the Griffiths'

words list (CVC) were performed across the recording conditions (105-dB stimuli of both

male and female speakers recorded in air, in the uterus, CM from ex utero fetus, and CM

from in utero fetus). The fundamental frequency (F0) and the first three formant frequencies

(F1, F2, and F3), and their relative intensity levels were measured by using a signal-

processing computer program (Cool Edit, Syntrillium Software Corporation, Phoenix, AZ).

Each real-time speech waveform was digitized with 44.1-kHz sampling rate and 16-bit

resolution. An averagel50-ms segment was selected around the steady-state portion of each

vowel. The F0 and formants (F,, F,, and F,) of each segment were measured by visual

inspection of the corresponding Fourier transform spectrum using Hamming window with







69
4096 Fourier size followed by smoothing (Lee, Potamianos and Narayanan, 1999).

According to the values measured by Peterson and Barney (1952), and Hillenbrand et al.

(1995), FO and formants frequencies (F|, F2, and F3) were estimated. The relative intensity

levels were also calculated by subtracting the background noise value from the peak value

under different recording conditions. Two-factor repeated measures ANOVAs were

performed on the data of relative intensity levels of F, F,, F,, and F, across the recording

locations for each vowel.













CHAPTER 4
RESULTS AND DISCUSSION



One hundred and thirty-nine judges completed the perceptual tests. Because the

speech stimuli were completed randomized and counter-balanced across gender of talkers

(male and female), stimulus levels (105 and 95 dB SPL) and recording locations (air, uterus,

CM ex utero, and CM in utero), learning effects were minimized.



Intelligibility

The speech intelligibility scores (percent correct) derived from the judges'

responses to the perceptual audio compact discs (CDs) for the VCV nonsense syllables

and CVC words are displayed in Figures 4-1 and 4-2, respectively. A few general

observations can be made about both Figures. First, intelligibility scores as a function of

location alone, decreased from air to hydrophone locations and decreased again from CM

ex utero to CM in utero. That is to say, intelligibility scores of the VCV and CVC lists

were high when recorded in air and slightly less when recorded with a hydrophone in the

uterus. The scores, when recorded from the inner ear of the fetus ex utero, are 20-40%

lower than recordings from either the air or hydrophone locations. The intelligibility

scores recorded from the inner ear of the fetus in utero are about 10-20% poorer than the

scores recorded from the fetal CM ex utero. Second, from casual inspection of the two

Figures, there appear to be a slight gender and level effects primarily for the VCV lists.
























Figure 4-1. Mean percent iniellicIhi of VCV nonsense stimuli spoken by a male and a female talker
recorded in air, in the uterus, from the fetal CM ex utero, and from fetal CM in utero at two airborne stimulus levels.
Bars equal the standard error of the mean.








100
00 VCV EMale-105 d
90 93 Female-10!
~o 80 [] Male-95 dB
o 80
M [ Female-95
>- 70
I-
60
50.o
- 40
30
-LJ
20
10
0
AIR UTERUS CM-EX CM-IN
TEST CONDITION
























Figure 4-2. Mean percent intelligibility of CVC words spoken by a male and a female talker recorded in air, in
the uterus, from the fetal CM ex utero, and from fetal CM in utero at two airborne stimulus levels. Bars equal the
standard error of the mean.








100
9CVC Male-105 d
90 Female-10t
80. .. Male-95 dB
80
..M Female-95
>- 70
60
rn 50 :::
- 40
S30
S20
10
0

AIR UTERUS CM-EX CM-IN

TEST CONDITION









Gender and level effects are more pronounced from recordings of the CM than from

recordings in air or in the uterus. Summaries of the means and standard deviations for

intelligibility by gender, stimulus level, and location that contributed to these figures are

presented in Tables 4-1 and 4-2.

The results of a three-factor repeated measure ANOVA are summarized for VCV

stimuli and given in Tables 4-3. There was a significant three-way interaction among

gender, stimulus level, and location (F3,96= 14.582, p < 0.0001). The main effects were

significant for each of the three factors: location (F3,96= 994.982, p < 0.0001), gender (F|,

32= 210.258, p < 0.0001), and stimulus level (F1,32= 25.869, p < 0.0001). The results of

the post hoc multiple comparison test (Newman-Keuls) are presented in Table 4-4. Not

all of the paired results were included in this table. Note that intelligibility in all cases

was significantly greater (p < 0.01) for CM ex utero than for CM in utero. Also,

intelligibility of the nonsense syllables (VCV) was better at higher presentation levels

than at lower presentation levels. When both stimulus levels were compared, statistical

significance (p < 0.01) was attained for the male voice recorded in the uterus, from CM

ex utero, and from CM in utero, as well as for the female voice recorded from CM in

utero.

The ANOVA results for CVC words (Table 4-5) showed a significant three-way

interaction among gender, stimulus level, and location (F3, 315 = 22.459, p < 0.0001). This

was similar to the results for the nonsense syllables (VCV). The main effects were

significant for location (F3,315= 1213.579, p < 0.0001) and stimulus level (F, o05s=

102.82, p < 0.0001), but not for gender (FI, 105 = 1.247, p = 0.267). The results of the post

hoc multiple comparison test (Newman-Keuls) are given in Table 4-6, in which not all of









Table 4-1. VCV stimulus intelligibility scores for each talker, stimulus level and recording site.


In Air In Uterus CM-ex utero CM-in utero

Male talker 105 dB 95 dB 105 dB 95 dB 105 dB 95 dB 105 dB 95 dB

Mean (%) 99.35% 98.48% 89.61% 96.10% 80.52% 70.13% 46.75% 32.47%

S.D. (%) 2.09% 2.97% 7.16% 5.08% 11.33% 8.83% 12.25% 9.46%

No. correct (N=14) 13.909 13.788 12.545 13.455 11.273 9.818 6.545 4.545

S.D. 0.292 0.415 1.003 0.711 1.587 1.236 1.716 1.325

No. ofjudges 33 33 33 33 33 33 33 33

Female talker

Mean (%) 90.26% 91.34% 82.90% 78.79% 50.22% 48.48% 39.39% 28.57%

S.D. (%) 5.87% 3.89% 8.74% 10.18% 7.68% 10.22% 11.73% 11.01%

No. correct (N=14) 12.636 12.788 11.606 11.030 7.030 6.788 5.515 4.000

S.D. 0.822 0.545 1.223 1.425 1.075 1.431 1.642 1.541

No. ofjudges 33 33 33 33 33 33 33 33









Table 4-2. CVC stimulus intelligibility scores for each talker, stimulus level and recording site.


In Air In Uterus CM-ex utero CM-in utero

Male talker 105 dB 95 dB 105 dB 95 dB 105 dB 95 dB 105 dB 95 dB

Mean (%) 95.47% 97.45% 93.40% 85.75% 62.26% 57.83% 60.09% 40.85%

S.D. (%) 6.19% 4.38% 7.55% 13.23% 16.69% 15.24% 12.31% 15.92%

No. correct (N=10) 9.547 9.745 9.340 8.575 6.226 5.783 6.009 4.085

S.D. 0.619 0.438 0.755 1.323 1.669 1.524 1.231 1.592

No. ofjudges 106 106 106 106 106 106 106 106

Female talker

Mean (%) 98.02% 92.74% 90.57% 86.70% 63.02% 62.74% 52.26% 46.23%

S.D. (%) 4.66% 6.25% 7.28% 11.85% 16.28% 16.07% 15.14% 15.58%

No. correct (N=10) 9.802 9.274 9.057 8.670 6.302 6.274 5.226 4.623

S.D. 0.466 0.625 0.728 1.185 1.628 1.607 1.514 1.558

No. of judges 106 106 106 106 106 106 106 106









Table 4-3. ANOVA summary table for VCV stimuli.


Source Sum of Squares df Mean Squares F p-value
Location 180.991 3 60.330 994.982 <0.0001

Error (Location) 5.821 96 0.06063

Gender 22.470 1 22.470 210.258 <0.0001

Error (Gender) 3.420 32 0.107

Level 0.894 1 0.894 25.869 <0.0001

Error (Level) 1.106 32 0.03456

Location x Gender 3.948 3 1.316 21.539 <0.0001

Error (Location x Gender) 5.866 96 0.0611

Location x Level 2.738 3 0.913 23.181 <0.0001

Error (Location x Level) 3.779 96 0.03936

Gender x Level 0.00407 1 0.0407 0.104 0.749

Error (Gender x Level) 1.249 32 0.03904

Location x Gender x Level 2.180 3 0.727 14.582 <0.0001

Error (Location x Gender x Level) 4.784 96 0.04983










Table 4-4. Post hoc multiple comparisons (Newman-Keuls test) for VCV stimuli.


Conditions
AMH AML UMH UML XMH XML IMH IML AFH AFL UFH UFL XFH XFL IFH IFL
AMH
AML
UMH **
UML **
XMH ** **
XML ** ** **
IMH ** ** **
IML ** ** ** **
AFH **
AFL **
UFH ** **
UFL ** **
XFH ** ** **
XFL ** ** **
IFH ** ** ** **
IFL ** ** ** **
Note: A = In Air; U = In Uterus; X = CM-ex utero; I= CM-in utero; M = Male; F = Female; H = 105 dB; L =95 dB.
-- p>0.05; p<0.05; ** p<0.01.










Table 4-5. ANOVA summary table for CVC stimuli.


Source Sum of Squares df Mean Squares F p-value

Location 505.738 3 168.579 1213.687 <0.0001


Error (Location)

Gender

Error (Gender)

Level

Error (Level)

Location x Gender

Error (Location x Gender)

Location x Level

Error (Location x Level)

Gender x Level

Error (Gender x Level)

Location x Gender x Level

Error (Location x Gender x Level)


43.753

0.192

16.154

9.484

9.685

1.2995

39.486

2.821

33.439

0.119

22.126

7.713

36.061


0.139

0.192

0.154

9.484

0.09224

0.433

0.125

0.940

0.106

0.119

0.211

2.571

0.114


1.247 0.267



102.820 <0.0001



3.456 0.0658



8.857 <0.0001



0.566 0.454



22.459 <0.0001













Table 4-6. Post hoc multiple comparisons (Newman-Keuls test) for CVC stimuli.


Conditions

AMH AML UMH UML XMH XML IMH IML AFH AFL UFH UFL XFH XFL IFH IFL


** **


AMH

AML

UMH

UML

XMH

XML

IMH

IML

AFH

AFL

UFH


** **


**

**

** **

** **L

** ** ** *4


Note: A = In Air; U = In Uterus; X = CM-ex utero; I = CM-in utero; M = Male; F = Female; H
-- p>0.05; p<0.05; ** p<0.01.


= 105 dB; L = 95 dB.


**



**


** **


**


**


**


**



**


~







82

the paired results were included. It is noted that intelligibility was significantly greater (p

< 0.01) for CM ex utero than for CM in utero, except for the male voice recorded at 105

dB SPL (p > 0.05). Also, intelligibility of the words (CVC) was better at higher

presentation levels than at lower presentation levels, except for the male voice recorded

in air. When both stimulus levels were compared, statistical significance (p < 0.01) was

achieved for the male voice recorded in air (p < 0.05), in the uterus, and from CM in

utero, as well as for the female voice recorded in air and from CM in utero.

Figures 4-3 simplifies those data presented in Figure 4-1 by combining levels.

For VCV stimuli, the average intelligibility scores for the male voice recorded in air, in

the uterus, from fetal CM ex utero, and from fetal CM in utero were 98.9%, 92.9%,

75.3%, and 39.6%, respectively. For the female voice recorded in air, in the uterus, from

fetal CM ex utero, and from fetal CM in utero, the intelligibility scores were 90.8%,

80.8%, 49.4%, and 34.0%, respectively. A two-factor repeated measures ANOVA

indicated significant interaction between gender and location (F3,96 = 20.925, p < 0.0001),

and main effects for gender (F1,32 = 192.744, p < 0.0001) and location (F3,96 = 1048.477,

p < 0.0001). The post hoc multiple comparison test (Newman-Keuls) indicated that the

intelligibility scores of the male voice were significantly higher (p < 0.01) than that of the

female voice at all four recording locations. Also, for both male and female talkers, the

intelligibility scores recorded in air were significantly higher (p < 0.01) than that of each

of the other three recording locations. The scores recorded in the uterus were

significantly higher (p < 0.01) than that of recordings from CM ex utero and CM in utero.

The scores recorded from CM ex utero were significantly higher (p < 0.01) than that from

CM in utero.

























Figure 4-3. Mean percent :n l ,ll Il. of VCV nonsense stimuli spoken by a male and a female talker
recorded in air, in the uterus, from the fetal CM ex utero, and from fetal CM in utero when combining two airborne
stimulus levels. Bars equal the standard error of the mean.








100
100 VCV Ma
90 --- -aFer
80
>70 -
-I 60
S50
"j 40 -
-J
u 30
z 20
10 -
0 1
AIR UTERUS CM-EX CM-IN
TEST CONDITION









Similarly, Figures 4-4 clarifies those data presented in Figure 4-2 by combining

levels. For CVC words, the average intelligibility scores for the male voice recorded in

air, in the uterus, from fetal CM ex utero, and from fetal CM in utero were 96.5%, 89.6%,

60.1%, and 50.5%, respectively. For the female voice recorded in air, in the uterus, from

fetal CM ex utero, and from fetal CM in utero, the intelligibility scores were 95.4%,

88.6%, 62.9%, and 49.3%, respectively. A two-factor repeated measures ANOVA

indicated significant interaction between gender and location (F3,315 = 3.386, p = 0.0184),

and main effects for location (F3,315 = 1045.347, p < 0.0001), but not for gender (FI, l05 =

1.427, p = 0.235). A post hoc multiple comparison test (Newman-Keuls) indicated that,

for both male and female talkers, the intelligibility scores recorded in air were

significantly higher (p < 0.01) than that of each of the other three recording locations.

The scores recorded in the uterus were significantly higher (p < 0.01) than that of

recordings from CM ex utero and CM in utero. The scores recorded from CM ex utero

were significantly higher (p < 0.01) than that from CM in utero. There were no statistical

differences (p > 0.05) between the male voice and the female voice across recording

locations, except when recorded in air (p < 0.05).

As reported above, speech (VCV and CVC stimuli) intelligibility scores were

significantly higher for the recordings in air than in the uterus. Likewise, the

intelligibility was significantly greater for the recordings from CM ex utero than from

CM in utero. The recordings within the uterus reflect the speech energies present in

amniotic fluid, whereas the recordings from CM in utero represent the actual fetal

physiological responses to externally generated speech. The characteristics of

transmission of external sound pressure into the maternal abdomen and uterus has been
























Figure 4-4. Mean percent intelligibility of CVC words spoken by a male and a female talker recorded in air, in
the uterus, from the fetal CM ex utero, and from fetal CM in utero when combining two airborne stimulus levels. Bars
equal the standard error of the mean.









100
CVC r'Male
90 Female
o80 -
70
F-
60
50 -
(9
4- 40
- N
w 30
F--
z 20 -
10 -
0
AIR UTERUS CM-EX CM-IN
TEST CONDITION









well described in humans (Querleu et al., 1988a; Richards et al., 1992) and sheep

(Armitage, Baldwin and Vince, 1980; Vince et al., 1982, 1985; Gerhardt, Abrams and

Oliver, 1990). The abdomen wall, uterus, and amniotic fluids can be characterized as a

low-pass filter with a high-frequency cutoff at 250 Hz and a rejection rate of

approximately 6 dB per octave. For frequencies below 250 Hz, sound pressures passing

through to the fetus are unattenuated, and, in some cases, are enhanced. Above 250 Hz,

sound pressures are increasingly attenuated by up to 20 dB (Gerhardt, Abrams and

Oliver, 1990). Thus, the speech signals would be altered as they passed through tissues

of the ewe into the uterus. Additionally, the spectral contents of external sounds are

further modified by the route of sound transmission into the fetal inner ear. Sound

pressures pass through the fetal head by a bone conduction pathway (Gerhardt et al.,

1996). For 125 to 250 Hz, an airborne signal would be reduced by 10-20 dB before

reaching the fetal inner ear. For 500 through 2000 Hz, the signal would be reduced by

35-45 dB (Gerhardt et al., 1992). Therefore, the recordings of speech from CM in utero

would be further degraded and less intelligible than the recordings in air and in the uterus.

The present findings reveal better intelligibility for speech in the uterus than has

been previously found (Querleu et al., 1988b; Griffiths et al., 1994). Querleu et al.

(1988b) found that about 30% of 3120 French phonemes recorded within the uterus of

pregnant women were recognized. In 1994, Griffiths et al. evaluated the intelligibility of

speech stimuli (VCV nonsense syllables and CVC words) recorded within the uterus of a

pregnant sheep. The intelligibility scores were approximately 55% and 34% for the male

and female talkers, respectively. However, the results from the current study showed that

the intelligibility scores averaged across the stimulus types and intensity levels, were




Full Text
INTELLIGIBILITY OF SPEECH PROCESSED THROUGH
THE COCHLEA OF FETAL SHEEP IN UTERO
By
XINYAN HUANG
A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
UNIVERSITY OF FLORIDA
1999

Dedicated to my wife, Min Feng

ACKNOWLEDGMENTS
First and foremost, I would like to express my sincerest appreciation and gratitude
to my committee chairman and mentor, Dr. Kenneth Gerhardt, for his constant guidance,
support, encouragement, and invaluable contribution to my professional and personal
development. I would like to respectfully thank Dr. Robert Abrams for the constant
support and encouragement he gave me regarding science, academics, and American
culture.
Secondly, my thanks go to my committee members, Dr. Scott Griffiths, Dr.
Francis Joseph Kemker, and Dr. Kyle Rarey, for their thoughtful suggestions and support.
I would like to thank the faculty and staff in the Department of Communication Sciences
and Disorders and in the Perinatology Research Laboratory for their valuable help during
this study. I especially thank Mr. Rodney Flousen for his computer programming
assistance.
Finally, I wish to express my deepest appreciation and thanks to my wife.
Without her love, patience, understanding, and continued support, this endeavor would
have not been possible. My love and appreciation are imparted to my parents whose
inspiration has kept me in constant pursuit of my dreams.

TABLE OF CONTENTS
page
ACKNOWLEDGMENTS iii
LIST OF TABLES vi
LIST OF FIGURES ix
ABSTRACT xi
CHAPTERS
1 INTRODUCTION 1
2 REVIEW OF LITERATURE 6
Fetal Hearing 6
Development of the Auditory System 6
Development of the Place Principle 9
Central Auditory System 13
Fetal Behavioral Response to Sound 14
Fetal Sound Enviroment 16
Intrauterine Background Noise 16
Sound Transmission into the Uterus 19
Fetal Sound Isolation 21
Route of Sound Transmission into the Fetal Inner Ear 23
Model of Fetal Hearing 25
Intelligibility of Speech Sounds Recorded within the Uterus 27
Fetal Auditory Experiences and Learning 31
Prenatal Effects of Sound Experience 31
Postnatal Effects of Prenatal Sound Experience 35
Speech Perception 44
Speech Perception in Infancy 44
Characteristic of Speech 45
Intelligibility of Speech 48
3 MATERIALS AND METHODS 56
Surgery 56
iv

Recording Speech Stimuli 58
Perceptual Testing 62
Subjects 62
Speech Stimuli 62
Procedures 64
Data Analyses 65
Statistical Analyses 65
Information Analyses 67
Acoustic Analyses 68
4 RESULTS AND DISCUSSION 70
Intelligibility 70
Consonant Feature Transmission 94
Acoustic Analyses of Vowel Transmission 117
5 SUMMARY AND CONCLUSIONS 153
APPENDICES
A SUBJECT RESPONSE SHEET 158
B RAW DATA FROM SUBJECT RESPONSE FORMS 161
C RAW DATA FROM ACOUSTIC ANALYSES OF VOWELS 169
REFERENCES 178
BIOGRAPHICAL SKETCH 190
v

LIST OF TABLES
Table page
3-1 Perceptual tests 63
4-1 VCV stimulus intelligibility scores 76
4-2 CVC stimulus intelligibility scores 77
4-3 ANOVA summary table for VCV stimuli 78
4-4 Post hoc multiple comparisons (Newman-Keuls test) for VCV stimuli 79
4-5 ANOVA summary table for CVC stimuli 80
4-6 Post hoc multiple comparisons (Newman-Keuls test) for CVC stimuli 81
4-7 Consonant confusion matrix for male talker, recorded in air at 105 dB SPL 95
4-8 Consonant confusion matrix for male talker, recorded in air at 95 dB SPL 96
4-9 Consonant confusion matrix for male talker, recorded in the uterus at 105 dB
SPL 97
4-10 Consonant confusion matrix for male talker, recorded in the uterus at 95 dB
SPL 98
4-11 Consonant confusion matrix for male talker, recorded from CM-ex útero at 105
dB SPL 99
4-12 Consonant confusion matrix for male talker, recorded from CM-ex útero at 95 dB
SPL 100
4-13 Consonant confusion matrix for male talker, recorded from CM-iti útero at 105
dB SPL 101
4-14 Consonant confusion matrix for male talker, recorded from CM-in útero at 95 dB
SPL 102
vi

4-15
Consonant confusion matrix for female talker, recorded in air at 105 dB SPL ..103
4-16
Consonant confusion matrix for female talker, recorded in air at 95 dB SPL ....104
4-17
Consonant confusion matrix for female talker, recorded in the uterus at 105 dB
SPL 105
4-18
Consonant confusion matrix for female talker, recorded in the uterus at 95 dB
SPL 106
4-19
Consonant confusion matrix for female talker, recorded from CM-ex útero at 105
dB SPL 107
4-20
Consonant confusion matrix for female talker, recorded from CM-ex útero at 95
dB SPL 108
4-21
Consonant confusion matrix for female talker, recorded from CM-in útero at 105
dB SPL 109
4-22
Consonant confusion matrix for female talker, recorded from CM-in útero at 95
dB SPL 110
4-23
Conditional percentage of voicing, manner, and place information received (of
bits sent) for each talker, recording location, and stimulus level condition for the
nonsense syllables (VCV) 112
4-24
Average fundamental frequencies (F0) and first three formant frequencies (F„ F2,
F3) for five vowels produced by each talker and recorded in air 128
4-25
Mean and standard deviation (S.D.) of relative intensity levels (dB) of
fundamental frequency (F0) and first three formant frequencies (F,, F2,F3) for
vowel ill produced by each talker at different recording sites in the 105 dB
condition 129
4-26
Mean and standard deviation (S.D.) of relative intensity levels (dB) of
fundamental frequency (F0) and first three formant frequencies (F,, F2, F3) for
vowel IV produced by each talker at different recording sites in the 105 dB
condition 135
4-27
Mean and standard deviation (S.D.) of relative intensity levels (dB) of
fundamental frequency (F0) and first three formant frequencies (F„ F2, F3) for
vowel IeI produced by each talker at different recording sites in the 105 dB
condition 138
Vil

4-28 Mean and standard deviation (S.D.) of relative intensity levels (dB) of
fundamental frequency (F0) and first three formant frequencies (F„ F2, F3) for
vowel /re/ produced by each talker at different recording sites in the 105 dB
condition 143
4-29 Mean and standard deviation (S.D.) of relative intensity levels (dB) of
fundamental frequency (F0) and first three formant frequencies (F,, F2, F3) for
vowel /A/ produced by each talker at different recording sites in the 105 dB
condition 146
4-30 Summary of acoustic analyses of vowels 150
viii

LIST OF FIGURES
Figure
page
3-1 Schematic drawing showing the animal and the setup of devices for stimulus
generation, stimulus measurement, and recording in air, in the uterus, and from
the fetal inner ear (cochlear microphonic) 59
3-2 Examples of CMs evoked by airborne pure tones at 0.5 and 2.0 kHz 61
3-3 The frequency responses of two types of earphones 66
4-1 Mean percent intelligibility of VCV nonsense stimuli spoken by a male and a
female talker recorded in air, in the uterus, from the fetal CM ex útero, and from
fetal CM in útero at two airborne stimulus levels 72
4-2 Mean percent intelligibility of CVC words spoken by a male and a female talker
recorded in air, in the uterus, from the fetal CM ex útero, and from fetal CM in
útero at two airborne stimulus levels 74
4-3 Mean percent intelligibility of VCV nonsense stimuli spoken by a male and a
female talker recorded in air, in the uterus, from the fetal CM ex útero, and from
fetal CM in útero when combining two airborne stimulus levels 84
4-4 Mean percent intelligibility of CVC words spoken by a male and a female talker
recorded in air, in the uterus, from the fetal CM ex útero, and from fetal CM in
útero when combining two airborne stimulus levels 87
4-5 Conditional percentage of voicing, manner and place information received for a
male (M) and a female (F) talker; in air (A), in the uterus (U), from the fetal CM
ex útero (X), and from the fetal CM in útero (I); at 105 dB (H) and 95 dB (L)
SPL 114
4-6 Spectrographic recordings of “Mark the word lash” at different recording
conditions 119
4-7 Mean of intensity levels (dB relative) of fundamental frequency (F0) and first
three formant frequencies (F„ F2, and F3) for vowel III produced by both talkers
recorded at different locations at 105 dB SPL 131
lx

4-8 Mean of intensity levels (dB relative) of fundamental frequency (F0) and first
three formant frequencies (F„ F2, and F3) for vowel /I/ produced by both talkers
recorded at different locations at 105 dB SPL 137
4-9 Mean of intensity levels (dB relative) of fundamental frequency (F0) and first
three formant frequencies (F,, F2> and F3) for vowel /s/ produced by both talkers
recorded at different locations at 105 dB SPL 140
4-10 Mean of intensity levels (dB relative) of fundamental frequency (F„) and first
three formant frequencies (F„ F2, and F3) for vowel /$/ produced by both talkers
recorded at different locations at 105 dB SPL 145
4-11 Mean of intensity levels (dB relative) of fundamental frequency (F0) and first
three formant frequencies (F„ F2, and F3) for vowel /A/ produced by both talkers
recorded at different locations at 105 dB SPL 148
x

Abstract of Dissertation Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Doctor of Philosophy
INTELLIGIBILITY OF SPEECH PROCESSED THROUGH
THE COCHLEA OF FETAL SHEEP IN UTERO
By
Xinyan Huang
August 1999
Chairman: Kenneth J. Gerhardt
Major Department: Communication Sciences and Disorders
The intelligibility of speech stimuli recorded from the fetal sheep inner ear
(cochlear microphonic, CM) in útero was determined perceptually using a group of
untrained judges. A fetus was prepared for acute recordings during a surgical procedure.
Two separate lists, one of meaningful and one of nonmeaningful speech, were spoken by a
male and a female talker, delivered through a loudspeaker to the side of a pregnant ewe,
and recorded with an air microphone, a hydrophone placed inside the uterus, and an
electrode secured to the round window of the fetus in útero. Perceptual test audio compact
discs (CDs) generated from these recordings were played to 139 judges.
The intelligibility of the phonemes recorded in air was significantly greater than the
intelligibility of these stimuli when recorded from within the uterus. The intelligibility of
the phonemes recorded from CM ex útero was significantly greater than from CM in útero.
Overall, male and female talker intelligibility scores recorded within the uterus averaged
xi

91% and 85%, respectively. When recorded from the fetal CM in útero, intelligibility
scores averaged 45% and 42% for the male and female talkers, respectively.
An analysis of the transmission of consonant feature information revealed that
“voicing” is better transmitted into the uterus and into the fetal inner ear in útero than
“manner” or “place.” Voicing information for the male, as well as manner and place
information, was better preserved in the fetal inner ear in útero than for the female.
Spectral analyses of vowels showed that the fundamental frequency (F0) and the first
three formants (F„ F2, and F3) were well preserved in the uterus recordings for both talkers,
but only F0, F„ and F2 (< 2000 Hz) were perceived in the fetal inner ear in útero. Only the
lower frequency contents of vowels were present in fetal inner ear recordings.
This study demonstrated the presence of external speech signals in the fetal inner
ear in útero and described the type of phonetic information that was detected at the fetal
inner ear in Utero.
xii

CHAPTER 1
INTRODUCTION
There is overwhelming evidence that the human fetus detects and responds to
sound in útero (Querleu et al., 1989; Hepper, 1992; Lecanuet and Schaal, 1996). Studies
in pregnant humans (Walker, Grimwade and Wood, 1971; Querleu et al., 1988a; Richards
et al., 1992) and sheep (Armitage, Baldwin and Vince, 1980; Vince et al., 1982, 1985;
Gerhardt, Abrams and Oliver, 1990) have shown the existence of a rich diversity of
sound in the fetal environment, heavily dominated by the mother's voice and other
internal noises and permeated by varied rhythmic and tonal sounds from the external
environment. The human fetus has a well-developed hearing mechanism by the sixth
month of gestation (Rubel, 1985a; Pujol and Uziel, 1988; Pujol, Lavigne-Rebillard and
Uziel, 1990). During the last trimester, sound exposure may have a pronounced effect on
fetal behavior and central nervous system maturation. Speech perception and voice
recognition by the newborn may result directly from its prenatal experience (Fifer and
Moon, 1988, 1995).
Linguistic theorists have proposed two alternative hypotheses regarding language
development that infants upon birth are equipped with either a generalized auditory
mechanism or a specialized speech-specific mechanism designed for perception of
speech. Some theorists hold that human infants are bom with a "speech module," a
mechanism designed specifically for processing the complex and intricate acoustic
1

2
signals needed by humans to communicate with one another (Liberman, 1982; Fodor,
1983; Liberman and Mattingly, 1985; Wilkins and Wakefield, 1995; Fowler, 1996). An
alternative theory of the neonate's initial state suggests that infants enter the world
without specialized mechanisms dedicated to speech and language, but rather respond to
speech using general sensory, motor, and cognitive abilities (Aslin, 1987; Kuhl, 1987,
1992; Jusczyk 1996; Ohala, 1996; Fitch, Miller and Tallal, 1997). Which theory, if
either, applies to the human fetus is not known. What is known is that the fetus is
beginning the dynamic process of acquiring the necessary skills for speech and language
acquisition during prenatal life in útero (Querleu et al., 1989; Lecanuet, Granier-Deferre
and Busnel, 1991; Lecanuet and Schaal, 1996).
The maternal voice is a naturally occurring and salient stimulus in útero that
occurs during a crucial time period of fetal ontogeny (Querleu et al„ 1988a; Benzaquen et
al., 1990; Richards et ah, 1992) in which several psychobiological systems, including the
auditory system, are developing. The immediate effects of exposure to the mother’s
voice on the fetus may provide a way of tracking auditory system development, as well as
measuring fetal ability to process sensory information (Fifer and Moon, 1988, 1994,
1995). Fetal auditory discrimination has also led to the hypothesis that prenatal
experience with auditory stimulation is the precursor to postnatal linguistic development
(Cooper and Aslin, 1989; Querleu et ah, 1989; Ruben, 1992; Abrams, Gerhardt and
Antonelli, 1998).
DeCasper and his colleagues (DeCasper and Fifer, 1980; DeCasper and Prescott,
1984) demonstrated that newborn infants preferred their mother's voice over that of other
talkers. While this preference was assumed to be the product of in útero exposure to the

3
mother's voice and suggested that the fetus detected maternal vocalizations and retained
memories of her speech patterns, it is not known what speech information actually
reaches the fetal inner ear nor the extent to which the auditory system responds to
externally generated speech. Querleu et al. (1988b) and more recently Griffiths et al.
(1994) reported on the intelligibility of speech recorded with a hydrophone in the human
(Querleu et al., 1988b) and sheep (Griffiths et al., 1994) uterus. In both studies, the
recordings were played back to juries of nonnal listeners and speech intelligibility was
calculated from their responses. The intelligibility of in ulero recordings of speech was
poorer than that of air recordings because the acoustic signature of human speech is
modified by the abdominal wall, uterus, and amniotic fluids as it passes from air to the
fetal head. The attenuation properties of the abdomen and uterus can be modeled as a
low-pass filter with a high frequency cutoff at 250 Hz and a rejection rate of
approximately 6 dB/octave (Gerhardt, Abrams and Oliver, 1990).
While the results of these studies reflect the perceptibility of the speech energies
present in the amniotic fluid, they do not specify what speech energy might be present at
the level of fetal inner ear. Measures of acoustic transmission to the fetal inner ear are
quite limited at present (Gerhardt et al., 1992). Much work needs to be completed before
conclusions can be drawn regarding what speech energies reach and are able to be
perceived by the fetus.
The present experiment was designed to evaluate the intelligibility of speech
produced through a loudspeaker and recorded with an electrode secured to the fetal sheep
round window. The electrode recorded a bioelectric potential called the cochlear
microphonic (CM). The CM is generated at the level of the hair cells and mimics the

4
input in amplitude and frequency (Gulick, Gescheider and Frisina, 1989). Recordings of
the CM represent the time displacement patterns of the basilar membrane and reflect the
initial response of the auditory periphery. The hypothesis is that speech is further
degraded as it passes into the inner ear. Sheep were used in this study not only because
sound attenuation characteristics of the abdominal contents of pregnant sheep are similar
to those of pregnant women (Armitage, Baldwin and Vince, 1980; Querleu et al., 1988a;
Gerhardt, Abrams and Oliver, 1990; Richards et al., 1992), but also because of the
precocious hearing and the similarity of auditory sensitivity to humans. Sheep’s hearing
is only slightly poorer than that of humans for frequencies below about 8000 Hz
(Wollack, 1963). The objective of this study was to determine what speech information
was transmitted into the uterus and presented within the inner ear of the sheep fetus in
útero.
The following hypotheses were tested:
1. The intelligibility of monosyllabic words and nonsense syllables will be reduced when
recorded in the uterus compared to air.
2. The intelligibility of monosyllabic words and nonsense syllables will be reduced when
recorded from the fetal inner ear in útero compared to uterus.
3. The intelligibility of a male talker will be greater than the intelligibility of a female
talker when recorded in the uterus and from the fetal inner ear in útero.
4. Transmission into the uterus and fetal inner ear will be greater for voicing
information than for manner and place information.

5
5. The transmission of voicing, manner, and place information will be better for males
than for females when recorded in the uterus and from the inner ear of the fetus in
ulero.
6. Acoustic energy in the second and third formants of vowels measured in air for both
male and female talkers will be reduced when recorded in the uterus, and will be
reduced to the noise floor when recorded from the fetal inner ear in útero.

CHAPTER 2
REVIEW OF LITERATURE
The human, unlike most mammalian species, is bom with highly developed
auditory sensitivity. By the 20th week of gestation, the structures of the peripheral
auditory system, including the outer, middle, and inner ear, are anatomically like that of
an adult, thus enabling the fetus to detect sounds during the last trimester of pregnancy
(Rubel, 1985a; Pujol and Uziel, 1988; Pujol, Lavigne-Rebillard and Uziel, 1990).
Responsiveness of the fetus to auditory stimuli begins during the 24th week of gestation
(Birnholz and Benacerraf, 1983; Shahidullah and Hepper 1993). Maturation of auditory
processing capabilities takes place through prenatal and perinatal periods. An
appreciation of the process of auditory development is important not only for an
understanding of the normal auditory system, but also for an understanding of the impact
of prenatal sound experience on the postnatal development, from structural, functional to
behavioral development (Lecanuet and Schaal, 1996).
Fetal Hearing
Development of the Auditory System
The earliest embryological signs of the human auditory apparatus are thickenings
of the ectoderm on the sides of the head, bilaterally, called the auditory placodes. About
6

7
the 23rd day of gestational age (GA), each placode begins to invaginate to form the
auditory pit, which then splits off from the overlying ectoderm to form an otocyst at the
30th day. At about 4 to 5 weeks, the otocyst divides into two parts, the vestibular portion
and the cochlea. During the 8th through 11th week, the two and a half coils of the
cochlea are attained. Complete maturation of sensory and supporting cells in the cochlea
does not occur until the 20th week when the cochlea reaches adult size (Northern and
Downs, 1991; Peck, 1994). Cytodifferentiation occurs during the 9th to 10th weeks
within the cochlear duct, where there is a thickening of epithelium. From the 3rd to the
5th month, the thickening epithelium differentiates into the distinct receptor and
supporting cells of the organ of Cord.
Comparing with that found in other mammals when the first responses to sound
can be evoked, the human cochlea has achieved a functional stage by 20 weeks of
gestation (Pujol and Uziel, 1988). At this time, the cochlea may have high thresholds and
very poor discriminative properties. It is thus not possible to detect signs of cochlear
activity using behavioral or electrophysiological methods, which explains why the first
responses to acoustic stimulation can only be recorded a few weeks later (Starr et al.
1977; Bimholzand Benacerraf, 1983).
Rubel (1984) indicated that no single event triggers the onset of cochlear function.
Many simultaneous and synchronous events contribute to the maturation of mechanical
and neural properties. These events include thinning of the basilar membrane, formation
of the inner spiral sulcus, maturation of the pillar cells, freeing of the inferior margin of
the tectorial membrane, opening of the tunnel of Corti, formation of Nuel’s spaces,

8
differentiation of the hair cells, establishment of mature cilia structure, and the maturation
of synapses (Pujol and Hilding, 1973).
These final maturational events do not occur simultaneously throughout the length
of the cochlea. There are two general developmental gradients in the differentiation and
maturation of cochlea hair cells and their neural connections. The first is the classic basal
to apical gradient, that at each maturation stage the mid-basal region develops first and
spreads in both directions, with the apex maturating last. The second gradient is from
inner hair cells (IHCs) to outer hair cells (OHCs); IHCs differentiate and develop first
(Pujol and Uziel, 1988; Pujol, Lavigne-Rebillard and Lenoir, 1998). This does not
necessarily imply that IHCs are the first to achieve all adult characteristics. For example,
the completion of the ciliogenesis process occurs first at OHCs. Generally, synapse
formation on IHCs occurs early and undergoes only minor modifications thereafter. The
OHCs are initially surrounded by afferent terminals, which are gradually replaced by
numerous efferents. Then the large calyciform efferent terminals form, typical of the
mature cochlea.
Based on cat studies, the functional development of the auditory system is divided
into three stages (Walsh and McGee, 1990). During the first stage, which is through the
cats’ first postnatal week and corresponds to the second trimester of human gestation,
auditory responses can be elicited, but hearing thresholds are very high and well outside
of the range of naturally occurring acoustic events. Response sensitivity does not
significantly improve during this stage and the responsive frequency range is limited to
low-frequency and mid-frequency sounds. During the second stage, in cats through the
third postnatal week and in humans probably through the final trimester, rapid maturation

9
of auditory function takes place. Thresholds decrease substantially, the adult frequency
response range is attained, and response duration is perceived. These changes are
attributable in large part to cochlear maturation, and to a lesser extent to maturation of the
central auditory system. During the final developmental stage, the remaining
components within the auditory system mature slowly and myelination is complete. The
adult characteristics for the cat are acquired during the second month after birth.
However, further maturation of the human auditory system occurs after birth and
continues for the next few years.
Development of the Place Principle
Young mammals do not respond initially to all of the frequencies to which they
respond as adults. Generally, initial responses are elicited by low- or mid-frequency
sounds. As development proceeds, responsiveness to both lower and higher frequencies
increases. Responsiveness to the highest frequencies develops last (Rubel, 1978; Rubel,
1985a). However, cochlear differentiation occurs first in basal or mid-basal high-
frequency regions, then spreads in both directions. The last part of the cochlea to
undergo differentiation is the apical, low-frequency region (Rubel, 1978). A similar
differentiation gradient also occurs in eighth-nerve ganglion cells and cochlear nuclei;
regions receiving input from the basal, high-frequency region of the cochlea mature prior
to the development of apical projection areas (Romand and Romand, 1982; Rubel, Smith
and Miller, 1976; Schweitzer and Cant, 1984).
A paradox of cochlear development was pointed out by Rubel in 1978. During
the early stages of hearing, the base or mid-basal region of the cochlea and the basal

10
representation areas of the central nervous system are the first to respond to sound.
However, these areas are initially most sensitive to relatively low-frequency sound, even
though this region of the cochlea has been tuned to being respond to high-frequency
sound. With maturation of both mechanical and neural properties of the cochlea, the
place code gradually shifts toward the apex until mature organization is achieved.
In an effort to understand more fully the mechanisms underlining this apparent
paradox, Rubel and Ryals (1983) studied the position of hair cell damage produced by
high-intensity pure tones of three different frequencies on three age groups of young
chicks. The results showed that the position of maximum damage produced by each
frequency shifted systematically toward the apex as a function of age. This experiment
was carried out during the late stages of hearing development in the chick, corresponding
to the perinatal or immediate postnatal periods in humans. On a related study, Lippe and
Rubel (1983) evaluated the relationship between the location of neurons of the brainstem
in chicks (nucleus magnocellularis and nucleus laminaris) and the frequency to which
they were most sensitive. In both nuclei of the brainstem, embryonic neurons were most
sensitive to tones 1-1.5 octaves below the frequencies that activate the same neurons one
to two weeks after hatching. These two experiments provided support for the model of
cochlear development offered by Rubel in 1978.
Later investigations, again in chicks, revealed some inconsistencies in the theory
developed by Rubel (1978). The discrepancy between these studies may be attributed to
developmental changes in middle-ear transfer function, the changes of the physical size
of the basilar papilla, and temperature effects on frequency tuning (Rilbsamen and Lippe,
1998). Currently, there are two alternative hypotheses for the development of the

11
cochlear frequency map in chicks. One theory suggests that frequency representation
does not change developmentally. Another theory proposes that frequency representation
shifts developmentally but that the shift is restricted to regions along the papilla that code
mid- and high-frequency sounds, while low-frequency sounds are always represented at
the apical location. Responses to mid-frequency sounds occur progressively more
apically as the base becomes responsive to high-frequency sounds (Riibsamen and Lippe,
1998).
Dallos and his colleagues (Harris and Dallos, 1984; Yancey and Dallos, 1985;
Arijmand, Harris and Dallos, 1988) studied the developmental change of the place code
in gerbils. They reported that the cutoff frequency of the cochlear microphonic (CM) and
the summating potential in the mid-basal turn (15 kHz location) increased about 1.5 to 2
octaves between the onset of sound evoked response on the 12th postnatal day when
frequency representation becomes adultlike on the 21st postnatal days. But, the cutoff
frequency of the CM at a second turn location (2.5 kHz) remains stable during
development.
More direct evidence was provided by the finding that the characteristic
frequencies of spiral ganglion neurons at a constant basal cochlear location increased up
to 1.5 octaves between the second and third postnatal weeks (Echteler, Arjmand and
Dallos, 1989). It has been uniformly reported that tonotopic organization in the mid- and
high-frequency regions of the cochlea and central auditory nuclei changes during
development. However, tonotopy in the cochlear apex and its central projection sites
appeared to be developmentally stable (Riibsamen and Lippe, 1998). As a result of this
new information, two updated explanations for the place code have been proposed. First,

12
the shifts in frequency code are attributed to maturational changes in the passive
mechanical properties of the cochlea (Lippe and Rubel, 1985). Second, Romand (1987)
proposed that the shifts in frequency organization should be attributed to maturational
changes in cochlear active processes mediated by the outer hair cells. Both factors were
examined by comparing tone-evoked distortion product otoacoustic emissions before and
after an injection of furosemide in gerbils between 14 days old and adult (Mills, Norton
and Rubel, 1994; Mills and Rubel, 1996). Results showed that increase in the passive
base cutoff frequency rather than maturational changes in active processes accounts for
the place code shift.
Currently, a revised model of the place code shift hypothesis for mammals, based
on the evidence from developmental studies of central and peripheral frequency maps, is
suggested. The entire length of the basilar membrane is capable of supporting a
traveling wave at or very soon after the onset of hearing. Frequency representation in the
cochlear apex is developmentally stable. From the very onset of hearing, the apex
responds to its correct (adult) frequency, although the sensitivity and sharpness of tuning
are reduced. In contrast, the more basal regions of the cochlea, mid- and high-frequency
regions, undergo a shift in frequency organization such that each location becomes
responsive to progressively higher frequencies in older animals. Shifts in the cochlear
map result largely from maturational changes in the mechanical properties of the cochlear
partition. The active mechanism also contributes to the shift in frequency organization
(Riibsamen and Lippe, 1998).

13
Central Auditory System
The development of the central auditory system and its relation to the maturation
of the auditory periphery has been studied in animal models (Rubel, 1985a). Normal
growth of central auditory neural elements requires an intact peripheral mechanism.
However, initial stages of development of the auditory centers in the central nervous
system are independent of peripheral regulation. The proliferation and migration of
neurons in the central auditory system do not depend on the cochlea. The major
pathways are established prior to or simultaneously with the development of peripheral
function. Marty (1962) showed that in newborn kittens, the cortical evoked responses
were elicited by electrical stimulation of the auditory nerve. The cochlea is immature at
this time, and it is not possible to reliably evoke cortical responses to sound.
Following the establishment of functional connections between the periphery and
the central nervous system, the continued maturation of neurons is highly dependent on
the functional integrity of their afferents. Rubel and his colleges (Rubel, Smith and
Miller, 1976; Jackson, Hackett and Rubel, 1982) revealed that in chicks after the time
when functional connections normally are established between the eighth nerve and the
cochlear nucleus cells, the absence of peripheral innervation caused rapid and severe
degeneration of the neurons. Abrams et al. (1987) demonstrated the impairment of
glucose utilization in the auditory as well as nonauditory portions of the brain after
cochlear ablation in fetal sheep.

14
Fetal Behavioral Response to Sound
The human fetal auditory system is functional by the start of the third trimester
(Bimholz and Benacerraf, 1983). Although direct measurement of fetal hearing cannot
be made by electrophysiological methods, indirect methods have been applied to measure
fetal behavioral responses to sound stimuli. The most common approaches used to
measure responsiveness to sound include the monitoring of fetal heart rate (Johansson,
Wedenberg and Westen, 1964), fetal movement (Shahidullah and Hepper, 1994) and
reflexive responses such as the auropalpebral reflex (Bimholz and Benacerraf, 1983).
Fetal movements in response to sound and to vibroacoustic stimulation or to both relate
closely to the development of fetal audition (Gelman et. al, 1982; Hepper and
Shahidullah, 1994a).
In 1983, Bimholz and Benacerraf measured fetal responsiveness to an electronic
artificial larynx (EAL) applied directly to the maternal abdomen. The auropalpebral
reflex (blink-startle response) of the 236 fetuses tested from 16 to 32 weeks of gestation
was monitored by ultrasonography. Reflexive eye movements were first elicited in some
fetuses between 24 and 25 weeks of gestational age, and responses increased in frequency
after 26 weeks. Consistent responses to EAL were observed after 28 weeks of
pregnancy.
Shahidullah and Hepper (1993) examined the response of fetuses to a 110 dB SPL
broadband air-bome stimulus (80-2000 Hz) at 15, 20 and 25 weeks of gestation. Using a
response, which consists of a movement within 4.5 seconds of the onset of the stimulus,
the investigators found that fetuses heard the noise at 25 weeks of gestation, but not
earlier. However, when the stimulus was changed from a single pulse to a series of ten

15
pulses with two-second duration and ten-second inter-stimulus interval, a response was
observed at 20 weeks of pregnancy. Thus, very early diffuse motor responses of slow
latency were appeared as early as 20 weeks of gestation; by 25 weeks the response had
become an immediate auditory startle response.
The auditory system of the fetus does not just begin to function uniformly across
frequency. While the adult range of audibility is ffom 20 Hz to 20,000 Hz with greatest
sensitivity in the 300 to 3000 Hz range, the fetus hears a much more limited range.
Hepper and Shahidullah (1994b) examined the range of frequencies and intensity levels
required to elicit human fetal movements as assessed with ultrasonography. Out of 450
fetuses involved in the study, only one demonstrated a response to a 500 Hz tone at 19
weeks gestational age. The range of frequencies to which the fetus responded expanded
first to low frequencies, 100 Hz and 250 Hz, and then to high frequencies, 1000 Hz and
3000 Hz. By 27 weeks, 96% of the fetuses responded to tones at 100, 250 and 500 Hz,
while none responded to frequencies at 1000 and 3000 Hz. It was not until weeks 29
(1000 Hz) and 31 (3000 Hz) that the fetuses responded to these tones. Between 33 and
35 weeks, the fetuses responded 100% of the time to presentations of 1000 and 3000 Hz.
As gestation progressed from 19 to 37 weeks, the fetuses exhibited responsiveness to
frequencies over a progressively wider frequency range. During this period, there was a
significant decrease (20-30 dB) in the intensity level of stimulus required to elicit a
response for all frequencies. This finding suggests that fetal hearing to pure tones
becomes more sensitive as gestation proceeds.
The ability to discriminate frequency is fundamental for the interpretation of
auditory information and for the development of speech perception and speech

16
production. Adults can detect changes of less than 2 Hz when the primary tone is
between 100 Hz and 1000 Hz (Yost, 1994). The development of frequency
discrimination in the human fetus was studied by Shahidullah and Hepper (1994) through
the method habituation/dishabituation measurement. Ultrasound imaging was used to
monitor fetal response to 250 and 500 Hz tones at 27 and 35 weeks gestation (N=48).
They found that 35-week-old fetuses were capable of distinguishing between the two
pure tones. However, fetuses at 27 weeks were not as likely to demonstrate this same
discrimination.
Shahidullah and Hepper (1994b) also evaluated the abilities of 36 fetuses to
differentiate between speech sounds. Fetuses at 27 and 35 weeks of age were exposed to
a pair of pre-recorded syllables presented at 110 dB SPL through an earphone placed on
the maternal abdomen. Half of the fetuses received /baba/ as their habituating stimuli and
/bibi/ as their dishabituating stimulus and vice versa. Although all fetuses habituated,
fewer stimuli were required for habituation for the 35-week-old fetuses than the 27-week-
olds, and a greater number of the 35-week-old fetuses (17 of 18) demonstrated
dishabituation compared to the younger ones (3 of 18). Thus, fetuses at thirty-five weeks
possess the ability to discriminate among different phonemes.
Fetal Sound Environment
Intrauterine Background Noise
The fetal sound environment is composed of a variety of internally generated
noises, as well as many sounds originating from the environment of its mother. The once

17
held belief that the fetus develops in an environment devoid of external stimulation
(Grimwarde, Walker and Wood, 1970) has been replaced by the fact that the fetus grows
in the uterus filled with rich and diversified sounds originated inside and outside the
mother (Gerhardt, 1989; Querleu et al., 1989).
The acoustic characteristics of internal noises and of external sounds that transmit
into the uterus have been described in the human from various recording sites including
inside the vagina (Bench, 1968), inside the cervix (Grimwarde, Walker and Wood, 1970),
and inside the uterus following amniotomy (Querleu et ah, 1988b; Benzaquen et ah,
1990; Richards et ah, 1992). These intrauterine sounds in humans were very similar to
those recorded in pregnant sheep, via a chronically implanted hydrophone on the fetal
head inside the uterus with an intact amniotic sac (Vince et ah, 1982, 1985; Gerhardt,
Abrams and Oliver, 1990).
Sounds generated inside the mother and present in the uterus are associated with
maternal respiration (Vince et ah, 1982; Gerhardt, Abrams and Oliver, 1990), maternal
heartbeats (Walker, Grimwarde, and Wood, 1971; Querleu et ah, 1988a), maternal
intestinal activity (Vince et ah, 1982; Gerhardt, Abrams and Oliver, 1990; Benzaquen et
ah, 1990), maternal physical movements (Vince et ah, 1982; Gerhardt, Abrams and
Oliver, 1990), and with placental and fetal circulation (Querleu et ah, 1988a). These
sounds provide a background or "noise floor" above which maternal vocalizations and
externally generated sounds emerge (Vince et al., 1982, 1985; Querleu et ah, 1988b;
Gerhardt, Abrams and Oliver, 1990; Benzaquen et ah, 1990; Richards et ah, 1992).
In 1968, Bench measured the intrauterine noise floor at 72 dB SPL in a pregnant
woman during labor. Three years later, Walker et ah (1971) reported an average intensity

18
of the background noise at 85 dB SPL (sound pressure level), with a peak at 95 dB SPL,
which was associate with maternal heartbeats. However, the accuracy of these early
studies was questioned by further studies using a hydrophone instead of a rubber-covered
microphone previously used to measure the intrauterine sound level.
The use of a hydrophone represented an important technological improvement
and provided more accurate data than was previously collected with air microphones.
Studies in pregnant sheep (Vince et al., 1982; Gerhardt, Abrams and Oliver, 1990) and
human (Querleu et ah, 1988a; Benzaquen et ah, 1990; Richards et ah, 1992) showed that
there is a quiet background with a muffled quality to sounds inside the uterus.
Intrauterine sounds are predominately low frequency (< 100 Hz) and reach 90 dB SPL
(Querleu, Renard and Crépin, 1981; Vince et ah, 1982; Gerhardt et ah, 1990). Spectral
levels decrease as frequency increases, and are as low as 40 dB for higher frequencies
(Benzaquen et al., 1990; Gagnon, Benzaquen and Hunse, 1992). Gagnon et al.
positioned a hydrophone in a pocket of fluid by the human fetal neck and measured
sound pressure levels of 85 dB SPL at 12.5 Hz, decreasing to 60 dB for 100 Hz and less
than 40 dB for 200 Hz and above. When measured in dBA, the human intrauterine sound
level was only 28 dBA (Querleu et ah, 1988a). Thus, for both humans and sheep, the
noise floor tends to be dominated by low-frequency energy less than 100 Hz and can
reach levels as high as 90 dB SPL.
Recently, Abrams et al. (1998) explored the origin of the intrauterine background
noise in sheep under well-controlled laboratory conditions. The intrauterine noise level
was measured before and after death of the ewe and fetus, and the average reduction in
sound level postmortem approached 10-15 dB for frequencies below 100 Hz. The result

19
showed that sounds originating in the ewe and fetus contribute significantly to the low
frequency (< 100 Hz) component of the background noise.
Sound Transmission into the Uterus
Specifications of the amplitudes and frequency distributions of external sounds
transmitted into the uterus have been well described in humans (Querleu et al., 1988a;
Richards et al., 1992) and sheep (Armitage, Baldwin and Vince, 1980; Vince et ah, 1982,
1985; Gerhardt, Abrams and Oliver, 1990). The attenuation of sound by the maternal
abdominal wall, uterus and amniotic fluid is low in the low frequencies and increases in
the high frequencies. In pregnant women, studied by Querleu et ah (1981), the
attenuation is 2 dB at 250 Hz, 14 dB at 500 Hz, 20 dB at 1000 Hz and 26 dB at 2000 Hz.
For high frequencies ranging from 3800 to above 18000 Hz, the attenuation is 20 to 40
dB (Querleu et ah, 1988a). More recent results from Richards et ah (1992) showed that
there was an average of 3.7 dB enhancement at 125 Hz, with progressively increasing
attenuation up to 10.0 dB at 4000 Hz. Similar conclusions came from studies in sheep
(Armitage, Baldwin and Vince, 1980; Vince et ah, 1982, 1985; Gerhardt, Abrams and
Oliver, 1990).
For frequencies below 250 Hz the reduction in sound pressure level through
maternal tissue and fluids was less than 5 dB. Some enhancement of low-frequency
sound pressures has been reported in both humans (Querleu et ah, 1981; Richards et ah,
1992) and sheep (Vince et ah, 1982, 1985; Gerhardt, Abrams and Oliver, 1990). That is,
the sound pressure in the amnion was greater than the sound pressure in air. Above 250
Hz, attenuation increased at a rate of about 6 dB per octave up to approximately 4000 Hz,

20
where the average attenuation was 20 to 25 dB. However, at 8000 Hz transmission loss
was 15 dB (Gerhardt, Abrams and Oliver, 1990). These general findings have been
refined and extended by Peters et al. (1993a, 1993b) who evaluated the transfer of
airborne sounds across the abdominal wall of sheep as a function of frequency and
intraabdominal location.
Peters et al. (1993a) studied the transmission of airborne sound into the abdomen
of sheep over a wide frequency range (50-20,000 Hz). They found that mean attenuation
varied from a high of 28 dB to a low of-3 dB. The greatest attenuation occurred for the
frequencies between 5,000 and 12,500 Hz. Surprisingly, sound attenuation varied
inversely as a function of stimulus level for low frequencies (50-125 Hz) and for high
frequencies (7,000-20,000 Hz). At higher stimulus levels (110 dB SPL in air),
attenuation was greater than the attenuation at lower stimulus levels (90 dB SPL). Thus,
the 90 dB stimulus was more efficient than the 110 dB. In the middle frequency range
(200-4,000 Hz), no effect of stimulus level was found.
In another study by Peters et al. (1993b), a hydrophone was positioned at each of
45 locations in a 20 x 20 x 20 array in the abdomen of five non-pregnant sheep post
mortem. Isoattenuation contours within the abdomen were obtained. The sound pressure
at different locations within the three-dimensional space of the sheep was highly variable.
Low-frequency bands (< 250 Hz) of noise revealed strong enhancement of sound
pressure by up to 12 dB in the ventral part of the abdomen. For mid-frequencies (250-
2000 Hz), attenuation reached as high as 20 dB. Attenuation for high frequencies (>
3150 Hz) were somewhat less than for mid-frequencies and reached an upper limit of
approximately 16 dB.

21
Over the frequency range from 250 to 4000 Hz, the abdomen can be characterized
as a low-pass filter with high-frequency energy rejected at a rate of approximately 6
dB/octave (Gerhardt, Abrams and Oliver, 1990). Thus, external stimuli are shaped by the
tissues and fluids of pregnancy before reaching the fetal head.
Fetal Sound Isolation
It is known how much sound pressure is present at the fetal head. Now there is
information about how much sound actually reaches the fetal inner ear (Gerhardt, et al.
1992). For the fetus in ulero, external airborne sound energy must pass from the air
medium to the fluid medium of the amnion before reaching the fetal inner ear. As sound
energy changes medium, it is reduced because of the impedance difference at the air-
tissue interface. The two quantities, pressure and particle velocity, are related and are
dependent on the acoustic impedance of the medium. The acoustic impedance of water is
much higher than that of air, for a given pressure disturbance, the particle velocity is
much less by a factor of approximately 3600 (10 log3600 = 35.5 dB) (Hawkins and
Myrberg, 1983). Thus, equal pressure in air and fluid differ in sound energy by
approximately 35 dB. One would assume that the sound pressure level required to
produce a physiological response from the fetus would be approximately 35 dB greater
than the sound pressure level in air necessary to produce the same response from the
newborn (Gerhardt, 1990; Gerhardt, et al. 1992). Factors that determine how much ex
útero sound reaches the inner ear of the fetus include the sound pressure attenuation
through maternal tissue and fluid and the transformation of this pressure into basilar
membrane displacement.

22
Gerhardt et al. (1992) studied the extent to which the fetal sheep in ulero is
isolated from sounds produced outside the mother. Inferences regarding sound
transmission to the inner ear were made from cochlear microphonic (CM) input-output
functions to stimuli with different frequency content. The CM, an alternating current
generated by the hair cells of the inner ear, mimics the input signal in frequency and
amplitude over a fairly wide range. As the signal amplitude increases, so does the
amplitude of the CM. Cochlear microphonics recorded from the round window are
sensitive indices of transmission characteristics of the middle ear. Thus, changes in the
condition of the middle ear influence the amplitude of the CM. By comparing the sound
pressure levels necessary to produce equal CM amplitude from the fetus in útero, and
later, from the newborn lamb in the same sound field, estimates of fetal sound isolation
can be made.
Cochlear microphonic input-output functions were recorded from in útero fetuses
in response to one-third octave band noises from 125 to 2000 Hz and then again from the
same animals after birth. The magnitude of fetal sound isolation was dependent upon
stimulus frequency. For 125 Hz, sound isolation ranged from 6 to 17 dB, whereas for
2000 Hz fetal sound isolation ranged from 27 to 56 dB. The averages for each stimulus
frequency were 11.1 dB for 125 Hz, 19.8 dB for 250 Hz, 35.3 dB for 500 Hz, 38.2 dB for
1000 Hz and 45.0 dB for 2000 Hz. Thus, for lower frequencies (< 500 Hz) the fetal
auditory system appears to be sensitive to pressure variations produced by the stimulus
originated from outside the mother.

23
Route of Sound Transmission into the Fetal Inner Ear
Another factor that influences how airborne stimuli affects the fetus is related to
the transmission of sound pressure from the fluid at the fetal head into the inner ear.
Transmission is governed by the route that pressure variations take to reach the inner ear.
The route of sound transmission postnatally is through the outer and middle ear system.
Normal auditory function requires an air-filled middle ear cavity, an intact tympanic
membrane, and functional hair cells and neural mechanism. In order to stimulate the hair
cells of the inner ear, the movement of the stapes footplate in and out of the oval window
creates hydraulic motion of the cochlear fluids, which causes basilar membrane
displacement. However, in the fetus this route is likely to be rendered less efficient
because the mechanical properties of the middle ear are highly dampened. The fetal
middle ear and external ear canal are filled with amniotic fluid, which decreases the
mechanical advantage of the middle ear. In addition, sound pressure may be present with
the same phase at the oval window and round window. The lack of a phase difference, as
well as the lack of a middle ear amplifier, may substantially decrease basilar membrane
displacement and therefore cause a decrease in hearing sensitivity.
Two hypotheses have been proposed that describe the route that exogenous
sounds take to reach the fetal cochlea. It has been suggested that acoustic stimuli in the
fetal environment pass easily through the fluid-filled external auditory canal and middle
ear system to the inner ear (Rubel, 1985b; Querleu et al., 1989). The impedance of inner
ear fluids is similar to that of amniotic fluid, thus, little acoustic energy is lost due to an
impedance mismatch (Querleu et al., 1989).

24
Hearing via bone conduction is a second alternative. Researchers have shown
that the contribution of the external auditory meatus to auditory sensitivity in underwater
divers is negligible (Hollien and Feinstein, 1975). By comparing the ability of a diver to
hear under different conditions while in water, bone conduction has been shown to be
much more effective in transmitting underwater sound energy. Similarly, fetal hearing
occurs in a fluid environment and sound transmission may be through bone conduction as
well.
Gerhardt, et al. (1996) compared the effectiveness of the two routes of sound
transmission (outer and middle ear vs. bone conduction) by recording CM amplitudes
from fetus sheep in ulero in response to airborne sounds. CM input-output functions
were obtained from the fetus in ulero during three different conditions: uncovered fetal
head, covered entire fetal head, and covered fetal head with exposed pinna and ear canal.
Results showed that when the fetal head was covered with sound attenuating
material, even though the pinna and ear canal remain uncovered, sound levels necessary
to evoke a response were greater than those necessary to evoke the same response from
the fetus with its head uncovered. This fact revealed that acoustic energy in amniotic
fluid reaches the fetal inner ear through a bone conduction route. External sounds
transmitted into uterus stimulate the inner ear by vibrating fetal skull directly, which in
turn results in the basilar membrane displacement. Thus, more sound energy is necessary
to vibrate the skull to stimulate hair cell by bone conduction than by air conduction.

25
Model of Fetal Hearing
Gerhardt and Abrams (1996) proposed a model of fetal hearing that considers
what sounds are present in the environment of the fetus and to what extent these sounds
can be detected. The model includes information regarding intrauterine background
noise, sound transmission through the tissues and fluids associated with pregnancy and
sound transmission through the fetal skull into the inner ear.
For the fetus to detect a signal from outside the mother, extrinsic sounds have to
exceed the ambient sound level in ulero. The internal noise floor of the mother is
dominated by low-frequency energy produced by respiration, intestinal function,
cardiovascular system, and maternal movements. Spectral levels decrease as frequency
increases, and are 60 dB for 100 Hz and lower than 40 dB for 200 Hz and above.
Presumably, the ability of the fetus to detect exogenous sounds will be dependent in part
on the spectrum level of the noise floor because of masking effects. As expected, high-
frequency sound pressures would be reduced by about 20 dB. The attenuation of low-
frequency sounds by the abdominal wall, uterus and fluids surrounding the fetal head is
quite small and in some cases enhancement of sound pressure of about 5 dB has been
noted. Between 250 and 4000 Hz, sound pressure levels drop at a rate of 6 dB/octave.
At 4000 Hz, maximum attenuation is approximately 20 dB. At frequencies higher than
4000 Hz, the attenuation is reduced to less than 20 dB.
Sound pressures at the fetal head create compressive forces through bone
conduction that result in displacements of the basilar membrane thereby producing a CM.
For 125 and 250 Hz, an airborne signal would be reduced by 10-20 dB in its passage to
the fetal inner ear over what would be expected to reach the inner ear of the organism in

26
air. For 500 through 2000 Hz, the signal would be reduced by 40-45 dB. For frequencies
in this range, the fetus is indeed buffered from sounds in the environment surrounding its
mother probably because of limited function of the ossicular chain. However, for low-
ffequency sounds, the fetus is not well isolated. Low-frequency stimuli reach the inner
ear of the fetus with far greater amplitudes than high-frequency stimuli. Interestedly, the
development of the inner ear is such that low-frequency stimuli are detected before high-
frequency stimuli. If the development of normal function is dependent on external
stimulation, then the developmental pattern of the auditory system provides a mechanism
to ensure each neuronal regions receive adequate stimulation from the environment
(Rubel, 1984).
The fetus in útero will detect speech, but probably only the low-frequency
components less than 500 Hz, and only when the airborne signal exceeds about 60 dB
SPL. If it is less than that, the signal could be masked by internal noises. It is predicted
that the human fetus could detect speech at conversational levels (65-75 dB SPL), but
would not be able to discriminate many of the speech sounds with high-frequency
components. Likewise, if music was played to the mother at comfortable listening levels,
the temporal characteristics of music, rhythms, could be sensed by the fetus, but the high-
frequency overtones would not be of sufficient amplitude to be detected (Abrams et al.,
1998). Simply put, the fetus would be stimulated by music with the "bass" register
turned up and the "treble" register turned down. This information may relate to in útero
development of speech and language, to musical preferences and to subsequent cognitive
development.

27
Intelligibility of Speech Sounds Recorded within the Uterus
Speech produced during normal conversation is approximately 70 dB SPL and is
comprised of acoustic energy primarily between 200 and 3000 Hz. The average
fundamental frequency of an adult is 125 Hz for male’s voice, and is 220 Hz for female’s
voice. Speech becomes unintelligible when the background noise in the speech-
frequency range exceeds the level of the message by approximately 10 dB.
There are many factors that determine how well a fetus will hear sounds from
outside its mother. These factors include: the frequency content and level of the internal
noise floor; the attenuation of external signals provided by the tissues and fluids
surrounding the fetal head; sound transmission into the fetal inner ear; and the sensitivity
of the auditory system at the time of sound stimulation.
As a result of experimental work, the characteristics of the intrauterine sound
environment are now fairly well understood. Studies in sheep (Vince et al„ 1982, 1985;
Gerhardt, Abrams and Oliver, 1990) and in humans (Querleu et al., 1988a; Benzaquen et
al., 1990; Richards et al., 1992) have shown that the mother’s voice and speech sounds
from outside the mother transmit easily into the uterus with little attenuation, and form
part of the intrauterine sound environment. Vince et al. (1982, 1985) implanted a
hydrophone inside the amniotic sac of pregnant ewes, and obtained long-term recordings.
They showed that the sound of maternal vocalizations forms a prominent part of the
intrauterine sound environment, and is louder inside the uterus than outside. Gerhardt et
al. (1990) also noted that when listening to the internal recordings from sheep,
conversations were recognized between experimenters with normal vocal effort 3 feet
from the ewe. Speech was muffled and intelligibility was poor, however, pitch.

28
intonation, and rhythm were quite clear. These findings are in accordance with data
provided by human studies. Querleu et al. (1988b) presented various human voices
through a loudspeaker to pregnant women and recorded the speech with a hydrophone in
the uterus. The voice included mother talking directly, the mother’s voice recorded on
tape and playback, and the recorded voices of other women and men. All types of
recorded voices (presented at 60 dBA) emerged above the basal noise floor (28 dBA) by
+8 to +12 dB. The mother’s voice recorded directly was 24 dB greater than the noise
floor. The intensity of the maternal voice transmitted to the uterine cavity was greater
than that of outside voices. Moreover, it was also transmitted to fetus more often than
any other voices. In 1990, Benzaquen et al. reported that maternal vocalization was
easily recorded in ulero in ten pregnant women tested in the study. The sound spectrum
produced by pronouncing the words of “99” was characterized by peak intensity of 70 to
75 dB SPL at 200 to 250 Hz and was approximately 20 dB above the intrauterine
background noise at those frequencies.
Richards et al. (1992) studied the transmission of speech into the uterus.
Intrauterine sound pressure levels of the mother’s voice were enhanced by an average of
5.2 dB in the low-frequency range, whereas external male and female voices were
attenuated by 2.1 and 3.2 dB, respectively. However, these studies only provided the
information about the existence of speech sound in the intrauterine sound environment.
The understandability of speech recorded from within the uterus is another critical issue
for our understanding of early speech and language development. Fetal identification of
its mother's voice and its ability to form memories of early exposure to speech are in part
dependent on the intelligibility of the speech message.

29
Currently, two published studies address the perceptibility of speech recorded
from inside the uterus. Querleu et al. (1988b) recorded the voices of five pregnant
women and voices of other male and female talkers with a modified microphone
positioned by the head of the fetus. Six listeners were able to recognize about 30% of the
3120 French phonemes. No significant difference was noted between the male and
female voice, and the mother’s voice was not better perceived although more intense.
The recognition of vowels was correlated with their second formant. The intonation
patterns, which frequencies were ranging from 100 to 1000 Hz, were perfectly well
discriminated compared to linguistic meaning.
In a more recent study conducted by Griffiths et al. (1994), a panel of over 100
untrained individuals judged the intelligibility of speech recorded in útero from a
pregnant ewe. Two separate word lists, one of meaningful and one of non-meaningful
speech stimuli were delivered to the side of the ewe through a loudspeaker and were
simultaneously recorded with an air microphone located 15 cm from the flank and with a
hydrophone previously sutured to the neck of the fetus. Perceptual test tapes generated
from these recordings were played to 102 judges. Intelligibility was influenced by three
factors: transducer site (maternal flank or in útero); gender of the talker (male or female);
and intensity level (65, 75 or 85 dB). For recordings made at the maternal flank, there
was no significant difference between male and female talkers. Intelligibility scores
increased with increased stimulus level for talkers and at both recording sites. However,
intelligibility scores were significantly lower for females than for males when the
recordings were made in útero.

30
An analysis of the feature information from recordings inside and outside the
uterus showed that voicing information is better transmitted in Utero than place or manner
information. "Voicing" refers to the presence or absence of vocal fold vibrations (e.g., /s/
vs. /z/), "place" of articulation refers to the location of the major air-flow constriction
during production (e.g., bilabial vs. alveolar), and " manner" refers to the way the speech
sound is produced (e.g., plosive vs. glide).
Miller and Nicely (1955) reported that low-pass filtering of speech signals
resulted in a greater loss of manner and place information than of voicing information.
They concluded that the higher frequency information in the speech signal is critical for
accurate identification of manner and place of articulation. The findings of Griffiths et al.
(1994) are consistent with those of Miller and Nicely (1955) in that transmission into the
uterus can be modeled as a low-pass filter. The poorer in Utero reception of place and
manner information is associated with the greater high frequency attenuation.
Voicing information from the male talker, which is carried by low-frequency
energy, was largely preserved in útero. The judges evaluated the male talker's voice
equally well regardless of transducer site. Speech of the female talker carried less well
into the uterus. The fundamental frequency of the female talker was higher than that of
the male talker. Thus, it is understandable that voicing information from the male would
carry better into the uterus than that from the female.
Male and female talker intelligibility scores averaged approximately 55% and
34%, respectively, when recorded from within the uterus. Although these results reflect
the perceptibility of the speech energies present in the amniotic fluid, they do not specify
what speech energy might be present at the fetal inner ear. Measures of acoustic

31
transmission to the fetal inner ear are quite limited at present. Much work needs to be
completed before conclusions can be drawn regarding what speech energies reach and are
able to be perceived by the fetus.
Fetal Auditory Experiences and Learning
During the last trimester, the human fetus, with a well-developed hearing
mechanism, is exposed to a large variety of simple and complex sounds. Prolonged
exposure, for several weeks or even months, to external and maternal sounds may have
several consequences to the fetus at structural, functional, and behavioral levels. Prenatal
activation of the auditory system may contribute to normal development of peripheral
structures and central connections, as well as maintenance of anatomic and functional
integrity during prenatal maturation. On a more general level, fetal auditory stimulation
may contribute to the formation of auditory perceptual abilities, and to the organization of
the newborn’s preferences for a particular acoustical signal (Lecanuet and Schaal, 1996).
Prenatal Effects of Sound Experience
Human fetal responsiveness to intense acoustical stimulation has been studied
only in the past two decades. Fetuses are not only responsive to intense stimulation, they
also display differential auditory responses as a function of the characteristics of the
stimulus. When acoustic or vibroacoustic stimuli are above 110 dB SPL, fetuses display
heart rate accelerations and motor-startle movement responses. Below 100 dB SPL, no
reliable movement responses can be recorded, but fetuses display small, transient heart-
rate decelerations rather than heart-rate accelerations (Lecanuet, Granier-Deferre and

32
Busnel, 1989, 1995). The heart-rate acceleration changes to auditory stimulation are
typically associated with so-called “startling” or defensive response, while deceleration
changes are “orienting” or attentive response (Berg and Berg, 1987).
Experiments have shown that repetition at a short interval (every 3-4 seconds) of
a 92 to 95 dB SPL acoustic stimulus led to the disappearance of a cardiac deceleration
response that had been induced by the first presentation of the stimulus, indicating an
habituation (Lecanuet et al., 1992). Habituation is defined as the decrement in response
after repeated presentation of a stimulus. Habituation is essential for the efficient
functioning and survival of the organism, enabling it to ignore familiar stimuli and attend
to new stimuli. Habituation represents one of the simplest yet most essential learning
processes the individual possesses, and underlies much of our functioning and
development (Hepper, 1992). Using a classical habituation / dishabituation procedure,
Kisilevsky and Muir (1991) obtained a significant decrement of both fetal cardiac
acceleration and movement responses to a complex noise (at 110 dB SPL), followed by a
recovery of these responses when triggered by a novel vibroacoustic stimulus. The
fetuses were between 37 and 42 weeks gestation during the experiment. Habituation in
útero relates not only to the reception of the sensory message, but also its integration at
lower levels of the central nervous system. Therefore, the fetus in útero is capable of
learning (Querleu et al., 1989).
Lecanuet et al. (1989, 1993) studied the auditory discriminative capacities of the
near-term fetus by using habituation/dishabituation of heart-rate deceleration responses.
In one study (Lecanuet, Granier-Deferre and Busnel, 1989), fetuses at 35 to 38 weeks
gestation displayed a transit heart-rate deceleration response when they were exposed to

33
the repeated presentation (every 3.5 second) of a pair of French syllables: /ba/ and /bi/ or
/bi/ and /ba/, spoken by a female talker at 95 dB SPL. Reversing the order of the paired
syllables after 16 presentations also reliably induced the same type of response. This was
observed in 15/19 fetuses in the BABI/BIBA condition and in 10/14 fetuses in the
BIBA/BABI condition. Response recovery suggested that fetuses discriminated between
the two stimuli. The discrimination that occurred may have been performed on the basis
of a perceptual difference in loudness (intensity) between the /ba/ and /bi/, since the
equalization of these syllables was presented with SPL, not hearing level. This intensity
adjustment makes /bi/ louder than /ba/ for audit listeners. Similarly, Shahidullah and
Hepper (1994) found that fetuses at 35 weeks gestation had the ability to discriminate
between /baba/ and /bibi/.
In another experiment (Lecanuet et al., 1993), the ability of near-term fetuses to
discriminate different speakers producing the same sentence was studied. The heart-rate
responses of fetuses between 36 to 39 weeks gestation were recorded before, during and
after stimulation to the sentence ‘Dick a du bon thé’ (Dick has some good tea). The
sentence was spoken by either a male talker (minimum fundamental frequency Fo= 83
Hz) or a female talker (minimum F0= 165 Hz) and delivered through a loudspeaker 20
cm above the mother’s abdomen at the same level (90-95 dB SPL). The fetuses were
exposed to the first voice presentation (male or female) and followed by the other voice
or the same voice (control condition) after fetal heart-rate response returned to baseline.
The results demonstrated that in the first 10 s after presentation of the initial voice, the
voice (male or female) induced a high and similar proportion of heart rate deceleration
changes (77% to the male voice, 66% to the female voice) compared to a group of non-

34
stimulated subjects (9% of deceleration and 46% of acceleration). Within the first 10 s
following the voice change, 69% of the fetuses exposed to the other voice displayed a
heart-rate deceleration response, whereas 43% of the fetuses in the control condition
displayed heart-rate acceleration change. The authors pointed out that near-term fetuses
might perceive a difference between the voice characteristics of two speakers, at least
when they are highly contrasted for Fo and timbre. The results cannot be generalized for
all male and female voices or for all speakers since voices with extremely low Fo were
used in the study (Lecanuet, Granier-Deferre and Busnel, 1995; Lecanuet, 1996).
Hepper et al. (1993) studied the ability of fetuses to discriminate between a
strange female’s voice and the mother’s voice by measurement of the number of fetal
movements during a 2-minute speech presentation. The results showed that fetuses at 36
weeks gestation did not discriminate between their mother’s voice and that of a stranger,
when tape recordings were played to them via an air-coupled loudspeaker placed on the
abdomen. However, the fetuses were able to discriminate between their mother’s voice
recorded on tape and played to them over the loudspeaker and the mother’s voice
produced naturally; less movements were noted in response to the mother’s direct
speaking voice when compared to a tape recording of her voice. According to the
authors, discrimination may be due to the presence of internally transmitted components
of speech which the fetus perceives when the mother is speaking, but that are not present
when the tape recording of the mother’s voice is played.
The possibility of prenatal recognition of a familiar child’s rhyme was studied by
DeCasper et al. (1994). Seventeen pregnant women recited a child’s rhyme aloud three
times a day from their 33rd to 37th week of pregnancy. Fetal heart-rate response was

35
used to assess differential fetal responsiveness to the target rhyme versus a novel rhyme.
During the 37th week of gestation, each fetus was stimulated to one rhyme for 30 seconds
through a loudspeaker placed over the mother’s abdomen. The first rhyme was followed
by 75 s of silence and then the other rhyme was presented for 30 s. Stimulus level for
both rhymes was set at 80-82 dB SPL. Care was taken during fetal testing to keep the
mother unaware of which rhyme was being presented so that she could not inadvertently
cue her fetus. The results showed that fetal heart rates significantly decreased from
prestimulus levels when the target rhyme was presented and significantly increased over
prestimulus levels when the novel rhyme was presented, regardless of presentation order.
This differential heart-rate change implied that the fetus discriminated the two rhymes.
Moreover, since these rhymes were counterbalanced across fetuses, the different patterns
of heart-rate responds could not be attributed to any unique acoustic attributes of one
rhyme.
There is now a growing body of data showing that fetuses perceive acoustical
stimuli. Near-term fetuses can discriminate between two complex stimuli (such as
syllables), between two speech passages, and they are able to learn. Such a competence
may be partly a consequence of fetal familiarization to speech sounds.
Postnatal Effects of Prenatal Sound Experience
Prenatal auditory experience may result in general and / or specific learning
effects that are evidenced in postnatal life. Stimuli familiar to the fetus may selectively
soothe the baby after birth or may elicit orienting responses during quiet states. Familiar
stimuli are more alerting than unfamiliar ones. It is well documented that prenatal

36
auditory experience plays a major role in the development of human newborn auditory
preferences and capabilities (Fifer, 1987; Leanuet, 1996).
It has been shown that maternal heartbeat (Salk, 1962) and recordings of
intrauterine noises (Rosner and Doherty, 1979) can calm a restless baby and serves as a
potent reinforcer during operant conditioning nonnutritive sucking procedures (DeCasper
and Sigafoos, 1983). Indeed, intrauterine cardiac rhythms are potent reinforces for 2- to
3-day-old newborns, a finding that suggests that prenatal auditory experience affects
postnatal behavior.
Nonnutritive sucking procedures made it possible to objectify newborn’s
discriminative abilities and to test the newborn’s preference for a given stimulus. The
human voice, especially that of its mother, is likely to have increased salience for the
fetus relative to other auditory stimuli. Mother’s voice in the fetal sound environment
differs from other sounds in its intensity, variability, and other multimodal characteristics.
Mother’s voice has been reported to be the most intense acoustic signal measured in the
amniotic environment (Querleu et al., 1988a; Benzaquen et ah, 1990; Richards et ah,
1992). The nature of the maternal voice may promote greater fetal responsiveness to
mother’s voice than any other prenatal sound. The earliest evidence for differential
responsiveness to maternal voice came from work with older infants (Mills and Meluish,
1974). The experiments demonstrated a differential sensitivity to the maternal voice in
20- to 30-day-old infants. The amount of time spent sucking and number of sucks per
minute were increased after a brief presentation of his/her mother’s voice. In a later
study using 1-month-old infants (Mehler et ah, 1978), sucks were reinforced with either a
mother’s or a stranger’s voice, intonated or monotone. A significant increase in sucking

37
was only observed when mother’s voice was normally intonated. The role of intonation
in recognition of the mother’s voice was suggested. Although these procedures clearly
demonstrate that infants respond differentially to their mother’s normal voice, the
differences in responding do not necessarily indicate a preference for her voice (Fifer,
1987).
The study by DeCasper and Fifer (1980), using two different nonnutritive sucking
procedures, was the first to provide direct experimental evidence that neonates prefer
their mother’s voice. Using a temporal discrimination procedure, 2- to 3-day-old infants
were observed for a 5-minute baseline period in which nonrewarded sucks on a
nonnutritive nipple were recorded. The median time of the interburst intervals (IBIs) was
calculated and used to set the contingency for the testing. For 5 of the 10 infants tested,
sucking bursts that ended IBIs shorter than the baseline median IBI (mIBI) turned on a
tape recording of the infant’s mother reading a children’s story. Whereas sucking bursts
that ended IBIs equal to or longer than the mIBI turned on a tape recording of another
infant’s mother reading the same story. For the other five infants, the IBI/story
contingency was reversed. The results showed that 8 of the 10 infants shifted their
overall medians significantly in the direction necessary to turn on the recording of its
mother’s voice. Also, the infants turned on the recording of their mother’s voice more
often and for a longer total period of time than the unfamiliar female voice.
In the second procedure, which involved a signal discrimination paradigm, the
presence or absence of a 4-s 400 Flz tone signaled the availability of the different voices,
and the voices remained on for the duration of the sucking burst. For 8 of the 16 infants
tested, sucking on the nipple during the tone resulted in the cessation of the tone and

38
turned on a recording of their own mother’s voice reading a children’s story, whereas
sucking during silence turned on a recording of another woman reading the same story.
For the other eight infants, the signal/story contingency was reversed. Again, evidence of
newborns’ preference for their own mother’s voice was obtained. Infants showed a
significantly greater probability of sucking during the signal (tone or silence) that led to
the presentation of the maternal voice recording.
Since it is possible that preference for the mother’s voice could be generated very
fast by the newborn’s initial postnatal contact with the mother, several subsequent studies
have attempted to rule out the effect of postnatal auditory experience. Fifer (1987) failed
to find any evidence that preference in newborns for maternal voice was related to either
postnatal age (1- vs. 3-day-olds) or method of feeding (bottle-fed vs. breast-fed).
Another study showed that 2-day-old newborns did not prefer its father’s voice to that of
another male’s voice, even though these newborns had 4 to 10 hours of postnatal contact
with their fathers (DeCasper and Prescott. 1984). This study also determined that the
absence of a preference for the paternal voice was not due to the inability of newborns to
discriminate between pairs of male voices. Furthermore, the authors compared the
preference between an airborne version of those mother’s voice and their “intrauterine”,
low-pass filtered version. Using tone/silence discriminative responding procedures, 2- to
3-day-old infants were given a choice of hearing their mother’s voice (or other female’s
voice) either unfiltered or low-pass filtered at 1000 Hz (Spence and DeCasper, 1987).
Infants showed no preference for either the unfiltered or low-pass filtered version of their
mother’s voice, whereas infants preferred the unfiltered version of the nonmaternal voice
to the filtered nonmaternal voice. According to the authors, since there is apparently little

39
prenatal experience with the low-frequency features of other female voices, but
considerable postnatal experience with their full spectral characteristics, the newborns
preferred the more familiar version of the female stranger’s voice. In contrast, both the
filtered and unfiltered versions of maternal voice contained the necessary low-frequency
features for maternal voice recognition, so the infants showed no preference.
Finally, Fifer and Moon (1989), using a modified version of the “intrauterine”
mother’s voice mixed or not mixed with maternal cardiovascular sounds, found that 2-
day-old newborns preferred a low-pass filtered version of the maternal voice to an
unfiltered version when 500 FIz was the cutoff frequency. Therefore, it is possible that
the infants in the previous study (Spence and DeCasper, 1987) did not show a preference
for the filtered maternal voice because it was more similar to their postnatal rather than
their prenatal experience with the maternal voice. Newborns’ prenatal familiarity with
maternal voice may explain the findings by Hepper et al. (1993). Using an analysis of
fetal movements, Hepper et al. demonstrated that 2- to 4-day-old newborns discriminated
normal speech from “motherese” speech of their mothers’ voice, but not between normal
intonated and one of “motherese” of a strange female’s voice. Newborns, however,
discriminated the maternal voice from a strange female voice.
Taken together, these results suggest that prenatal auditory experience determines
at least some of the infant’s early auditory preferences. This prenatal effect was
demonstrated more directly by the study conducted by DeCasper and Spence (1986).
Sixteen pregnant women recited one of the three children’s stories aloud twice each day
during the final 6 weeks of their pregnancies. After birth, the newborns (average age of
55.8 hours) were tested using the nonnutritive IBI contingent sucking procedure. For

40
eight of the infants in the prenatal group, sucking bursts following IBIs < mIBI turned on
a recording of a woman (either the infant’s own mother or the mother of another infant)
reading the story that the infant’s mother had read while pregnant. Sucking bursts which
followed IBIs > mIBI turned on a recording of that same woman reading a novel story.
For the other eight infants in the prenatal group, the IBI/story contingency was reversed.
Additionally, a control group (12 infants) was tested under the same conditions except
that these infants had no experience with any of three stories. The results showed that
regardless of which story the mothers had recited while pregnant and regardless of the
IBI/story contingency, the newborns in the prenatal group were more likely to suck after
IBIs required to turn on the familiar story, the one they had heard prenatally, whereas
infants in the control group showed no systematic change in their sucking pattern from
baseline. Moreover, these preferences for one of three stories were not dependent on the
specific voice of the storyteller. This result showed that the induction of a preference for
a story (speech passage) generalized from maternal to nonmaternal voice. It implies that
the newborn retains two different kinds of acoustic information from prenatal experience:
information about specific characteristics of the mother’s voice (perhaps fundamental
frequency) and more general characteristics that are not necessarily mother-specific, such
as intonation contours and / or temporal characteristics.
These studies provide strong evidence that the late-term human fetus is able to
process some aspects of vocal stimulation presented by the mother and retain some of
that information for at least several days after birth. It remains unclear, however, which
specific aspects of prenatal auditory stimulation were responsible for postnatal auditory
preferences.

41
Because external low-frequency sound is transmitted into the uterus with little
attenuation and because high-frequency sound is attenuated, the fetus can only detect the
low-frequency components of passage presented by the mother. It appears that these
newborns could not merely depend on segmental information (phonetic components of
speech, i.e., the specific consonants and vowels making up the words), which they
experienced prenatally, as the basis for their postnatal recognition, since segmental
information is carried by those frequencies that appear to be most attenuated in útero
(frequencies above 1000 Hz). In contrast, the suprasegmental information (intonation,
frequency variation, stress, and rhythm) contained in the maternal voice and in the stories
recited by the mother is available to the fetus with very little attenuation. The hypothesis
about the role of suprasegmental information in fetal auditory perception has been
investigated (Cooper and Aslin, 1989).
In an effort to test whether prenatally available suprasegmental information would
be sufficient to induce a postnatal preference, the authors had 13 pregnant women sing
the lyrics of the tune to “Mary Had A Little Lamb” using the syllable “la” instead of the
actual words of the melody (Cooper and Aslin, 1989). Each woman sang the melody 5
minutes daily starting on the 14th day prior to her due date. The newborns of these
mothers were tested between 34 and 72 hours after birth (mean age = 52 hours old) using
the IBI procedure. For the seven infants in the prenatal group, sucking bursts that ended
IBIs < mIBI turned on a recording of “Mary Had A Little Lamb” sung by a professional
female singer (using “/a” instead of the words), whereas sucking bursts that ended IBIs >
mIBI turned on a recording of the same singer singing “¿ove Somebody", also with “la”
instead of the words. These two melodies were sung in the same key and contained the

42
same absolute notes, but the notes occurred in different orders to yield different melodic
contours. For the other six infants in the prenatal group, the IBI/melody contingency was
reversed. In addition, a control group of eight newborns was tested under the identical
condition except that they had no prior experience with either melody. The results
showed that the newborns in the prenatal group produced more of the IBIs to turn on their
familiar melody compared to their baseline performance, while the newborns in the
control group did not, regardless of condition. This study demonstrated that the
suprasegmental characteristics of a prenatally experienced melody were sufficient to
induce a postnatal preference for that melody.
Further supporting evidence for the salience of suprasegmental information in
fetal perception comes from the demonstration that newborns discriminated and preferred
their native language to a foreign language (Mehler et al., 1988; Moon, Cooper and Fifer,
1993). Using the /a/ or I'll signal discrimination procedure (Moon and Fifer, 1990), Moon
et al. (1993) demonstrated that 2-day-old newborns whose mothers were monolingual
speakers of Spanish or English, preferred their mother’s language to the other one.
Demonstration of a preference for the native language at such an early age favors an
interpretation of the study by Mehler et al. (1988) in terms of a prenatal familiarization.
In the latter studies, using a noncontingent habituation / dishabituation of high-amplitude
sucking procedure, Mehler et al. (1988) demonstrated that 4-day-old native French
newborns could discriminate a recording of a woman speaking Russian from the same
woman speaking French, but did not differentially respond to English from Italian
recordings. Also, 4-day-olds of non-French parents did not respond differentially to
either Russian or French recordings. Thus, very young infants seem to require some

43
experience with a language in order to respond differentially to languages. This
interpretation is strengthened by additional data (Mehler et al., 1988) showing that native
English 2-month-olds also did not respond differentially to Russian or French, but easily
discriminated English from Italian. Thus, it was not merely the young age of the
newborns that resulted in their failure to respond differentially to normative languages.
Prenatal maternal speech is one likely source of native language experience for the
newborns.
Finally, Mehler et al. (1988) demonstrated that native French 4-day-old newborns
and native English 2-month-olds could still discriminate French from Russian and
English from Italian, respectively, even when all of the these recordings were low-pass
filtered at 400 Flz, which effectively removed most segmental information and
maintained their intonational and temporal structures. It is more likely that prenatal
auditory experience with the suprasegmental features of maternal speech influences the
ability of newborns to discriminated their native language from other normative language,
although it certainly is possible that newborns rely on both segmental and suprasegmental
information when discriminating their native language from a foreign language.
There is now clear evidence that from the earliest days of postnatal life the human
infant is actively engaged in processing sounds, particularly those containing acoustic
attributes of the infant’s native language. The infant’s prenatal experience with maternal
speech may, in large part, determine the early postnatal perceptual salience of a specific
mother’s speech and native speech.

Speech Perception
44
Speech Perception in Infancy
There are two characterizations of infants’ “initial state” regarding speech
perception. One argues that infants enter the world equipped with specialized speech-
specific mechanisms evolved for the perception of speech, and that infants are born with
a “speech module” to decode the complex and intricate speech signals (Foder, 1983;
Mehler and Dupoux, 1994). The other holds that infants begin life without specialized
mechanisms dedicated to speech, and that infants’ initial responsiveness to speech can be
attributed to their more general sensory and cognitive abilities (Aslin, 1987; Kuhl, 1987;
Jusczyk, 1996).
In fact, the capacity of newborns to distinguish minimal speech contrasts is
remarkable (Aslin, Pisoni and Jusczyk, 1983; Aslin, 1987; Kuhl, 1987; Mehler and
Dupoux, 1994). Eimas et al. (1971) were the first to demonstrate that human infants, as
young as one month old, can discriminate subtle acoustic properties in a categorical
manner that differentiate for English-speaking adults the stop-consonant-vowel syllables
Ibal from /pa/, which are different in voice onset time (VOT). In their study, computer¬
generated (synthetic) speech differing only VOT was presented in pairs to infants for
testing with the high-amplitude sucking procedure. Only one of these VOT pairs spanned
the boundary between English-speaking adults’ phonemic categories for Ibal and /pa/.
This between-category VOT pair was discriminated by the infants, whereas several other
within-category pairs were not discriminated, even though the VOT difference between
each pair was identical (20 second). Since then, there is growing body of evidence that
nearly all speech contrasts (phonetic contrasts) used in any of the world’s natural

45
languages can be discriminated by 6 months of age (Aslin, Pisoni and Jusczyk, 1983;
Aslin, 1987; Kuhl, 1987; Jusczyk, 1996). There are also indications that during the early
stages, the mechanisms that underlie speech processing by infants may be a part of more
general auditory processing capacities (Aslin, Pisoni and Jusczyk, 1983; Aslin, 1987;
Kuhl, 1987; Jusczyk, 1996). Prior to 6 months of age, infants are performing their
analysis of speech sounds solely on the basis of acoustic differences. These acoustic
differences are sufficient to permit categorical perception, just as similar acoustic
mechanisms presumably support the processing of nonspeech contrasts by infants
(Jusczyk et al., 1983) and the processing of speech contrasts by nonhumans (Kuhl and
Miller, 1975, 1978).
Characteristic of Speech
Speech signals have numerous distinctive acoustic properties or attributes that are
used in the earliest stages of perceptual analysis. The average intensity of normal speech,
measured at a distance of 30 centimeter from the speaker’s lips, is about 66 dB intensity
level (IL), and individual variation between speakers is about ±5 dB (Dunn and White,
1940). If the pauses (silent intervals) are excluded, the experimental data indicated that
these levels would be increased 3 dB (Fletcher, 1953). Loud speech may reach 86 dB IL,
while soft speech may be as low as 46 dB. In the course of ordinary conversation, the
dynamic range of speech is about 35-40 dB (Fletcher, 1953). In a more recent study (Cox
and Moore, 1988), the mean sound pressure level at 1 meter for a male talker speaking
with normal vocal effort was 61 dB and for a female talker was 59 dB. The average
spectra were similar in the range from 400 to 5000 Hz between male and female talkers.

46
Interestingly, the comparison of long-term average speech spectra over 12 languages
showed that the spectrum was similar for all languages although there were many small
differences (Byrne, et al., 1994). The average value of sound pressure level at 20
centimeter for males was 71.8 dB SPL, while that for females was 71.5 dB SPL. For
one-third octave bands of speech, the maximum short-term r.m.s. level was 10 dB above
the maximum long-term r.m.s. level, and was consistent across languages and frequency.
Most of the energy of speech derives from vowels. Vowels are usually more
intense and relatively longer in duration than consonants. The average difference in
intensity between vowels and consonants is about 12 dB. In English, the intensity
difference between the weakest consonants /0/ and the strongest vowel /o/ is about 28 dB
(Fletcher, 1953). The frequency range of speech extends from 80 Hz to several thousand
Hertz, while the frequencies important to the speech signal are within the 100 to 5000 Hz
range (Borden and Harris, 1984). The human voice is composed of many frequencies.
The lowest frequency is the fundamental frequency of the voice, driven by the vibration
of the vocal folds. The fundamental frequency is constantly changing during articulation,
and varies considerably from one person to another. The fundamental frequency of a
low-pitched male voice is about 90 Hz, while a woman with a high-pitched voice may
speak at a fundamental frequency of about 300 Hz. On average, the average female voice
corresponds to middle C or 256 Hz, whereas the male voice is about an octave lower
(Fletcher, 1953).
The energy in vowels is concentrated mainly in the harmonic sounds of the
fundamental frequency, which for each vowel is divided into several typical frequency
regions, called formants, whose center frequency depends on the shape of the vocal tract

47
(resonance of the vocal tract). In addition to the fundamental frequency (Fo), four
formants are usually recognized; the lowest two formants (Fi and F2) are stronger than
the other two and occur at frequencies typical for each vowel. The lowest three formants
are the most important for correct recognition of English vowels. The frequency range of
these formants fits fairly well within the 300-3500 Hz range, which is the standard
bandwidth used in the telephone industry (Borden and Harris. 1984; Kent, 1997). If the
fundamental frequency is raised by an octave, the formant values increase by only 17
percent (Peterson and Barney, 1952).
The consonants differ essentially from the vowels in that they usually have no
distinct formant composition; they are composed of mostly high-frequency noise
components. In most consonants, however, energy is concentrated mainly in
characteristic frequency regions. Thus, consonant sounds have components that are
higher in frequency and lower in intensity than vowel sounds. The intensity tends to be
scattered continuously over the frequency region characteristic of each consonant sound
(French and Steinberg, 1947; Borden and Harris, 1984; Kent, 1997).
In contrast to acoustic phonetics that identifies speech sounds in terms of acoustic
parameters (frequency composition, relative intensity, and duration changes), traditional
phonetics describes speech sounds in terms of the way they are produced. The main
divisions are voicing, place and manner. “Voicing” is related to vocal fold vibration, e.g.,
voiced or voiceless. “Place” is related to the location of the major airflow constriction of
the vocal tract during articulation, e.g., bilabial, labio-dental, lingui-dental, alveolar,
palatal or velar. “Manner” is related to the degree of nasal, oral, or pharyngeal cavity

48
construction, e.g., vowels, stops (plosives), nasals, fricates, affricates, liquids or glides.
Thus, Pol in the word “best” is a voiced bilabial stop (plosive) (Borden and Harris, 1984).
Intelligibility of Speech
The ability to understand speech is the most important measurable aspect of
human auditory function. Speech can be detected as a signal as soon as the most intense
point of its spectrum exceeds the ear's pure tone threshold at the frequency concerned.
This intensity is called the speech detection threshold or threshold of detectability (Egan.
1948; Schill, 1985). At this intensity level, a listener is just able to detect the presence of
speech sounds about 50% of the time. When the intensity is increased by some 8 dB, the
subjects begin to understand some words and can repeat half of the speech material
presented; this is the speech reception threshold or threshold of perceptibility (Egan,
1948; Hawkins and Stevens, 1950; Schill, 1985). The speech reception threshold of
spondee words (two syllables), which is considerably lower than one-syllable words, is at
about 20 dB SPL (Davis, 1948; Penord, 1985). However, only after the average intensity
of speech has reached between 30 to 33 dB SPL, are 50 percent of monosyllabic words
understood (Kryter, 1946; French and Steinberg, 1947; Davis, 1948; Egan, 1948).
Speech intelligibility or speech discrimination, expressed in terms of percentage correct,
is used to describe how much speech sound can be understood. The factors affecting
speech intelligibility are numerous. These include physical factors related to the speech
stimuli such as level of presentation, frequency composition, distortion, and signal to
noise ratio.

49
French and Steinberg (1947) used nonsense monosyllables of the consonant-
vowel-consonant (CVC) type as word material in their studies, and examined
intelligibility after low-pass and high-pass filtering. They found that when intensity was
increased, discrimination improved up to a certain limit, after which it remained largely
constant even if intensity was further increased. Optimal intensity with different filter
settings proved to be approximately the same, within a range of 10 dB. The optimal
intensity was 75 dB SPL. At this level, when all frequencies above 1000 Hz were passed
through the filter, 90% of CVC syllables were recognized correctly. However, when only
the frequencies below 1000 Hz were presented, correct identification of the CVC
syllables declined to 27%. The French and Steinberg study clearly demonstrated the
importance of the high frequencies for correct identification of CVC syllables.
Furthermore, when intelligibility scores were plotted as a function of cutoff-frequency of
at optimal intensity levels, the low-pass and high-pass curves intersected at 1900 Hz,
where the intelligibility score was 68%. It was said that the crossover point divided the
frequency scale into two equivalent parts; the frequencies above the cross were as
important as the frequencies below the crossover frequency.
The type of speech material distinctly affects the intelligibility of filtered speech
(Hirsh, Reynolds and Joseph, 1954). The speech materials in their study included
nonsense syllables, monosyllabic words (Central Institute for the Deaf Auditory Test W-
22), disyllabic words (spondees, iambs and trochees) and polysyllabic words. The input
speech level for all filter conditions was 95 dB SPL. They found that nonsense
monosyllables and monosyllable words suffered most in intelligibility during frequency
filtering. When the cutoff frequency (high-pass filter) was less than 3200 Hz, the

50
intelligibility did not decrease significantly. But intelligibility decreased rapidly as the
cutoff frequency increased above 3200 Hz. Under low-pass filter conditions, it was only
when all the frequencies above 800 Hz were eliminated that the intelligibility decreased
noticeably from its maximum, and then it dropped rapidly as the more extreme filter
conditions were reached. The functional curves for the different speech materials
remained nearly constant under both high-pass and low-pass filtering. The fewer
syllables there were in a meaningful word the lower its intelligibility. Nonsense
monosyllables were the least intelligible of all. Intelligibility of nonsense syllables and
monosyllable words is severely affected by frequency distortion. However, as word
length increases, intelligibility is retained. For nonsense syllables, the low-pass and high-
pass functional curves intersected atl700 Hz, where the intelligibility score was 75%.
The higher crossover frequency (1900 Hz) with lower intelligibility score (68%) in the
French and Steinberg (1947) curves may be due to the high rejection rate of the filters.
Hirsh et al. (1954) also studied noise-masking effects on the intelligibility of different
types of speech materials. The intelligibility of easy speech material increased more
rapidly as a function of signal-to-noise (S/N) ratio than did the intelligibility of more
difficult material. At a given S/N ratio, noise levels significantly affect intelligibility. In
general, intelligibility at a noise level of 70 dB was higher than that at other noise levels.
The results also showed that the intelligibility of polysyllabic, disyllabic and
monosyllabic words in noise was higher when they appeared in sentences than when they
appeared as discrete items on a list. Differences among the intelligibility of the different
types of words were much smaller when the words appeared in sentences. Sentence
context had the greatest benefit on understanding monosyllabic words.

51
Pollack (1948) increased the difficulty of the test method for studying the effect
of low-pass and high-pass filtering by adding continuous spectrum white noise at 81.5 dB
SPL as a constant background noise. The test material consisted of monosyllabic,
phonetically balanced words. The overall speech level was about 68 dB SPL at a
distance of 1 meter from the talker. In general, the results indicated that speech
intelligibility increased as the intensity level of the speech signal and the frequency range
were increased. Owing to the background noise, +10 dB orthotelephonic gain (ratio of
the sound intensity at the listener’s ear produced by the test system to the orthotelephonic
reference system, about 75 dB SPL) gave only 30 percent discrimination even to
unfiltered speech. With low-pass and high-pass filtering, the intelligibility improved
continuously with increasing intensity, up to a +50 dB orthotelephonic gain with different
filter settings, even though the rise of the curves between orthotelephonic gain of+30 and
+50 dB was fairly slight. The introduction of background noise resulted in shifting
optimal intensity from +10 dB orthotelephonic gain (French and Steinberg, 1947) to the
+30 to +50 dB level.
The Pollack (1948) study also demonstrated that the contribution to the
intelligibility of the higher speech frequencies alone was small. When a high-pass filter
with a 2375 Hz cutoff was used, intelligibility was only 5% at maximal gain. However,
these same frequencies made an appreciable difference in intelligibility when the low
frequency sounds were also passed at the same time. When the cutoff frequency of low-
pass filter was extended from 2500 Hz to 3950 Hz, the intelligibility was improved from
70% to 90%. It was suggested that the contribution to intelligibility of a given band of
speech frequencies was not independent of the contribution being made at the same time

52
by other bands of frequencies. There was an interaction among the contributions of the
various bands. Similarly, the contribution to intelligibility of very low speech
frequencies was also small. No words were recognized when the frequencies below 425
Hz alone were heard. However, when high-pass cutoff frequency was decreased from
580 Hz to 350 Hz, the intelligibility was improved from 85% to 93%.
A study of the effects of noise and frequency filtering on the perceptual
confusions of English consonants revealed that noise and low-pass filtering ensured more
homogeneous and well-defined results, whereas the mistakes from high-pass filtering
were more indefinite (Miller and Nicely, 1955). Nonsense consonant-vowel (CV)
syllables were used as the test material. The 16 consonants were spoken initially before
the vowel /a/. The results showed that voicing and nasality (manner of articulation) were
much less affected by a random masking noise than were the other features. Affrication
and duration (manner of articulation) were somewhat superior to place but far inferior to
voicing and nasality. Voicing and nasality were discriminable at S/N ratio as poor as -12
dB whereas the place of articulation was hard to distinguish at S/N ratio less than 6 dB,
an 18 dB difference in efficiency. After low-pass filtering (cutoff frequency ranged from
5000 Hz to 300 Hz), voicing and nasality features were well preserved compared with
affrication and place information although affrication was superior to place of
articulation. These results showed the considerable similarity between masking by
broadband noise and filtering by low-pass filters. The authors explained that the uniform
noise spectrum masked high frequencies more than low frequencies since the high-
frequency components of speech were relative weaker than low-frequency components,
so it was in effect a kind of low-pass filter. However, high-pass filtering (cutoff

53
frequency ranged from 1000 Hz to 4500 Hz) produced a totally different pattern. All
features deteriorated in about the same way as the low frequencies were removed. Thus,
low-pass filters affected linguistic features differentially, leaving the phonemes audible
but similar in predictable ways, whereas high-pass filters removed most of the acoustic
power in the consonants, leaving them inaudible and producing quite random confusions.
Audibility was the problem for high-pass filtering and confusibility was the problem for
low-pass filtering. In addition, the crossover point of the high-pass and low-pass function
curves was 1550 Hz, and it became 1250 Hz when plotted by the relative amount of
information transmitted instead of the intelligibility score. The downward shift of
crossover point in frequency indicated that relative to the intelligibility, the low-pass
information was greater and the high-pass information was smaller in consonant
recognition.
Wang and her colleagues studied perceptual features of consonant confusions in
noise (Wang and Bilger, 1973), and following filtering distortion of speech (Wang, Reed
and Bilger, 1978), by sequential information analysis (SINFA), which sequentially
identifies features with a high proportion of transmitted information contributing to
consonant perception. Nonsense syllables were used as test materials in their studies.
The stimuli represented all phonologically permissible consonant-vowel (CV) and vowel-
consonant (VC) syllables, which were formed by combing one of 25 consonants with the
vowels/i/, /a/or/u/. Wang and Bilger (1973) demonstrated that articulatory and
phonological features could account for a large proportion of transmitted information.
The particular features, which resulted in high levels of performance, varied significantly
from one syllable set to another and in some cases varied within syllable sets as a

54
function of listening conditions. Voice and nasal features were well perceived both in
noise and in quiet, and they were identified as perceptually important in every syllable set
where they were distinctive. The feature round (/w/ and /hw/) was also well perceived
both in noise and in quiet. Other features, such as frication and place, appeared to have
different perceptual importance depending upon the listening condition. Under filtering
conditions, there were differential effects of high-pass and low-pass filtering on feature
recognition (Wang, Reed and Bilger, 1978). Low-pass filtering (cutoff frequency ranged
from 5600 Hz to 500 Hz) produced systematic changes in the importance of different
features, whereas high-pass filtering (cutoff frequency ranged from 355 Hz to 4000 Hz)
produced less consistent changes in features recognition. When the low-pass cutoff was
lowered from 2800 to 1400 Hz, sibilance (/si, Izl, /SI, /tS/, IZJ and /dZ/) (manner of
articulation) quickly lost its perceptibility. The high-pass filtering had little effect on the
recognition of sibilance. The high crossover point of the functions at 2800 Hz indicated
that cues for sibilant sound lay in the high-frequency region of the spectrum, above 2000
Hz. High (/k/, /g/, IS/, ItSI, I'Ll, IdZI, /rj/, /w/ and /j/) and anterior (/p/, /t/, Ibl, Id/, If/, Is/,
Ivl, Izl, Iml, Ini, /l/, /9/ and Id/) features (place of articulation) also dropped noticeably
when the cutoff of low-pass filter was lowered to 1400 Hz. For CV syllables, the
crossover point, approximately 1700 Hz, was lower than that for VC syllables, about
2400 Hz. Thus, the cues for high / anterior features were partly dependent on the position
of the consonant within the syllables. However, voice and nasality became increasingly
important as the low-pass cutoff was lowered, while they were adversely affected by
high-pass filtering. The characteristics of consonant confusions following filtering were
quite similar to that noted by Miller and Nicely (1955).

55
The patterns of consonant confusions generated by subjects with sensorineural
hearing loss were like those generated by normal hearing subjects in response to the
appropriate filtering distortion of speech (Bilger and Wang, 1976; Wang, Reed and
Bilger, 1978). For example, severe low-pass filtering produced consonant confusions
comparable to those of listeners with high-frequency hearing loss. Severe high-pass
filtering gave a result comparable to that of patients with flat or rising hearing loss.
In 1994, Griffiths et al. investigated the intelligibility of speech stimuli recorded
within the uterus of a pregnant sheep. The results showed that the intelligibility of the
phonemes recorded in the air was significantly greater than the intelligibility of phonemes
recorded in útero. A male talker’s voice was more intelligible than a female talker’s
voice when the recordings were made in útero. Furthermore, an analysis of the feature
information transmission from recordings inside and outside the uterus revealed that
voicing information is better transmitted in útero than place or manner information. The
findings are quite similar to those of studies conducted by Miller and Nicely (1955) and
Wang et al. (1978) in that transmission into the uterus can be modeled as a low-pass
filter. While the results of Griffiths et al. (1994) study only reflect the perceptibility of the
speech energies present in the amniotic fluid, they do not specify what speech energy might
be present at the level of fetal inner ear. Measurements of acoustic transmission to the fetal
inner ear are quite limited at present. The purpose of current study was to evaluate the
intelligibility of externally generated speech utterances transmitted to and recorded at the
fetal sheep inner ear in útero.

CHAPTER 3
MATERIALS AND METHODS
The overall aims of this project were to determine the intelligibility of speech
information that was transmitted into the uterus and present within the inner ear of the sheep
fetus in Utero. Cues inherent in the speech of both the mother and external talkers may be
perceived by the fetus, thus forming the basis for language acquisition. This study was
intended to provide evidence of fetal inner ear physiological responses to externally
generated speech and to address the hypotheses included in Chapter 1. The study had two
distinct components. The first involved recording speech produced through a loudspeaker
with an air microphone, a hydrophone placed in the uterus of a pregnant sheep and an
electrode secured to the round window of the fetus in útero (cochlear microphonic, CM).
The second portion of the study involved playing the recordings to a jury of normal hearing
adults so speech intelligibility could be evaluated.
Surgery
Eight time-mated pregnant ewes carrying fetuses at gestational ages from 130-140
days were prepared for surgery (term is 145 days). From this group, speech stimuli
recorded from only one animal were used in this study. Recordings from this animal were
judged by the experimenter to have the best fidelity. Speech signals produced from a
56

57
loudspeaker were recorded with an air microphone, a hydrophone placed in the uterus of
pregnant sheep and an electrode secured to the round window of the fetus. The Animal Use
Protocol in this study was approved by the Institutional Animal Care and Use Committee
(IACUC) of the University of Florida.
In preparation for measurements of fetal cochlear microphonic (CM), ewes were
fasted, anesthetized and maintained on a mixture of oxygen and halothane (1.5-2%) during
surgery and subsequent experimentation. The ewe was placed in the supine position and
the fetal head was delivered through a midline hysterotomy. An incision was made over the
fetal right bulla posterior and inferior to the pinna. The incision was located at the
attachment of the cartilaginous portion of the canal to the lateral surface of the skull and
was made parallel to the posterior border of the mandibular ramus. The bulla was exposed
and a small hole was opened through the bulla. The round window was located with an
operating microscope. An electrode was made from insulated stranded stainless steel wire
(Cooner Wire Company, Chatesworth, CA) with the insulation removed from one end. The
uninsulated end was rolled into a 2-mm diameter ball and placed inside the round window
niche (positive electrode). After verifying the impedance of the round window electrode (<
10 ki2), the bulla was refilled with amniotic fluid and sealed over with methylmethacrylate.
Additional Cooner wire electrodes were sutured to tissue overlying the bulla (negative
electrode) and to tissue at a remote site (ground electrode). The skin over the bulla was
sutured and the electrodes were carefully secured to the fetus with silk thread. The fetus
was returned to the uterus and the uterus and abdomen were closed with clamps. Electrode

wires passed through the incisions and were connected to a biological amplifier (Grass
58
Instruments Co., model P51 IK, Quincy, MA).
Recording Speech Stimuli
The anesthetized ewe was placed supine on a stretcher and transported to a sound-
treated booth (Industrial Acoustics Co., model GDC-1L, Bronx, NY). Speech stimuli for
producing fetal CM were prerecorded on cassette tape and consisted of Vowel-Consonant-
Vowel (VCV) nonsense syllables and Consonant-Vowel-Consonant (CVC) monosyllable
words spoken by a male and a female talker. The center of a loudspeaker was one meter
from the ewe and was adjusted to the same height as the center of the lateral wall of the
ewe’s abdomen. A calibrated air microphone (Briiel and Kjael, type 4165, Marlborough,
MA) was positioned over the maternal abdomen at a distance of 10 cm. A miniature
hydrophone (Briiel and Kjael, model 8103), calibrated with a pistonphone (Briiel and Kjael,
model 4223), was inserted in the uterus and connected to a charge amplifier (Briiel and
Kjael, type 2635). The output from the tape player (Harman Kardon, model TD 392,
Woodbury, NY) was routed through a power amplifier (Peavey DECA/1200, Peavey
Electronics Corp., Meridian, MS) that activated the loudspeaker (Peavey HDH-2). The
cochlear potentials, CMs recorded from the fetal inner ear in response to the speech stimuli,
were amplified (Grass Instruments Co., model P51 IK, Quincy, MA) and high-pass filtered
at 100 Hz (Kron-Hite Corp., model 3550, Avon, MA, 24 dB/octave). Figure 3-1 showed
the schematic drawing of recording system set-up.
Because the CM is produced during acoustic stimulation, the potential can be
contaminated with electromagnetic artifact emanating from the loudspeaker and associated

Figure 3-1. Schematic drawing showing the aminal and the setup of devices for stimulus generation, stimulus
measurement, and recording in air, in the uterus, and from the fetal inner ear (cochlear microphonic).
vO

60
wires. The electrical interference produces a voltage output from the biological amplifier
that mimics the true biologic potential. Because electromagnetic energy travels at the speed
of light, whereas acoustic energy travels at the speed of sound (344 m/s), uncontaminated
CM occurred approximately 3 ms after the onset of the stimulus. If this onset delay was not
present in the recording, then measurements were repeated after appropriate equipment
adjustment and / or grounding. The presence of an onset delay confirmed that the recorded
waveform was bioelectric rather than electromagnetic (Gerhardt et al., 1992).
Before recording speech stimuli, CMs (Figure 3-2) were verified by using tone-
bursts (0.5, 1.0 and 2.0 kHz). An evoked potential averaging computer (Tucker-Davis
Technologies, Gainesville, FL) delivered stimuli to the loudspeaker. Tone bursts were
delivered to the ewe’s flank at intensity levels that were capable of producing CM
responses. Twenty stimuli were delivered and averaged for each CM response. Stimulus
duration (10 or 20 ms), sweep time (20 or 50 ms) and filtering (100-3,000 Flz or 100-10,000
Hz) varied with stimulus frequency (0.5, 1.0 and 2.0 kHz). The rate of stimulation was 5/s
and the rise/fall time was 0.2 ms.
The speech stimuli were delivered to the flank of pregnant ewes at two intensity
levels (105 and 95 dB SPL). First, the signals were simultaneously detected with a
microphone located over the abdomen and electrodes placed on the fetal round window in
útero. The outputs from the microphone and inner ear (CM) were recorded on two separate
channels of a DAT tape recorder (SONY Corporation, type ZA5ES, Japan). Then, the same
speech stimuli were repeated and recorded with a hydrophone placed in the uterus and
electrodes placed on the fetal round window ex útero. The fetal external canal and middle
ear cavity were cleared of fluids during ex útero measurement. At the completion of all

500 Hz - 70 dB
500 Hz - 60 dB
500 Hz - 50 dB
Figure 3-2. CM responses obtained from a fetal sheep. Examples of CMs evoked by airborne pure tones at 0.5 and
2.0 kHz and at stimulus levels indicated under each waveform. The apparent onset latency represents the acoustic travel-time
from the loudspeaker to the fetal inner.

measurements, the ewe and fetus were euthanized as prescribed by the IACUC of the
62
University of Florida.
Perceptual Testing
Subjects
A total of 155 undergraduate students from the Department of Communication
Sciences and Disorders at University of Florida volunteered to participate in this study.
From this group, responses from 139 students who judged the intelligibility of speech
stimuli were used. Sixteen students were excluded from the study for the following
reasons: eight judges used unreadable symbols; four judges were normative American
English speakers; and four judges reported hearing loss. The descriptive information of the
perceptual tests is presented in Table 3-1.
All of the judges had taken or were taking an undergraduate course in phonetics,
although as a group they would not be considered experienced phoneticians. All testing
was completed in a single 45-minute session. The protocol for the perceptual testing was
approved by the University of Florida Institutional Review Board (UFIRB Project # 1998-
563).
Speech Stimuli
Two sets of stimuli were used, vowel-consonant-vowel (VCV) nonsense syllables
and consonant-vowel-consonant (CVC) words spoken by male and female talkers and
words based on the Griffiths word lists (1967). Each stimulus item was presented in a

Table 3-1. Perceptual tests.
63
Perceptual audio CD
Contents
Number of judges
A
VCV
33
B
CVC
19
C
CVC
21
D
CVC
20
E
CVC
21
F
CVC
25

64
carrier phrase, “Mark the word Thel4 nonsense syllables (C=/p, t, k, b, d, g, f, v, s,
z, m, n, S, tS/) spoken by both a male and a female talker were preceded and followed by
the vowel laj (e.g. /aga/). The mean fundamental frequencies were 120 and 225 Hz for the
male and female talkers, respectively. Sixty-four items were recorded at each of 16
conditions among gender of talker (male and female), stimulus levels (105 and 95 dB SPL),
and recording locations (air, uterus, CM ex ulero, and CM in útero).
Procedures
The word list, spoken by both male and female talkers, were played through the
loudspeaker via a cassette tape recorder at two different airborne levels measured at the
maternal flank: 105 and 95 dB SPL (dB re: 20 pPa). The outputs from the air microphone,
the hydrophone, and the fetus inner ear (CM) ex útero and in Utero were recorded on DAT
tapes. One set of recordings with the best quality sound from one fetus was chosen for
constructing perceptual tapes. First, speech stimuli were digitized and reproduced via a
computer program (Cool Edit, Syntrillium Software Corporation, Phoenix, AZ) with 44.1-
kHz sampling rate and 16-bit resolution. The amplitudes of the speech stimuli were
adjusted to the same relative voltage levels. Second, each syllable item with a carrier phrase
was saved as an individual file. Then a computer program was used to randomize and
counter-balance the speech stimuli among gender of talker (male and female), stimulus
levels (105 and 95 dB SPL), and recording locations (air, uterus, CM ex útero, and CM in
útero). Finally, six different perceptual audio compact discs (CDs) were created. One
contained randomized recordings of 224 nonsense items (14 nonsense syllables recorded

65
under 16 conditions). The five other CDs contained recordings of 800 monosyllabic words,
each version consisted of 160 words (10 words recorded under 16 conditions, the same
word occurred no more than 4 times in each version). A 5-second silence interval separated
each test item.
The recordings were used to conduct a perceptual test of speech intelligibility. The
test required groups of judges to listen to the utterances in the carrier phrase and mark on
paper what they heard. The judges’ responses provided the basis for determining
intelligibility scores (percent correct) associated with the VCV nonsense items and the CVC
words.
For the 14 VCV nonsense items, the judges filled in a blank in a /a_a / frame with
the vowel set to /a/. For example, if a judge heard “Mark the word /apa/,” he or she would
have to write a “p” in the blank to be correct.
For the 50 CVC words, each judge selected his or her response from a closed set of
six monosyllable words that differed in either the initial or final consonant. For example,
one stimulus item was “Mark the word bat” and the response list included “batch, bash, bat,
bass, back, badge.” To be correct, the judge would have to mark the word “bat.”
Each version of perceptual audio CDs were played to a group of judges comprising
20-30 normal hearing young adults. All testing were conducted in a specially designed
listening laboratory which accommodated up to 25 people at one time. The perceptual
audio CD were played over earphones (HS-95 and HS-56, SONY) to the judges at an
output level set to be comfortably loud (approximately 70 dB SPL). Figure 3-3 showed the
frequency responses of two types of earphones used in the perceptual tests. Each listening

dB RELATIVE
Figure 3-3. The frequency responses of two types of earphones: SONY HS-95 (dot line) and HS-56 (solid line)
used for the perceptual tests.
On
ON

test was preceded by a brief practice session using a version of perceptual audio CD
67
different from the real testing CD to ensure that subjects understood the perceptual tests.
Data Analyses
Statistical Analyses
Intelligibility, consonant confusion matrices and spectral analyses of recorded
speech signals were assessed. The speech intelligibility scores (percent correct) were
derived from the judges’ responses to the perceptual audio CDs for the VCV nonsense
syllables and CVC words by gender, intensity level, and recording location. Multifactor
analysis of variance (ANOVA) was performed on the data of the VCV nonsense syllables
and CVC words separately. The independent variables included three factors: gender of the
talker (male and female), sound pressure level of the airborne stimulus (105 and 95 dB), and
location of recording (air, uterus, CM from ex útero fetus, and CM from in útero fetus).
The dependent variables were percentage of correct identification of nonsense syllables and
monosyllabic words (perceptual scores). In order to meet the variance assumptions for
statistical analysis, the percent intelligibility data, which are binomial variables (Thornton
and Raffin, 1978), were transformed using an arcsine function (2xarcsinxV(%/100)) to
normalize the variance prior to further analysis (Winer, Brown and Michels, 1991).

Information Analyses
68
Data were presented in the form of a 14 x 14-item confusion matrix for each
condition. A total of 16 matrices for VCV nonsense syllables were collected. Sequential
Information Analysis (SINFA; Wang, 1976) of perceptual pattern was performed. SINFA
is applied to the error matrices in order to evaluate the amount of feature information
received. SINFA allows for the partitioning of the contingent information transmitted and
received for particular features of the stimuli (e.g., voicing, manner, and place). From these
results a relative measure of performance may be calculated (the ratio of the bits of
information received to the bits sent, with the effects of other features held constant). The
data from all 16 conditions were analyzed using SINFA.
Acoustic Analyses
Acoustic analyses of five vowels (III, IV, lei, /ae/, /A/) selected from the Griffiths’
words list (CVC) were performed across the recording conditions (105-dB stimuli of both
male and female speakers recorded in air, in the uterus, CM from ex útero fetus, and CM
from in útero fetus). The fundamental frequency (F0) and the first three formant frequencies
(F,, F2, and F3), and their relative intensity levels were measured by using a signal¬
processing computer program (Cool Edit, Syntrillium Software Corporation, Phoenix, AZ).
Each real-time speech waveform was digitized with 44.1-kHz sampling rate and 16-bit
resolution. An average 150-ms segment was selected around the steady-state portion of each
vowel. The F0 and formants (F„ F2, and F,) of each segment were measured by visual
inspection of the corresponding Fourier transform spectrum using Hamming window with

69
4096 Fourier size followed by smoothing (Lee, Potamianos and Narayanan, 1999).
According to the values measured by Peterson and Barney (1952), and Hillenbrand et al.
(1995), F0 and formants frequencies (F„ F2, and F3) were estimated. The relative intensity
levels were also calculated by subtracting the background noise value from the peak value
under different recording conditions. Two-factor repeated measures ANOVAs were
performed on the data of relative intensity levels of F0, F„ F2, and F3 across the recording
locations for each vowel.

CHAPTER 4
RESULTS AND DISCUSSION
One hundred and thirty-nine judges completed the perceptual tests. Because the
speech stimuli were completed randomized and counter-balanced across gender of talkers
(male and female), stimulus levels (105 and 95 dB SPL) and recording locations (air, uterus,
CM ex ulero, and CM in útero), learning effects were minimized.
Intelligibility
The speech intelligibility scores (percent correct) derived from the judges’
responses to the perceptual audio compact discs (CDs) for the VCV nonsense syllables
and CVC words are displayed in Figures 4-1 and 4-2, respectively. A few general
observations can be made about both Figures. First, intelligibility scores as a function of
location alone, decreased from air to hydrophone locations and decreased again from CM
ex útero to CM in útero. That is to say, intelligibility scores of the VCV and CVC lists
were high when recorded in air and slightly less when recorded with a hydrophone in the
uterus. The scores, when recorded from the inner ear of the fetus ex Utero, are 20-40%
lower than recordings from either the air or hydrophone locations. The intelligibility
scores recorded from the inner ear of the fetus in útero are about 10-20% poorer than the
scores recorded from the fetal CM ex útero. Second, from casual inspection of the two
Figures, there appear to be a slight gender and level effects primarily for the VCV lists.
70

Figure 4-1. Mean percent intelligibility of VCV nonsense stimuli spoken by a male and a female talker
recorded in air, in the uterus, from the fetal CM ex útero, and from fetal CM in útero at two airborne stimulus levels.
Bars equal the standard error of the mean.

100
90
80
70
60
50
40
30
20
10
0
AIR UTERUS CM-EX CM-IN
TEST CONDITION

Figure 4-2. Mean percent intelligibility of CVC words spoken by a male and a female talker recorded in air, in
the uterus, from the fetal CM ex útero, and from fetal CM in útero at two airborne stimulus levels. Bars equal the
standard error of the mean.

100
90
80
70
60
50
40
30
20
10
0
AIR UTERUS CM-EX CM-IN
TEST CONDITION
-P*-

75
Gender and level effects are more pronounced from recordings of the CM than from
recordings in air or in the uterus. Summaries of the means and standard deviations for
intelligibility by gender, stimulus level, and location that contributed to these figures are
presented in Tables 4-1 and 4-2.
The results of a three-factor repeated measure ANOVA are summarized for VCV
stimuli and given in Tables 4-3. There was a significant three-way interaction among
gender, stimulus level, and location (F3,96 = 14.582, p < 0.0001). The main effects were
significant for each of the three factors: location (F3,96= 994.982, p < 0.0001), gender (Fi,
32= 210.258, p < 0.0001), and stimulus level (Fi,32= 25.869, p < 0.0001). The results of
the post hoc multiple comparison test (Newman-Keuls) are presented in Table 4-4. Not
all of the paired results were included in this table. Note that intelligibility in all cases
was significantly greater (p < 0.01) for CM ex útero than for CM in útero. Also,
intelligibility of the nonsense syllables (VCV) was better at higher presentation levels
than at lower presentation levels. When both stimulus levels were compared, statistical
significance (p < 0.01) was attained for the male voice recorded in the uterus, from CM
ex útero, and from CM in útero, as well as for the female voice recorded from CM in
útero.
The ANOVA results for CVC words (Table 4-5) showed a significant three-way
interaction among gender, stimulus level, and location (F3,315 = 22.459, p < 0.0001). This
was similar to the results for the nonsense syllables (VCV). The main effects were
significant for location ^3,315= 1213.579, p < 0.0001) and stimulus level (Fi, 105 =
102.82, p < 0.0001), but not for gender (Fi, 105 = 1.247, p = 0.267). The results of the post
hoc multiple comparison test (Newman-Keuls) are given in Table 4-6, in which not all of

Table 4-1. VCV stimulus intelligibility scores for each talker, stimulus level and recording site.
In Air
In Uterus
CM-ex útero
CM-/n útero
Male talker
105 dB
95 dB
105 dB
95 dB
105 dB
95 dB
105 dB
95 dB
Mean (%)
99.35%
98.48%
89.61%
96.10%
80.52%
70.13%
46.75%
32.47%
S.D. (%)
2.09%
2.97%
7.16%
5.08%
11.33%
8.83%
12.25%
9.46%
No. correct (N=14)
13.909
13.788
12.545
13.455
11.273
9.818
6.545
4.545
S.D.
0.292
0.415
1.003
0.711
1.587
1.236
1.716
1.325
No. of judges
33
33
33
33
33
33
33
33
Female talker
Mean (%)
90.26%
91.34%
82.90%
78.79%
50.22%
48.48%
39.39%
28.57%
S.D. (%)
5.87%
3.89%
8.74%
10.18%
7.68%
10.22%
11.73%
11.01%
No. correct (N=14)
12.636
12.788
11.606
11.030
7.030
6.788
5.515
4.000
S.D.
0.822
0.545
1.223
1.425
1.075
1.431
1.642
1.541
No. of judges
33
33
33
33
33
33
33
33

Table 4-2. CVC stimulus intelligibility scores for each talker, stimulus level and recording site.
In Air
In Uterus
CM-ex útero
CM-/n útero
Male talker
105 dB
95 dB
105 dB
95 dB
105 dB
95 dB
105 dB
95 dB
Mean (%)
95.47%
97.45%
93.40%
85.75%
62.26%
57.83%
60.09%
40.85%
S.D. (%)
6.19%
4.38%
7.55%
13.23%
16.69%
15.24%
12.31%
15.92%
No. correct (N=10)
9.547
9.745
9.340
8.575
6.226
5.783
6.009
4.085
S.D.
0.619
0.438
0.755
1.323
1.669
1.524
1.231
1.592
No. ofjudges
106
106
106
106
106
106
106
106
Female talker
Mean (%)
98.02%
92.74%
90.57%
86.70%
63.02%
62.74%
52.26%
46.23%
S.D. (%)
4.66%
6.25%
7.28%
11.85%
16.28%
16.07%
15.14%
15.58%
No. correct (N=10)
9.802
9.274
9.057
8.670
6.302
6.274
5.226
4.623
S.D.
0.466
0.625
0.728
1.185
1.628
1.607
1.514
1.558
No. of judges
106
106
106
106
106
106
106
106

Table 4-3. ANOVA summary table for VCV stimuli.
Source
Sum of Squares
df
Mean Squares
F
p-value
Location
180.991
3
60.330
994.982
<0.0001
Error (Location)
5.821
96
0.06063
Gender
22.470
1
22.470
210.258
<0.0001
Error (Gender)
3.420
32
0.107
Level
0.894
1
0.894
25.869
<0.0001
Error (Level)
1.106
32
0.03456
Location x Gender
3.948
3
1.316
21.539
<0.0001
Error (Location x Gender)
5.866
96
0.0611
Location x Level
2.738
3
0.913
23.181
<0.0001
Error (Location x Level)
3.779
96
0.03936
Gender x Level
0.00407
1
0.0407
0.104
0.749
Error (Gender x Level)
1.249
32
0.03904
Location x Gender x Level
2.180
3
0.727
14.582
<0.0001
Error (Location x Gender x Level)
4.784
96
0.04983

Table 4-4. Post hoc multiple comparisons (Newman-Keuls test) for VCV stimuli.
Conditions
AMH
AML
UMH
UML
XMH
XML
IMH IML AFH
AFL
UFH
UFL
XFH XFL IFH IFL
AMH
AML
-
UMH
**
UML
*
**
XMH
**
**
XML
**
**
**
IMH
**
**
**
IML
**
**
**
**
AFH
**
AFL
**
-
UFH
**
**
UFL
**
**
-
XFH
**
**
**
XFL
**
**
**
-
IFH
** **
**
**
IFL
~
**
**
** **
Note: A - In Air; U = In Uterus; X = CM-ex útero; I = CM-m útero; M = Male; F = Female; H = 105 dB; L = 95 dB.
-- p>0.05; * p<0.05; ** p<0.01.
-j
vO

Table 4-5. ANOVA summary table for CVC stimuli.
Source
Sum of Squares
df
Mean Squares
F
p-value
Location
505.738
3
168.579
1213.687
<0.0001
Error (Location)
43.753
315
0.139
Gender
0.192
1
0.192
1.247
0.267
Error (Gender)
16.154
105
0.154
Level
9.484
1
9.484
102.820
<0.0001
Error (Level)
9.685
105
0.09224
Location x Gender
1.2995
3
0.433
3.456
0.0658
Error (Location x Gender)
39.486
315
0.125
Location x Level
2.821
3
0.940
8.857
<0.0001
Error (Location x Level)
33.439
315
0.106
Gender x Level
0.119
1
0.119
0.566
0.454
Error (Gender x Level)
22.126
105
0.211
Location x Gender x Level
7.713
3
2.571
22.459
<0.0001
Error (Location x Gender x Level)
36.061
315
0.114

Table 4-6. Post hoc multiple comparisons (Newman-Keuls test) for CVC stimuli.
Conditions
AMH
AML
UMH
UML XMH
XML
IMH IML AFH
AFL
UFH
UFL XFH XFL IFH IFL
AMH
AML
*
UMH
*
UML
**
**
XMH
**
**
XML
**
**
IMH
**
**
-
IML
**
**
**
**
AFH
**
AFL
**
**
UFH
**
**
UFL
-
**
--
XFH
--
**
**
XFL
-
**
**
IFH
** **
**
**
IFL
**
**
** ** **
Note: A = In Air; U = In Uterus; X = CM-ex ulero; I = CM-m ulero; M = Male; F = Female; H = 105 dB; L = 95 dB.
- p>0.05; * p<0.05; ** p<0.01.

82
the paired results were included. It is noted that intelligibility was significantly greater (p
<0.01) for CM ex útero than for CM in útero, except for the male voice recorded at 105
dB SPL (p > 0.05). Also, intelligibility of the words (CVC) was better at higher
presentation levels than at lower presentation levels, except for the male voice recorded
in air. When both stimulus levels were compared, statistical significance (p < 0.01) was
achieved for the male voice recorded in air (p < 0.05), in the uterus, and from CM in
Utero, as well as for the female voice recorded in air and from CM in útero.
Figures 4-3 simplifies those data presented in Figure 4-1 by combining levels.
For VCV stimuli, the average intelligibility scores for the male voice recorded in air, in
the uterus, from fetal CM ex útero, and from fetal CM in útero were 98.9%, 92.9%,
75.3%, and 39.6%, respectively. For the female voice recorded in air, in the uterus, from
fetal CM ex útero, and from fetal CM in Utero, the intelligibility scores were 90.8%,
80.8%, 49.4%, and 34.0%, respectively. A two-factor repeated measures ANOVA
indicated significant interaction between gender and location (F3, % = 20.925, p < 0.0001),
and main effects for gender (Fi_32 = 192.744, p < 0.0001) and location (F3,96= 1048.477,
p < 0.0001). The post hoc multiple comparison test (Newman-Keuls) indicated that the
intelligibility scores of the male voice were significantly higher (p < 0.01) than that of the
female voice at all four recording locations. Also, for both male and female talkers, the
intelligibility scores recorded in air were significantly higher (p < 0.01) than that of each
of the other three recording locations. The scores recorded in the uterus were
significantly higher (p < 0.01) than that of recordings from CM ex útero and CM in útero.
The scores recorded from CM ex útero were significantly higher (p < 0.01) than that from
CM in útero.

Figure 4-3. Mean percent intelligibility of VCV nonsense stimuli spoken by a male and a female talker
recorded in air, in the uterus, from the fetal CM ex útero, and from fetal CM in útero when combining two airborne
stimulus levels. Bars equal the standard error of the mean.

AIR UTERUS CM-EX CM-IN
TEST CONDITION

85
Similarly, Figures 4-4 clarifies those data presented in Figure 4-2 by combining
levels. For CVC words, the average intelligibility scores for the male voice recorded in
air, in the uterus, from fetal CM ex útero, and from fetal CM in útero were 96.5%, 89.6%,
60.1%, and 50.5%, respectively. For the female voice recorded in air, in the uterus, from
fetal CM ex útero, and from fetal CM in útero, the intelligibility scores were 95.4%,
88.6%, 62.9%, and 49.3%, respectively. A two-factor repeated measures ANOVA
indicated significant interaction between gender and location (F3t315 = 3.386, p = 0.0184),
and main effects for location (F3,3is= 1045.347, p < 0.0001), but not for gender (Fi, 105 =
1.427, p = 0.235). A post hoc multiple comparison test (Newman-Keuls) indicated that,
for both male and female talkers, the intelligibility scores recorded in air were
significantly higher (p < 0.01) than that of each of the other three recording locations.
The scores recorded in the uterus were significantly higher (p < 0.01) than that of
recordings from CM ex útero and CM in útero. The scores recorded from CM ex útero
were significantly higher (p < 0.01) than that from CM in útero. There were no statistical
differences (p > 0.05) between the male voice and the female voice across recording
locations, except when recorded in air (p < 0.05).
As reported above, speech (VCV and CVC stimuli) intelligibility scores were
significantly higher for the recordings in air than in the uterus. Likewise, the
intelligibility was significantly greater for the recordings from CM ex ulero than from
CM in útero. The recordings within the uterus reflect the speech energies present in
amniotic fluid, whereas the recordings from CM in útero represent the actual fetal
physiological responses to externally generated speech. The characteristics of
transmission of external sound pressure into the maternal abdomen and uterus has been

Figure 4-4. Mean percent intelligibility of CVC words spoken by a male and a female talker recorded in air, in
the uterus, from the fetal CM ex útero, and from fetal CM in útero when combining two airborne stimulus levels. Bars
equal the standard error of the mean.

100
90
80
70
60
50
40
30
20
10
0
â– 
cvc
â–¡ Male
Up
â– 
lgp
HI
X
Ü
â– 
ÃœP
â– 
p
ÉÜ
iü
â– 
AIR UTERUS CM-EX CM-IN
TEST CONDITION
oo
"J

88
well described in humans (Querleu et al., 1988a; Richards et al., 1992) and sheep
(Armitage, Baldwin and Vince, 1980; Vince et al., 1982, 1985; Gerhardt, Abrams and
Oliver, 1990). The abdomen wall, uterus, and amniotic fluids can be characterized as a
low-pass filter with a high-frequency cutoff at 250 Hz and a rejection rate of
approximately 6 dB per octave. For frequencies below 250 Hz, sound pressures passing
through to the fetus are unattenuated, and, in some cases, are enhanced. Above 250 Hz,
sound pressures are increasingly attenuated by up to 20 dB (Gerhardt, Abrams and
Oliver, 1990). Thus, the speech signals would be altered as they passed through tissues
of the ewe into the uterus. Additionally, the spectral contents of external sounds are
further modified by the route of sound transmission into the fetal inner ear. Sound
pressures pass through the fetal head by a bone conduction pathway (Gerhardt et al.,
1996). For 125 to 250 Hz, an airborne signal would be reduced by 10-20 dB before
reaching the fetal inner ear. For 500 through 2000 Hz, the signal would be reduced by
35-45 dB (Gerhardt et al., 1992). Therefore, the recordings of speech from CM in útero
would be further degraded and less intelligible than the recordings in air and in the uterus.
The present findings reveal better intelligibility for speech in the uterus than has
been previously found (Querleu et al., 1988b; Griffiths et al., 1994). Querleu et al.
(1988b) found that about 30% of 3120 French phonemes recorded within the uterus of
pregnant women were recognized. In 1994, Griffiths et al. evaluated the intelligibility of
speech stimuli (VCV nonsense syllables and CVC words) recorded within the uterus of a
pregnant sheep. The intelligibility scores were approximately 55% and 34% for the male
and female talkers, respectively. However, the results from the current study showed that
the intelligibility scores averaged across the stimulus types and intensity levels, were

89
approximately 91% and 85% for the male and female voices recorded in the uterus,
respectively. The lower intelligibility of speech achieved by Querleu et al. (1988b) has
been explained by the location of the transducer within the uterus (Griffiths et al. 1994)
and by the type of transducer. A modified microphone used in Querleu’s study was
positioned at the crown of the fetal head, potentially closer to vascular beds and better
able to pick up maternal heart sounds. In both the present study and the study by
Griffiths et al. (1994), a hydrophone positioned by the fetal neck was used. The absence
of detectable heart sounds in the recordings from these two studies supports that the
hydrophone placement results in less vascular noise. However, the recordings within the
uterus in the current study showed much higher intelligibility scores than that in
Griffiths’ study (1994), although both sets of data were obtained using the same speech
stimuli (VCV nonsense syllable and CVC words) spoken by male and female speakers.
The discrepancy could result from the higher stimulus levels (105 and 95 dB SPL vs. 85,
75, and 65 dB SPL) and better perceptual testing condition (earphone vs. sound field)
used in the current study.
Griffiths et al. (1994) also demonstrated that the male talker’s voice was more
intelligible than the female talker’s voice for both VCV and CVC stimuli when recorded
within the uterus, although the intelligibility scores for both talkers were not significant
different regardless of stimulus type when recorded in air. The results of the present data
indicated that the intelligibility scores of the male voice were significantly higher than
that of the female voice across all four recording locations (in air, in the uterus, from CM
ex útero, and from CM in útero) for VCV nonsense syllables, but not for CVC words.
The differences of intelligibility scores for VCV nonsense syllables between the male

90
talker and the female talker were 8.1% in air (98.9% for male and 90.8% for female),
12.1% in the uterus (92.9% for male and 80.8% for female), 25.1% from CM ex útero
(75.3% for male and 49.4% for female), and 5.6% from CM in útero (39.6% for male and
34.0% for female). When listening to the female speaker’s original tape, it is difficult for
investigators to distinguish the consonant /v/ from /b/. Twenty-nine out of 33 judges
responded VCV stimulus item /ava1 as /aba/ in the air condition for the female talker.
The unclear pronunciation of the consonant /v/ accounted for the decreases in the
intelligibility of the female talker in air and, therefore, for the other recording locations.
The differences in the intelligibility scores between the male and the female
talkers ranged from 5.6% (CM in útero) to 25.1% (CM ex Utero). These differences were
quite small (except 25.1% for CM ex útero) relative to the 14-item perceptual test (14
VCV items). Thus, the differences between talker gender may not be clinically
significant, although they are statistically significant. Thornton and Raffin (1978) studied
the binomial characteristics of speech discrimination (intelligibility) scores and pointed
out the relation between measurement error and sample size (number of test item). As
sample size was reduced, variability in scores increased, and the farther the score from
100% or 0% the less confidence one can have in the specific value. The authors have
provided confidence intervals and expected ranges of scores based on evaluations of 4120
subjects with CID Auditory Test W-22 (monosyllabic words). For example, a listener
who makes a score of 92% may vary between 78 and 98% on a 50-item list and still be
within expected variation (95% confidence interval) while the expected range of variation
for a 25-item list is even greater at 72 to 100%. For the subject with a score of 48%, the
range of variation for 50 items is from 30 to 66%, and for 25 items is 24 to 72%.

91
The CM is an AC receptor potential produced primarily by the outer hair cells of
the organ of Corti during acoustic stimulation, and mimics the acoustic input in amplitude
and frequency over a remarkably wide range (Gulick, Gescheider and Frisina, 1989). In
response to complex stimuli, like speech or music, the CM continues to follow the
stimulus waveform, although there is some phase distortion due to the differing travel
times necessary for the distribution of the various frequencies to their appropriate places
along the cochlear basilar membrane. Nevertheless, when the CM is suitably amplified
and converted back into sound, speech and music are easily recognizable.
In the current study, the recordings from the CM ex útero condition represented
the actual fetal responses to speech in air that simulated the auditory condition of after
birth. The CM in útero recordings reflected the speech information preserved in the fetal
peripheral auditory system after transmission of external speech from air through the
maternal tissues and fluids into the fetal inner ear. However, since CM is not an ideal
“microphone,” the overall intelligibility from CM ex útero recordings was only 61.9%
when averaged across gender, intensity level, and stimulus type. Several factors can be
accounted for this low intelligibility score. First, a high-level background noise was
created by the biological amplifier used during CM recordings. This would decrease the
S/N ratio and increase the difficulty of the perceptual test. Second, during the ex Utero
CM recordings, fluids might have been retained in the middle ear cavity and perhaps
external ear canal, although special attention was paid to the clearing of these fluids. The
retained fluid would increase the mass of the middle ear, which could reduce the
transmission of high-frequency sounds into the inner ear (Pickles, 1988; Gulick,
Gescheider and Frisina, 1989). Thus, high-frequency components of speech would be

92
attenuated in the recordings from CM ex útero, if fluid remained in the middle ear cavity.
Finally, the CM produced by any particular pure tone has its maximum sensitivity at a
specific place along the cochlear basilar membrane (Gulick, Gescheider and Frisina,
1989). Honrubia and Ward (1968) determined the spatial distribution of the CM inside
the scala media by recording simultaneously from each of four electrodes in the scala
media, one in each turn of the guinea pig cochlea. They found that the places of
maximum CM shifted toward the basal end of the cochlea as the frequency of the driving
stimulus increased. The spread of the electrical potential was less for the higher
frequencies than for the lower frequencies, just as anticipated from the basis of the
traveling wave. Therefore, the CM measured with a single electrode placed on the round
window membrane, which was used in the present study, only accurately measured the
response of hair cells from the basal turn, and cannot record the entire cochlear response
to the input signals. The low-frequency information of the speech signal would be
reduced in the CM recordings by using a single round window electrode. Overall, in the
present study, the recordings of speech from CMs underestimated the speech information
actually preserved in the fetal inner ear.
In summary, when the mean intelligibility scores were averaged across two
stimulus levels (105 and 95 dB SPL) and stimulus types (VCV and CVC stimuli), they
were 97.7% and 93.1% for the male and female voices recorded in air. Within the uterus,
scores were 91.2% and 84.7% for the male and the female voices, respectively. The
decline in intelligibility was only 6.5% for the male speaker and 8.4% for the female
speaker from in air recordings to in the uterus recordings. The reduction of intelligibility
reflected the filter effect produced by the maternal abdomen, uterus and amniotic fluid.

93
In contrast, the mean intelligibility scores recorded from CM in útero, averaged across
two levels and stimulus types for the male and female voices, were 45.0% and 41.6%,
respectively. For CM ex ulero, scores were 67.7% and 56.1% for the male and the
female talkers. Thus the reduction in intelligibility recordings made from CM ex ulero to
CM in Utero was 22.7% for the male speaker and 14.5% for the female speaker, which
was greater than that from in air recordings to in the uterus recordings. These declines in
intelligibility represented the loss of speech information after transmission from air
through the tissues and fluids associated with pregnancy and transmission through the
fetal skull into the inner ear.
The results reported in this section support the hypotheses that the intelligibility of
monosyllabic words and nonsense syllables will be reduced when recorded in the uterus
compared to air. The results also explain the hypotheses that the intelligibility of
monosyllabic words and nonsense syllables will be reduced when recorded from the fetal
inner ear in ulero compare to uterus.
Finally, the hypotheses were not supported that the intelligibility of a male talker
will be greater than the intelligibility of a female talker when recorded in the uterus and
from the fetal inner ear in Utero. Two explanations for the lack of support for these
hypotheses are offered. First, high level presentations (105 and 95 dB SPL) of the
nonsense syllables and monosyllabic words may have produced improved intelligibility
for the female talker when recorded in the uterus and from the fetal inner ear. And earlier
study with sheep that showed a gender effect used lower levels of stimulus presentations
(Griffiths et al., 1994). Second, in the CM in útero recording condition, the gender effect
on the intelligibility of speech stimuli was minimized because the cutoff frequency of the

94
low-pass filter (bone conduction route into the fetal inner ear) was further lowered when
compared to the uterus recording condition (Gerhardt et ah, 1992). The high-frequency
component of speech that cued the gender effect on the intelligibility of speech was
eliminated when transmitted into the fetal inner ear in útero.
Consonant Feature Transmission
Consonant confusion matrices were constructed from the responses of all subjects
to the VCV nonsense syllables for each recording condition. They are presented in
Tables 4-7 to 4-14 for the male talker, at each of the four recording locations (air, uterus,
CM ex útero, and CM in útero), and at each of the stimulus levels (105 and 95 dB SPL).
Tables 4-15 to 4-22 are the consonant confusion matrices for the female talker under the
different recording conditions. In general, some consonant confusion patterns can be
derived from inspecting these matrices. First, all 14 consonants were identified with high
accuracy from recordings made in air. The accuracy of identification was slightly less in
the uterus for both male and female speakers. In the recordings from CM ex útero and
from CM in útero, accuracy of identification decreased dramatically.
Some consonants were correctly identified consistently across the recording
conditions, while others were not. For example, the nasal /n/ was perceived quite
accurately in all recording conditions, while correct identification of the fricative /S/ and
the affricate /tS/ were much lower in the recordings from the fetal inner ear. The correct
identification of the Ini sound was 100% in the recordings made in air, in the uterus, and
from CM ex útero for both male and female talkers at 105 dB SPL. It dropped slightly to
73% and 83% in CM in útero at 105 dB SPL for the male and female talkers,

Table 4-7. Consonant confusion matrix for male talker, recorded in air at 105 dB SPL.
Stimulus
Ibl
/p/
Id/
hi
/g/
Ikl
If/
M
Is/
Izl
Iml
Ini
ISI
/tS/
Ibl /p/ Id/ hi
33 0 0 0
0 33 0 0
0 0 33 0
0 0 0 33
10 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
Response
Igl Dd W l\l Is/ Izl Iml Ini
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
32 0 0 0
0 33 0 0
0 0 32 0
0 0 0 33
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
10 0 0
0 0 0 0
32 1 0 0
0 33 0 0
0 0 33 0
0 0 0 33
0 0 0 0
0 0 0 0
IS/
0
0
0
0
0
0
0
0
0
0
0
0
33
0
Its/
0
0
0
0
0
0
0
0
0
0
0
0
0
33

Table 4-8. Consonant confusion matrix for male talker, recorded in air at 95 dB SPL.
Response
Stimulus Ibl /p/ /d/ /t/ Igl /k/ IV M Is/ /z/ /m/ /n/ /S/ /tS/
/b/
/p/
/d/
/t/
/g/
/k/
/S'
/v/
/s/
/z/
/m/
/n/
/S/
33 0 0 0
0 33 0 0
0 0 32 0
0 0 0 33
0 0 0 0
0 0 0 0
0 0 0 3
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
10 0 0
0 0 0 0
33 0 0 0
0 33 0 0
0 0 29 0
0 0 0 33
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 1
0 0
32 1
0 33
0 0
0 0
0 0
0
0
0
0
0
0
0
0
0
0
33
0
0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
33 0
0 32
0
0
0
0
0
0
0
0
0
0
0
0
1
Its/
33
VO
Ov

Table 4-9. Consonant confusion matrix for male talker, recorded in the uterus at 105 dB SPL.
Stimulus
/b/
/p/
/d/
hi
/g/
/k/
/£/
Ivl
/s/
Izl
Iml
Ini
IS/
ItS/
Response
/b/ /p/ /d/ /t/ /g/ /k/ /f/ /v/ /s/
33 0 0 0 0
0 32 0 1 0
0 0
0 0
0 0
0 0
0 0 25 0 8
0 0 0 0
0 0
0 21 0 12 0
0 0
0 0
0 0
0 0 33 0 0
0 0 0 33 0
0
0
0
0
0 0 0 3 0
0 0 0 0 0
0 26 1 2
0 0 33 0
0 0 0 0 0
0 0 10 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 17 0 16
0 0 2 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
Izl Iml Ini IS/ Its/
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 1
0 0 0 0 0
0 0 0 0 0
30 0 0 0 0
0 33 0 0 0
0 0 33 0 0
0 0 0 33 0
0 0 0 0 33

Table 4-10. Consonant confusion matrix for male talker, recorded in the uterus at 95 dB SPL.
Stimulus
Response
/b/
/p/
/d/
/t/
/g/
/k/
IV
/v/
/s/
Izl
/m/
Ini
IS/
/ts/
/b/
33
0
0
0
0
0
0
0
0
0
0
0
0
0
/p/
0
33
0
0
0
0
0
0
0
0
0
0
0
0
/d/
0
0
24
0
9
0
0
0
0
0
0
0
0
0
N
0
0
0
28
0
5
0
0
0
0
0
0
0
0
0
0
0
0
33
0
0
0
0
0
0
0
0
0
/k/
0
0
0
0
0
33
0
0
0
0
0
0
0
0
iv
0
1
0
2
0
0
30
0
0
0
0
0
0
0
M
0
0
0
0
0
0
0
33
0
0
0
0
0
0
/s/
0
0
0
0
0
0
0
0
33
0
0
0
0
0
Izl
0
0
0
0
0
0
0
0
0
33
0
0
0
0
/m/
0
0
0
0
0
0
0
0
0
0
33
0
0
0
/n/
0
0
0
0
0
0
0
0
0
0
1
32
0
0
/s/
0
0
0
0
0
0
0
0
0
0
0
0
33
0
/ts/
0
0
0
0
0
0
0
0
0
0
0
0
0
33
VO
oo

Table 4-11. Consonant confusion matrix for male talker, recorded from CM-ex útero at 105 dB SPL.
Stimulus
Response
/b/
V
Id/
hi
!%/
/k/
lit
M
/s/
Izl
/m/
/n/
IS/
/ts/
Ibl
33
0
0
0
0
0
0
0
0
0
0
0
0
0
Ipl
0
27
0
4
0
2
0
0
0
0
0
0
0
0
/dj
1
0
25
0
7
0
0
0
0
0
0
0
0
0
hi
0
0
0
30
0
3
0
0
0
0
0
0
0
0
/g'J
0
0
0
0
32
0
0
0
0
1
0
0
0
0
/k/
1
0
0
0
0
31
1
0
0
0
0
0
0
0
If/
0
4
0
0
0
0
25
0
4
0
0
0
0
0
M
0
0
0
0
0
0
0
33
0
0
0
0
0
0
/s/
1
1
0
5
1
4
7
0
11
0
0
0
2
1
/z/
0
0
1
0
7
0
0
1
0
22
0
0
1
1
/m/
2
0
0
0
0
0
0
0
0
0
30
1
0
0
/n/
0
0
0
0
0
0
0
0
0
0
0
33
0
0
/s/
0
0
0
0
0
0
0
0
5
0
0
0
28
0
/ts/
0
0
0
14
1
6
0
0
0
0
0
0
0
12
SO
SO

Table 4-12. Consonant confusion matrix for male talker, recorded from CM-ex útero at 95 dB SPL.
Stimulus
Response
Ibl
/p/
/d/
/t/
/g/
Ik/
/{/
M
Is/
IzJ
/m/
/n/
/s /
/ts/
lb/
33
0
0
0
0
0
0
0
0
0
0
0
0
0
/p/
0
30
0
2
0
1
0
0
0
0
0
0
0
0
Id1
0
0
18
0
15
0
0
0
0
0
0
0
0
0
N
0
0
0
18
0
15
0
0
0
0
0
0
0
0
Igl
0
0
0
0
33
0
0
0
0
0
0
0
0
0
M
0
0
0
1
0
31
0
0
1
0
0
0
0
0
If!
0
0
0
10
0
9
9
0
3
0
0
0
1
1
M
0
0
0
0
0
0
0
30
0
3
0
0
0
0
Isl
0
0
0
2
2
14
6
0
7
1
0
0
1
0
Izl
0
0
0
0
3
0
0
0
0
30
0
0
0
0
Iml
0
0
0
0
0
0
0
0
0
0
33
0
0
0
kd
0
0
1
0
0
0
0
0
0
0
3
29
0
0
IS/
0
1
0
2
0
8
0
0
2
0
0
0
19
1
/ts/
0
1
0
3
0
14
0
1
4
0
0
0
6
4
o
o

Table 4-13. Consonant confusion matrix for male talker, recorded from CM-m útero at 105 dB SPL.
Response
Stimulus /b/ /p/ /d/ /t/ /g/ /k/ If/ Ivl /s/ IzJ /ml /n/ /S/ /tS/
/b/
/p/
/d/
/t/
/g/
/k/
22 11
0 4
0 0
0 3
0 0
0 1
0 0 0 0 0
0 18 0 7 4
1 0 32 0 0
0 4 0 26 0
0 0 31 1 0
0 5 0 27 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 0
0 0 0 1
0 0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
0 0 0
Itl
M
0 3 0 1
0 0 0 0
0 2 21 0 6
0 0 0 27 0
0
6
0 0 0 0
0 0 0 0
/s/
IzJ
/ml
Ini
IS/
ItSI
3
0
0
0
1
15
15
0
0
0
6
0
6
0
0
0
21
10
0
18
0
0
0
0
1
0
27
9
0
0
0
0
6
24
0
0

Table 4-14. Consonant confusion matrix for male talker, recorded from CM-m útero at 95 dB SPL.
Response
Stimulus /b/ /p/ /d/ /t/ /g/ /k/ ffl M /s/
/b/
/p/
/d/
/t/
/g/
/k/
/f/
28 0
3 3
0 0
1 6
2 2
0 1
0 0
2 2 0 0 0
0 10 6 7
1 0 25 0 0
02 1 15 6
3 3 18 2 0
0 13 0 11 4
0 4 0 4 6
0
0
6
0
1
0
0
0
4
0
0
0
0
8
M
3 0 2 0 9 0
0 16 0
/s/
/z/
/m/
/n/
/S/
/tS/
1 3 0
0 0 4
0 0 0
0 0 0
2 110
0 0 0
5 0 4 11 0
0 13 0 0 0
0 0 0 0 0
0 0 0 0 0
0 4 5 10 0
3 0 9 8 1
4
0
0
0
1
6
IzJ Iml /n/ /S/ /tS/
0 10 0 0
1 0 0 8 0
1 0 0 0 0
0 0 0 2 0
110 0 0
0 0 0 13
0 0 0 4 7
3 0 0 0 0
0 0 0 3 2
15 0 0 1 0
0 32 1 0 0
0 20 13 0 0
0 0 0 0 0
1 0 0 4 1

Table 4-15. Consonant confusion matrix for female talker, recorded in air at 105 dB SPL.
Stimulus
Response
fbl
/p/
/d/
It/
/g/
fkf
Iff
M
1st
Izl
/m/
Ini
ISI
ItSI
/b/
33
0
0
0
0
0
0
0
0
0
0
0
0
0
/p/
0
30
0
0
0
3
0
0
0
0
0
0
0
0
Id/
0
0
33
0
0
0
0
0
0
0
0
0
0
0
ft/
0
0
0
33
0
0
0
0
0
0
0
0
0
0
/g/
0
0
0
0
33
0
0
0
0
0
0
0
0
0
/k/
0
0
0
0
0
32
0
1
0
0
0
0
0
0
/f/
0
0
0
1
0
0
31
0
1
0
0
0
0
0
M
29
0
0
0
0
0
0
4
0
0
0
0
0
0
Isl
0
0
0
0
0
0
0
0
29
4
0
0
0
0
/z/
0
0
0
0
0
0
0
0
2
31
0
0
0
0
/m/
0
0
0
0
0
0
0
0
0
0
33
0
0
0
Ini
0
0
0
0
0
0
0
0
0
0
0
33
0
0
/SI
0
0
0
0
1
0
0
0
1
2
0
0
29
0
Its/
0
0
0
0
0
0
0
0
0
0
0
0
0
33

Table 4-16. Consonant confusion matrix for female talker, recorded in air at 95 dB SPL.
Response
Stimulus /b/ /p/ /d/ /t/ /g/ /k/ Ifl M /s/ Izl Iml Ini ISI /tS/
lb/
Ipl
Id/
Itl
/g/
fkl
IV
M
32
0
0
0
0
0
1
29
0
32
0
0
0
0
1
0
0
0
33
0
0
0
0
0
0
0
0
33
0
0
1
0
1
0
0
0
33
0
0
0
0
1
0
0
0
33
0
0
0
0
0
0
0
0
30
0
Is/
Izl
Iml
Ini
/S/
/tS/
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0
0 0
0 0
0 0
0 0
0 0
0
0
0
0
0
28 5 0 0 0
1 32 0 0 0
0 0 33 0 0
0 0 0 33 0
0 0 0 0 33
0
0
0
0
0
0 0 0 0
0 0 33

Table 4-17. Consonant confusion matrix for female talker, recorded in the uterus at 105 dB SPL.
Response
Stimulus
Ibl
/p/
Idl
HI
Ikl
IV
M
/s/
Izl
Iml
Ini
IS/
/tS/
/b/
19
0
14
0
0
0
0
0
0
0
0
0
0
0
/p/
0
27
0
0
1
4
1
0
0
0
0
0
0
0
Idl
0
0
31
0
2
0
0
0
0
0
0
0
0
0
IM
0
0
0
33
0
0
0
0
0
0
0
0
0
0
/g/
0
0
0
0
33
0
0
0
0
0
0
0
0
0
/k/
0
0
0
0
0
33
0
0
0
0
0
0
0
0
lit
0
4
0
1
0
1
27
0
0
0
0
0
0
0
M
29
0
0
0
0
0
0
4
0
0
0
0
0
0
/s/
0
0
0
0
0
0
0
0
18
15
0
0
0
0
IzJ
0
0
0
0
0
0
0
0
0
33
0
0
0
0
Iml
0
0
0
0
0
0
0
0
0
0
30
3
0
0
Ini
0
0
0
0
0
0
0
0
0
0
0
33
0
0
IS/
0
0
0
0
0
0
0
0
1
2
0
0
29
1
/ts/
0
0
0
0
0
0
0
0
0
0
0
0
0
33
o

Table 4-18. Consonant confusion matrix for female talker, recorded in the uterus at 95 dB SPL.
Response
Stimulus
Ibl
/p/
Id/
M
/g/
M
Ifl
M
Is/
ItJ
/m/
/n/
/s/
/ts/
lb/
30
0
3
0
0
0
0
0
0
0
0
0
0
0
/p/
0
28
0
0
0
5
0
0
0
0
0
0
0
0
Id/
0
0
15
0
18
0
0
0
0
0
0
0
0
0
It/
0
0
0
33
0
0
0
0
0
0
0
0
0
0
/g/
0
0
0
0
33
0
0
0
0
0
0
0
0
0
Ik/
0
0
0
0
0
33
0
0
0
0
0
0
0
0
/{/
0
2
0
0
0
2
23
0
4
2
0
0
0
0
M
28
0
0
0
0
0
0
5
0
0
0
0
0
0
Is/
1
0
0
0
0
0
1
0
17
12
0
0
2
0
/zJ
0
0
3
0
5
0
0
4
1
20
0
0
0
0
/ml
0
0
0
0
0
0
0
0
0
0
33
0
0
0
/n/
0
0
0
0
0
0
1
0
0
0
1
31
0
0
/SI
0
0
0
0
0
0
0
0
0
3
0
0
30
0
Its/
0
0
0
0
0
0
0
0
0
0
0
0
0
33
o
Os

Table 4-19. Consonant confusion matrix for female talker, recorded from CM-ex útero at 105 dB SPL.
Stimulus
/b/
/p/
/d/
/t/
/&/
/k/
Ifl
M
Is/
Izl
Iml
/n/
/S/
/tS/
A)/ /p/ /d/
30 0 2
0 19 0
1 1 22
0 4 0
4 0 7
0 0 0
0 110
20 0 5
0 1 2
0 0 19
0 0 0
0 0 0
0 3 2
0 1 3
!M /g / /k/
1 0 0
6 0 8
0 9 0
22 0 6
0 22 0
3 0 30
4 0 1
0 8 0
6 2 18
0 12 0
0 0 0
0 0 0
112 3
15 0 7
Response
IV M
0 0
0 0
0 0
0 0
0 0
0 0
11 0
0 0
1 0
0 0
0 0
0 0
2 0
1 0
/s/
0
0
0
1
0
0
2
0
2
0
0
0
4
1
Izl Iml
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
1 0
2 0
0 33
0 0
4 0
0 0
/n/ IS/
0 0
0 0
0 0
0 0
0 0
0 0
0 3
0 0
0 0
0 0
0 0
33 0
0 1
0 0
Its/
0
0
0
0
0
0
1
0
0
0
0
0
1
5

Table 4-20. Consonant confusion matrix for female talker, recorded from CM-ex útero at 95 dB SPL.
Stimulus
Ibl
Ipl
Id/
N
/gI
Ik/
IV
M
Is/
Izl
Iml
Ini
IS/
ItS/
Response
Ibl Ipl Id/ It/ IgJ Ikl Ifl M Is/
22
0
0
0
0
0
0
16
0
0
11
0
2
0
0
6
0
5
9
1
11
0
19
0
0
5
2
0
4
0
22
0
6
5
0
2
1
22
0
14
1
0
0
16
0
6
0
26
7
0
6
0 0
0 0
0 0
0 2
0 0
7 0 8
0 0 0
0 0 0 0 0
0 0 0 0 0
1 6 4 16 1
3 4 0 3 0
0
0
0
0
0
0
1
0
IzJ Iml Ini IS/ /tS/
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 3
0 0 0 0 0
0 0 0 0 0
0 0 0 5 2
4 0 0 0 0
0 0 0 1 0
17 0 0 0 0
0 33 0 0 0
0 0 33 0 0
1 0 0 0 1
0 0 0 0 23
o
oo

Table 4-21. Consonant confusion matrix for female talker, recorded from CM-z'« útero at 105 dB SPL.
Response
Stimulus
/b/
/p/
Id/
hi
/g/
/k/
If/
M
Is/
Izl
Iml
Ini
IS/
AS/
/bl
16
0
12
0
5
0
0
0
0
0
0
0
0
0
/p/
1
17
0
3
1
8
3
0
0
0
0
0
0
0
/d/
0
0
20
0
13
0
0
0
0
0
0
0
0
0
N
0
5
0
19
0
9
0
0
0
0
0
0
0
0
1
0
13
0
19
0
0
0
0
0
0
0
0
0
/k/
0
7
0
11
0
10
4
0
0
0
0
0
0
1
Iff
0
9
0
1
1
5
11
0
2
0
0
0
3
1
M
11
0
0
1
21
0
0
0
0
0
0
0
0
0
/s/
0
6
0
0
1
6
11
0
2
2
0
0
5
0
IzJ
0
0
4
0
8
0
0
0
0
21
0
0
0
0
/m/
0
0
0
0
0
0
0
0
0
0
3
30
0
0
/n/
0
0
0
0
0
0
0
0
0
0
6
27
0
0
/s/
1
3
0
6
1
1
15
0
0
3
0
0
2
1
/ts/
0
8
0
3
0
0
2
0
0
0
0
0
5
15
o
SO

Table 4-22. Consonant confusion matrix for female talker, recorded from CM-m útero at 95 dB SPL.
Response
Stimulus Ibl /p/ /d/ /t/ /g/ /k/ /{/ M /s/ /z/ Iml M /S/ /tS/
/b/
/p/
18 0 0 0
0 15 0 0
7 1 0
0 11 6
6 0 0 1 0 0 0
0 1 0 0 0 0 0
/d/
/t/
0
19
16
0
/g/
/k/
/fr
/v/
/s/
/z/
/m/
/n/
/S/
/tS/
19
7
0
15
2 0 0 0 0
0 0 0 0 1
0 0
0 0
0 9 0
10 0 4
2 0 7 11 0
0 19 0 0 0
1
0
6 5 2 0 7 6
2 0 2
0 0 0
0 0 0
2 1 3
0 16 1
0 1 0
0 0 0
3 6 6
5 0 1
0 0 1
0 0 0
0 0 0
0 0 3
18 0 3
2 6 2 0
1
0 0 0 1 2
0 0 0 0 0
1 0 0 0 0
8 0 0 3 0
0 9 23 0 0
1 28 4 0 0
2 3 0 3 1
0 0 0 5 5

Ill
respectively. In constrast, for the male voice recorded at 105 dB SPL, correct
identifications of /S/ and /tS/ were 85% and 36% from CM ex ulero, and 12% and 0%
from CM in ulero, respectively, although both consonants were perfectly identified
(100%) in air and in the uterus conditions. For the female voice recorded at 105 dB SPL,
correct identification of /S/ and /tS/ were 3% and 15% from CM ex ulero, and 6% and
45% from CM in ulero, respectively, while /S/ was 88% identified, and /tS/ was 100%
identified both in air and in the uterus conditions. Further analyses of the consonant
feature transmission under different recording conditions were made using a special
computer program.
Because the features of voicing, manner, and place are strongly interdependent, the
sequential information analysis (SINFA), which sequentially identifies features with a high
proportion of transmitted information, was applied to partial out the effects of the features
on each other (Wang and Bilger, 1973; Wang, 1976). SINFA focuses on the transmitted
information associated with a given stimulus-response confusion matrix and identifies the
contributions of various phonological features to the transmitted information. The results of
SINFA are given in Table 4-23, which contains the percentage of contingent voicing,
manner, and place information received (bits received / bits sent) for each talker and
recording location for 105-dB and 95-dB stimuli. The SINFA results are graphically
displayed in Figure 4-5.
A number of points can be made from inspection of Figure 4-5. First, all three
features, voicing, manner and place, appeared to be well transmitted in recordings made in
air regardless of talker gender and stimulus levels. Second, voicing information received
from in the uterus recordings was slightly reduced, about 7%, for the female talker but not at

Table 4-23. Conditional percentage of voicing, manner, and place information received (of bits sent) for each talker, recording
location, and stimulus level condition for the nonsense syllables (VCV).
Condition
Location
Talker
Level (dB)
In Air
In Uterus
CM-ex útero
CM-in útero
Male
Female
Male
Female
Male
Female
Male
Female
105
95
105
95
105
95
105
95
105
95
105
95
105
95
105
95
Information
Voicing
97.9
96.4
90.2
88.5
98.0
100
82.7
81.8
90.1
93.7
78.0
79.5
80.2
69.8
84.0
52.8
Manner
100
98.7
87.5
86.5
84.4
97.2
82.8
79.1
67.7
57.7
35.7
46.9
58.8
33.4
45.3
28.5
97.8 96.7 91.7 97.5 82.0 90.1 82.6 73.9 72.4 58.3 42.4 31.2 26.7 26.8 13.3 20.0
Place

Figure 4-5. Conditional percentage of voicing, manner and place information received for a male (M) and a
female (F) talker; in air (A), in the uterus (U), from the fetal CM ex ulero (X), and from the fetal CM in ulero (I); at
105 dB (H) and 95 dB (L) SPL.

1 ¿ i r-J i ¿ x
2 2 Li. ll ^ 5 L-
< < < < 3 3 =3
CONDITION
SINFA
â–  Voicing
â–¡ Manner
£1 Place
í

115
all for the male talker across the stimulus levels. However, manner and place information
were reduced about 6-8% and 10-15%, respectively, for both male and female talkers when
recorded in the uterus and averaged across stimulus levels. Third, information about all
three features decreased from hydrophone recordings within the uterus to recordings from
fetal CM ex ulero, and to that from CM in ulero. However, voicing information appeared to
be better preserved than manner and place information for both male and female talkers.
Voicing information received from CM ex útero and CM in útero was ranged from 94% to
70% for the male talker, and from 84% to 53% for the female talker. Information about
manner and place was reduced markedly in CM ex Utero and CM in útero recordings,
especially for the female talker. For CM in útero recordings, manner information was
reduced less than place information. In all cases of feature information received from CM
recordings, there was a greater loss of each of the three features information for the female
speaker than for the male speaker, except for voicing information received from CM in
útero at 105 dB SPL.
In the previous study conducted by Griffiths et al. (1994), a panel of 102
untrained individuals judged the intelligibility of speech recorded in útero from a
pregnant sheep. The same VCV and CVC stimuli were used as the present study. An
analysis (SINFA) of the feature information from recordings inside and outside the uterus
showed that voicing information is better transmitted in ulero than place or manner
information. The current study confirmed the findings regarding voicing information
inside the uterus. Furthermore, the results of SINFA from the present study indicated that
voicing information was accurately perceived in the fetal inner ear (CM recordings) ex
útero and in ulero, and the male voicing information was better preserved than that of the

116
female. Maimer and place information were not received as well as voicing information
by the fetal inner ear; there were remarkable reductions in CM recordings, especially for
the female voice.
Miller and Nicely (1955) reported that low-pass filtering of speech signals
resulted in a greater loss of manner and place information than of voicing information.
They concluded that the higher frequency information in the speech signal is critical for
accurate identification of manner and place of articulation. Wang et al. (1978) had the
same conclusion on consonant feature recognition of low-pass filtering speech by using
SINFA.
The findings of both Griffiths et al. (1994) and the current study are consistent
with those of Miller and Nicely (1955) and Wang et al. (1978) in that transmission into
the uterus can be modeled as a low-pass filter. The poorer in ulero reception of place and
manner information is associated with the greater high-frequency attenuation. Moreover,
the spectral contents of external speech signals are further modified by the route of bone
conduction through the fetal skull to the inner ear (Gerhardt et al., 1996). For low
frequencies, 125 and 250 Hz, an airborne signal would be reduced by 10-20 dB to reach
the fetal inner ear in útero. For 500 through 2000 Hz, the signal would be reduced by 35-
45 dB (Gerhardt et al., 1992). Thus, the high-frequency components of speech would be
attenuated once again when transmitted through the skull into the fetal inner ear in ulero.
Manner and place information were lost to a great degree in the recordings from CM in
ulero, since high-frequency information was attenuated most after transmission from air
through the maternal abdomen, uterus, and fetal head to the fetal inner ear.

117
The results derived from SINFA support the hypotheses that transmission into the
uterus and fetal inner ear will be greater for voicing information than for manner and
place information. The results further support the hypotheses that the transmission of
voicing, manner, and place information will be better for males than for females when
recorded in the uterus and from the inner ear of the fetus in útero.
Voicing information from the male talker, which is carried by low-frequency
energy, was largely preserved inside the uterus and also in the fetal inner ear in útero.
The judges evaluated the male talker's voice equally well regardless of recording
location. Speech of the female talker carried less well into the uterus and into the fetal
inner ear in útero. The fundamental frequency of the female talker was about an octave
higher than that of the male talker. Thus, it is predictable that voicing information from
the male would carry better into the uterus, and into the fetal inner ear in útero than that
from the female.
Acoustic Analyses of Vowel Transmission
Figure 4-6 A-H includes sample spectrographs displaying one stimulus item
recorded in eight conditions: the male and female talkers recorded in air, in the uterus,
from CM ex útero and from CM in útero at 105 dB SPL. The phrase spoken in each of
the eight spectrograms is “Mark the word lash.” The amplitudes of each recording were
adjusted to the same relative voltage level on the spectrographic analysis. The contrast
between voiced and voiceless portions of the phrase is apparent to some degree in all
eight spectrograms. The high-frequency noise associated with the release of the fricative,

Figure 4-6. Spectrographic recordings of “Mark the word lash” spoken by: A. the male talker recorded in air;
B. the female talker recorded in air; C. the male talker recorded in the uterus; D. the female talker recorded in the
uterus; E. the male talker recorded from the fetal CM ex útero; F. the female talker recorded from the fetal CM ex
útero; G. the male talker recorded from the fetal CM in útero; H. the female talker recorded from the fetal CM in útero.

Fre«t •
Figure 4-6 A.

Figure 4-6 B. Continued.

Freq. Figure 4-6 C. Continued.

Figure 4-6 D. Continued.

Figure 4-6 E. Continued.

Freq.CHz >
Figure 4-6 F. Continued.

Figure 4-6 G. Continued.

Figure 4-6 H. Continued.

127
IS/, is undetectable in the CM in ulero spectrograms for both talkers, consistent with the
low-pass filtering of the maternal tissues, fluids, and fetal skull.
Acoustic measurements for the CVC words containing one of the five vowels (/i/,
/I/, /a/, /as/, /A/) were performed. For each of the vowels /i/, /I/, /as/, and /A/, five CVC
words were selected for spectral analyses. For the vowel lei, four CVC words were
analyzed. The means of the fundamental frequency (Fo) and the first three formant
frequencies (Fi, F2, and F3) of the male and female speakers averaged across each of the five
vowels are presented in Table 4-24. For the purpose of comparison, Table 4-24 also
includes the values obtained from two large studies of vowel formant frequencies, a classic
paper by Peterson and Barney (1952) and a recent replication by Hillenbrand et al. (1995).
There were clear similarities in the present data to the data from Peterson and Barney
(1952), and from Hillenbrand et al. (1995).
To evaluate the characteristics of vowel transmission under different recording
conditions, the relative intensity levels of Fo, Fi, F2, and F3 were calculated by subtracting
the background noise level from the peak amplitudes of Fo, Fi, F2, and F3 for both the male
and female speakers across the five vowels. Table 4-25 contains the means and standard
deviations of relative intensity levels of Fo, Fi, F2, and F3 for vowel lil produced by the male
and female talkers under different recording conditions. These data are also displayed in
Figure 4-7. Vowel lil has a low F1 frequency (345 Hz for the male speaker and 353 Hz for
female) and a high F2 frequency (2490 Hz for male and 2841 Hz for female), as well as a
high F3 frequency (3590 Hz for male and 3337 FIz for female). From an inspection of
Figure 4-7, a general transmission pattern for vowel III can be drawn. In the air recording
condition, Fo, Fi, F2, and F3 were well identified for both male and female talkers. For the

128
Table 4-24. Average fundamental frequencies (Fo) and first three formant
frequencies (Fi, F2, F3) for five vowels produced by each talker and recorded in air. The
second row includes the value from Peterson and Barney (1952). The third row is from
Hillenbrand et al. (1995).
III
m
/e/
/as/
IAI
Fo
Male
136
123
128
113
118
(1952)
136
135
130
127
130
(1995)
138
135
127
123
133
Female
242
224
220
217
221
(1952)
275
232
223
210
221
(1995)
270
224
214
215
218
F,
Male
345
397
584
666
622
(1952)
270
390
530
660
640
(1995)
342
427
580
588
623
Female
353
442
650
1069
670
(1952)
310
430
610
860
760
(1995)
437
483
731
669
753
F2
Male
2490
2076
1831
1676
1242
(1952)
2290
1990
1840
1720
1190
(1995)
2322
2034
1799
1952
1200
Female
2841
2376
1975
1926
1278
(1952)
2790
2480
2330
2050
1400
(1995)
2761
2365
2058
2349
1426
f3
Male
3597
2690
2766
2567
2696
(1952)
3010
2550
2480
2410
2390
(1995)
3000
2684
2605
2601
2550
Female
3337
2889
2845
2904
2789
(1952)
3310
3070
2990
2850
2780
(1995)
3372
3053
2979
2972
2933

129
Table 4-25. Mean and standard deviation (S.D.) of relative intensity levels (dB)
of fundamental frequency (Fo) and first three formant frequencies (Fi, F2, F3) for vowel I'll
produced by each talker at different recording locations in the 105 dB condition.
Male 1
Condition
alker, III
In Air
In Uterus
CM-ex útero
CM-m útero
Fo
Mean
48.12
39.51
5.70
16.00
S.D.
1.69
7.40
3.40
5.51
Fi
Mean
41.38
29.30
19.78
10.68
S.D.
5.32
9.95
7.24
3.97
f2
Mean
30.50
9.50
1.20
1.54
S.D.
4.92
7.93
3.20
4.04
f3
Mean
19.20
2.52
1.70
0.02
S.D.
2.20
8.75
1.94
3.13
Female talker, III
Fo
Mean
46.82
48.64
20.98
22.60
S.D.
6.72
3.51
4.88
3.32
Fi
Mean
20.32
12.36
3.76
-0.40
S.D.
7.80
3.09
2.69
3.12
f2
Mean
39.92
13.72
3.00
1.08
S.D.
5.96
4.38
3.70
1.76
f3
Mean
30.54
12.28
-2.52
-2.94
S.D.
3.13
3.91
4.02
5.43

Figure 4-7. Mean of intensity levels (dB relative) of fundamental frequency (Fo)
and first three formant frequencies (Fi, F2, and F3) for vowel III produced by both talkers
recorded at different locations at 105 dB SPL. Bars equal one standard deviation. Male
talker results - upper panel; female talker results - lower panel.

dB (Relative) dB (Relative)
131
FORMANT
-10
FORMANT

132
female, the intensity levels of F2 and F3 were 10 dB higher than that of male. However, Fi
of the male talker was 20 dB greater than that of the female.
Now, considering the levels in the uterus, Fo, Fi, F2, and F3 were well represented for
both talkers, with the exception that F3 for the male talker was only about 3 dB above noise
floor. The drop in levels as a function of formant frequency is predicted based upon
transmission loss at higher frequencies.
From CM ex ulero and in Utero recordings, Fo and F1 for male and Fo only for
female were preserved, F2 and F3 (Fi also for female) merged in the background noise. It
was also noted that the intensity level of Fo from CM in ulero was greater than that from
CM ex útero for both talkers, especially for the male talker. The explanation is that low-
frequency signals, less than 250 Hz (Fo were 136 Hz for the male talker and 242 Hz for
female), would be enhanced when transmitted into the uterus (Vince et al., 1982; Gerhardt,
Abrams and Oliver, 1990). Similar enhancement of Fo in the recordings from CM in útero
was noted in other vowel measurements. Additionally, for the male talker the intensity
levels of Fo were lower than female in the CM recordings, although Fo was equal intense in
air. The CM measured by using a single round window electrode can not accurately record
cochlear responses to the low-frequency input signals. Because the male Fo was one octave
lower than female, it is understandable that the male Fo would be less detected than female
by round window electrode. Less intense male Fo in CM recordings was noted in all five
vowels. Thus, /i/ could be easily recognized in the uterus recordings for both talkers;
however, its identification might not be made from CM ex útero and in útero recordings for
the male talker because F2 was not perceived, and definitely not for the female talker
because both F1 and F2 were not perceived.

133
Two separate, two-factor repeated measures ANOVA were applied to the data
derived from vowel /i/ according to the talker gender. For the male talker, the results
indicated significant interaction between formant (Fo, Fi, F2, and F3) and recording location
(F9 36 = 7.334, p < 0.0001), main effects for formant (F3,12 = 43.543, p < 0.0001) and
location (F3,12 = 203.061, p < 0.0001). The post hoc multiple comparison test (Newman-
Keuls) indicated that the intensity levels of Fo, Fi, F2 and F3 measured in air condition were
significantly greater (p < 0.01) than those recorded in the uterus, from CM ex útero, and
from CM in útero, except that of Fo measured in the uterus (p > 0.05). In the uterus
condition, the intensity levels of Fo and Fi were greater (p < 0.01; for Fi from CM ex útero p
< 0.05) than that from CM ex útero and from CM in útero, but not F2 and F3 (p > 0.05). In
the CM conditions, only Fo from CM ex útero was significantly different (p < 0.05) from
CM in útero-, there were no difference (p > 0.05) for the first three formant frequencies.
For the female talker, the results indicated significant interaction between formant
(Fo. Fi, F2 and F3) and recording location (Fg,36 = 13.49, p < 0.0001), main effects for
formant (F3,12 = 87.767, p < 0.0001) and location (F3,12 = 117.211, p < 0.0001). The post
hoc multiple comparison test (Newman-Keuls) indicated that the intensity levels of Fo, Fi,
F2, and F3 measured in air condition were significantly greater (p < 0.01) than those
recorded in the uterus, from CM ex útero, and from CM in útero, except that of F(J measured
in the uterus (p > 0.05). In the uterus recording condition, the intensity levels of Fo, F|, F2,
and F3 were greater (p < 0.01) than that from CM ex útero and from CM in útero.
Comparing conditions of CM ex útero and CM in útero, there were no difference (p > 0.05)
for the intensity levels of the fundamental frequency and the first three formant frequencies.

134
The explanation for the lack of significant differences is because most levels for F2 and F3
were indistinguishable from the noise floor.
Table 4-26 contains the means and standard deviations of relative intensity levels of
Fo, Fi, F2, and F3 recorded in different locations for the vowel HJ produced by the male and
female talkers. The data are also displayed in Figure 4-8. Vowel /I/, similar to vowel /i/,
has a low F1 frequency (397 Hz for the male speaker and 442 Hz for female) and a high F2
frequency (2076 Hz for male and 2376 Hz for female), as well as a high F3 frequency (2690
Hz for male and 2889 Hz for female), fairly close to F2 frequency. The results from spectral
analyses and statistical analyses (ANOVA) were quite similar to that for vowel /i/. In the
uterus, Fo, Fi, F2, and F3 were also well received for both talkers. From CM ex útero and in
útero recordings, F0 and F1 for both talkers were preserved, but F2 and F3 were less than 5
dB above the background noise. Therefore, /I/, like ill, could be easily identified in the
uterus recordings for both talkers, however, its identification might not be made from CM ex
útero and in útero recordings for both talkers, because F2 was not well perceived.
Table 4-27 contains the means and standard deviations of relative intensity levels of
Fo, F|, F2, and F3 recorded in different locations for the vowel /e/ produced by the male and
female talkers. The data are also displayed in Figure 4-9. In contrast to vowels III and III,
vowel /e/ has a high F1 frequency (584 Hz for the male speaker and 650 Hz for female) and
a relative low F2 frequency (1831 Hz for male and 1975 Hz for female), as well as a high F3
frequency (2766 Hz for male and 2845 Hz for female). From an inspection of Figure 4-9, a
general characteristic of transmission for the vowel lei can be derived. In the air recording
condition, Fo, Fi, F2, and F3 were well identified for both male and female talkers, and for
the female the intensity levels of F2 and F3 were about 10 dB and 5 dB higher than that of

135
Table 4-26. Mean and standard deviation (S.D.) of relative intensity levels (dB)
of fundamental frequency (F0) and first three formant frequencies (Fi, F2, F3) for vowel
/!/ produced by each talker at different recording locations in the 105 dB condition.
Male1
Condition
talker, /I/
In Air
In Uterus
CM-ex útero
CM-in útero
Fo
Mean
51.64
45.50
6.18
11.04
S.D.
5.29
5.62
3.04
2.51
F,
Mean
53.28
48.96
33.12
22.82
S.D.
5.54
8.04
4.32
8.42
f2
Mean
36.90
19.40
0.48
1.66
S.D.
6.93
9.77
2.71
3.51
f3
Mean
39.34
10.80
3.68
3.96
S.D.
3.90
10.60
9.06
2.15
Female talker, III
Fo
Mean
44.64
39.88
18.10
20.30
S.D.
4.23
4.21
3.09
5.50
F,
Mean
50.48
51.44
29.18
26.76
S.D.
8.49
2.85
9.17
5.48
f2
Mean
37.76
21.62
3.08
1.22
S.D.
9.87
4.98
4.86
4.41
f3
Mean
34.40
11.74
2.58
-0.82
S.D.
9.29
8.35
1.96
4.59

Figure 4-8. Mean of intensity levels (dB relative) of fundamental frequency (Fo)
and first three formant frequencies (F|, F2, and F3) for vowel 11/ produced by both talkers
recorded at different locations at 105 dB SPL. Bars equal one standard deviation. Male
talker results - upper panel; female talker results - lower panel.

dB (Relative) dB (Relative)
137
FORMANT
60
50
40
30
20
10
0
-10
FORMANT

138
Table 4-27. Mean and standard deviation (S.D.) of relative intensity levels (dB)
of fundamental frequency (Fo) and first three formant frequencies (Fi, F2, F3) for vowel
/e/ produced by each talker at different recording locations in the 105 dB condition.
Male 1
Condition
talker, /e/
In Air
In Uterus
CM-ex útero
CM-/n útero
Fo
Mean
50.53
44.60
8.98
16.65
S.D.
4.24
4.04
5.62
4.33
F,
Mean
51.10
40.28
28.15
17.08
S.D.
5.10
4.18
7.60
5.82
f2
Mean
37.58
23.40
5.83
1.15
S.D.
6.56
3.24
4.89
3.47
f3
Mean
32.48
9.38
-0.95
-3.23
S.D.
4.46
2.70
3.11
2.41
Female talker, /e/
Fo
Mean
43.25
37.98
14.85
18.40
S.D.
3.83
5.73
2.28
5.16
F,
Mean
49.15
43.83
19.58
25.55
S.D.
4.52
1.96
8.59
4.05
f2
Mean
45.18
35.80
15.55
5.83
S.D.
6.41
5.74
4.71
1.15
f3
Mean
38.20
15.90
1.90
-0.85
S.D.
8.14
5.50
4.12
3.49

Figure 4-9. Mean of intensity levels (dB relative) of fundamental frequency (Fo)
and first three formant frequencies (Fi, F2, and F3) for vowel IE/ (=/e/) produced by both
talkers recorded at different locations at 105 dB SPL. Bars equal one standard deviation.
Male talker results - upper panel; female talker results - lower panel.

dB (Relative) dB (Relative)
140
60
50
40
30
20
10
0
-10
FORMANT
FORMANT

141
the male, respectively. The female talker’s higher intensity levels of F2 and F3 than the male
in air resulted in higher levels of F2 and F3 measured in the uterus and fetal inner ear. In the
uterus, Fo, Fi, F2, and F3 were also well received for both talkers. From CM ex útero
recordings, Fo, Fi, and F2 for both talkers were transmitted into the fetal inner ear, but F3
merged in the background noise. From CM in útero recordings, F0, F,, and F2 were
preserved for the female talker, but only Fo and F1 were received for the male talker, since F2
was close to the level of background noise. Thus, le/ could be easily identified in the uterus
recordings for both talkers, and could be recognized from CM ex útero because F2 was well
perceived for both talkers. However, its identification might be made from CM in útero
recordings for the female talker, but might not be for the male because F2 was not well
perceived in the fetal inner ear in útero.
Two separate, two-factor repeated measures ANOVA were applied to the data for
the vowel /e/ for both the male and female talker. For the male talker, the results indicated
significant interaction between formant (Fo, Fi, F2, and F3) and recording location (F9i27 =
6.612, p < 0.0001), main effects for formant (F3>9 = 68.103, p < 0.0001) and location (F3>9 =
163.051, p < 0.0001). The post hoc multiple comparison test (Newman-Keuls) showed that
the intensity levels of Fo, Fi, F2, and F3 measured in air condition were significantly greater
(p < 0.01) than those recorded in the uterus, from CM ex útero, and from CM in útero,
except that of Fo measured in the uterus (p > 0.05). In the uterus condition, the intensity
levels of Fo, Fi, F2, and F3 were greater (p < 0.01, p < 0.05 for F3 CM ex Utero) than that
from CM ex útero and from CM in útero. In the CM conditions, only F0 (p < 0.05) and Fi
(p < 0.01) from CM ex útero were significantly different from CM in útero.

142
For the female talker, the results indicated significant interaction between formant
(Fo, Fi, F2, and F3) and recording location (F9,27 = 6.693, p < 0.0001), main effects for
formant ^9 = 24.298, p = 0.0001) and location (F3,9 = 136.027, p <0.0001). The post hoc
multiple comparison test (Newman-Keuls) indicated that the intensity levels of Fo, Fi, F2,
and F3 measured in air condition were significantly greater (p < 0.01, p < 0.05 for F2 in the
uterus) than those recorded in the uterus, from CM ex ulero and from CM in útero, but not
that of Fo and F1 measured in the uterus (p > 0.05). In the uterus recording condition, the
intensity levels of Fo, F|, F2, and F3 were greater (p < 0.01) than that from CM ex útero and
from CM in útero. Between the conditions of CM ex útero and CM in útero, only Fi (p <
0.05) and F2 (p < 0.01) from CM ex útero were significantly different from CM in útero.
Table 4-28 contains the means and standard deviations of relative intensity levels of
Fo, Fi, F2, and F3 recorded in different locations for the vowel /as/ produced by the male and
female talkers. The data are also graphically displayed in Figure 4-10. For the vowel /A/,
the data are displayed in Table 4-31 and Figure 4-11. Similar to the vowel /e/, vowels /as/
and /A/ have high F1 frequencies, low F2 frequencies (< 2000 Hz), and high F3 frequencies.
The spectral analyses and statistical analyses (ANOVA) clearly showed the similarities of
characteristics of transmission into the uterus and into the fetal inner ear in Utero among the
vowels IeI, /as/, and /A/. For both vowel /as/ and /A/, in the uterus recordings, Fo, Fi, F2, and
F3 were well received for both talkers. From CM ex útero recordings, Fo, Fi, and F2 for both
talkers were transmitted into the fetal inner ear, but F3 was close to the level of background
noise. From CM in útero recordings, Fo, Fi, and F2 of the vowel /as/ were preserved for the
female talker, but only Fo and F1 were received for the male talker, since F2 was close to the
level of background noise. For the vowel/A/, Fo, Fi, and F2 were preserved for both talkers,

143
Table 4-28. Mean and standard deviation (S.D.) of relative intensity levels (dB)
of fundamental frequency (Fo) and first three formant frequencies (Fi, F2, F3) for vowel
Ieel produced by each talker at different recording locations in the 105 dB condition.
Male 1
Condition
talker, /as/
In Air
In Uterus
CM-ex útero
CM-in útero
Fo
Mean
47.26
38.70
4.90
7.24
S.D.
2.51
4.92
8.16
6.09
F,
Mean
48.26
37.64
21.62
13.98
S.D.
6.45
5.52
10.05
8.43
f2
Mean
43.04
25.26
11.94
0.12
S.D.
2.62
3.61
2.98
5.84
f3
Mean
33.52
6.72
0.90
-0.34
S.D.
5.65
4.99
3.95
2.10
Female talker, /as/
Fo
Mean
42.78
33.40
11.68
17.96
S.D.
3.56
3.65
1.99
1.62
Fi
Mean
48.94
38.92
22.50
17.84
S.D.
4.82
6.79
4.84
4.75
f2
Mean
48.70
33.88
15.30
5.56
S.D.
4.74
6.07
7.04
0.99
f3
Mean
41.14
14.50
2.86
-3.26
S.D.
1.67
6.48
4.23
1.53

Figure 4-10. Mean of intensity levels (dB relative) of fundamental frequency (Fo)
and first three formant frequencies (Fi, F2, and F3) for vowel /ae/ produced by both talkers
recorded at different locations at 105 dB SPL. Bars equal one standard deviation. Male
talker results - upper panel; female talker results - lower panel.

dB (Relative) dB (Relative)
145
60
50
40
30
20
10
0
-10
FORMANT
60
50
40
30
20
10
0
-10
FORMANT

146
Table 4-29. Mean and standard deviation (S.D.) of relative intensity levels (dB)
of fundamental frequency (Fo) and first three formant frequencies (Ft, F2, F3) for vowel
/A/ produced by each talker at different recording locations in the 105 dB condition.
Male 1
Condition
talker, /A/
In Air
In Uterus
CM-ex útero
CM-in Utero
Fo
Mean
45.90
41.12
8.48
14.18
S.D.
3.29
4.65
4.24
2.91
Ft
Mean
53.08
37.08
22.30
12.08
S.D.
1.21
3.46
6.33
8.89
f2
Mean
46.90
35.80
16.02
4.04
S.D.
3.92
1.45
2.14
4.85
f3
Mean
27.14
4.02
-1.24
-1.30
S.D.
3.55
5.54
3.58
2.97
Female talker, /A/
Fo
Mean
44.22
37.44
13.24
17.00
S.D.
2.67
6.10
5.39
4.64
Ft
Mean
49.80
41.44
20.98
20.40
S.D.
7.76
5.77
7.67
4.44
f2
Mean
46.96
40.22
20.56
3.20
S.D.
5.04
6.01
5.12
4.56
f3
Mean
31.10
8.18
-0.08
0.90
S.D.
2.98
6.94
3.95
5.31

Figure 4-11. Mean of intensity levels (dB relative) of fundamental frequency (Fo)
and first three formant frequencies (Fj, F2, and F3) for vowel /A/ (=/A/) produced by both
talkers recorded at different locations at 105 dB SPL. Bars equal one standard deviation.
Male talker results - upper panel; female talker results - lower panel.

dB (Relative) dB (Relative)
148
FORMANT
FORMANT

149
but F2 was only 5 dB above the level of background noise in the CM in útero recording
condition. Thus, lie/ and /A/ could be well identified in the uterus recordings for both
talkers, and also could be recognized from CM ex útero because F2 was well perceived (10-
20 dB above the noise floor) for both talkers. Furthermore, the identification of the vowels
/as/ and /A/ might be made from CM in útero recordings for both talkers, since F2 was still 5
dB above background noise, except of the vowel /as/ by the male talker, and should be
perceived in the fetal inner ear in útero. Table 4-30 provides a summary of information
presented above regarding the characteristics of the five vowels.
The results from the spectrum analyses of vowels support the hypotheses that
acoustic energy in the second and third formants measured in air for both male and female
talkers will be reduced when recorded in the uterus, and will be reduced to the noise floor
when recorded from fetal inner ear in Utero.
The transmission of vowels into the uterus and into the fetal inner ear in útero
follows the same pattern of low-pass filter characteristics as external sounds transmitted
inside the uterus and to the fetal inner ear in útero. Low-frequency sounds penetrate the
maternal tissues and fluids, and the fetal head more effectively than high frequencies
(Gerhardt, Abrams and Oliver, 1990; Gerhardt et al., 1992). From air through the maternal
tissues and fluids into the uterus, sounds are attenuated by 5-10 dB in the low-frequency
range (< 1000 Hz) and 20-30 dB for higher frequencies (> 1000 Hz). To reach the fetal
inner ear, the spectral contents of airborne sounds are further modified by the bone
conduction route through the fetal head. For low frequencies from 125 to 250 Hz, airborne
sounds would be reduced by 10-20 dB to reach the fetal inner ear. For frequencies from
500 to 2000 Hz, sounds would be reduced by 35-45 dB. In general, low-frequency

Table 4-30. Summary of acoustic analyses of vowels
Articulation
Formant Frequency
Stimulus Present at F2
Vowel
Tongue Position
Fi
f2
In Uterus
CM in útero
N
Front
High
Low
High
Yes
No
ill
Front
High
Low
High
Yes
No
/s/
Front
Low
High
Low
Yes
Yes
/as/
Front
Low
High
Low
Yes
Yes
/A/
Central
Low
High
Low
Yes
Yes
Note: Decisions about if the stimulus was present at F2 (> 5 dB) were made from inspection of Figures 4-7 through 4-11.
<-n
o

151
components of external sounds are well perceived at the level of fetal inner ear, while high-
frequency components are reduced to a great degree before reaching the fetal inner ear.
The data from the current study clearly showed that the fundamental frequency (Fo)
and the first three formants (Fi, F2, and F3) of all five vowels were well preserved in the
uterus recordings for both the male and female talkers. These results are consistent with the
high intelligibility scores obtained in this study. Querleu et al. (1988b) also found that F2
had critical effect on the recognition of French vowels recorded within the uterus.
The acoustic cues necessary for the perception of vowels lie in the patterns of
formants. The first two lowest frequency formants are usually required to identify the
vowels. Generally, two formants are required for front vowels, which have a high F2
frequency (/i/, /I/, /s/, and /as/; /A/ is a central vowel). A single formant can be used to
approximate the back vowels, which have a low F2 frequency (/u/, /U/, /o/, /O/, and /a/). F3
is more important for front vowels than for back vowels. Flowever, the steady-state formant
frequency patterns are not the only factors determining listener identification of vowels. For
example, men, women, and children produce the same vowel with different formant
frequencies. In this case, listeners must use general patterns for formant relationships rather
than exact frequencies or even an exact ratio of frequencies. In addition, listeners also have
to use contextual cues for vowel identification in those speakers who use a fast rate of
speech (Borden and Harris, 1984).
In the present study, the spectral analyses of vowels from the CM recordings
indicated that fundamental frequency (Fo) and low-frequency formants, F1 and F2 (< 2000
Hz) were well preserved in the fetal inner ear in ulero. For vowels III and d/ that have high
frequency second formants (> 2000 Hz), only Fo and F1 were perceived in the recordings

152
from CM in ulero. Whereas for vowels lei, /as/, and /A/ that have low frequency second
formants (< 2000 Hz), Fo, Fi, and F2 were all perceived in the recordings from CM in útero.
Thus, vowels {/el, /as/, and /Af) with low frequency second formants (< 2000 Hz) might be
easily identified from CM in útero recordings. Because F3 of all five vowels were higher
than 2000 Hz (F3 of lil is even above 3000 Hz), the third formants were not preserved in the
fetal inner ear in Utero. The identification of vowels in the recordings from CM in útero for
both male and female speakers might be easy because they are voiced, relative high in
intensity, and have prominent formant frequencies.

CHAPTER 5
SUMMARY AND CONCLUSIONS
This study had two distinct components. The first involved recording speech
produced through a loudspeaker with an air microphone, a hydrophone placed In the
uterus of a pregnant sheep, and an electrode surgically secured to the round window of
the fetus ex útero and in útero (cochlear microphonic, CM). The speech stimuli consisted
of two separate lists, Vowel-Consonant-Vowel (VCV) nonsense syllables and Consonant-
Vowel- Consonant (CVC) monosyllable words spoken by a male and a female talker.
They were presented at two airborne intensity levels, 105 and 95 dB SPL. Perceptual
audio CDs were constructed from one recording with the best quality sound.
The second portion of the study involved playing the recordings to a group of
normal hearing adults (N=139) over earphones. The intelligibility of speech was
evaluated from the judges’ responses to the speech stimuli under 16 different recording
conditions.
The speech (VCV nonsense syllables and CVC words) intelligibility scores as a
function of recording location alone, decreased from the air to the uterus locations and
further decreased from the CM ex útero to the CM in útero conditions. Intelligibility was
significantly higher for the recordings in air than in the uterus, and significantly higher
for the recordings from CM ex útero than from CM in útero. In addition, the
intelligibility scores of the male voice were significantly higher than that of the female
153

154
voice across all four recording locations for VCV nonsense syllables, but not for CVC
words. The results also showed stimulus level effect on the intelligibility. Overall, when
the mean intelligibility scores were averaged across two stimulus levels (105 and 95 dB
SPL) and stimulus types (VCV and CVC stimuli), they were 91.2% and 84.7% for the
male and female voices recorded within the uterus, respectively. Whereas, the mean
intelligibility scores recorded from CM in ulero, averaged across two levels and stimulus
types for the male and female voices, were 45.0% and 41.6%, respectively. The
recordings within the uterus reflect the speech energies present in the amniotic fluid,
whereas the recordings from CM in ulero represent the actual fetal physiological
responses of the auditory periphery to externally generated speech.
Previous studies on the transmission of sound pressure into the maternal abdomen
and uterus have shown consistent low-pass filter characteristics for external sound at the
fetal head (Vince et al., 1982; Querleu et ah, 1988a; Gerhardt, Abrams and Oliver, 1990;
Richards et al., 1992; Peters et al., 1993a, 1993b). For frequencies less than 250 Hz,
external sound passes through the uterus to the fetus with little reduction in sound
pressure, and in some instances the pressure is greater within the uterus than it is outside
the abdomen. Above 250 Hz, sound pressure attenuation occurs at a rate of
approximately 6 dB per octave and reaches about 20 dB for 4000 Hz (Gerhardt, Abrams
and Oliver, 1990). Thus, external speech signals would be shaped by the tissues and
fluids of pregnancy before reaching the fetal head. Moreover, sound transmission
properties through the fetal head to the inner ear by bone conduction further modified the
stimulus (Gerhardt et al., 1992; Gerhardt et al., 1996). This influence coupled to the
attenuation of sound pressures provided by the tissues and fluids of pregnancy result in

155
some isolation of the fetus from external sounds. Fetal sheep probably detect low-
frequency sound produced outside its mother with a loss of 10 to 20 dB for 125 and 250
Hz, respectively. For frequencies from 500 to 2000 Hz, the fetus is isolated by 35-45 dB
(Gerhardt et al., 1992). Therefore, the recordings of external speech from CM in útero
would be degraded to a greater degree for the high-frequency components of speech
rather than the low-frequency components. Intelligibility would be expected to follow.
The present findings showed much better intelligibility of speech recorded within
the uterus than previously found (Querleu et al., 1988b; Griffiths et al., 1994). Querleu et
al. (1988b) found that about 30% of 3120 French phonemes recorded within the uterus of
pregnant women were recognized. Griffiths et al. (1994) showed the intelligibility of
speech stimuli recorded within the uterus of a pregnant sheep, was 55% and 34% for the
male and female talkers, respectively. However, from the current study the intelligibility
was 91.2% and 84.7% for the male and female voices recorded in the uterus, respectively.
The discrepancy might be accounted for by the higher stimulus levels and the use of
earphones.
Consonant feature transmission was analyzed using SINFA. The results
confirmed the findings that voicing information is well retained inside the uterus
(Griffiths et al., 1994). Furthermore, the present study demonstrated that voicing
information is also accurately represented in the fetal inner ear (CM recordings) in útero.
Manner and place information were not maintained as well as voicing information at the
fetal inner ear. These results are consistent with those of Miller and Nicely (1955), and
Wang et al. (1978), in which low-pass filtering of speech signals resulted in a greater loss
of manner and place information than of voicing information. They concluded that the

156
higher frequency information in the speech signal is critical for accurate identification of
manner and place of articulation. Voicing information was well preserved in the fetal
inner ear in ulero after low-pass filtering by the tissues and fluids associated with
pregnancy, and the fetal skull. However, manner and place information, high-frequency
components of speech, were lost in the transmission to the fetal inner ear in útero,
especially for the female voice.
In the present study, the results of spectral analyses of vowels clearly showed that
the fundamental frequency (Fo) and the first three formants (Fi, F2, and F3) of all five vowels
(/i/, /I/, lei, /s/, /A/) were well preserved in the uterus recordings for both the male and
female talkers. They were also reflected in the results of high intelligibility scores obtained
in this study. Querleu et al. (1988b) noted that F2 had a critical effect on the recognition
of French vowels recorded within the uterus.
It is well known that the acoustic cues necessary for the identification of vowels lie
in the patterns of the formants. The first two lowest frequency formants (F1 and F2) are
usually required to identity the vowels. Generally, two formants are required for front
vowels which have a high F2 frequency (/i/, ÍU, lei, and /ael; IAJ is a central vowel), a single
formant (Fi) can be used to approximate the back vowels which have a low F2 frequency
(/u/, IV/, lo/, IOI, and /a/). F3 is more important for front vowels than for back vowels
(Borden and Harris, 1984).
The data from the CM recordings indicated that fundamental frequency (Fo) and
low-frequency formants, Fi and F2 (< 2000 Hz) were well represented in the fetal inner ear
in útero. For vowels /i/ and ill that have high-frequency F2 (> 2000 Hz), only Fo and F1
were perceived in recordings from CM in útero; whereas for vowels lei, /as/, and IAI that

157
have low-frequency F2 (< 2000 Hz), Fo, Fi, and F2 were all perceived in recording from CM
in ulero. Thus, vowels (/s/, /as/, and /A/) with low-frequency F2 (< 2000 Hz) might be easy
identified from CM in útero recordings. Because F3 of all five vowels were higher than
2000 Hz (F3 of /i/ is even above 3000 Hz), F3 were not preserved in the fetal inner in útero.
This study demonstrated that externally generated speech signals could reach the
fetal inner ear in útero. The most relevant features of the speech signal for purposes of
identification are received by the low-frequency content of the signal. Consistent with
the low-pass filtering, by maternal tissues and fluids and fetal skull, of external generated
sounds, voicing information is received by the fetal inner ear in Utero, while speech
energy conveying manner and place information is attenuated and less detected at the
fetal inner ear. Male and female talker intelligibility scores averaged 45% and 42%,
respectively, when recorded from the fetal CM in útero. They represent the speech
energies received by the fetal inner ear in útero, which are underestimated by using round
window electrode placements.
The implications of this research relate to theories regarding the prenatal
functional development of auditory pathways and to the foundations for the later
acquisition of speech and language (Cooper and Aslin, 1989; Querleu et al., 1989; Ruben,
1992; Abrams, Gerhardt and Antonelli, 1998). It has been postulated that prenatal
sensory and learning experiences help to organize higher cortical function and provide
the foundation for future learning abilities (Fifer and Moon, 1988; Hepper, 1992;
Smotherman and Robinson, 1995). When discussing the concept of innate abilities, one
should take into account the fact that a neonate is not without experience with speech
stimuli.

APPENDIX A
SUBJECT RESPONSE SHEET
VCV Nonsense Syllables
1.
/a_b_a/
2.
/apa/
3.
/a d al
4.
/a_t_a/
5.
/a g a/
6.
/a_k_a/
7.
lafjal
8.
la\_al
9.
/a_s_a/
10.
/a_za/
11.
lam a!
12.
/a_n_a/
13.
laSaJ
14.
/atS a/
CVC Words
1.
bass
2.
loss
3.
wick
4.
duff
batch
laws
with
duth
badge
lodge
wit
dumb
bat
log
wig
dove
bash
long
witch
dub
back
lob
will
dug
5.
cup
6.
dim
7.
dung
8.
fit
cub
did
duv
fib
cud
dill
dug
fig
come
dip
dud
fill
cuff
dig
dun
fin
cut
din
dub
fizz
9.
leash
10.
toss
11.
lag
12.
man
leave
talks
lash
mat
liege
tall
lath
mad
leach
tog
lack
mack
lead
tong
lass
mass
leap
taj
laugh
math
158

159
13.
17.
21.
25.
29.
33.
base
14.
pan
15.
peach
16.
pitch
bays
pass
peas
pip
bayed
pack
peal
pig
beige
path
peat
pick
bake
pad
peak
pill
bathe
pat
peace
pit
pus
18.
has
19.
weave
20.
sash
putt
hag
wean
sack
puff
have
week
sad
puck
half
weed
sap
EME
hath
we're
sag
pub
hash
weal
sat
sheath
22.
sin
23.
sud
24.
tam
sheave
sill
sup
tag
sheaf
sip
sub
tap
sheik
sick
sum
tang
sheathe
sing
sun
tan
sheen
sit
sung
tab
tear
26.
red
27.
sold
28.
wig
teeth
wed
hold
rig
teethe
dead
cold
gig
teel
led
told
big
tease
shed
gold
Pig
team
fed
mold
dig
thick
30.
tin
31.
mark
32.
tale
chick
kin
park
gale
kick
fin
dark
male
lick
shin
bark
bale
sick
thin
lark
pale
pick
pin
shark
rail
feel
34.
till
35.
peal
36.
same
eel
kill
zeal
tame
peel
hill
feel
shame
keel
mill
reel
game
reel
will
veal
lame
heel
bill
seal
came

160
then
38.
fin
39.
chin
40.
zee
ten
win
gin
thee
fen
pin
tin
dee
hen
din
sin
knee
den
sin
shin
see
pen
tin
thin
lee
tent
42.
rip
43.
shop
44.
vore
pent
lip
pop
for
bent
chip
top
gore
dent
tip
lop
wore
rent
dip
cop
roar
went
hip
hop
lore
fie
46.
dip
47.
nest
48.
rust
thy
zip
west
gust
vie
gyp
best
bust
lie
ship
rest
lust
thigh
nip
jest
just
high
lip
vest
dust
rat
50.
may
mat
they
bat
gay
vat
bay
fat
nay
that
wav

APPENDIX B
RAW DATA FROM SUBJECT RESPONSE FORMS
The following tables contain the individual responses (number of correct
responses) to VCV (A) and CVC (B) stimuli under 16 recording conditions.
Letter Codes:
A = In Air
U = In Uterus
X = CM-ex ulero
I = CM-in ulero
M = Male
F = Female
H = 105 dB
L = 95 dB
161

A. VCV Nonsense Syllables
Conditions
Subjects
AMH
AML
UMH
UML
XMH
XML
IMH
IML
AFH
AFL
UFH
UFL
XFH
XFL
IFH
IFL
1
14
14
12
14
12
11
5
4
14
13
12
11
8
8
6
7
2
14
14
13
14
12
10
7
4
13
13
10
9
6
7
7
5
3
14
14
12
13
11
9
7
3
13
13
12
12
6
5
4
3
4
14
14
13
14
13
11
5
6
13
13
13
12
8
7
6
5
5
13
13
14
13
11
10
8
2
13
13
11
13
5
9
9
5
6
14
14
13
14
12
9
5
3
13
13
11
10
8
6
4
4
7
14
14
10
13
10
10
6
6
13
13
13
10
6
5
5
4
8
14
13
13
14
11
8
6
6
13
13
13
12
7
6
6
5
9
14
14
14
14
10
12
6
5
12
12
10
12
6
6
6
2
10
14
14
13
14
13
12
8
5
12
12
11
11
7
6
4
5
11
14
14
13
14
13
11
7
6
12
13
13
12
8
10
9
6
12
14
14
13
14
8
10
7
4
13
12
11
12
8
7
6
4
13
14
14
12
14
10
10
6
6
13
13
12
13
7
8
6
6
14
14
14
12
14
11
11
8
5
13
14
13
11
7
7
6
3
15
14
14
13
14
13
11
4
3
12
13
14
11
5
9
4
5
16
13
13
13
13
9
9
7
5
13
13
9
7
5
6
4
5
17
14
14
14
14
13
11
11
5
12
12
12
9
6
4
3
3
18
13
14
12
14
12
8
5
7
13
13
13
10
7
8
5
3
19
14
14
11
13
10
8
7
3
13
12
11
10
7
7
3
6
20
14
13
12
13
11
8
7
6
10
12
10
10
6
6
7
2
21
14
13
13
14
10
10
5
6
12
13
10
11
8
6
4
1
22
14
14
11
12
13
9
5
2
13
12
12
13
6
5
5
3
23
14
14
11
12
9
8
3
4
12
12
10
11
7
5
8
4
24
14
14
13
12
11
8
4
5
13
13
12
11
9
5
8
4

Conditions
Subjects
AMH
AML
UMH
UML
XMH
XML
IMH
IML
AFH
AFL
UFH
UFL
XFH
XFL
1FH
IFL
25
14
14
13
13
14
11
8
6
13
13
10
11
8
8
6
1
26
14
14
14
14
10
8
7
6
14
14
11
9
7
6
2
2
27
14
14
13
13
13
9
4
5
13
13
12
10
8
8
6
4
28
14
13
13
14
11
11
8
4
13
13
11
12
8
9
6
3
29
14
14
12
13
10
10
7
3
13
13
11
11
7
6
5
4
30
14
14
11
12
13
10
9
3
11
12
12
10
7
7
5
3
31
14
14
12
13
8
10
8
4
13
13
13
12
9
8
5
5
32
14
13
12
14
12
10
7
4
13
13
12
14
7
6
5
7
33
14
14
14
14
13
11
9
4
11
13
13
12
8
8
7
3

bje
T
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
4
5
4
3
4
5
7
4
4
4
6
5
4
4
4
4
8
7
7
B. CVC Words
Conditions
AMH
AML
UMH
UML
XMH
XML
IMH
IML
AFH
AFL
UFH
UFL
XFH
10
10
10
7
3
6
5
6
10
9
9
9
5
10
10
9
10
6
6
6
6
10
8
9
9
8
10
10
10
9
6
8
3
8
10
10
9
10
7
10
10
9
8
4
6
5
6
10
9
9
8
5
10
10
10
8
5
6
6
6
10
9
9
7
6
10
10
10
8
3
8
6
8
10
9
8
9
8
10
10
10
10
6
7
5
7
10
9
8
9
3
10
10
10
9
5
8
6
8
10
8
9
9
6
10
10
10
9
6
5
7
5
10
8
9
10
7
10
10
9
9
8
7
6
7
10
9
10
9
5
10
10
10
8
4
7
4
7
10
10
9
7
7
10
10
10
8
4
6
4
6
10
10
9
9
9
10
10
10
10
7
8
5
8
10
9
10
9
7
10
10
10
9
4
7
5
7
10
9
9
10
6
10
10
10
9
3
8
4
8
10
8
9
7
6
10
10
10
10
5
8
5
8
10
9
9
10
6
10
9
10
7
6
4
4
4
10
9
9
9
4
10
10
10
7
5
4
5
4
10
9
9
8
7
10
10
10
10
5
7
5
7
10
9
9
8
4

Test 2
Conditions
Subjects
AMH
AML
UMH
UML
XMH
XML
1MH IML
AFH
AFL
UFH
UFL
XFH
XFL
IFH
IFL
1
10
10
9
10
4
6
6
4
10
10
10
8
7
7
8
5
2
10
10
9
10
6
8
7
7
9
8
10
8
6
9
9
5
3
8
10
9
10
4
6
8
5
8
8
10
10
7
7
3
4
4
9
10
7
9
5
6
9
4
9
9
10
8
6
5
8
2
5
10
10
8
8
5
3
7
5
10
9
10
9
7
7
5
3
6
10
10
8
10
6
5
8
3
10
9
10
9
6
10
4
3
7
10
10
8
9
5
7
7
6
9
9
10
9
7
9
4
7
8
9
10
8
8
5
3
6
5
10
9
10
9
6
7
5
4
9
8
10
9
10
3
3
7
3
9
8
9
9
4
7
6
3
10
10
10
9
8
5
5
7
2
10
9
9
8
7
6
6
2
11
10
10
9
8
6
7
8
3
10
10
10
8
7
8
4
3
12
10
10
8
10
5
5
8
5
8
8
10
10
8
8
7
7
13
8
10
9
10
5
6
7
4
9
9
10
7
8
6
6
7
14
9
10
8
10
6
6
8
6
9
9
9
10
9
10
7
9
15
10
10
9
10
4
6
4
2
10
9
10
8
9
9
6
2
16
10
10
9
10
5
4
8
5
9
10
9
9
6
6
6
4
17
10
10
8
9
6
5
7
2
10
8
10
10
6
5
4
4
18
10
10
9
8
5
7
7
3
10
10
10
7
6
6
7
2
19
10
10
8
9
5
4
6
6
10
10
10
9
8
5
4
5
20
10
10
8
9
6
5
5
4
10
9
10
8
5
9
7
6
21
10
10
9
8
4
3
7
2
10
10
10
9
7
7
5
4

tye
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
IFL
3
7
7
4
7
3
6
7
5
7
5
5
2
5
4
5
6
6
7
7
Conditions
AMH
AML
UMH
UML
XMH
XML
IMH
IML
AFH
AFL
UFH
UFL
XFH
XFL
9
10
10
7
2
4
7
3
10
10
8
6
5
8
10
9
7
7
5
3
6
5
10
10
9
10
5
5
10
10
10
7
8
3
7
6
10
10
9
9
7
7
10
10
10
5
6
5
5
3
10
10
10
10
3
7
10
10
10
7
6
6
5
6
10
10
9
9
3
6
9
10
9
7
8
4
9
5
10
10
9
10
7
6
10
9
10
7
4
3
5
7
9
10
9
10
3
9
10
10
10
6
4
5
5
6
10
10
9
10
3
7
10
10
10
7
6
4
5
3
10
10
9
10
4
7
10
9
9
7
5
5
6
4
10
9
9
10
4
8
9
10
10
6
5
4
5
6
10
10
9
10
4
7
9
9
8
7
5
3
6
5
9
10
9
10
5
7
10
9
10
7
7
8
6
6
10
10
9
10
6
8
10
9
9
6
5
3
5
4
10
8
9
9
4
5
10
10
10
6
5
6
5
4
10
10
9
10
5
5
10
9
9
7
6
6
5
3
10
10
9
8
3
9
10
9
9
7
7
4
5
5
10
10
9
9
3
6
9
10
10
7
8
4
7
5
10
9
9
9
5
7
10
10
9
6
7
5
5
6
10
10
8
9
7
6
10
10
10
7
6
6
8
4
9
10
9
10
5
6

9
10
10
9
10
10
10
10
10
10
9
10
10
10
10
10
9
9
10
10
10
5
4
4
5
7
4
6
4
4
4
4
3
3
2
7
3
4
5
6
7
Conditions
AML UMH UML XMH XML IMH IML AFH AFL UFH UFL XFH XFL
9
8
10
8
5
5
3
10
9
9
10
6
4
10
10
7
6
5
6
2
10
10
8
8
8
8
10
9
7
8
6
5
4
10
10
9
9
6
6
10
10
10
6
4
5
3
10
10
9
10
4
7
9
9
9
7
5
6
4
10
9
9
10
7
4
10
9
7
8
5
6
2
10
10
9
9
9
6
9
9
9
7
8
6
3
10
10
10
10
9
8
10
10
8
8
5
7
2
10
10
9
9
6
8
10
9
9
8
6
6
2
10
10
9
9
9
6
10
10
7
8
7
7
4
10
9
8
9
7
7
10
9
10
6
7
5
4
10
10
10
9
6
5
10
10
8
8
6
5
2
10
10
9
10
9
8
9
10
8
9
6
6
4
10
10
8
9
7
6
10
10
10
7
5
7
5
9
10
9
10
6
7
9
9
10
6
6
7
1
10
10
10
9
8
9
9
9
9
9
6
7
4
10
9
10
10
9
10
9
9
7
9
5
5
5
10
9
9
10
9
6
9
9
8
9
5
6
5
10
9
9
10
4
6
10
10
9
7
4
7
4
10
9
10
10
7
8
10
10
8
8
7
6
3
10
9
10
10
7
7
10
10
8
8
7
5
3
10
10
9
10
5
7

Test 5
Subjects
Conditions
AMH
AML
UMH
UML
XMH
XML
IMH
IML
AFH
AFL
UFH
UFL
XFH
XFL
IFH
IFL
1
8
10
10
10
9
4
8
5
10
9
8
9
7
4
2
4
2
9
9
9
9
7
7
5
5
10
9
10
7
8
3
7
3
3
9
10
9
10
9
8
7
7
10
9
9
7
7
4
7
4
4
8
10
10
10
5
6
5
4
10
9
8
6
7
6
3
4
5
9
10
10
9
6
5
4
4
10
9
8
7
7
6
5
5
6
9
9
9
10
7
7
7
5
10
9
8
8
6
5
7
5
7
9
10
10
10
8
6
7
6
10
9
8
8
10
7
6
6
8
8
9
9
10
7
7
6
8
10
9
10
5
7
5
8
5
9
9
10
10
10
8
6
7
6
9
9
8
7
6
6
7
5
10
9
10
10
10
7
5
5
5
9
9
8
8
7
8
9
5
11
9
10
10
10
8
6
5
6
10
9
8
7
5
6
3
4
12
9
9
9
10
7
8
5
5
10
9
9
8
8
7
5
3
13
9
10
10
10
9
6
8
5
10
9
8
7
7
6
5
4
14
9
9
9
9
7
8
5
7
10
9
10
7
7
9
6
6
15
9
10
10
10
9
5
8
6
10
9
9
8
6
5
4
4
16
9
9
10
8
5
5
4
4
8
9
7
7
6
5
7
2
17
8
10
10
10
6
7
7
6
10
9
8
7
6
6
7
6
18
9
9
9
9
7
8
6
3
10
9
10
8
5
5
7
3
19
9
9
9
9
7
8
6
3
10
9
8
8
7
5
6
4
20
9
9
10
10
7
9
5
4
10
9
9
8
8
6
8
4
21
9
9
9
10
10
5
6
6
10
9
8
7
6
5
8
2
22
9
10
10
9
8
7
8
5
9
9
8
7
6
3
6
3
23
9
10
8
9
9
7
6
5
10
9
8
8
9
5
3
3
24
9
10
9
10
7
9
7
5
10
9
9
7
6
8
6
6
25
9
10
10
9
6
7
5
6
9
9
8
7
7
6
7
3

APPENDIX C
RAW DATA FROM ACOUSTIC ANALYSES OF VOWELS
The following tables contain the values of spectral analyses of vowels under
different recording locations for male and female speakers. A. In air; B. In the uterus; C.
CM-ex útero; D. CM-in útero.
169

A. In Air
Male
Formant (Hz)
Stimulus Level (dB)
Noise Level (dB)
Relative dB
Vowel
Word
F„
F,
f2
f3
F0
F,
f2
f3
F„
F,
f2
f3
F0
F,
f2
f3
lil
leave
132
353
2437
3630
26.1
30.0
45.5
57.3
74.6
66.6
82.8
78.8
48.5
36.6
37.3
21.5
peak
124
361
2409
3587
27.0
29.2
52.3
61.0
72.9
66.5
81.5
81.5
45.9
37.3
29.2
20.5
sheen
135
357
2584
3504
25.5
30.6
54.9
64.8
76.0
69.3
78.8
81.4
50.5
38.7
23.9
16.6
teethe
126
337
2524
3546
31.1
26.1
49.5
61.5
78.4
73.5
82.1
81.8
47.3
47.4
32.6
20.3
peel
163
317
2495
3716
26.9
24.1
48.7
65.1
75.3
71.0
78.2
82.2
48.4
46.9
29.5
17.1
/V
wig
116
374
2117
2614
20.3
18.5
53.1
45.9
66.0
72.4
82.4
82.5
45.7
53.9
29.3
36.6
dig
113
397
2093
2740
22.5
20.3
45.3
41.4
75.0
73.9
83.5
85.6
52.5
53.6
38.2
44.2
fill
124
406
1928
2614
20.6
13.5
38.8
40.9
76.4
72.3
83.9
83.1
55.8
58.8
45.1
42.2
pick
127
357
1997
2645
25.9
21.9
52.2
51.6
72.6
66.0
82.5
86.3
46.7
44.1
30.3
34.7
sing
135
451
2245
2838
22.6
19.3
40.4
40.9
80.1
75.3
82.0
79.9
57.5
56.0
41.6
39.0
Id
led
117
626
1735
2805
21.4
25.7
39.2
47.6
68.3
82.2
81.8
79.0
46.9
56.5
42.6
31.4
ten
135
591
1928
2772
22.1
23.5
38.8
43.3
73.4
75.4
82.3
82.1
51.3
51.9
43.5
38.8
rent
124
538
1755
2676
20.4
24.7
43.8
48.6
76.6
76.5
78.0
80.0
56.2
51.8
34.2
31.4
nest
138
582
1905
2809
18.9
29.1
50.4
53.6
66.6
73.3
80.4
81.9
47.7
44.2
30.0
28.3
/as/
bat
112
688
1776
2437
18.8
22.2
38.2
45.2
68.9
78.4
80.8
83.4
50.1
56.2
42.6
38.2
lash
113
696
1655
2614
20.4
31.6
37.5
54.3
68.7
78.3
79.7
81.5
48.3
46.7
42.2
27.2
mat
115
626
1735
2645
22.3
27.4
34.3
45.0
70.9
80.7
80.0
81.3
48.6
53.3
45.7
36.3
pass
113
672
1598
2614
25.3
35.5
40.1
51.4
70.5
75.8
85.5
79.0
45.2
40.3
45.4
27.6
hath
113
649
1617
2524
23.8
33.7
38.3
46.0
67.9
78.5
77.6
84.3
44.1
44.8
39.3
38.3
IAJ
dumb
116
634
1192
2772
17.7
25.2
33.5
57.4
66.0
79.3
84.3
81.6
48.3
54.1
50.8
24.2
cuff
113
641
1206
2645
24.0
27.7
32.4
52.3
67.5
78.8
82.6
80.5
43.5
51.1
50.2
28.2
dun
113
626
1235
2740
20.3
24.1
34.5
53.5
68.6
77.7
82.3
76.5
48.3
53.6
47.8
23.0
pup
113
605
1235
2645
27.8
26.1
35.7
54.3
69.1
78.9
77.6
82.8
41.3
52.8
41.9
28.5
sud
135
605
1341
2676
26.2
25.2
38.1
51.0
74.3
79.0
81.9
82.8
48.1
53.8
43.8
31.8
o

Female Formant (Ffz) Stimulus Level (dB)
Vowel
Word
Fo
F,
f2
F,
F„
F,
f2
f3
m
leave
235
352
2809
3285
14.6
45.8
38.2
51.3
peak
235
358
2763
3423
17.9
42.7
37.0
46.2
sheen
245
364
2951
3452
5.8
46.0
34.4
51.6
teethe
245
357
2974
3463
10.5
45.6
38.8
51.5
peel
248
333
2708
3060
13.2
41.4
41.0
54.1
rv
wig
218
433
2382
3025
16.1
10.7
41.6
41.2
dig
216
429
2362
2786
16.5
10.1
34.5
37.9
fill
216
429
2362
2786
19.2
16.3
58.2
54.8
pick
234
456
2219
2838
19.7
21.0
36.0
40.0
sing
234
462
2554
3009
10.1
17.0
36.0
43.9
/s/
led
229
670
2020
2903
15.1
17.6
27.7
36.4
ten
226
675
2037
2951
13.5
21.6
38.7
49.1
rent
218
622
1891
2786
16.4
26.4
28.5
37.2
nest
208
634
1951
2740
14.3
25.5
34.6
43.0
/ae/
bat
216
1061
1883
2939
20.3
29.0
32.0
37.4
lash
218
1053
1907
2951
19.5
19.6
21.3
36.3
mat
216
1053
1907
2974
19.6
29.3
31.3
40.4
pass
216
1079
1938
2786
18.6
27.4
31.5
38.6
hath
221
1098
1997
2871
19.5
33.1
32.0
37.7
/A/
dumb
208
627
1252
2695
16.2
23.4
26.5
49.9
cuff
216
704
1292
2809
22.6
29.9
35.9
44.3
dun
216
643
1273
2763
13.4
24.4
32.5
45.4
pup
242
712
1250
2838
18.6
25.3
33.2
48.7
sud
221
664
1325
2838
16.2
21.3
35.5
46.3
Noise Level (dB) Relative dB
F„
F,
f2
F,
Fo
F,
f2
f3
65.4
59.6
77.2
83.1
50.8
33.3
39.0
31.8
56.2
64.1
81.2
79.9
38.3
16.9
44.2
33.7
59.8
58.3
79.2
84.4
54.0
18.1
44.8
32.8
51.7
62.0
80.3
79.1
41.2
12.7
41.5
27.6
63.0
67.5
71.1
80.9
49.8
20.6
30.1
26.8
62.1
62.9
76.3
73.7
46.0
63.4
34.7
32.5
59.5
60.4
82.9
79.2
43.0
52.8
48.4
41.3
57.3
62.8
80.6
75.5
38.1
44.1
22.4
20.7
67.0
67.3
78.2
84.6
47.3
41.8
42.2
44.6
58.9
70.9
77.1
76.8
48.8
50.3
41.1
32.9
61.1
74.4
81.1
82.1
46.0
53.3
53.4
45.7
55.0
71.2
77.2
76.1
41.5
52.8
38.5
27.0
63.2
71.2
75.1
79.5
46.8
44.8
46.6
42.3
53.0
65.4
76.8
80.8
38.7
45.7
42.2
37.8
66.0
77.4
79.0
80.3
45.7
48.4
47.0
42.9
64.5
73.6
78.4
77.0
45.0
54.0
57.1
40.7
58.8
72.1
77.4
78.9
39.2
42.8
46.1
38.5
64.0
80.9
78.9
80.4
45.4
53.5
47.4
41.8
58.1
79.1
77.9
79.5
38.6
46.0
45.9
41.8
62.7
72.0
74.8
77.0
46.5
44.1
48.3
27.1
64.0
83.8
90.4
77.4
41.4
42.1
54.5
33.1
60.4
72.0
77.3
78.5
47.0
59.4
44.8
33.1
60.1
78.0
79.6
82.2
41.5
46.7
46.4
33.5
60.9
74.1
76.3
75.0
44.7
56.7
40.8
28.7

_Fo_
132
124
135
126
163
116
113
124
127
135
117
135
124
138
112
113
115
113
113
116
113
113
113
135
B. In Uterus
Formant (Hz) Stimulus Level (dB) Noise Level (dB) Relative dB
F,
F2
f3
F„
F,
f2
F,
F„
F,
f2
f3
F0
F,
f2
f3
353
2437
3630
14.6
53.3
53.5
66.8
52.6
70.8
74.9
73.8
38.0
17.5
21.4
7.0
361
2409
3587
16.6
33.8
63.4
83.9
52.3
71.2
75.9
72.3
35.7
37.4
12.5
-11.6
357
2584
3504
10.4
54.7
69.0
67.8
55.1
74.1
69.6
79.6
44.7
19.4
0.6
11.8
337
2524
3546
26.3
34.6
66.7
73.0
56.5
70.3
71.8
75.2
30.2
35.7
5.1
2.2
317
2495
3716
13.9
35.0
66.6
71.4
62.8
71.5
74.5
74.6
48.9
36.5
7.9
3.2
374
2117
2614
12.0
17.1
66.9
73.3
51.4
67.1
73.6
72.6
39.4
50.0
6.7
-0.7
397
2093
2740
14.1
15.0
51.7
56.6
54.7
66.8
75.3
75.6
40.6
51.8
23.6
19.0
406
1928
2614
11.0
5.3
45.5
66.5
59.4
62.6
77.9
72.4
48.4
57.3
32.4
5.9
357
1997
2645
15.6
34.4
60.0
72.0
61.7
70.0
73.7
77.1
46.1
35.6
13.7
5.1
451
2245
2838
8.2
17.5
52.7
53.3
61.2
67.6
73.3
78.0
53.0
50.1
20.6
24.7
626
1735
2805
12.2
34.1
48.9
65.1
55.4
69.8
76.0
72.9
43.2
35.7
27.1
7.8
591
1928
2772
11.2
32.6
49.8
61.9
57.7
70.6
74.3
75.3
46.5
38.0
24.5
13.4
538
1755
2676
10.6
23.2
49.5
63.8
50.3
68.1
72.1
71.7
39.7
44.9
22.6
7.9
582
1905
2809
7.6
34.5
53.5
68.1
56.6
77.0
72.9
76.5
49.0
42.5
19.4
8.4
688
1776
2437
10.7
28.5
51.9
60.5
54.8
74.3
78.6
74.9
44.1
45.8
26.7
14.4
696
1655
2614
11.7
32.8
49.9
71.0
53.8
71.5
73.7
74.1
42.1
38.7
23.8
3.1
626
1735
2645
14.1
33.5
46.4
73.3
53.2
71.9
76.5
74.9
39.1
38.4
30.1
1.6
672
1598
2614
23.0
39.4
49.8
71.7
54.5
70.7
75.2
78.3
31.5
31.3
25.4
6.6
649
1617
2524
16.8
38.7
51.3
66.3
53.5
72.7
71.6
74.2
36.7
34.0
20.3
7.9
634
1192
2772
8.9
34.3
38.9
69.3
52.5
72.7
75.0
80.9
43.6
38.4
36.1
11.6
641
1206
2645
15.5
35.1
36.3
72.5
51.1
69.9
72.1
76.8
35.6
34.8
35.8
4.3
626
1235
2740
11.9
31.4
37.1
64.6
56.1
74.0
73.5
71.4
44.2
42.6
36.4
6.8
605
1235
2645
19.4
35.1
37.3
72.5
56.0
70.2
74.6
71.9
36.6
35.1
37.3
-0.6
605
1341
2676
13.2
35.3
47.1
73.7
58.8
69.8
80.5
71.7
45.6
34.5
33.4
-2.0

Female
Formant (Hz)
Stimulus Level (dB)
Noise Level (dB)
Relative dB
Vowel
Word
F.
F,
f2
F,
F0
F,
f2
f3
F0
F,
f2
f3
F0
F,
f2
f3
lit
leave
235
352
2809
3285
15.9
54.0
52.6
56.9
64.0
63.0
66.8
66.8
48.1
9.0
14.2
9.9
peak
235
358
2763
3423
18.2
46.4
49.3
54.1
62.6
60.6
70.3
71.8
44.4
14.2
21.0
17.7
sheen
245
364
2951
3452
6.5
54.2
54.2
62.0
60.3
63.9
66.4
69.4
53.8
9.7
12.2
7.4
teethe
245
357
2974
3463
12.8
52.2
57.6
59.0
62.7
64.7
69.1
72.7
49.9
12.5
11.5
13.7
peel
248
333
2708
3060
14.0
49.2
56.3
60.2
61.0
65.6
66.0
72.9
47.0
16.4
9.7
12.7
m
wig
218
433
2382
3025
23.6
12.7
45.9
49.3
61.2
61.9
68.8
66.7
37.6
49.2
22.9
17.4
dig
216
429
2362
2786
23.2
5.8
44.3
53.8
60.0
59.0
67.5
70.0
36.8
53.2
23.2
16.2
fill
216
429
2362
2786
18.3
9.4
58.0
71.9
58.7
62.1
71.9
70.2
40.4
52.7
13.9
-1.7
pick
234
456
2219
2838
20.1
16.8
45.0
54.7
57.7
64.5
72.5
72.6
37.6
47.7
27.5
17.9
sing
234
462
2554
3009
12.3
14.7
47.0
58.8
59.3
69.1
67.6
67.7
47.0
54.4
20.6
8.9
/s/
led
229
670
2020
2903
18.8
19.7
30.2
52.2
59.2
64.3
72.5
73.4
40.4
44.6
42.3
21.2
ten
226
675
2037
2951
16.4
23.2
41.2
54.3
61.0
69.2
69.7
67.5
44.6
46.0
28.5
13.2
rent
218
622
1891
2786
24.3
25.4
31.9
55.7
59.7
68.7
69.3
65.2
35.4
43.3
37.4
9.5
nest
208
634
1951
2740
22.8
26.1
37.0
52.9
54.3
67.5
72.0
72.6
31.5
41.4
35.0
19.7
/as/
bat
216
1061
1883
2939
28.2
26.5
36.8
48.2
58.4
65.0
69.8
67.6
30.2
38.5
33.0
19.4
lash
218
1053
1907
2951
28.6
17.3
27.2
52.3
58.6
66.2
68.4
68.3
30.0
48.9
41.2
16.0
mat
216
1053
1907
2974
25.1
27.7
39.6
63.0
61.4
65.5
64.7
67.2
36.3
37.8
25.1
4.2
pass
216
1079
1938
2786
23.7
28.6
38.3
58.4
56.1
68.2
70.8
71.1
32.4
39.6
32.5
12.7
hath
221
1098
1997
2871
20.8
34.7
32.6
52.2
58.9
64.5
70.2
72.4
38.1
29.8
37.6
20.2
/AJ
dumb
208
627
1252
2695
23.6
27.5
22.8
68.9
53.7
65.7
69.0
75.5
30.1
38.2
46.2
6.6
cuff
216
704
1292
2809
27.2
33.3
30.2
58.0
58.9
67.6
66.1
67.0
31.7
34.3
35.9
9.0
dun
216
643
1273
2763
20.0
26.0
26.1
62.4
62.0
66.1
70.3
60.3
42.0
40.1
44.2
-2.1
pup
242
712
1250
2838
17.7
25.3
30.0
65.6
61.0
73.4
72.8
75.9
43.3
48.1
42.8
10.3
sud
221
664
1325
2838
20.1
22.2
33.5
54.2
60.2
68.7
65.5
71.3
40.1
46.5
32.0
17.1

C. CM-ex útero
Male
Formant (Hz)
Stimulus Level (dB)
Noise Level (dB)
Relative dB
Vowel
Word
F0
F,
f2
f3
F,
F,
f2
f3
F„
F,
f2
f3
F„
F,
f2
f3
/¡/
leave
132
353
2437
3630
52.2
43.7
50.6
51.9
55.5
52.9
52.2
53.3
3.3
9.2
1.6
1.4
peak
124
361
2409
3587
49.1
27.6
51.2
49.6
51.3
52.8
49.9
53.5
2.2
25.2
-1.3
3.9
sheen
135
357
2584
3504
43.4
32.8
50.1
50.3
54.4
48.1
52.8
51.7
11.0
15.3
2.7
1.4
teethe
126
337
2524
3546
37.2
22.2
44.3
39.2
43.2
45.8
49.8
42.2
6.0
23.6
5.5
3.0
peel
163
317
2495
3716
44.5
26.0
53.2
53.4
50.5
51.6
50.7
52.2
6.0
25.6
-2.5
-1.2
tv
wig
116
374
2117
2614
48.2
16.5
53.6
51.9
50.0
50.2
51.8
49.0
1.8
33.7
-1.8
-2.9
dig
113
397
2093
2740
44.9
15.8
49.1
46.8
52.2
50.2
50.0
63.3
7.3
34.4
0.9
16.5
fill
124
406
1928
2614
42.7
10.4
44.3
53.3
52.6
47.7
49.2
48.3
9.9
37.3
4.9
-5.0
pick
127
357
1997
2645
48.5
22.5
48.9
47.4
53.3
48.3
47.3
56.9
4.8
25.8
-1.6
9.5
sing
135
451
2245
2838
45.8
16.1
47.6
52.3
52.9
50.5
47.6
52.6
7.1
34.4
0.0
0.3
tel
led
117
626
1735
2805
46.6
31.7
49.0
51.6
48.8
48.9
55.2
52.4
2.2
17.2
6.2
0.8
ten
135
591
1928
2772
46.4
22.7
46.1
50.9
53.2
55.3
48.1
51.7
6.8
32.6
2.0
0.8
rent
124
538
1755
2676
43.8
15.4
47.5
51.1
55.8
49.3
50.0
51.3
12.0
33.9
2.5
0.2
nest
138
582
1905
2809
38.5
23.0
45.6
54.9
53.4
51.9
58.2
49.3
14.9
28.9
12.6
-5.6
/as/
bat
112
688
1776
2437
44.1
21.5
44.7
49.1
49.7
54.0
52.5
44.3
5.6
32.5
7.8
-4.8
lash
113
696
1655
2614
41.3
23.5
36.4
48.3
47.8
51.8
50.9
49.5
6.5
28.3
14.5
1.2
mat
115
626
1735
2645
42.8
28.0
38.8
50.7
57.0
53.2
51.1
52.9
14.2
25.2
12.3
2.2
pass
113
672
1598
2614
56.4
32.5
39.7
51.6
48.1
45.1
54.6
51.4
-8.3
12.6
14.9
-0.2
hath
113
649
1617
2524
44.5
39.9
39.6
49.1
51.0
49.4
49.8
55.2
6.5
9.5
10.2
6.1
/A/
dumb
116
634
1192
2772
38.5
36.8
29.7
50.0
49.7
48.3
44.5
51.7
11.2
11.5
14.8
1.7
cuff
113
641
1206
2645
47.5
36.6
28.6
52.7
55.1
61.6
47.2
54.1
7.6
25.0
18.6
1.4
dun
113
626
1235
2740
43.0
28.2
32.2
57.6
48.2
50.5
48.5
50.8
5.2
22.3
16.3
-6.8
pup
113
605
1235
2645
48.9
25.9
32.1
48.9
53.0
53.6
49.4
46.1
4.1
27.7
17.3
-2.8
sud
135
605
1341
2676
41.7
28.0
37.0
47.1
56.0
53.0
50.1
47.4
14.3
25.0
13.1
0.3

Female Formant (FIz) Stimulus Level (dB) Noise Level (dB) Relative dB
Vowel
Word
F„
F,
f2
F,
Fo
F,
f2
f3
Fo
F,
f2
f3
F„
F,
f2
f3
lil
leave
235
352
2809
3285
27.4
48.8
51.0
50.3
44.5
48.5
52.6
49.9
17.1
-0.3
1.6
-0.4
peak
235
358
2763
3423
30.8
43.3
50.3
53.1
46.5
48.2
49.3
45.6
15.7
4.9
-1.0
-7.5
sheen
245
364
2951
3452
18.7
43.9
46.9
50.9
46.7
50.1
52.2
47.2
28.0
6.2
5.3
-3.7
teethe
245
357
2974
3463
24.1
44.9
44.0
49.5
45.5
50.5
52.2
52.6
21.4
5.6
8.2
3.1
peel
248
333
2708
3060
27.4
48.0
47.7
53.4
50.1
50.4
48.6
49.3
22.7
2.4
0.9
-4.1
/V
wig
218
433
2382
3025
36.4
12.5
44.9
45.9
54.5
44.6
52.4
50.1
18.1
32.1
7.5
4.2
dig
216
429
2362
2786
36.9
11.2
47.1
53.5
53.5
43.3
52.6
53.9
16.6
32.1
5.5
0.4
fill
216
429
2362
2786
36.0
29.4
52.8
44.6
58.2
45.3
51.4
49.1
22.2
15.9
-1.4
4.5
pick
234
456
2219
2838
32.1
17.9
55.7
47.3
46.1
43.2
52.8
50.5
14.0
25.3
-2.9
3.2
sing
234
462
2554
3009
26.0
13.5
48.2
49.3
45.6
54.0
54.9
49.9
19.6
40.5
6.7
0.6
Is/
led
229
670
2020
2903
36.5
20.6
31.2
50.9
53.6
43.2
51.8
50.8
17.1
22.6
20.6
-0.1
ten
226
675
2037
2951
31.7
21.7
43.8
54.0
48.1
51.7
55.0
51.4
16.4
30.0
11.2
-2.6
rent
218
622
1891
2786
37.7
36.3
37.5
47.7
50.0
46.6
49.4
51.2
12.3
10.3
11.9
3.5
nest
208
634
1951
2740
41.3
35.7
34.9
45.2
54.9
51.1
53.4
52.0
13.6
15.4
18.5
6.8
/ae/
bat
216
1061
1883
2939
41.4
30.0
39.1
48.6
51.2
51.2
44.1
54.4
9.8
21.2
5.0
5.8
lash
218
1053
1907
2951
41.8
22.8
28.4
51.1
51.2
51.9
50.5
53.4
9.4
29.1
22.1
2.3
mat
216
1053
1907
2974
38.2
32.3
40.4
48.5
52.1
49.3
51.6
50.9
13.9
17.0
11.2
2.4
pass
216
1079
1938
2786
38.2
26.7
35.1
45.4
50.5
46.3
54.3
52.8
12.3
19.6
19.2
7.4
hath
221
1098
1997
2871
34.5
23.1
32.6
52.1
47.5
48.7
51.6
48.5
13.0
25.6
19.0
-3.6
/A/
dumb
208
627
1252
2695
37.5
29.8
22.1
55.4
50.5
49.0
50.6
49.3
13.0
19.2
28.5
-6.1
cuff
216
704
1292
2809
38.6
32.2
30.5
52.7
52.0
52.2
51.8
53.1
13.4
20.0
21.3
0.4
dun
216
643
1273
2763
38.7
37.9
29.0
48.8
49.9
48.4
49.6
52.7
11.2
10.5
20.6
3.9
pup
242
712
1250
2838
27.9
21.9
31.7
53.1
49.6
53.6
46.6
51.7
21.7
31.7
14.9
-1.4
sud
221
664
1325
2838
39.2
24.9
34.1
50.3
46.1
48.4
51.6
53.1
6.9
23.5
17.5
2.8

D. CM -in útero
Male
Formant (Hz)
Stimulus Level (dB)
Noise Level (dB)
Relative dB
Vowel
Word
Fo
F,
f2
f3
Fo
F,
f2
f3
F0
F,
f2
f3
F0
F,
f2
f3
m
leave
132
353
2437
3630
38.5
29.8
44.7
48.4
48.6
44.4
40.4
44.2
10.1
14.6
-4.3
-4.2
peak
124
361
2409
3587
34.4
31.3
43.0
46.3
45.9
44.8
47.0
46.8
11.5
13.5
4.0
0.5
sheen
135
357
2584
3504
34.8
34.4
49.2
44.8
49.8
44.0
52.6
48.2
15.0
9.6
3.4
3.4
teethe
126
337
2524
3546
33.2
34.8
42.1
48.5
55.3
46.0
47.6
46.5
22.1
11.2
5.5
-2.0
peel
163
317
2495
3716
24.7
41.6
47.6
47.5
46.0
46.1
46.7
49.9
21.3
4.5
-0.9
2.4
tv
wig
116
374
2117
2614
35.1
19.9
46.9
44.0
46.5
44.8
46.4
50.3
11.4
24.9
-0.5
6.3
dig
113
397
2093
2740
39.7
17.0
47.4
44.0
46.9
50.6
47.6
49.0
7.2
33.6
0.2
5.0
fill
124
406
1928
2614
32.9
21.5
41.8
45.6
44.5
48.4
47.9
48.7
11.6
26.9
6.1
3.1
pick
127
357
1997
2645
35.8
27.0
47.7
50.2
46.6
42.5
45.6
50.9
10.8
15.5
-2.1
0.7
sing
135
451
2245
2838
32.4
32.3
46.5
44.0
46.6
45.5
51.1
48.7
14.2
13.2
4.6
4.7
Id
led
117
626
1735
2805
35.0
23.8
46.7
50.2
46.1
45.3
44.2
46.1
11.1
21.5
-2.5
-4.1
ten
135
591
1928
2772
29.3
35.5
43.6
48.2
44.9
47.6
44.8
48.4
15.6
12.1
1.2
0.2
rent
124
538
1755
2676
28.1
23.3
45.1
50.2
49.2
46.0
45.2
46.6
21.1
22.7
0.1
-3.6
nest
138
582
1905
2809
32.9
36.6
41.1
48.5
51.7
48.6
46.9
43.1
18.8
12.0
5.8
-5.4
/ae/
bat
112
688
1776
2437
47.7
45.2
49.5
49.0
44.6
46.8
47.9
46.9
-3.1
1.6
-1.6
-2.1
lash
113
696
1655
2614
34.0
22.7
44.3
44.0
42.6
43.9
48.3
46.7
8.6
21.2
4.0
2.7
mat
115
626
1735
2645
35.3
30.6
47.2
52.4
48.0
47.7
50.4
50.7
12.7
17.1
3.2
-1.7
pass
113
672
1598
2614
36.6
30.3
51.0
45.8
46.9
39.5
41.6
46.8
10.3
9.2
-9.4
1.0
hath
113
649
1617
2524
37.1
27.7
47.9
48.7
44.8
48.5
52.3
47.1
7.7
20.8
4.4
-1.6
/A/
dumb
116
634
1192
2772
30.3
27.4
37.2
41.4
47.6
44.2
44.8
42.8
17.3
16.8
7.6
1.4
cuff
113
641
1206
2645
33.0
25.2
37.6
48.2
48.6
46.1
42.9
46.6
15.6
20.9
5.3
-1.6
dun
113
626
1235
2740
32.7
27.1
39.8
46.1
48.3
43.6
47.0
44.0
15.6
16.5
7.2
-2.1
pup
113
605
1235
2645
35.2
40.3
41.8
50.0
45.3
47.6
46.2
44.3
10.1
7.3
4.4
-5.7
sud
135
605
1341
2676
30.5
43.4
51.1
48.7
42.8
42.3
46.8
50.2
12.3
-1.1
-4.3
1.5
-o
Os

Female
Formant (Hz)
Stimulus Level (dB)
Noise Level (dB)
Relative dB
Vowel
Word
F„
F,
f2
f3
F„
F,
f2
f3
F0
F,
f2
f3
F0
F,
f2
f3
/¡/
leave
235
352
2809
3285
19.5
43.4
48.2
47.9
39.3
40.5
47.0
43.2
19.8
-2.9
-1.2
-4.7
peak
235
358
2763
3423
22.0
41.0
46.8
52.4
42.2
44.4
50.1
46.2
20.2
3.4
3.3
-6.2
sheen
245
364
2951
3452
12.3
45.6
42.9
51.0
39.4
43.3
42.9
41.8
27.1
-2.3
0.0
-9.2
teethe
245
357
2974
3463
15.9
48.4
46.2
43.8
41.1
45.6
47.4
45.7
25.2
-2.8
1.2
1.9
peel
248
333
2708
3060
18.6
42.6
43.2
45.1
39.3
45.2
45.3
48.6
20.7
2.6
2.1
3.5
rv
wig
218
433
2382
3025
26.2
11.2
42.1
45.3
48.3
40.5
42.3
46.7
22.1
29.3
0.2
1.4
dig
216
429
2362
2786
27.2
8.4
39.8
51.6
47.0
38.5
45.1
52.5
19.8
30.1
5.3
0.9
fill
216
429
2362
2786
21.5
20.6
40.0
42.5
42.3
38.7
46.3
47.1
20.8
18.1
6.3
4.6
pick
234
456
2219
2838
25.4
18.9
48.7
52.4
37.2
43.6
45.1
45.6
11.8
24.7
-3.6
-6.8
sing
234
462
2554
3009
17.2
13.8
49.8
48.2
44.2
45.4
47.7
44.0
27.0
31.6
-2.1
-4.2
Id
led
229
670
2020
2903
22.6
12.2
40.2
43.9
43.6
39.1
44.6
39.6
21.0
26.9
4.4
-4.3
ten
226
675
2037
2951
20.3
14.0
41.8
40.3
44.6
42.7
47.8
43.4
24.3
28.7
6.0
3.1
rent
218
622
1891
2786
29.5
21.9
38.0
48.1
44.7
41.5
45.2
44.9
15.2
19.6
7.2
-3.2
nest
208
634
1951
2740
29.7
17.7
43.5
46.8
42.8
44.7
49.2
47.8
13.1
27.0
5.7
1.0
/as/
bat
216
1061
1883
2939
32.9
24.6
43.1
47.5
50.6
44.4
49.4
43.6
17.7
19.8
6.3
-3.9
lash
218
1053
1907
2951
32.8
19.7
38.0
45.9
48.9
44.9
42.4
43.4
16.1
25.2
4.4
-2.5
mat
216
1053
1907
2974
28.3
33.1
43.0
47.7
47.0
46.6
49.5
44.3
18.7
13.5
6.5
-3.4
pass
216
1079
1938
2786
28.9
23.6
37.8
50.2
45.9
38.2
43.8
44.9
17.0
14.6
6.0
-5.3
hath
221
1098
1997
2871
26.6
29.0
39.3
44.0
46.9
45.1
43.9
42.8
20.3
16.1
4.6
-1.2
/A/
dumb
208
627
1252
2695
28.6
27.8
38.7
45.8
45.6
43.0
42.1
47.6
17.0
15.2
3.4
1.8
cuff
216
704
1292
2809
33.8
24.6
39.2
46.1
43.4
47.7
43.2
50.6
9.6
23.1
4.0
4.5
dun
216
643
1273
2763
25.7
19.5
43.2
48.1
42.4
45.5
45.8
41.2
16.7
26.0
2.6
-6.9
pup
242
712
1250
2838
24.1
19.1
44.1
46.8
44.1
40.0
40.7
53.4
20.0
20.9
-3.4
6.6
sud
221
664
1325
2838
26.3
17.7
42.4
46.8
48.0
34.5
51.8
45.3
21.7
16.8
9.4
-1.5
'•J
-o

REFERENCES
Abrams, R. M., Gerhardt, K. J., & Antonelli, P. J. (1998). Fetal hearing. Developmental
Psychobiology. 33 (11.1-3.
Abrams, R. M, Gerhardt, K. J., Griffiths, S. K., Huang, X., & Antonelli, P. J. (1998).
Intrauterine sound in sheep. Journal of Sound and Vibration. 216 131. 539-542.
Abrams, R. M., Griffiths, S. K., Huang, X., Sain, J., Langford, G., & Gerhardt, K. J.
(1998). Fetal music perception: the role of sound transmission. Music
Perception. 15.307-317.
Abrams, R. M., Hutchinson, A. A., McTineman, M. J., & Merwin, G. E. (1987). Effects
of cochlear ablation on local cerebral glucose utilization in fetal sheep. American
Journal of Obstetrics and Gynecology. 157.1438-1442.
Aijmand, E., Harris, D. M., & Dallos, P. (1988). Developmental changes in frequency
mapping of the gerbil cochlea: comparison of two cochlea locations. Hearing
Research. 32. 93-97.
Armitage, S. E., Baldwin, B. A., & Vince, M. A. (1980). The fetal sound environment of
sheep. Science. 208. 1173-1174.
Aslin, R. N. (1987). Visual and auditory development in infancy. In: Osofsky, J. (Ed.),
Handbook of Infant Development C2nd Edition). New York: A Wiley-
Interscience Publication, John Wiley & Sons, Inc. 5-97.
Aslin, R. N., Pisoni, D. B., & Jusczyk, P. W. (1983). Auditory development and speech
perception in infancy. In: Haith, M. M., & Campos, J. J. (Eds.), Handbook of
Child Psychology, Volume 2: Infancy and Developmental Psychobiology (4th
Edition). New York: John Wiley & Sons, Inc. 573-687.
Bench, J. (1968). Sound transmission to the human foetus through the maternal
abdominal wall. The Journal of Genetic Psychology. 113. 85-87.
178

179
Benzanquen, S., Gagnon, R., Hunse, C., & Foreman, J. (1990). The intrauterine sound
environment of the human fetus during labor. American Journal of Obstetrics and
Gynecology. 163 (21.484-490.
Berg, W. K., & Berg, K. M. (1987). Psychophysiological development in infancy: State,
startle, and attention. In: Osofsky, J. (Ed.), Handbook of Infant Development
(2nd Edition). New York: A Wiley-Interscience Publication, John Wiley & Sons,
Inc. 238-317.
Bilger, R. C., & Wang, M. D. (1976). Consonant confusions in patients with
sensorineural hearing loss. Journal of Speech and Hearing Research. 19, 718-748.
Bimholz, J. C., & Benacerraf, B. R. (1983). The development of the human fetal
hearing. Science, 222, 516-518.
Borden, G. J., & Harris, K. S. (1984). Speech Science Primer: Physiology. Acoustics,
and Perception of Speech (2nd Edition). Baltimore, MD: Williams and Wilkins.
Byrne, D., Dillon, H., Tran, K., Arlinger, S., Wilbraham, K., Cox, R., Hagerman, B.,
Hetu, R., Kei, J., Lui, C., Kiessling, J., Kotby, M. N., Nasser, N. H. A., El Kholy,
W. A. H., Nakanish, Y., Oyer, H., Powell, R., Stenphens, D., Meredith, R.,
Sirimanna, T., Tavartkiladze, G., Frolenkov, G. I., Westerman, S., & Ludvigsen,
C. (1994). An international comparison of long-term average speech spectra.
The Journal of the Acoustical Society of America. 96, 2108-2120.
Cooper, R. P., & Aslin, R. N. (1989). The language environment of the young infant:
implications for early perceptual development. Canadian Journal of Psychology.
43 (21.247-265.
Cox, R. M., & Moore, J. N. (1988). Composite speech spectrum for hearing aid gain
prescriptions. Journal of Speech and Hearing Research. 31. 102-107
Davis, H. (1948). The articulation area and the social adequacy index for hearing.
Laryngoscope. 58. 761-778.
DeCasper, A. J., & Fifer, W. P. (1980). Of human bonding: newborns prefer their
mothers’ voice. Science. 208 (61. 1174-1176.
DeCasper, A. J., Lecanuet, J.-P., Busnel, M.-C., Granier-Deferre, C., & Maugeais, R.
(1994). Fetal reaction to recurrent maternal speech. Infant Behavior and
Development. 17. 159-164.
DeCasper, A. J., & Prescott, P. A. (1984). Human newborns’ perception of male voices:
preference, discrimination, and reinforcing value. Developmental Psychobiology.
17151, 481-491.

180
DeCasper, A. J., & Sigafoos, A. D. (1983). The intrauterine heartbeat: a potent
reinforcer for newborns. Infant Behavior and Development. 6. 19-25.
DeCasper, A. J., & Spence, M. J. (1986). Prenatal maternal speech influences newborns’
perception of speech sounds. Infant Behavior and Development. 9, 133-150.
Dunn, H. K., & White, S. D. (1940). Statistical measurements on conversational speech.
The Journal of the Acoustical Society of America. Ü, 278-288.
Echteler, S. M, Aijmand, E., & Dallos, P. (1989). Developmental alterations in the
frequency map of the mammalian cochlea. Nature. 341. 147-149.
Egan, J. P. (1948). Articulation testing methods. Laryngoscope. 58. 955-991.
Eimas, P. D., Siqueland, E. R., Jusczyk, P., & Vigorito, J. (1971). Speech perception in
infants. Science. 171. 303-306.
Fifer, W. P. (1995). Neonatal preference for mother’s voice. In: Krasnegor, N. A.,
Blass, E. M., Hofer, M. A., & Smotherman, W. P. (Eds.), Perinatal Development:
A Psvchobiological Perspective. Orlando, FL: Academic Press, Inc., Flarcourt
Brace Jovanovich, Publishers. 111-124.
Fifer, W. P., & Moon, C. M. (1988). Auditory experience in the fetus. In: Smotherman,
W. P., & Robinson, S. R. (Eds.), Behavior of the Fetus. West Coldwell, NJ:
Telford Press. 175-188.
Fifer, W. P., & Moon, C. M. (1989). Psychobiology of newborn auditory preferences.
Seminars in Perinatology. 13 (51. 430-433.
Fifer, W. P., & Moon, C. M. (1994). The role of mother’s voice in the organization of
brain function in the newborn. Acta Paediatr ÍStockholm). Suppl. 397. 86-93.
Fifer, W. P., & Moon, C. M. (1995). The effects of fetal experience with sound. In:
Lecanuet, J.-P., Fifer, W. P., Krasnegor, N. A., & Smotherman, W. P. (Eds.),
Fetal Development: A Psvchobiological Perspective. New Jersey: Lawrence
Erlbaum Associates, Inc. 351-368.
Fitch, R. H., Miller, S., & Tallal, P. (1997). Neurobiology of speech perception. Annual
Review of Neuroscience. 20. 331-351.
Fletcher, H. (1953). Speech and Hearing in Communication. New York: D. Van
Nostrand Company, Inc.
Fodor, J. A. (1983). The Modularity of the Mind. Cambridge, MA: MIT Press.

181
Fowler, C. A. (1996). Listeners do hear sounds, not tongues. The Journal of the
Acoustical Society of America. 99. 1730-1741.
French, N. R., & Steinberg, J. C. (1947). Factors governing the intelligibility of speech
sound. The Journal of the Acoustical Society of America. 19. 90-119.
Gagnon, R., Benzaquen, S., & Hunse, C. (1992). The fetal sound environment during
vibroacoustic stimulation in labor: effect on fetal heart rate response. Obstetric &
Gynecology. 79,950-955.
Gelman, S. R., Wood, S., Spellacy, W. N., & Abrams, R. M. (1982). Fetal movements
in response to sound stimulation. American Journal of Obstetrics and
Gynecology. 143.484-485.
Gerhardt, K. J. (1989). Characteristics of the fetal sheep sound environment. Seminars
in Perinatology. 13 (53. 362-370.
Gerhardt, K. J. (1990). Prenatal and perinatal risks of hearing loss. Seminars in
Perinatology. 14J4), 299-304.
Gerhardt, K. J., & Abrams, R. M. (1996). Fetal hearing: Characterization of the stimulus
and response. Seminars in Perinatology. 20 (11. 11-20.
Gerhardt, K. J., Abrams, R. M., & Oliver, C. C. (1990). Sound environment of the fetal
sheep. American Journal of Obstetrics and Gynecology. 162. 282-287.
Gerhardt, K. J., Huang, X., Arrington, K. E., Meixner, K., Abrams, R. M., & Antonelli, P.
J. (1996). Fetal sheep in ulero hear through bone conduction. American Journal
of Otolaryngology. 17. 374-379.
Gerhardt, K. J., Otto, R., Abrams, R. M., Colie, J. J., Burchfield, D. J., & Peters, A. J. M.
(1992). Cochlear microphonics recorded from fetal and newborn sheep.
American Journal of Otolaryngology. 13,226-233.
Griffiths, J. D. (1967). Rhyming minimal contrasts: a simplified diagnostic articulation
test. The Journal of the Acoustical Society of America. 42. 236-241.
Griffiths, S. K., Brown, W. S., Gerhardt, K. J., Abrams, R. M., & Morris, R. J. (1994).
The perception of speech sounds recorded within the uterus of a pregnant sheep.
The Journal of the Acoustical Society of America. 96, 2055-2063.
Grimwade, J. C., Walker, D. W., & Wood, C. (1970). Sensory stimulation of the human
fetus. Australian Journal of Mental Retardation. 2, 63-64.

182
Gulick, W. L., Gescheider, G. A., & Frisina, R. D. (1989). Hearing: Physiological
Acoustics. Neural Coding, and Psvchoacoustics. New York: Oxford University
Press, Inc.
Harris, D. M., & Dallos, P. (1984). Ontogenetic changes in frequency mapping of a
mammalian ear. Science. 225. 741-743.
Hawkins, A. D., & Myrberg, A. A. (1983). Hearing and sound communication under
water. In: Lewis, B. (Ed.), Bioacoustics: A Comparative Approach. New York:
Academic Press. 347-405.
Hawkins, J. E., Jr., & Stevens, S. S. (1950). The masking of pure tones and of speech by
white noise. The Journal of the Acoustical Society of America. 22. 6-13.
Hepper, P. G. (1992). Fetal psychology: an embryonic science. In: Nijhuis, J. G. (Ed.),
Fetal Behaviour: Developmental and Perinatal Aspects. Oxford: Oxford
University Press. 129-156.
Hepper, P. G., Scott, D., & Shahidullah, S. (1993). Newborn and fetal response to
maternal voice. Journal of Reproductive and Infant Psychology. 11. 147-153.
Hepper, P. G., & Shahidullah, S. B. (1994a). The development of fetal hearing. Fetal
and Maternal Medicine Review. 6. 167-179.
Hepper, P. G., & Shahidullah, S. B. (1994b). Development of fetal hearing. Archives of
Disease in Childhood. 71. F81-F87.
Hillenbrand, J., Getty, L. A., Clark M. J., & Wheeler, K. (1995). Acoustic characteristics
of American English vowels. The Journal of the Acoustical Society of America.
97,3099-3 111.
Hirsh, I. J., Reynolds, E. G., & Joseph, M. (1954). Intelligibility of different speech
materials. The Journal of the Acoustical Society of America. 26. 530-538.
Hollien, H., & Feinstein, S. (1975). Contribution of the external auditory meatus to
auditory sensitivity underwater. The Journal of the Acoustical Society of
America. 57, 1488-1492.
Honrubia, V., & Ward, P. H. (1968). Longitudinal distribution of the cochlear
microphonics inside the cochlear duct (guinea pig). The Journal of the Acoustical
Society of America. 44, 951-958.
Jackson, H., Hackett, J. T., & Rubel, E. W. (1982). Organization and development of
brain stem auditory nuclei in the chicken: ontogeny of postsynaptic responses.
Journal of Comparative Neurology. 210. 80-86.

183
Johansson, B., Wedenberg, E., & Westen, B. (1964). Measurement of tone response by
the human foetus: A preliminary report. Acta Otolaryngology (Stockholm). 57.
188-192.
Jusczyk, P. W. (1996). Developmental speech perception. In: Lass, N. J. (Ed.),
Principles of Experimental Phonetics. St. Louis, MO: Mosby-Year Book, Inc.
328-361.
Jusczyk, P. W., Pisoni, D. B., Reed, M. A., Femald, A., & Myers, M. (1983). Infants’
discrimination of the duration of a rapid spectrum change in nonspeech signals.
Science. 222. 175-176.
Kent, R. D. (1997). The Speech Sciences. San Diego, CA: Singular Publishing Group,
Inc.
Kisilevsky, B. S., & Muir, D. W. (1991). Human fetal and subsequent newborn
responses to sound and vibration. Infant Behavior and Development. 14. 1-26.
Kryter, K. D. (1946). Effects of ear protective devices on the intelligibility of speech in
noise. The Journal of the Acoustical Society of America. 18. 413-417.
Kuhl, P. K. (1987). Perception of Speech and Sound in Early Infancy. In: Salapatek, P.,
& Cohen, L. (Eds), Handbook of Infant Perception. Volume 2: From Perception
to Cognition. New York: Academic Press, Inc. 275-382.
Kuhl, P. K. (1992). Psychoacoustics and speech perception: internal standards,
perceptual anchors, and prototypes. In: Werner, L. A., & Rubel, E. W. (Eds.),
Developmental Psvchoacoustics. Washington, DC: American Psychological
Association. 293-332.
Kuhl, P. K., & Miller, J. D. (1975). Speech perception by the chinchilla: voiced-
voiceless distinction in alveolar plosive consonants. Science. 190. 69-72.
Kuhl, P. K., & Miller, J. D. (1978). Speech perception by the chinchilla: identification
functions for synthetic VOT stimuli. The Journal of the Acoustical Society of
America. 63, 905-917.
Lecanuet, J.-P. (1996). Prenatal auditory experience. In: Deliege, L, & Sloboda, J.
(Eds.), Musical Beginnings: Origins and Development of Musical Competence.
Oxford: Oxford University Press. 3-34.
Lecanuet, J.-P., Granier-Deferre, C., & Busnel, M.-C. (1989). Differential fetal auditory
reactiveness as a function of stimulus characteristics and state. Seminars in
Perinatology. 13 (5). 421-429.

184
Lecanuet, J.-P., Granier-Deferre, C., & Busnel, M.-C. (1991). Prenatal familiarization.
In: Bonniec, G. P.-L., & Dolitsky, M. (Eds.), Language Bases... Discourse
Bases: Some Aspects of Contemnorarv French-Language Psycholinguistics
Research. Amsterdam, Netherlands: John Benjamins Publishing Company. 31-
44.
Lecanuet, J.-P., Granier-Deferre, C., & Busnel, M.-C. (1995). Human fetal auditory
perception. In: Lecanuet, J.-P., Fifer, W. P., Krasnegor, N. A., & Smotherman,
W. P. (Eds.), Fetal Development: A Psvchobiological Perspective. New Jersey:
Lawrence Erlbaum Associates, Inc. 239-262.
Lecanuet, J.-P., Granier-Deferre, C., Jacquet, A.-Y., & Busnel, M.-C. (1992).
Decelerative cardiac responsiveness to acoustic stimulation in the near term fetus.
Ouaterlv Journal of Experimental Psychology, 44b. 279-303.
Lecanuet, J.-P., Granier-Deferre, C., Jacquet, A.-Y., Capponi, I., & Ledro, L. (1993).
Prenatal discrimination of a male and a female voice uttering the same sentence.
Early Development and Parenting, 2 (4), 217-228.
Lecanuet, J.-P., & Schaal, B. (1996). Fetal sensory competencies. European Journal of
Obstetric & Gynecology and Reproductive Biology, 68, 1-23.
Lee, S., Potamianos, A., & Narayanan, S. (1999). Acoustics of children’s speech:
developmental changes of temporal and spectral parameters. The Journal of the
Acoustical Society of America. 105,1455-1468.
Liberman, A. M. (1982). On the finding that speech is special. American Psychologist,
37,148-167.
Liberman, A. M., & Mattingly, I. G. (1985). The motor theory of speech perception
revised. Cognition. 21, 1-36.
Lippe, W. R., & Rubel, E. W. (1983). Development of the place principle: tonotopic
organization. Science. 219. 514-516.
Lippe, W. R., & Rubel, E. W. (1985). Ontogeny of tonotopic organization of brain stem
auditory nuclei in the chicken: implications of development of the place principle.
Journal of Comparative Neurology. 237. 273-289.
Marty, R. (1962). Développment postnatal des réponses sensorielles du cortex cérébral
chez et le lapin. Archives d’Anatomie Microscopiaue et de Morphologie
Expérimentale. 51, 129-264.

185
Mehler, J., Bertoncini, J., Barriere, M„ & Jassik-Gerschenfeld, D. (1978). Infant
recognition of mother’s voice. Perception. 7,491-497.
Mehler, J., & Dupoux, E. (1994). What Infants Know: The New Cognitive Science of
Early Development (Translated by Southgate, P.). Cambridge, MA: Blackwell.
Mehler, J., Jusczyk, P., Lamberte, G., Halsted, N., Bertoncini, J., & Amiel-Tison, C.
(1988). A precursor of language acquisition in young infants. Cognition. 29.
143-178.
Miller, G. A., & Nicely, P. E. (1955). An Analysis of perceptual confusions among
some English consonants. The Journal of the Acoustical Society of America. 27.
338-352,
Mills, D. M., Norton S. J., & Rubel, E. W. (1994). Development of active and passive
mechanics in the mammalian cochlea. Auditory Neuroscience, 1, 77-99.
Mills, D. M., & Rubel, E. W. (1996). Development of the cochlear amplifier. The
Journal of the Acoustical Society of America. 100. 1-15.
Mills, M., & Melhuish, E. (1974). Recognition of mother’s voice in early infancy.
Nature. 252 Í8J. 123-124.
Moon, C. M., Cooper, R. P., & Fifer, W. P. (1993). Two-day-olds prefer their native
language. Infant Behavior and Development. 16, 495-500.
Moon, C. M., & Fifer, W. P. (1990). Syllables as signals for 2-day-old infants. Infant
Behavior and Development. 13. 377-390.
Northern, J. L., & Downs, M. P. (1991). Hearing in Children 14th Edition). Baltimore,
MD: Williams & Wilkins.
Ohala, J. J. (1996). Speech perception is hearing sounds, not tongues. The Journal of
the Acoustical Society of America. 99. 1718-1725.
Peck, J. E. (1994). Development of hearing, part II: embryology. Journal of American
Academic of Audiology. 5,359-365.
Penrod, J. P. (1985). Speech discrimination testing. In: Katz. J. CEd.l. Handbook of
Clinical Audiology (3rd Edition). Baltimore, MD: Williams & Wilkins. 235-
255.
Peters, A. J. M., Abrams, R. M., Gerhardt, K. J., & Griffiths, S. K. (1993a).
Transmission of airborne sound from 50-20,000 Hz into the abdomen of sheep.
Journal of Low Frequency Noise and Vibration. 12. 16-24.

186
Peters, A. J. M., Gerhardt, K. J., Abrams, R. M., & Longmate, J. A. (1993b). Three-
dimensional intraabdominal sound pressures in sheep produced by airborne
stimuli. American Journal of Obstetric and Gynecology. 169. 1304-1315.
Peterson, G. E., & Barney, H. L. (1952). Control methods used in a study of the vowels.
The Journal of the Acoustical Society of America. 24. 175-184.
Pickles, J. O. (1988). An Introduction to the Physiology of Hearing Í2nd Edition). San
Diego, CA: Academic Press, Inc.
Pollack, I. (1948). Effects of high pass and low pass filtering on the intelligibility of
speech in noise. The Journal of the Acoustical Society of America. 20,259-266.
Pujol, R., & Hilding, D. (1973). Anatomy and physiology of the onset of auditory
function. Acta Otoloarvngologv (Stockholm). 76. 1-11.
Pujol, R., Lavigne-Rebillard, M., & Lenoir, M. (1998). Development of sensory and
neural structures in the mammalian cochlea. In: Rubel, E. W., Popper, A. N., &
Fay, R. R. (Eds.-). Development of Auditory System. New York: Springer-
Verlag New York Inc. 146-192.
Pujol, R., Lavigne-Rebillard, M., & Uziel, A. (1989). Physiological correlates of
development of the human cochlea. Seminars in Perinatology. 14 (41. 275-280.
Pujol, R., & Uziel, A. (1989). Auditory development: Peripheral aspects. In: Timiras,
P.S., & Meisami, E. (Eds.), Ftandbook of Human Biologic Developmental
Biology, Vol.I: Neural. Sensory. Motor, and Integrative Development. Part B:
Sensory, Motor, and Integrative Development. Boca Raton, FL: CRC Press. 109-
BO.
Querleu, D., Renard, X., Boutteville, C., & Crepin, G. (1989). Hearing by the human
fetus? Seminars in Perinatology. 13 (5). 409-420.
Querleu, D., Renard, X., & Crépin, G. (1981). Perception auditive et réactivité foetale
aux stimulations sonores. Journal of Gynecology & Obstetric and Biological
Reproduction. 10. 307-314.
Querleu, D., Renard, X., Versyp, F., Paris-Delrue, L., & Crepin, G. (1988a). Fetal
hearing. European Journal of Obstetric & Gynecology and Reproductive Biology.
29, 191-212.
Querleu, D., Renard, X., Versyp, F., Paris-Delrue, L., & Vervoot, P. (1988b). Intra-
amniotic transmission of the human voice. Review of French Obstetric &
Gynecology. 83 (11. 43-50.

187
Richards, D. S., Frentzen, B., Gerhardt, K. J., McCann, M. E., & Abrams, R. M. (1992).
Sound levels in the human uterus. Obstetrics & Gynecology. 80.186-190.
Romand, R. (1987). Tonotopic evolution during development. Hearing Research, 28,
117-123.
Romand, R., & Romand, M.-R. (1982). Myelination kinetics of spiral ganglion cells.
Journal of Comparative Neurology. 204. 933-942.
Rosner, B. S., & Doherty, N. E. (1979). The response of neonates to intra-uterine
sounds. Developmental Medicine and Child Neurology. 21. 723-729.
Rubel, E. W. (1978). Ontogeny of structure and function in the vertebrate auditory
system. In: Jacobson, M. (Ed.), Handbook of Sensory Physiology, Development
of Sensory Systems (Vol. 1X1. New York: Springer-Verlag Press. 135-237.
Rubel, E. W. (1984). Ontogeny of auditory system function. Annual Review of
Physiology. 46. 213-219.
Rubel, E. W. (1985a). Auditory system development. In: Gottlieb, G., & Krasnegor, N.
A. (T.ds.l. Measurement of Audition and Vision in the First Year of Postnatal
Life: A Methodological Overview. Norwood, NJ: Ablex Publishing Corporation.
53-90.
Rubel, E. W. (1985b). Strategies and problems for future studies of auditory
development. Acta Otolaryngology (Stockholm*). Suppl. 421. 114-128.
Rubel, E. W., & Ryals, B. M. (1983). Development of the place principle: acoustic
trauma. Science. 219. 512-514.
Rubel. E. W., Smith, D. J., & Miller, L. C. (1976). Organization and development of
brain stem auditory nuclei of the chicken: ontogeny of nucleus magnocellularis
and nucleus laminiaris. Journal of comparative Neurology. 166. 469-490.
Ruben, R. J. (1992). The ontogeny of human hearing. Acta Otolarvngolology
(Stockholm). 112.192-196.
Rübsamen, R., & Lippe, W. R. (1998). The development of cochlear function. In:
Rubel, E. W., Popper, A. N., & Fay, R. R. (Eds.), Development of Auditory
System. New York: Springer-Verlag New York Inc. 193-270.
Salk, L. (1962). Mother’s heartbeat as an imprinting stimulus. Transactions of the New
York Academy of Sciences. Series 2 (41. 753-763.

188
Schill, H. A. (1985). Threshold for speech. In: Katz. J. (Ed.1. Handbook of Clinical
Audiology (3rd Edition). Baltimore, MD: Williams & Wilkins. 224-234.
Schweitzer, L., & Cant, N. B. (1984). Development of the cochlear innervation of the
dorsal cochlear nucleus of the hamster. Journal of Comparative Neurology. 225.
228-243.
Shahidullah, S., & Hepper, P. G. (1993). The developmental origins of fetal
responsiveness to an acoustic stimulus. Journal of Reproductive and Infant
Psychology. 11. 135-142.
Shahidullah, S., & Hepper, P. G. (1994). Frequency discrimination by the fetus. Early
Human Development. 36, 13-26.
Smotherman, W. P., & Robinson, S. R. (1995). Tracing developmental trajectories into
the prenatal period. In: Lecanuet, J.-P., Fifer, W. P., Krasnegor, N. A., &
Smotherman, W. P. (Eds.), Fetal Development: A Psvchobiological Perspective.
New Jersey: Lawrence Erlbaum Associates, Inc. 15-32.
Spence, M. J., & DeCasper, A. J. (1987). Prenatal Experience with low-frequency
maternal-voice sounds influence neonatal perception of maternal voice samples.
Infant Behavior and Development. 10. 133-142.
Starr, A., Amlie, R. N., Martin, W. H., & Sanders, S. (1977). Development of auditory
function in newborn infants revealed by auditory brainstem potentials. Pediatrics.
60 (6). 831-839.
Thornton, A. R., & Raffin, M. J. M. (1978). Speech-discrimination scores modeled as a
binomial variable. Journal of Speech and Hearing Research. 21., 507-518.
Vince, M. A., Armitage, S. E., Baldwin, B. A., Toner, J., & Moore, B. C. J. (1982). The
sound environment of the foetal sheep. Behaviour. 81, 296-315.
Vince, M. A., Billing, A. E„ Baldwin, B. A., Toner, J. N., & Weller, C. (1985).
Maternal vocalizations and other sounds in the fetal lamb's sound environment.
Early Human Development. 11. 179-190.
Walker, D., Grimwade, J., & Wood, C. (1971). Intrauterine noise: a component of the
fetal environment. American Journal of Obstetric and Gynecology. 109. 91-95.
Walsh, E. J., & McGee, J. (1990). Development of auditory coding in the central
nervous system: implications for in ulero hearing. Seminars in Perinatology. 14
£4), 281-293.

189
Wang, M. D. (1976). SINFA: multivariate uncertainty analysis for confusion matrices.
Behavior Research Methods and Instrumentation. 8,471-472.
Wang, M. D., & Bilger, R. C. (1973). Consonant confusions in noise: a study of
perceptual features. The Journal of the Acoustical Society of America. 54. 1248-
1266.
Wang, M. D., Reed, C. M, & Bilger, R. C. (1978). A comparison of the effects of
filtering and sensorineural hearing loss on patterns of consonant confusions.
Journal of Speech and Hearing Research. 21. 5-36.
Wilkins, W. K., & Wakefield, J. (1995). Brain evolution and neurolinguistic
preconditions. Behavioral and Brain Sciences. 18. 161-226.
Winer, B. J., Brown, D. R., & Michels, K. M. (1991). Statistical Principles in
Experimental Design (3rd Edition). New York: McGraw-Hill, Inc.
Wollack, C. H. (1963). The auditory activity of the sheep (ovis aries). Journal of
Auditory Research. 3, 121-132.
Yancey, D., & Dallos, P. (1985). Ontogenetic changes in cochlear characteristic
frequency at a basal turn location as reflected in the summating potential. Hearing
Research. 18. 189-195.
Yost, W. A. (1994). Fundamentals of Hearing: An Introduction (3rd Edition). San
Diego, CA: Academic Press, Inc.

BIOGRAPHICAL SKETCH
Xinyan Huang was bom on July 9, 1964, in Beijing, China, where he was raised
and educated. He obtained his M.D. degree from Beijing Medical University in 1988,
and started his residency in otolaryngology-head and neck surgery at the Third Teaching
Hospital, Beijing Medical University, where he was honored as Doctor of the Year in
1991 and as Teacher of the Year in 1992. Treating patients with sensorineural hearing
loss stimulated his interest in studying hearing science. As a result, he came to the
United States to pursue his Ph.D. degree after completing his otolaryngology residency in
1993. As a Graduate Research Associate, he joined the Perinatology Research
Laboratory at the University of Florida in 1993. Working under the direction of Dr.
Kenneth J. Gerhardt and Dr. Robert M. Abrams, he had been involved in several research
projects on fetal hearing. In 1998, he was honored to receive the Outstanding Academic
Achievement Award by the University of Florida. After completed his graduate study, he
will begin his postdoctoral training at San Diego, California. He married Min Feng in
1993. Their son, Alvin Tianyi Huang, was bom on June 17, 1999.
190

I certify that I have read this study and that in my opinion it conforms to
acceptable standards of scholarly presentation and is fully adequate, in scope and quality,
as a dissertation for the degree of Doctor of Philosophy.
pfr
Kenneth J. Oerhardt, Chairman
Professor of Communication Sciences
and Disorders
1 certify that I have read this study and that in my opinion it conforms to
acceptable standards of scholarly presentation and is fully adequate, in scope and quality,
as a dissertation for the degree of Doctor of Philosophy.
Associate Professor of Communication
Sciences and Disorders
I certify that I have read this study and that in my opinion it conforms to
acceptable standards of scholarly presentation and is fully adequate, in scope and quality,
as a dissertation for the degree of Doctor of Philosophy.
-^
F. JosephiCemker
Professor of Communicative Disorders
I certify that I have read this study and that in my opinion it conforms to
acceptable standards of scholarly presentation and is fully adequate, in scope and quality,
as a dissertation for the degree of Doctor of Philosophy.
Robert M. Abrams
Professor of Obstetrics and Gynecology

I certify that I have read this study and that in my opinion it conforms to
acceptable standards of scholarly presentation and is fully adequate, in scope and quality,
as a dissertation for the degree of Doctor of Philosophy.
Professor of Anatomy and Cell Biology
This dissertation was submitted to the Graduate Faculty of the Department of
Communication Sciences and Disorders in the College of Liberal Arts and Sciences and
to the Graduate School and was accepted as partial fulfillment of the requirements for the
degree of Doctor of Philosophy.
August 1999
Dean, Graduate School

LD
1780
1995



xml version 1.0 encoding UTF-8
REPORT xmlns http:www.fcla.edudlsmddaitss xmlns:xsi http:www.w3.org2001XMLSchema-instance xsi:schemaLocation http:www.fcla.edudlsmddaitssdaitssReport.xsd
INGEST IEID EUH4BMYWP_2CU14P INGEST_TIME 2013-03-27T17:07:59Z PACKAGE AA00013620_00001
AGREEMENT_INFO ACCOUNT UF PROJECT UFDC
FILES



PAGE 1

,17(//,*,%,/,7< 2) 63((&+ 352&(66(' 7+528*+ 7+( &2&+/($ 2) )(7$/ 6+((3 ,1 87(52 %\ ;,1<$1 +8$1* $ ',66(57$7,21 35(6(17(' 72 7+( *5$'8$7( 6&+22/ 2) 7+( 81,9(56,7< 2) )/25,'$ ,1 3$57,$/ )8/),//0(17 2) 7+( 5(48,5(0(176 )25 7+( '(*5(( 2) '2&725 2) 3+,/2623+< 81,9(56,7< 2) )/25,'$

PAGE 2

'HGLFDWHG WR P\ ZLIH 0LQ )HQJ

PAGE 3

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

PAGE 4

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

PAGE 5

5HFRUGLQJ 6SHHFK 6WLPXOL 3HUFHSWXDO 7HVWLQJ 6XEMHFWV 6SHHFK 6WLPXOL 3URFHGXUHV 'DWD $QDO\VHV 6WDWLVWLFDO $QDO\VHV ,QIRUPDWLRQ $QDO\VHV $FRXVWLF $QDO\VHV 5(68/76 $1' ',6&866,21 ,QWHOOLJLELOLW\ &RQVRQDQW )HDWXUH 7UDQVPLVVLRQ $FRXVWLF $QDO\VHV RI 9RZHO 7UDQVPLVVLRQ 6800$5< $1' &21&/86,216 $33(1',&(6 $ 68%-(&7 5(63216( 6+((7 % 5$: '$7$ )520 68%-(&7 5(63216( )2506 & 5$: '$7$ )520 $&2867,& $1$/<6(6 2) 92:(/6 5()(5(1&(6 %,2*5$3+,&$/ 6.(7&+ Y

PAGE 6

/,67 2) 7$%/(6 7DEOH SDJH 3HUFHSWXDO WHVWV 9&9 VWLPXOXV LQWHOOLJLELOLW\ VFRUHV &9& VWLPXOXV LQWHOOLJLELOLW\ VFRUHV $129$ VXPPDU\ WDEOH IRU 9&9 VWLPXOL 3RVW KRF PXOWLSOH FRPSDULVRQV 1HZPDQ.HXOV WHVWf IRU 9&9 VWLPXOL $129$ VXPPDU\ WDEOH IRU &9& VWLPXOL 3RVW KRF PXOWLSOH FRPSDULVRQV 1HZPDQ.HXOV WHVWf IRU &9& VWLPXOL &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG LQ DLU DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG LQ DLU DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG LQ WKH XWHUXV DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG LQ WKH XWHUXV DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG IURP &0H[ WHUR DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG IURP &0H[ WHUR DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG IURP &0LWL WHUR DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG IURP &0P WHUR DW G% 63/ YL

PAGE 7

&RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG LQ DLU DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG LQ DLU DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG LQ WKH XWHUXV DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG LQ WKH XWHUXV DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG IURP &0H[ WHUR DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG IURP &0H[ WHUR DW G% 63/ L &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG IURP &0LQ WHUR DW G% 63/ &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG IURP &0LQ WHUR DW G% 63/ &RQGLWLRQDO SHUFHQWDJH RI YRLFLQJ PDQQHU DQG SODFH LQIRUPDWLRQ UHFHLYHG RI ELWV VHQWf IRU HDFK WDONHU UHFRUGLQJ ORFDWLRQ DQG VWLPXOXV OHYHO FRQGLWLRQ IRU WKH QRQVHQVH V\OODEOHV 9&9f $YHUDJH IXQGDPHQWDO IUHTXHQFLHV )f DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )f ) )f IRU ILYH YRZHOV SURGXFHG E\ HDFK WDONHU DQG UHFRUGHG LQ DLU 0HDQ DQG VWDQGDUG GHYLDWLRQ 6'f RI UHODWLYH LQWHQVLW\ OHYHOV G%f RI IXQGDPHQWDO IUHTXHQF\ )f DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV ) ))f IRU YRZHO LOO SURGXFHG E\ HDFK WDONHU DW GLIIHUHQW UHFRUGLQJ VLWHV LQ WKH G% FRQGLWLRQ 0HDQ DQG VWDQGDUG GHYLDWLRQ 6'f RI UHODWLYH LQWHQVLW\ OHYHOV G%f RI IXQGDPHQWDO IUHTXHQF\ )f DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV ) ) )f IRU YRZHO LOO SURGXFHG E\ HDFK WDONHU DW GLIIHUHQW UHFRUGLQJ VLWHV LQ WKH G% FRQGLWLRQ 0HDQ DQG VWDQGDUG GHYLDWLRQ 6'f RI UHODWLYH LQWHQVLW\ OHYHOV G%f RI IXQGDPHQWDO IUHTXHQF\ )f DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )f ) )f IRU YRZHO ,H, SURGXFHG E\ HDFK WDONHU DW GLIIHUHQW UHFRUGLQJ VLWHV LQ WKH G% FRQGLWLRQ 9LO

PAGE 8

0HDQ DQG VWDQGDUG GHYLDWLRQ 6'f RI UHODWLYH LQWHQVLW\ OHYHOV G%f RI IXQGDPHQWDO IUHTXHQF\ )f DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )f ) )f IRU YRZHO UH SURGXFHG E\ HDFK WDONHU DW GLIIHUHQW UHFRUGLQJ VLWHV LQ WKH G% FRQGLWLRQ 0HDQ DQG VWDQGDUG GHYLDWLRQ 6'f RI UHODWLYH LQWHQVLW\ OHYHOV G%f RI IXQGDPHQWDO IUHTXHQF\ )f DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )f ))f IRU YRZHO $ SURGXFHG E\ HDFK WDONHU DW GLIIHUHQW UHFRUGLQJ VLWHV LQ WKH G% FRQGLWLRQ 6XPPDU\ RI DFRXVWLF DQDO\VHV RI YRZHOV YLLL

PAGE 9

/,67 2) ),*85(6 )LJXUH SDJH 6FKHPDWLF GUDZLQJ VKRZLQJ WKH DQLPDO DQG WKH VHWXS RI GHYLFHV IRU VWLPXOXV JHQHUDWLRQ VWLPXOXV PHDVXUHPHQW DQG UHFRUGLQJ LQ DLU LQ WKH XWHUXV DQG IURP WKH IHWDO LQQHU HDU FRFKOHDU PLFURSKRQLFf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f DQG D IHPDOH )f WDONHU LQ DLU $f LQ WKH XWHUXV 8f IURP WKH IHWDO &0 H[ WHUR ;f DQG IURP WKH IHWDO &0 LQ WHUR ,f DW G% +f DQG G% /f 63/ 6SHFWURJUDSKLF UHFRUGLQJV RI f0DUN WKH ZRUG ODVKf DW GLIIHUHQW UHFRUGLQJ FRQGLWLRQV 0HDQ RI LQWHQVLW\ OHYHOV G% UHODWLYHf RI IXQGDPHQWDO IUHTXHQF\ )f DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )f ) DQG )f IRU YRZHO ,,, SURGXFHG E\ ERWK WDONHUV UHFRUGHG DW GLIIHUHQW ORFDWLRQV DW G% 63/ O[

PAGE 10

0HDQ RI LQWHQVLW\ OHYHOV G% UHODWLYHf RI IXQGDPHQWDO IUHTXHQF\ )f DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )f ) DQG )f IRU YRZHO SURGXFHG E\ ERWK WDONHUV UHFRUGHG DW GLIIHUHQW ORFDWLRQV DW G% 63/ 0HDQ RI LQWHQVLW\ OHYHOV G% UHODWLYHf RI IXQGDPHQWDO IUHTXHQF\ )f DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV ) )! DQG )f IRU YRZHO V SURGXFHG E\ ERWK WDONHUV UHFRUGHG DW GLIIHUHQW ORFDWLRQV DW G% 63/ 0HDQ RI LQWHQVLW\ OHYHOV G% UHODWLYHf RI IXQGDPHQWDO IUHTXHQF\ )ff DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )f ) DQG )f IRU YRZHO SURGXFHG E\ ERWK WDONHUV UHFRUGHG DW GLIIHUHQW ORFDWLRQV DW G% 63/ 0HDQ RI LQWHQVLW\ OHYHOV G% UHODWLYHf RI IXQGDPHQWDO IUHTXHQF\ )f DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )f ) DQG )f IRU YRZHO $ SURGXFHG E\ ERWK WDONHUV UHFRUGHG DW GLIIHUHQW ORFDWLRQV DW G% 63/ [

PAGE 11

$EVWUDFW RI 'LVVHUWDWLRQ 3UHVHQWHG WR WKH *UDGXDWH 6FKRRO RI WKH 8QLYHUVLW\ RI )ORULGD LQ 3DUWLDO )XOILOOPHQW RI WKH 5HTXLUHPHQWV IRU WKH 'HJUHH RI 'RFWRU RI 3KLORVRSK\ ,17(//,*,%,/,7< 2) 63((&+ 352&(66(' 7+528*+ 7+( &2&+/($ 2) )(7$/ 6+((3 ,1 87(52 %\ ;LQ\DQ +XDQJ $XJXVW &KDLUPDQ .HQQHWK *HUKDUGW 0DMRU 'HSDUWPHQW &RPPXQLFDWLRQ 6FLHQFHV DQG 'LVRUGHUV 7KH LQWHOOLJLELOLW\ RI VSHHFK VWLPXOL UHFRUGHG IURP WKH IHWDO VKHHS LQQHU HDU FRFKOHDU PLFURSKRQLF &0f LQ WHUR ZDV GHWHUPLQHG SHUFHSWXDOO\ XVLQJ D JURXS RI XQWUDLQHG MXGJHV $ IHWXV ZDV SUHSDUHG IRU DFXWH UHFRUGLQJV GXULQJ D VXUJLFDO SURFHGXUH 7ZR VHSDUDWH OLVWV RQH RI PHDQLQJIXO DQG RQH RI QRQPHDQLQJIXO VSHHFK ZHUH VSRNHQ E\ D PDOH DQG D IHPDOH WDONHU GHOLYHUHG WKURXJK D ORXGVSHDNHU WR WKH VLGH RI D SUHJQDQW HZH DQG UHFRUGHG ZLWK DQ DLU PLFURSKRQH D K\GURSKRQH SODFHG LQVLGH WKH XWHUXV DQG DQ HOHFWURGH VHFXUHG WR WKH URXQG ZLQGRZ RI WKH IHWXV LQ WHUR 3HUFHSWXDO WHVW DXGLR FRPSDFW GLVFV &'Vf JHQHUDWHG IURP WKHVH UHFRUGLQJV ZHUH SOD\HG WR MXGJHV 7KH LQWHOOLJLELOLW\ RI WKH SKRQHPHV UHFRUGHG LQ DLU ZDV VLJQLILFDQWO\ JUHDWHU WKDQ WKH LQWHOOLJLELOLW\ RI WKHVH VWLPXOL ZKHQ UHFRUGHG IURP ZLWKLQ WKH XWHUXV 7KH LQWHOOLJLELOLW\ RI WKH SKRQHPHV UHFRUGHG IURP &0 H[ WHUR ZDV VLJQLILFDQWO\ JUHDWHU WKDQ IURP &0 LQ WHUR 2YHUDOO PDOH DQG IHPDOH WDONHU LQWHOOLJLELOLW\ VFRUHV UHFRUGHG ZLWKLQ WKH XWHUXV DYHUDJHG [L

PAGE 12

b DQG b UHVSHFWLYHO\ :KHQ UHFRUGHG IURP WKH IHWDO &0 LQ WHUR LQWHOOLJLELOLW\ VFRUHV DYHUDJHG b DQG b IRU WKH PDOH DQG IHPDOH WDONHUV UHVSHFWLYHO\ $Q DQDO\VLV RI WKH WUDQVPLVVLRQ RI FRQVRQDQW IHDWXUH LQIRUPDWLRQ UHYHDOHG WKDW fYRLFLQJf LV EHWWHU WUDQVPLWWHG LQWR WKH XWHUXV DQG LQWR WKH IHWDO LQQHU HDU LQ WHUR WKDQ fPDQQHUf RU fSODFHf 9RLFLQJ LQIRUPDWLRQ IRU WKH PDOH DV ZHOO DV PDQQHU DQG SODFH LQIRUPDWLRQ ZDV EHWWHU SUHVHUYHG LQ WKH IHWDO LQQHU HDU LQ WHUR WKDQ IRU WKH IHPDOH 6SHFWUDO DQDO\VHV RI YRZHOV VKRZHG WKDW WKH IXQGDPHQWDO IUHTXHQF\ )f DQG WKH ILUVW WKUHH IRUPDQWV )f ) DQG )f ZHUH ZHOO SUHVHUYHG LQ WKH XWHUXV UHFRUGLQJV IRU ERWK WDONHUV EXW RQO\ ) )f DQG ) +]f ZHUH SHUFHLYHG LQ WKH IHWDO LQQHU HDU LQ WHUR 2QO\ WKH ORZHU IUHTXHQF\ FRQWHQWV RI YRZHOV ZHUH SUHVHQW LQ IHWDO LQQHU HDU UHFRUGLQJV 7KLV VWXG\ GHPRQVWUDWHG WKH SUHVHQFH RI H[WHUQDO VSHHFK VLJQDOV LQ WKH IHWDO LQQHU HDU LQ WHUR DQG GHVFULEHG WKH W\SH RI SKRQHWLF LQIRUPDWLRQ WKDW ZDV GHWHFWHG DW WKH IHWDO LQQHU HDU LQ 8WHUR [LL

PAGE 13

&+$37(5 ,1752'8&7,21 7KHUH LV RYHUZKHOPLQJ HYLGHQFH WKDW WKH KXPDQ IHWXV GHWHFWV DQG UHVSRQGV WR VRXQG LQ WHUR 4XHUOHX HW DO +HSSHU /HFDQXHW DQG 6FKDDO f 6WXGLHV LQ SUHJQDQW KXPDQV :DONHU *ULPZDGH DQG :RRG 4XHUOHX HW DO D 5LFKDUGV HW DO f DQG VKHHS $UPLWDJH %DOGZLQ DQG 9LQFH 9LQFH HW DO *HUKDUGW $EUDPV DQG 2OLYHU f KDYH VKRZQ WKH H[LVWHQFH RI D ULFK GLYHUVLW\ RI VRXQG LQ WKH IHWDO HQYLURQPHQW KHDYLO\ GRPLQDWHG E\ WKH PRWKHUnV YRLFH DQG RWKHU LQWHUQDO QRLVHV DQG SHUPHDWHG E\ YDULHG UK\WKPLF DQG WRQDO VRXQGV IURP WKH H[WHUQDO HQYLURQPHQW 7KH KXPDQ IHWXV KDV D ZHOOGHYHORSHG KHDULQJ PHFKDQLVP E\ WKH VL[WK PRQWK RI JHVWDWLRQ 5XEHO D 3XMRO DQG 8]LHO 3XMRO /DYLJQH5HELOODUG DQG 8]LHO f 'XULQJ WKH ODVW WULPHVWHU VRXQG H[SRVXUH PD\ KDYH D SURQRXQFHG HIIHFW RQ IHWDO EHKDYLRU DQG FHQWUDO QHUYRXV V\VWHP PDWXUDWLRQ 6SHHFK SHUFHSWLRQ DQG YRLFH UHFRJQLWLRQ E\ WKH QHZERUQ PD\ UHVXOW GLUHFWO\ IURP LWV SUHQDWDO H[SHULHQFH )LIHU DQG 0RRQ f /LQJXLVWLF WKHRULVWV KDYH SURSRVHG WZR DOWHUQDWLYH K\SRWKHVHV UHJDUGLQJ ODQJXDJH GHYHORSPHQW WKDW LQIDQWV XSRQ ELUWK DUH HTXLSSHG ZLWK HLWKHU D JHQHUDOL]HG DXGLWRU\ PHFKDQLVP RU D VSHFLDOL]HG VSHHFKVSHFLILF PHFKDQLVP GHVLJQHG IRU SHUFHSWLRQ RI VSHHFK 6RPH WKHRULVWV KROG WKDW KXPDQ LQIDQWV DUH ERP ZLWK D VSHHFK PRGXOH D PHFKDQLVP GHVLJQHG VSHFLILFDOO\ IRU SURFHVVLQJ WKH FRPSOH[ DQG LQWULFDWH DFRXVWLF

PAGE 14

VLJQDOV QHHGHG E\ KXPDQV WR FRPPXQLFDWH ZLWK RQH DQRWKHU /LEHUPDQ )RGRU /LEHUPDQ DQG 0DWWLQJO\ :LONLQV DQG :DNHILHOG )RZOHU f $Q DOWHUQDWLYH WKHRU\ RI WKH QHRQDWHnV LQLWLDO VWDWH VXJJHVWV WKDW LQIDQWV HQWHU WKH ZRUOG ZLWKRXW VSHFLDOL]HG PHFKDQLVPV GHGLFDWHG WR VSHHFK DQG ODQJXDJH EXW UDWKHU UHVSRQG WR VSHHFK XVLQJ JHQHUDO VHQVRU\ PRWRU DQG FRJQLWLYH DELOLWLHV $VOLQ .XKO -XVF]\N 2KDOD )LWFK 0LOOHU DQG 7DOODO f :KLFK WKHRU\ LI HLWKHU DSSOLHV WR WKH KXPDQ IHWXV LV QRW NQRZQ :KDW LV NQRZQ LV WKDW WKH IHWXV LV EHJLQQLQJ WKH G\QDPLF SURFHVV RI DFTXLULQJ WKH QHFHVVDU\ VNLOOV IRU VSHHFK DQG ODQJXDJH DFTXLVLWLRQ GXULQJ SUHQDWDO OLIH LQ WHUR 4XHUOHX HW DO /HFDQXHW *UDQLHU'HIHUUH DQG %XVQHO /HFDQXHW DQG 6FKDDO f 7KH PDWHUQDO YRLFH LV D QDWXUDOO\ RFFXUULQJ DQG VDOLHQW VWLPXOXV LQ WHUR WKDW RFFXUV GXULQJ D FUXFLDO WLPH SHULRG RI IHWDO RQWRJHQ\ 4XHUOHX HW DO D %HQ]DTXHQ HW DO 5LFKDUGV HW DK f LQ ZKLFK VHYHUDO SV\FKRELRORJLFDO V\VWHPV LQFOXGLQJ WKH DXGLWRU\ V\VWHP DUH GHYHORSLQJ 7KH LPPHGLDWH HIIHFWV RI H[SRVXUH WR WKH PRWKHUfV YRLFH RQ WKH IHWXV PD\ SURYLGH D ZD\ RI WUDFNLQJ DXGLWRU\ V\VWHP GHYHORSPHQW DV ZHOO DV PHDVXULQJ IHWDO DELOLW\ WR SURFHVV VHQVRU\ LQIRUPDWLRQ )LIHU DQG 0RRQ f )HWDO DXGLWRU\ GLVFULPLQDWLRQ KDV DOVR OHG WR WKH K\SRWKHVLV WKDW SUHQDWDO H[SHULHQFH ZLWK DXGLWRU\ VWLPXODWLRQ LV WKH SUHFXUVRU WR SRVWQDWDO OLQJXLVWLF GHYHORSPHQW &RRSHU DQG $VOLQ 4XHUOHX HW DK 5XEHQ $EUDPV *HUKDUGW DQG $QWRQHOOL f 'H&DVSHU DQG KLV FROOHDJXHV 'H&DVSHU DQG )LIHU 'H&DVSHU DQG 3UHVFRWW f GHPRQVWUDWHG WKDW QHZERUQ LQIDQWV SUHIHUUHG WKHLU PRWKHUnV YRLFH RYHU WKDW RI RWKHU WDONHUV :KLOH WKLV SUHIHUHQFH ZDV DVVXPHG WR EH WKH SURGXFW RI LQ WHUR H[SRVXUH WR WKH

PAGE 15

PRWKHUnV YRLFH DQG VXJJHVWHG WKDW WKH IHWXV GHWHFWHG PDWHUQDO YRFDOL]DWLRQV DQG UHWDLQHG PHPRULHV RI KHU VSHHFK SDWWHUQV LW LV QRW NQRZQ ZKDW VSHHFK LQIRUPDWLRQ DFWXDOO\ UHDFKHV WKH IHWDO LQQHU HDU QRU WKH H[WHQW WR ZKLFK WKH DXGLWRU\ V\VWHP UHVSRQGV WR H[WHUQDOO\ JHQHUDWHG VSHHFK 4XHUOHX HW DO Ef DQG PRUH UHFHQWO\ *ULIILWKV HW DO f UHSRUWHG RQ WKH LQWHOOLJLELOLW\ RI VSHHFK UHFRUGHG ZLWK D K\GURSKRQH LQ WKH KXPDQ 4XHUOHX HW DO Ef DQG VKHHS *ULIILWKV HW DO f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f :KLOH WKH UHVXOWV RI WKHVH VWXGLHV UHIOHFW WKH SHUFHSWLELOLW\ RI WKH VSHHFK HQHUJLHV SUHVHQW LQ WKH DPQLRWLF IOXLG WKH\ GR QRW VSHFLI\ ZKDW VSHHFK HQHUJ\ PLJKW EH SUHVHQW DW WKH OHYHO RI IHWDO LQQHU HDU 0HDVXUHV RI DFRXVWLF WUDQVPLVVLRQ WR WKH IHWDO LQQHU HDU DUH TXLWH OLPLWHG DW SUHVHQW *HUKDUGW HW DO f 0XFK ZRUN QHHGV WR EH FRPSOHWHG EHIRUH FRQFOXVLRQV FDQ EH GUDZQ UHJDUGLQJ ZKDW VSHHFK HQHUJLHV UHDFK DQG DUH DEOH WR EH SHUFHLYHG E\ WKH IHWXV 7KH SUHVHQW H[SHULPHQW ZDV GHVLJQHG WR HYDOXDWH WKH LQWHOOLJLELOLW\ RI VSHHFK SURGXFHG WKURXJK D ORXGVSHDNHU DQG UHFRUGHG ZLWK DQ HOHFWURGH VHFXUHG WR WKH IHWDO VKHHS URXQG ZLQGRZ 7KH HOHFWURGH UHFRUGHG D ELRHOHFWULF SRWHQWLDO FDOOHG WKH FRFKOHDU PLFURSKRQLF &0f 7KH &0 LV JHQHUDWHG DW WKH OHYHO RI WKH KDLU FHOOV DQG PLPLFV WKH

PAGE 16

LQSXW LQ DPSOLWXGH DQG IUHTXHQF\ *XOLFN *HVFKHLGHU DQG )ULVLQD f 5HFRUGLQJV RI WKH &0 UHSUHVHQW WKH WLPH GLVSODFHPHQW SDWWHUQV RI WKH EDVLODU PHPEUDQH DQG UHIOHFW WKH LQLWLDO UHVSRQVH RI WKH DXGLWRU\ SHULSKHU\ 7KH K\SRWKHVLV LV WKDW VSHHFK LV IXUWKHU GHJUDGHG DV LW SDVVHV LQWR WKH LQQHU HDU 6KHHS ZHUH XVHG LQ WKLV VWXG\ QRW RQO\ EHFDXVH VRXQG DWWHQXDWLRQ FKDUDFWHULVWLFV RI WKH DEGRPLQDO FRQWHQWV RI SUHJQDQW VKHHS DUH VLPLODU WR WKRVH RI SUHJQDQW ZRPHQ $UPLWDJH %DOGZLQ DQG 9LQFH 4XHUOHX HW DO D *HUKDUGW $EUDPV DQG 2OLYHU 5LFKDUGV HW DO f EXW DOVR EHFDXVH RI WKH SUHFRFLRXV KHDULQJ DQG WKH VLPLODULW\ RI DXGLWRU\ VHQVLWLYLW\ WR KXPDQV 6KHHSfV KHDULQJ LV RQO\ VOLJKWO\ SRRUHU WKDQ WKDW RI KXPDQV IRU IUHTXHQFLHV EHORZ DERXW +] :ROODFN f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

PAGE 17

7KH WUDQVPLVVLRQ RI YRLFLQJ PDQQHU DQG SODFH LQIRUPDWLRQ ZLOO EH EHWWHU IRU PDOHV WKDQ IRU IHPDOHV ZKHQ UHFRUGHG LQ WKH XWHUXV DQG IURP WKH LQQHU HDU RI WKH IHWXV LQ XOHUR $FRXVWLF HQHUJ\ LQ WKH VHFRQG DQG WKLUG IRUPDQWV RI YRZHOV PHDVXUHG LQ DLU IRU ERWK PDOH DQG IHPDOH WDONHUV ZLOO EH UHGXFHG ZKHQ UHFRUGHG LQ WKH XWHUXV DQG ZLOO EH UHGXFHG WR WKH QRLVH IORRU ZKHQ UHFRUGHG IURP WKH IHWDO LQQHU HDU LQ WHUR

PAGE 18

&+$37(5 5(9,(: 2) /,7(5$785( 7KH KXPDQ XQOLNH PRVW PDPPDOLDQ VSHFLHV LV ERP ZLWK KLJKO\ GHYHORSHG DXGLWRU\ VHQVLWLYLW\ %\ WKH WK ZHHN RI JHVWDWLRQ WKH VWUXFWXUHV RI WKH SHULSKHUDO DXGLWRU\ V\VWHP LQFOXGLQJ WKH RXWHU PLGGOH DQG LQQHU HDU DUH DQDWRPLFDOO\ OLNH WKDW RI DQ DGXOW WKXV HQDEOLQJ WKH IHWXV WR GHWHFW VRXQGV GXULQJ WKH ODVW WULPHVWHU RI SUHJQDQF\ 5XEHO D 3XMRO DQG 8]LHO 3XMRO /DYLJQH5HELOODUG DQG 8]LHO f 5HVSRQVLYHQHVV RI WKH IHWXV WR DXGLWRU\ VWLPXOL EHJLQV GXULQJ WKH WK ZHHN RI JHVWDWLRQ %LUQKRO] DQG %HQDFHUUDI 6KDKLGXOODK DQG +HSSHU f 0DWXUDWLRQ RI DXGLWRU\ SURFHVVLQJ FDSDELOLWLHV WDNHV SODFH WKURXJK SUHQDWDO DQG SHULQDWDO SHULRGV $Q DSSUHFLDWLRQ RI WKH SURFHVV RI DXGLWRU\ GHYHORSPHQW LV LPSRUWDQW QRW RQO\ IRU DQ XQGHUVWDQGLQJ RI WKH QRUPDO DXGLWRU\ V\VWHP EXW DOVR IRU DQ XQGHUVWDQGLQJ RI WKH LPSDFW RI SUHQDWDO VRXQG H[SHULHQFH RQ WKH SRVWQDWDO GHYHORSPHQW IURP VWUXFWXUDO IXQFWLRQDO WR EHKDYLRUDO GHYHORSPHQW /HFDQXHW DQG 6FKDDO f )HWDO +HDULQJ 'HYHORSPHQW RI WKH $XGLWRU\ 6\VWHP 7KH HDUOLHVW HPEU\RORJLFDO VLJQV RI WKH KXPDQ DXGLWRU\ DSSDUDWXV DUH WKLFNHQLQJV RI WKH HFWRGHUP RQ WKH VLGHV RI WKH KHDG ELODWHUDOO\ FDOOHG WKH DXGLWRU\ SODFRGHV $ERXW

PAGE 19

WKH UG GD\ RI JHVWDWLRQDO DJH *$f HDFK SODFRGH EHJLQV WR LQYDJLQDWH WR IRUP WKH DXGLWRU\ SLW ZKLFK WKHQ VSOLWV RII IURP WKH RYHUO\LQJ HFWRGHUP WR IRUP DQ RWRF\VW DW WKH WK GD\ $W DERXW WR ZHHNV WKH RWRF\VW GLYLGHV LQWR WZR SDUWV WKH YHVWLEXODU SRUWLRQ DQG WKH FRFKOHD 'XULQJ WKH WK WKURXJK WK ZHHN WKH WZR DQG D KDOI FRLOV RI WKH FRFKOHD DUH DWWDLQHG &RPSOHWH PDWXUDWLRQ RI VHQVRU\ DQG VXSSRUWLQJ FHOOV LQ WKH FRFKOHD GRHV QRW RFFXU XQWLO WKH WK ZHHN ZKHQ WKH FRFKOHD UHDFKHV DGXOW VL]H 1RUWKHUQ DQG 'RZQV 3HFN f &\WRGLIIHUHQWLDWLRQ RFFXUV GXULQJ WKH WK WR WK ZHHNV ZLWKLQ WKH FRFKOHDU GXFW ZKHUH WKHUH LV D WKLFNHQLQJ RI HSLWKHOLXP )URP WKH UG WR WKH WK PRQWK WKH WKLFNHQLQJ HSLWKHOLXP GLIIHUHQWLDWHV LQWR WKH GLVWLQFW UHFHSWRU DQG VXSSRUWLQJ FHOOV RI WKH RUJDQ RI &RUG &RPSDULQJ ZLWK WKDW IRXQG LQ RWKHU PDPPDOV ZKHQ WKH ILUVW UHVSRQVHV WR VRXQG FDQ EH HYRNHG WKH KXPDQ FRFKOHD KDV DFKLHYHG D IXQFWLRQDO VWDJH E\ ZHHNV RI JHVWDWLRQ 3XMRO DQG 8]LHO f $W WKLV WLPH WKH FRFKOHD PD\ KDYH KLJK WKUHVKROGV DQG YHU\ SRRU GLVFULPLQDWLYH SURSHUWLHV ,W LV WKXV QRW SRVVLEOH WR GHWHFW VLJQV RI FRFKOHDU DFWLYLW\ XVLQJ EHKDYLRUDO RU HOHFWURSK\VLRORJLFDO PHWKRGV ZKLFK H[SODLQV ZK\ WKH ILUVW UHVSRQVHV WR DFRXVWLF VWLPXODWLRQ FDQ RQO\ EH UHFRUGHG D IHZ ZHHNV ODWHU 6WDUU HW DO %LPKRO]DQG %HQDFHUUDI f 5XEHO f LQGLFDWHG WKDW QR VLQJOH HYHQW WULJJHUV WKH RQVHW RI FRFKOHDU IXQFWLRQ 0DQ\ VLPXOWDQHRXV DQG V\QFKURQRXV HYHQWV FRQWULEXWH WR WKH PDWXUDWLRQ RI PHFKDQLFDO DQG QHXUDO SURSHUWLHV 7KHVH HYHQWV LQFOXGH WKLQQLQJ RI WKH EDVLODU PHPEUDQH IRUPDWLRQ RI WKH LQQHU VSLUDO VXOFXV PDWXUDWLRQ RI WKH SLOODU FHOOV IUHHLQJ RI WKH LQIHULRU PDUJLQ RI WKH WHFWRULDO PHPEUDQH RSHQLQJ RI WKH WXQQHO RI &RUWL IRUPDWLRQ RI 1XHOfV VSDFHV

PAGE 20

GLIIHUHQWLDWLRQ RI WKH KDLU FHOOV HVWDEOLVKPHQW RI PDWXUH FLOLD VWUXFWXUH DQG WKH PDWXUDWLRQ RI V\QDSVHV 3XMRO DQG +LOGLQJ f 7KHVH ILQDO PDWXUDWLRQDO HYHQWV GR QRW RFFXU VLPXOWDQHRXVO\ WKURXJKRXW WKH OHQJWK RI WKH FRFKOHD 7KHUH DUH WZR JHQHUDO GHYHORSPHQWDO JUDGLHQWV LQ WKH GLIIHUHQWLDWLRQ DQG PDWXUDWLRQ RI FRFKOHD KDLU FHOOV DQG WKHLU QHXUDO FRQQHFWLRQV 7KH ILUVW LV WKH FODVVLF EDVDO WR DSLFDO JUDGLHQW WKDW DW HDFK PDWXUDWLRQ VWDJH WKH PLGEDVDO UHJLRQ GHYHORSV ILUVW DQG VSUHDGV LQ ERWK GLUHFWLRQV ZLWK WKH DSH[ PDWXUDWLQJ ODVW 7KH VHFRQG JUDGLHQW LV IURP LQQHU KDLU FHOOV ,+&Vf WR RXWHU KDLU FHOOV 2+&Vf ,+&V GLIIHUHQWLDWH DQG GHYHORS ILUVW 3XMRO DQG 8]LHO 3XMRO /DYLJQH5HELOODUG DQG /HQRLU f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f 'XULQJ WKH ILUVW VWDJH ZKLFK LV WKURXJK WKH FDWVf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

PAGE 21

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
PAGE 22

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f VWXGLHG WKH SRVLWLRQ RI KDLU FHOO GDPDJH SURGXFHG E\ KLJKLQWHQVLW\ SXUH WRQHV RI WKUHH GLIIHUHQW IUHTXHQFLHV RQ WKUHH DJH JURXSV RI \RXQJ FKLFNV 7KH UHVXOWV VKRZHG WKDW WKH SRVLWLRQ RI PD[LPXP GDPDJH SURGXFHG E\ HDFK IUHTXHQF\ VKLIWHG V\VWHPDWLFDOO\ WRZDUG WKH DSH[ DV D IXQFWLRQ RI DJH 7KLV H[SHULPHQW ZDV FDUULHG RXW GXULQJ WKH ODWH VWDJHV RI KHDULQJ GHYHORSPHQW LQ WKH FKLFN FRUUHVSRQGLQJ WR WKH SHULQDWDO RU LPPHGLDWH SRVWQDWDO SHULRGV LQ KXPDQV 2Q D UHODWHG VWXG\ /LSSH DQG 5XEHO f HYDOXDWHG WKH UHODWLRQVKLS EHWZHHQ WKH ORFDWLRQ RI QHXURQV RI WKH EUDLQVWHP LQ FKLFNV QXFOHXV PDJQRFHOOXODULV DQG QXFOHXV ODPLQDULVf DQG WKH IUHTXHQF\ WR ZKLFK WKH\ ZHUH PRVW VHQVLWLYH ,Q ERWK QXFOHL RI WKH EUDLQVWHP HPEU\RQLF QHXURQV ZHUH PRVW VHQVLWLYH WR WRQHV RFWDYHV EHORZ WKH IUHTXHQFLHV WKDW DFWLYDWH WKH VDPH QHXURQV RQH WR WZR ZHHNV DIWHU KDWFKLQJ 7KHVH WZR H[SHULPHQWV SURYLGHG VXSSRUW IRU WKH PRGHO RI FRFKOHDU GHYHORSPHQW RIIHUHG E\ 5XEHO LQ /DWHU LQYHVWLJDWLRQV DJDLQ LQ FKLFNV UHYHDOHG VRPH LQFRQVLVWHQFLHV LQ WKH WKHRU\ GHYHORSHG E\ 5XEHO f 7KH GLVFUHSDQF\ EHWZHHQ WKHVH VWXGLHV PD\ EH DWWULEXWHG WR GHYHORSPHQWDO FKDQJHV LQ PLGGOHHDU WUDQVIHU IXQFWLRQ WKH FKDQJHV RI WKH SK\VLFDO VL]H RI WKH EDVLODU SDSLOOD DQG WHPSHUDWXUH HIIHFWV RQ IUHTXHQF\ WXQLQJ 5LOEVDPHQ DQG /LSSH f &XUUHQWO\ WKHUH DUH WZR DOWHUQDWLYH K\SRWKHVHV IRU WKH GHYHORSPHQW RI WKH

PAGE 23

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f 'DOORV DQG KLV FROOHDJXHV +DUULV DQG 'DOORV
PAGE 24

WKH VKLIWV LQ IUHTXHQF\ FRGH DUH DWWULEXWHG WR PDWXUDWLRQDO FKDQJHV LQ WKH SDVVLYH PHFKDQLFDO SURSHUWLHV RI WKH FRFKOHD /LSSH DQG 5XEHO f 6HFRQG 5RPDQG f SURSRVHG WKDW WKH VKLIWV LQ IUHTXHQF\ RUJDQL]DWLRQ VKRXOG EH DWWULEXWHG WR PDWXUDWLRQDO FKDQJHV LQ FRFKOHDU DFWLYH SURFHVVHV PHGLDWHG E\ WKH RXWHU KDLU FHOOV %RWK IDFWRUV ZHUH H[DPLQHG E\ FRPSDULQJ WRQHHYRNHG GLVWRUWLRQ SURGXFW RWRDFRXVWLF HPLVVLRQV EHIRUH DQG DIWHU DQ LQMHFWLRQ RI IXURVHPLGH LQ JHUELOV EHWZHHQ GD\V ROG DQG DGXOW 0LOOV 1RUWRQ DQG 5XEHO 0LOOV DQG 5XEHO f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f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f

PAGE 25

&HQWUDO $XGLWRU\ 6\VWHP 7KH GHYHORSPHQW RI WKH FHQWUDO DXGLWRU\ V\VWHP DQG LWV UHODWLRQ WR WKH PDWXUDWLRQ RI WKH DXGLWRU\ SHULSKHU\ KDV EHHQ VWXGLHG LQ DQLPDO PRGHOV 5XEHO Df 1RUPDO JURZWK RI FHQWUDO DXGLWRU\ QHXUDO HOHPHQWV UHTXLUHV DQ LQWDFW SHULSKHUDO PHFKDQLVP +RZHYHU LQLWLDO VWDJHV RI GHYHORSPHQW RI WKH DXGLWRU\ FHQWHUV LQ WKH FHQWUDO QHUYRXV V\VWHP DUH LQGHSHQGHQW RI SHULSKHUDO UHJXODWLRQ 7KH SUROLIHUDWLRQ DQG PLJUDWLRQ RI QHXURQV LQ WKH FHQWUDO DXGLWRU\ V\VWHP GR QRW GHSHQG RQ WKH FRFKOHD 7KH PDMRU SDWKZD\V DUH HVWDEOLVKHG SULRU WR RU VLPXOWDQHRXVO\ ZLWK WKH GHYHORSPHQW RI SHULSKHUDO IXQFWLRQ 0DUW\ f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f UHYHDOHG WKDW LQ FKLFNV DIWHU WKH WLPH ZKHQ IXQFWLRQDO FRQQHFWLRQV QRUPDOO\ DUH HVWDEOLVKHG EHWZHHQ WKH HLJKWK QHUYH DQG WKH FRFKOHDU QXFOHXV FHOOV WKH DEVHQFH RI SHULSKHUDO LQQHUYDWLRQ FDXVHG UDSLG DQG VHYHUH GHJHQHUDWLRQ RI WKH QHXURQV $EUDPV HW DO f GHPRQVWUDWHG WKH LPSDLUPHQW RI JOXFRVH XWLOL]DWLRQ LQ WKH DXGLWRU\ DV ZHOO DV QRQDXGLWRU\ SRUWLRQV RI WKH EUDLQ DIWHU FRFKOHDU DEODWLRQ LQ IHWDO VKHHS

PAGE 26

)HWDO %HKDYLRUDO 5HVSRQVH WR 6RXQG 7KH KXPDQ IHWDO DXGLWRU\ V\VWHP LV IXQFWLRQDO E\ WKH VWDUW RI WKH WKLUG WULPHVWHU %LPKRO] DQG %HQDFHUUDI f $OWKRXJK GLUHFW PHDVXUHPHQW RI IHWDO KHDULQJ FDQQRW EH PDGH E\ HOHFWURSK\VLRORJLFDO PHWKRGV LQGLUHFW PHWKRGV KDYH EHHQ DSSOLHG WR PHDVXUH IHWDO EHKDYLRUDO UHVSRQVHV WR VRXQG VWLPXOL 7KH PRVW FRPPRQ DSSURDFKHV XVHG WR PHDVXUH UHVSRQVLYHQHVV WR VRXQG LQFOXGH WKH PRQLWRULQJ RI IHWDO KHDUW UDWH -RKDQVVRQ :HGHQEHUJ DQG :HVWHQ f IHWDO PRYHPHQW 6KDKLGXOODK DQG +HSSHU f DQG UHIOH[LYH UHVSRQVHV VXFK DV WKH DXURSDOSHEUDO UHIOH[ %LPKRO] DQG %HQDFHUUDI f )HWDO PRYHPHQWV LQ UHVSRQVH WR VRXQG DQG WR YLEURDFRXVWLF VWLPXODWLRQ RU WR ERWK UHODWH FORVHO\ WR WKH GHYHORSPHQW RI IHWDO DXGLWLRQ *HOPDQ HW DO +HSSHU DQG 6KDKLGXOODK Df ,Q %LPKRO] DQG %HQDFHUUDI PHDVXUHG IHWDO UHVSRQVLYHQHVV WR DQ HOHFWURQLF DUWLILFLDO ODU\Q[ ($/f DSSOLHG GLUHFWO\ WR WKH PDWHUQDO DEGRPHQ 7KH DXURSDOSHEUDO UHIOH[ EOLQNVWDUWOH UHVSRQVHf RI WKH IHWXVHV WHVWHG IURP WR ZHHNV RI JHVWDWLRQ ZDV PRQLWRUHG E\ XOWUDVRQRJUDSK\ 5HIOH[LYH H\H PRYHPHQWV ZHUH ILUVW HOLFLWHG LQ VRPH IHWXVHV EHWZHHQ DQG ZHHNV RI JHVWDWLRQDO DJH DQG UHVSRQVHV LQFUHDVHG LQ IUHTXHQF\ DIWHU ZHHNV &RQVLVWHQW UHVSRQVHV WR ($/ ZHUH REVHUYHG DIWHU ZHHNV RI SUHJQDQF\ 6KDKLGXOODK DQG +HSSHU f H[DPLQHG WKH UHVSRQVH RI IHWXVHV WR D G% 63/ EURDGEDQG DLUERPH VWLPXOXV +]f DW DQG ZHHNV RI JHVWDWLRQ 8VLQJ D UHVSRQVH ZKLFK FRQVLVWV RI D PRYHPHQW ZLWKLQ VHFRQGV RI WKH RQVHW RI WKH VWLPXOXV WKH LQYHVWLJDWRUV IRXQG WKDW IHWXVHV KHDUG WKH QRLVH DW ZHHNV RI JHVWDWLRQ EXW QRW HDUOLHU +RZHYHU ZKHQ WKH VWLPXOXV ZDV FKDQJHG IURP D VLQJOH SXOVH WR D VHULHV RI WHQ

PAGE 27

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f H[DPLQHG WKH UDQJH RI IUHTXHQFLHV DQG LQWHQVLW\ OHYHOV UHTXLUHG WR HOLFLW KXPDQ IHWDO PRYHPHQWV DV DVVHVVHG ZLWK XOWUDVRQRJUDSK\ 2XW RI IHWXVHV LQYROYHG LQ WKH VWXG\ RQO\ RQH GHPRQVWUDWHG D UHVSRQVH WR D +] WRQH DW ZHHNV JHVWDWLRQDO DJH 7KH UDQJH RI IUHTXHQFLHV WR ZKLFK WKH IHWXV UHVSRQGHG H[SDQGHG ILUVW WR ORZ IUHTXHQFLHV +] DQG +] DQG WKHQ WR KLJK IUHTXHQFLHV +] DQG +] %\ ZHHNV b RI WKH IHWXVHV UHVSRQGHG WR WRQHV DW DQG +] ZKLOH QRQH UHVSRQGHG WR IUHTXHQFLHV DW DQG +] ,W ZDV QRW XQWLO ZHHNV +]f DQG +]f WKDW WKH IHWXVHV UHVSRQGHG WR WKHVH WRQHV %HWZHHQ DQG ZHHNV WKH IHWXVHV UHVSRQGHG b RI WKH WLPH WR SUHVHQWDWLRQV RI DQG +] $V JHVWDWLRQ SURJUHVVHG IURP WR ZHHNV WKH IHWXVHV H[KLELWHG UHVSRQVLYHQHVV WR IUHTXHQFLHV RYHU D SURJUHVVLYHO\ ZLGHU IUHTXHQF\ UDQJH 'XULQJ WKLV SHULRG WKHUH ZDV D VLJQLILFDQW GHFUHDVH G%f LQ WKH LQWHQVLW\ OHYHO RI VWLPXOXV UHTXLUHG WR HOLFLW D UHVSRQVH IRU DOO IUHTXHQFLHV 7KLV ILQGLQJ VXJJHVWV WKDW IHWDO KHDULQJ WR SXUH WRQHV EHFRPHV PRUH VHQVLWLYH DV JHVWDWLRQ SURFHHGV 7KH DELOLW\ WR GLVFULPLQDWH IUHTXHQF\ LV IXQGDPHQWDO IRU WKH LQWHUSUHWDWLRQ RI DXGLWRU\ LQIRUPDWLRQ DQG IRU WKH GHYHORSPHQW RI VSHHFK SHUFHSWLRQ DQG VSHHFK

PAGE 28

SURGXFWLRQ $GXOWV FDQ GHWHFW FKDQJHV RI OHVV WKDQ +] ZKHQ WKH SULPDU\ WRQH LV EHWZHHQ +] DQG +]
PAGE 29

KHOG EHOLHI WKDW WKH IHWXV GHYHORSV LQ DQ HQYLURQPHQW GHYRLG RI H[WHUQDO VWLPXODWLRQ *ULPZDUGH :DONHU DQG :RRG f KDV EHHQ UHSODFHG E\ WKH IDFW WKDW WKH IHWXV JURZV LQ WKH XWHUXV ILOOHG ZLWK ULFK DQG GLYHUVLILHG VRXQGV RULJLQDWHG LQVLGH DQG RXWVLGH WKH PRWKHU *HUKDUGW 4XHUOHX HW DO f 7KH DFRXVWLF FKDUDFWHULVWLFV RI LQWHUQDO QRLVHV DQG RI H[WHUQDO VRXQGV WKDW WUDQVPLW LQWR WKH XWHUXV KDYH EHHQ GHVFULEHG LQ WKH KXPDQ IURP YDULRXV UHFRUGLQJ VLWHV LQFOXGLQJ LQVLGH WKH YDJLQD %HQFK f LQVLGH WKH FHUYL[ *ULPZDUGH :DONHU DQG :RRG f DQG LQVLGH WKH XWHUXV IROORZLQJ DPQLRWRP\ 4XHUOHX HW DO E %HQ]DTXHQ HW DO 5LFKDUGV HW DO f 7KHVH LQWUDXWHULQH VRXQGV LQ KXPDQV ZHUH YHU\ VLPLODU WR WKRVH UHFRUGHG LQ SUHJQDQW VKHHS YLD D FKURQLFDOO\ LPSODQWHG K\GURSKRQH RQ WKH IHWDO KHDG LQVLGH WKH XWHUXV ZLWK DQ LQWDFW DPQLRWLF VDF 9LQFH HW DO *HUKDUGW $EUDPV DQG 2OLYHU f 6RXQGV JHQHUDWHG LQVLGH WKH PRWKHU DQG SUHVHQW LQ WKH XWHUXV DUH DVVRFLDWHG ZLWK PDWHUQDO UHVSLUDWLRQ 9LQFH HW DO *HUKDUGW $EUDPV DQG 2OLYHU f PDWHUQDO KHDUWEHDWV :DONHU *ULPZDUGH DQG :RRG 4XHUOHX HW DO Df PDWHUQDO LQWHVWLQDO DFWLYLW\ 9LQFH HW DO *HUKDUGW $EUDPV DQG 2OLYHU %HQ]DTXHQ HW DO f PDWHUQDO SK\VLFDO PRYHPHQWV 9LQFH HW DO *HUKDUGW $EUDPV DQG 2OLYHU f DQG ZLWK SODFHQWDO DQG IHWDO FLUFXODWLRQ 4XHUOHX HW DO Df 7KHVH VRXQGV SURYLGH D EDFNJURXQG RU QRLVH IORRU DERYH ZKLFK PDWHUQDO YRFDOL]DWLRQV DQG H[WHUQDOO\ JHQHUDWHG VRXQGV HPHUJH 9LQFH HW DO 4XHUOHX HW DO E *HUKDUGW $EUDPV DQG 2OLYHU %HQ]DTXHQ HW DOf 5LFKDUGV HW DO f ,Q %HQFK PHDVXUHG WKH LQWUDXWHULQH QRLVH IORRU DW G% 63/ LQ D SUHJQDQW ZRPDQ GXULQJ ODERU 7KUHH \HDUV ODWHU :DONHU HW DO f UHSRUWHG DQ DYHUDJH LQWHQVLW\

PAGE 30

RI WKH EDFNJURXQG QRLVH DW G% 63/ VRXQG SUHVVXUH OHYHOf ZLWK D SHDN DW G% 63/ ZKLFK ZDV DVVRFLDWH ZLWK PDWHUQDO KHDUWEHDWV +RZHYHU WKH DFFXUDF\ RI WKHVH HDUO\ VWXGLHV ZDV TXHVWLRQHG E\ IXUWKHU VWXGLHV XVLQJ D K\GURSKRQH LQVWHDG RI D UXEEHUFRYHUHG PLFURSKRQH SUHYLRXVO\ XVHG WR PHDVXUH WKH LQWUDXWHULQH VRXQG OHYHO 7KH XVH RI D K\GURSKRQH UHSUHVHQWHG DQ LPSRUWDQW WHFKQRORJLFDO LPSURYHPHQW DQG SURYLGHG PRUH DFFXUDWH GDWD WKDQ ZDV SUHYLRXVO\ FROOHFWHG ZLWK DLU PLFURSKRQHV 6WXGLHV LQ SUHJQDQW VKHHS 9LQFH HW DO *HUKDUGW $EUDPV DQG 2OLYHU f DQG KXPDQ 4XHUOHX HW DK D %HQ]DTXHQ HW DK 5LFKDUGV HW DK f VKRZHG WKDW WKHUH LV D TXLHW EDFNJURXQG ZLWK D PXIIOHG TXDOLW\ WR VRXQGV LQVLGH WKH XWHUXV ,QWUDXWHULQH VRXQGV DUH SUHGRPLQDWHO\ ORZ IUHTXHQF\ +]f DQG UHDFK G% 63/ 4XHUOHX 5HQDUG DQG &USLQ 9LQFH HW DK *HUKDUGW HW DK f 6SHFWUDO OHYHOV GHFUHDVH DV IUHTXHQF\ LQFUHDVHV DQG DUH DV ORZ DV G% IRU KLJKHU IUHTXHQFLHV %HQ]DTXHQ HW DO *DJQRQ %HQ]DTXHQ DQG +XQVH f *DJQRQ HW DK SRVLWLRQHG D K\GURSKRQH LQ D SRFNHW RI IOXLG E\ WKH KXPDQ IHWDO QHFN DQG PHDVXUHG VRXQG SUHVVXUH OHYHOV RI G% 63/ DW +] GHFUHDVLQJ WR G% IRU +] DQG OHVV WKDQ G% IRU +] DQG DERYH :KHQ PHDVXUHG LQ G%$ WKH KXPDQ LQWUDXWHULQH VRXQG OHYHO ZDV RQO\ G%$ 4XHUOHX HW DK Df 7KXV IRU ERWK KXPDQV DQG VKHHS WKH QRLVH IORRU WHQGV WR EH GRPLQDWHG E\ ORZIUHTXHQF\ HQHUJ\ OHVV WKDQ +] DQG FDQ UHDFK OHYHOV DV KLJK DV G% 63/ 5HFHQWO\ $EUDPV HW DK f H[SORUHG WKH RULJLQ RI WKH LQWUDXWHULQH EDFNJURXQG QRLVH LQ VKHHS XQGHU ZHOOFRQWUROOHG ODERUDWRU\ FRQGLWLRQV 7KH LQWUDXWHULQH QRLVH OHYHO ZDV PHDVXUHG EHIRUH DQG DIWHU GHDWK RI WKH HZH DQG IHWXV DQG WKH DYHUDJH UHGXFWLRQ LQ VRXQG OHYHO SRVWPRUWHP DSSURDFKHG G% IRU IUHTXHQFLHV EHORZ +] 7KH UHVXOW

PAGE 31

VKRZHG WKDW VRXQGV RULJLQDWLQJ LQ WKH HZH DQG IHWXV FRQWULEXWH VLJQLILFDQWO\ WR WKH ORZ IUHTXHQF\ +]f FRPSRQHQW RI WKH EDFNJURXQG QRLVH 6RXQG 7UDQVPLVVLRQ LQWR WKH 8WHUXV 6SHFLILFDWLRQV RI WKH DPSOLWXGHV DQG IUHTXHQF\ GLVWULEXWLRQV RI H[WHUQDO VRXQGV WUDQVPLWWHG LQWR WKH XWHUXV KDYH EHHQ ZHOO GHVFULEHG LQ KXPDQV 4XHUOHX HW DO D 5LFKDUGV HW DO f DQG VKHHS $UPLWDJH %DOGZLQ DQG 9LQFH 9LQFH HW DK *HUKDUGW $EUDPV DQG 2OLYHU f 7KH DWWHQXDWLRQ RI VRXQG E\ WKH PDWHUQDO DEGRPLQDO ZDOO XWHUXV DQG DPQLRWLF IOXLG LV ORZ LQ WKH ORZ IUHTXHQFLHV DQG LQFUHDVHV LQ WKH KLJK IUHTXHQFLHV ,Q SUHJQDQW ZRPHQ VWXGLHG E\ 4XHUOHX HW DK f WKH DWWHQXDWLRQ LV G% DW +] G% DW +] G% DW +] DQG G% DW +] )RU KLJK IUHTXHQFLHV UDQJLQJ IURP WR DERYH +] WKH DWWHQXDWLRQ LV WR G% 4XHUOHX HW DK Df 0RUH UHFHQW UHVXOWV IURP 5LFKDUGV HW DK f VKRZHG WKDW WKHUH ZDV DQ DYHUDJH RI G% HQKDQFHPHQW DW +] ZLWK SURJUHVVLYHO\ LQFUHDVLQJ DWWHQXDWLRQ XS WR G% DW +] 6LPLODU FRQFOXVLRQV FDPH IURP VWXGLHV LQ VKHHS $UPLWDJH %DOGZLQ DQG 9LQFH 9LQFH HW DK *HUKDUGW $EUDPV DQG 2OLYHU f )RU IUHTXHQFLHV EHORZ +] WKH UHGXFWLRQ LQ VRXQG SUHVVXUH OHYHO WKURXJK PDWHUQDO WLVVXH DQG IOXLGV ZDV OHVV WKDQ G% 6RPH HQKDQFHPHQW RI ORZIUHTXHQF\ VRXQG SUHVVXUHV KDV EHHQ UHSRUWHG LQ ERWK KXPDQV 4XHUOHX HW DK 5LFKDUGV HW DK f DQG VKHHS 9LQFH HW DK *HUKDUGW $EUDPV DQG 2OLYHU f 7KDW LV WKH VRXQG SUHVVXUH LQ WKH DPQLRQ ZDV JUHDWHU WKDQ WKH VRXQG SUHVVXUH LQ DLU $ERYH +] DWWHQXDWLRQ LQFUHDVHG DW D UDWH RI DERXW G% SHU RFWDYH XS WR DSSUR[LPDWHO\ +]

PAGE 32

ZKHUH WKH DYHUDJH DWWHQXDWLRQ ZDV WR G% +RZHYHU DW +] WUDQVPLVVLRQ ORVV ZDV G% *HUKDUGW $EUDPV DQG 2OLYHU f 7KHVH JHQHUDO ILQGLQJV KDYH EHHQ UHILQHG DQG H[WHQGHG E\ 3HWHUV HW DO D Ef ZKR HYDOXDWHG WKH WUDQVIHU RI DLUERUQH VRXQGV DFURVV WKH DEGRPLQDO ZDOO RI VKHHS DV D IXQFWLRQ RI IUHTXHQF\ DQG LQWUDDEGRPLQDO ORFDWLRQ 3HWHUV HW DO Df VWXGLHG WKH WUDQVPLVVLRQ RI DLUERUQH VRXQG LQWR WKH DEGRPHQ RI VKHHS RYHU D ZLGH IUHTXHQF\ UDQJH +]f 7KH\ IRXQG WKDW PHDQ DWWHQXDWLRQ YDULHG IURP D KLJK RI G% WR D ORZ RI G% 7KH JUHDWHVW DWWHQXDWLRQ RFFXUUHG IRU WKH IUHTXHQFLHV EHWZHHQ DQG +] 6XUSULVLQJO\ VRXQG DWWHQXDWLRQ YDULHG LQYHUVHO\ DV D IXQFWLRQ RI VWLPXOXV OHYHO IRU ORZ IUHTXHQFLHV +]f DQG IRU KLJK IUHTXHQFLHV +]f $W KLJKHU VWLPXOXV OHYHOV G% 63/ LQ DLUf DWWHQXDWLRQ ZDV JUHDWHU WKDQ WKH DWWHQXDWLRQ DW ORZHU VWLPXOXV OHYHOV G% 63/f 7KXV WKH G% VWLPXOXV ZDV PRUH HIILFLHQW WKDQ WKH G% ,Q WKH PLGGOH IUHTXHQF\ UDQJH +]f QR HIIHFW RI VWLPXOXV OHYHO ZDV IRXQG ,Q DQRWKHU VWXG\ E\ 3HWHUV HW DO Ef D K\GURSKRQH ZDV SRVLWLRQHG DW HDFK RI ORFDWLRQV LQ D [ [ DUUD\ LQ WKH DEGRPHQ RI ILYH QRQSUHJQDQW VKHHS SRVW PRUWHP ,VRDWWHQXDWLRQ FRQWRXUV ZLWKLQ WKH DEGRPHQ ZHUH REWDLQHG 7KH VRXQG SUHVVXUH DW GLIIHUHQW ORFDWLRQV ZLWKLQ WKH WKUHHGLPHQVLRQDO VSDFH RI WKH VKHHS ZDV KLJKO\ YDULDEOH /RZIUHTXHQF\ EDQGV +]f RI QRLVH UHYHDOHG VWURQJ HQKDQFHPHQW RI VRXQG SUHVVXUH E\ XS WR G% LQ WKH YHQWUDO SDUW RI WKH DEGRPHQ )RU PLGIUHTXHQFLHV +]f DWWHQXDWLRQ UHDFKHG DV KLJK DV G% $WWHQXDWLRQ IRU KLJK IUHTXHQFLHV +]f ZHUH VRPHZKDW OHVV WKDQ IRU PLGIUHTXHQFLHV DQG UHDFKHG DQ XSSHU OLPLW RI DSSUR[LPDWHO\ G%

PAGE 33

2YHU WKH IUHTXHQF\ UDQJH IURP WR +] WKH DEGRPHQ FDQ EH FKDUDFWHUL]HG DV D ORZSDVV ILOWHU ZLWK KLJKIUHTXHQF\ HQHUJ\ UHMHFWHG DW D UDWH RI DSSUR[LPDWHO\ G%RFWDYH *HUKDUGW $EUDPV DQG 2OLYHU f 7KXV H[WHUQDO VWLPXOL DUH VKDSHG E\ WKH WLVVXHV DQG IOXLGV RI SUHJQDQF\ EHIRUH UHDFKLQJ WKH IHWDO KHDG )HWDO 6RXQG ,VRODWLRQ ,W LV NQRZQ KRZ PXFK VRXQG SUHVVXUH LV SUHVHQW DW WKH IHWDO KHDG 1RZ WKHUH LV LQIRUPDWLRQ DERXW KRZ PXFK VRXQG DFWXDOO\ UHDFKHV WKH IHWDO LQQHU HDU *HUKDUGW HW DO f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f +DZNLQV DQG 0\UEHUJ f 7KXV HTXDO SUHVVXUH LQ DLU DQG IOXLG GLIIHU LQ VRXQG HQHUJ\ E\ DSSUR[LPDWHO\ G% 2QH ZRXOG DVVXPH WKDW WKH VRXQG SUHVVXUH OHYHO UHTXLUHG WR SURGXFH D SK\VLRORJLFDO UHVSRQVH IURP WKH IHWXV ZRXOG EH DSSUR[LPDWHO\ G% JUHDWHU WKDQ WKH VRXQG SUHVVXUH OHYHO LQ DLU QHFHVVDU\ WR SURGXFH WKH VDPH UHVSRQVH IURP WKH QHZERUQ *HUKDUGW *HUKDUGW HW DO f )DFWRUV WKDW GHWHUPLQH KRZ PXFK H[ WHUR VRXQG UHDFKHV WKH LQQHU HDU RI WKH IHWXV LQFOXGH WKH VRXQG SUHVVXUH DWWHQXDWLRQ WKURXJK PDWHUQDO WLVVXH DQG IOXLG DQG WKH WUDQVIRUPDWLRQ RI WKLV SUHVVXUH LQWR EDVLODU PHPEUDQH GLVSODFHPHQW

PAGE 34

*HUKDUGW HW DO f VWXGLHG WKH H[WHQW WR ZKLFK WKH IHWDO VKHHS LQ XOHUR LV LVRODWHG IURP VRXQGV SURGXFHG RXWVLGH WKH PRWKHU ,QIHUHQFHV UHJDUGLQJ VRXQG WUDQVPLVVLRQ WR WKH LQQHU HDU ZHUH PDGH IURP FRFKOHDU PLFURSKRQLF &0f LQSXWRXWSXW IXQFWLRQV WR VWLPXOL ZLWK GLIIHUHQW IUHTXHQF\ FRQWHQW 7KH &0 DQ DOWHUQDWLQJ FXUUHQW JHQHUDWHG E\ WKH KDLU FHOOV RI WKH LQQHU HDU PLPLFV WKH LQSXW VLJQDO LQ IUHTXHQF\ DQG DPSOLWXGH RYHU D IDLUO\ ZLGH UDQJH $V WKH VLJQDO DPSOLWXGH LQFUHDVHV VR GRHV WKH DPSOLWXGH RI WKH &0 &RFKOHDU PLFURSKRQLFV UHFRUGHG IURP WKH URXQG ZLQGRZ DUH VHQVLWLYH LQGLFHV RI WUDQVPLVVLRQ FKDUDFWHULVWLFV RI WKH PLGGOH HDU 7KXV FKDQJHV LQ WKH FRQGLWLRQ RI WKH PLGGOH HDU LQIOXHQFH WKH DPSOLWXGH RI WKH &0 %\ FRPSDULQJ WKH VRXQG SUHVVXUH OHYHOV QHFHVVDU\ WR SURGXFH HTXDO &0 DPSOLWXGH IURP WKH IHWXV LQ WHUR DQG ODWHU IURP WKH QHZERUQ ODPE LQ WKH VDPH VRXQG ILHOG HVWLPDWHV RI IHWDO VRXQG LVRODWLRQ FDQ EH PDGH &RFKOHDU PLFURSKRQLF LQSXWRXWSXW IXQFWLRQV ZHUH UHFRUGHG IURP LQ XOHUR IHWXVHV LQ UHVSRQVH WR RQHWKLUG RFWDYH EDQG QRLVHV IURP WR +] DQG WKHQ DJDLQ IURP WKH VDPH DQLPDOV DIWHU ELUWK 7KH PDJQLWXGH RI IHWDO VRXQG LVRODWLRQ ZDV GHSHQGHQW XSRQ VWLPXOXV IUHTXHQF\ )RU +] VRXQG LVRODWLRQ UDQJHG IURP WR G% ZKHUHDV IRU +] IHWDO VRXQG LVRODWLRQ UDQJHG IURP WR G% 7KH DYHUDJHV IRU HDFK VWLPXOXV IUHTXHQF\ ZHUH G% IRU +] G% IRU +] G% IRU +] G% IRU +] DQG G% IRU +] 7KXV IRU ORZHU IUHTXHQFLHV +]f WKH IHWDO DXGLWRU\ V\VWHP DSSHDUV WR EH VHQVLWLYH WR SUHVVXUH YDULDWLRQV SURGXFHG E\ WKH VWLPXOXV RULJLQDWHG IURP RXWVLGH WKH PRWKHU

PAGE 35

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f 7KH LPSHGDQFH RI LQQHU HDU IOXLGV LV VLPLODU WR WKDW RI DPQLRWLF IOXLG WKXV OLWWOH DFRXVWLF HQHUJ\ LV ORVW GXH WR DQ LPSHGDQFH PLVPDWFK 4XHUOHX HW DO f

PAGE 36

+HDULQJ YLD ERQH FRQGXFWLRQ LV D VHFRQG DOWHUQDWLYH 5HVHDUFKHUV KDYH VKRZQ WKDW WKH FRQWULEXWLRQ RI WKH H[WHUQDO DXGLWRU\ PHDWXV WR DXGLWRU\ VHQVLWLYLW\ LQ XQGHUZDWHU GLYHUV LV QHJOLJLEOH +ROOLHQ DQG )HLQVWHLQ f %\ FRPSDULQJ WKH DELOLW\ RI D GLYHU WR KHDU XQGHU GLIIHUHQW FRQGLWLRQV ZKLOH LQ ZDWHU ERQH FRQGXFWLRQ KDV EHHQ VKRZQ WR EH PXFK PRUH HIIHFWLYH LQ WUDQVPLWWLQJ XQGHUZDWHU VRXQG HQHUJ\ 6LPLODUO\ IHWDO KHDULQJ RFFXUV LQ D IOXLG HQYLURQPHQW DQG VRXQG WUDQVPLVVLRQ PD\ EH WKURXJK ERQH FRQGXFWLRQ DV ZHOO *HUKDUGW HW DO f FRPSDUHG WKH HIIHFWLYHQHVV RI WKH WZR URXWHV RI VRXQG WUDQVPLVVLRQ RXWHU DQG PLGGOH HDU YV ERQH FRQGXFWLRQf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

PAGE 37

0RGHO RI )HWDO +HDULQJ *HUKDUGW DQG $EUDPV f SURSRVHG D PRGHO RI IHWDO KHDULQJ WKDW FRQVLGHUV ZKDW VRXQGV DUH SUHVHQW LQ WKH HQYLURQPHQW RI WKH IHWXV DQG WR ZKDW H[WHQW WKHVH VRXQGV FDQ EH GHWHFWHG 7KH PRGHO LQFOXGHV LQIRUPDWLRQ UHJDUGLQJ LQWUDXWHULQH EDFNJURXQG QRLVH VRXQG WUDQVPLVVLRQ WKURXJK WKH WLVVXHV DQG IOXLGV DVVRFLDWHG ZLWK SUHJQDQF\ DQG VRXQG WUDQVPLVVLRQ WKURXJK WKH IHWDO VNXOO LQWR WKH LQQHU HDU )RU WKH IHWXV WR GHWHFW D VLJQDO IURP RXWVLGH WKH PRWKHU H[WULQVLF VRXQGV KDYH WR H[FHHG WKH DPELHQW VRXQG OHYHO LQ XOHUR 7KH LQWHUQDO QRLVH IORRU RI WKH PRWKHU LV GRPLQDWHG E\ ORZIUHTXHQF\ HQHUJ\ SURGXFHG E\ UHVSLUDWLRQ LQWHVWLQDO IXQFWLRQ FDUGLRYDVFXODU V\VWHP DQG PDWHUQDO PRYHPHQWV 6SHFWUDO OHYHOV GHFUHDVH DV IUHTXHQF\ LQFUHDVHV DQG DUH G% IRU +] DQG ORZHU WKDQ G% IRU +] DQG DERYH 3UHVXPDEO\ WKH DELOLW\ RI WKH IHWXV WR GHWHFW H[RJHQRXV VRXQGV ZLOO EH GHSHQGHQW LQ SDUW RQ WKH VSHFWUXP OHYHO RI WKH QRLVH IORRU EHFDXVH RI PDVNLQJ HIIHFWV $V H[SHFWHG KLJK IUHTXHQF\ VRXQG SUHVVXUHV ZRXOG EH UHGXFHG E\ DERXW G% 7KH DWWHQXDWLRQ RI ORZ IUHTXHQF\ VRXQGV E\ WKH DEGRPLQDO ZDOO XWHUXV DQG IOXLGV VXUURXQGLQJ WKH IHWDO KHDG LV TXLWH VPDOO DQG LQ VRPH FDVHV HQKDQFHPHQW RI VRXQG SUHVVXUH RI DERXW G% KDV EHHQ QRWHG %HWZHHQ DQG +] VRXQG SUHVVXUH OHYHOV GURS DW D UDWH RI G%RFWDYH $W +] PD[LPXP DWWHQXDWLRQ LV DSSUR[LPDWHO\ G% $W IUHTXHQFLHV KLJKHU WKDQ +] WKH DWWHQXDWLRQ LV UHGXFHG WR OHVV WKDQ G% 6RXQG SUHVVXUHV DW WKH IHWDO KHDG FUHDWH FRPSUHVVLYH IRUFHV WKURXJK ERQH FRQGXFWLRQ WKDW UHVXOW LQ GLVSODFHPHQWV RI WKH EDVLODU PHPEUDQH WKHUHE\ SURGXFLQJ D &0 )RU DQG +] DQ DLUERUQH VLJQDO ZRXOG EH UHGXFHG E\ G% LQ LWV SDVVDJH WR WKH IHWDO LQQHU HDU RYHU ZKDW ZRXOG EH H[SHFWHG WR UHDFK WKH LQQHU HDU RI WKH RUJDQLVP LQ

PAGE 38

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f 7KH IHWXV LQ WHUR ZLOO GHWHFW VSHHFK EXW SUREDEO\ RQO\ WKH ORZIUHTXHQF\ FRPSRQHQWV OHVV WKDQ +] DQG RQO\ ZKHQ WKH DLUERUQH VLJQDO H[FHHGV DERXW G% 63/ ,I LW LV OHVV WKDQ WKDW WKH VLJQDO FRXOG EH PDVNHG E\ LQWHUQDO QRLVHV ,W LV SUHGLFWHG WKDW WKH KXPDQ IHWXV FRXOG GHWHFW VSHHFK DW FRQYHUVDWLRQDO OHYHOV G% 63/f EXW ZRXOG QRW EH DEOH WR GLVFULPLQDWH PDQ\ RI WKH VSHHFK VRXQGV ZLWK KLJKIUHTXHQF\ FRPSRQHQWV /LNHZLVH LI PXVLF ZDV SOD\HG WR WKH PRWKHU DW FRPIRUWDEOH OLVWHQLQJ OHYHOV WKH WHPSRUDO FKDUDFWHULVWLFV RI PXVLF UK\WKPV FRXOG EH VHQVHG E\ WKH IHWXV EXW WKH KLJK IUHTXHQF\ RYHUWRQHV ZRXOG QRW EH RI VXIILFLHQW DPSOLWXGH WR EH GHWHFWHG $EUDPV HW DO f 6LPSO\ SXW WKH IHWXV ZRXOG EH VWLPXODWHG E\ PXVLF ZLWK WKH EDVV UHJLVWHU WXUQHG XS DQG WKH WUHEOH UHJLVWHU WXUQHG GRZQ 7KLV LQIRUPDWLRQ PD\ UHODWH WR LQ WHUR GHYHORSPHQW RI VSHHFK DQG ODQJXDJH WR PXVLFDO SUHIHUHQFHV DQG WR VXEVHTXHQW FRJQLWLYH GHYHORSPHQW

PAGE 39

,QWHOOLJLELOLW\ RI 6SHHFK 6RXQGV 5HFRUGHG ZLWKLQ WKH 8WHUXV 6SHHFK SURGXFHG GXULQJ QRUPDO FRQYHUVDWLRQ LV DSSUR[LPDWHO\ G% 63/ DQG LV FRPSULVHG RI DFRXVWLF HQHUJ\ SULPDULO\ EHWZHHQ DQG +] 7KH DYHUDJH IXQGDPHQWDO IUHTXHQF\ RI DQ DGXOW LV +] IRU PDOHfV YRLFH DQG LV +] IRU IHPDOHf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f DQG LQ KXPDQV 4XHUOHX HW DO D %HQ]DTXHQ HW DO 5LFKDUGV HW DO f KDYH VKRZQ WKDW WKH PRWKHUfV YRLFH DQG VSHHFK VRXQGV IURP RXWVLGH WKH PRWKHU WUDQVPLW HDVLO\ LQWR WKH XWHUXV ZLWK OLWWOH DWWHQXDWLRQ DQG IRUP SDUW RI WKH LQWUDXWHULQH VRXQG HQYLURQPHQW 9LQFH HW DO f LPSODQWHG D K\GURSKRQH LQVLGH WKH DPQLRWLF VDF RI SUHJQDQW HZHV DQG REWDLQHG ORQJWHUP UHFRUGLQJV 7KH\ VKRZHG WKDW WKH VRXQG RI PDWHUQDO YRFDOL]DWLRQV IRUPV D SURPLQHQW SDUW RI WKH LQWUDXWHULQH VRXQG HQYLURQPHQW DQG LV ORXGHU LQVLGH WKH XWHUXV WKDQ RXWVLGH *HUKDUGW HW DO f DOVR QRWHG WKDW ZKHQ OLVWHQLQJ WR WKH LQWHUQDO UHFRUGLQJV IURP VKHHS FRQYHUVDWLRQV ZHUH UHFRJQL]HG EHWZHHQ H[SHULPHQWHUV ZLWK QRUPDO YRFDO HIIRUW IHHW IURP WKH HZH 6SHHFK ZDV PXIIOHG DQG LQWHOOLJLELOLW\ ZDV SRRU KRZHYHU SLWFK

PAGE 40

LQWRQDWLRQ DQG UK\WKP ZHUH TXLWH FOHDU 7KHVH ILQGLQJV DUH LQ DFFRUGDQFH ZLWK GDWD SURYLGHG E\ KXPDQ VWXGLHV 4XHUOHX HW DO Ef SUHVHQWHG YDULRXV KXPDQ YRLFHV WKURXJK D ORXGVSHDNHU WR SUHJQDQW ZRPHQ DQG UHFRUGHG WKH VSHHFK ZLWK D K\GURSKRQH LQ WKH XWHUXV 7KH YRLFH LQFOXGHG PRWKHU WDONLQJ GLUHFWO\ WKH PRWKHUfV YRLFH UHFRUGHG RQ WDSH DQG SOD\EDFN DQG WKH UHFRUGHG YRLFHV RI RWKHU ZRPHQ DQG PHQ $OO W\SHV RI UHFRUGHG YRLFHV SUHVHQWHG DW G%$f HPHUJHG DERYH WKH EDVDO QRLVH IORRU G%$f E\ WR G% 7KH PRWKHUfV YRLFH UHFRUGHG GLUHFWO\ ZDV G% JUHDWHU WKDQ WKH QRLVH IORRU 7KH LQWHQVLW\ RI WKH PDWHUQDO YRLFH WUDQVPLWWHG WR WKH XWHULQH FDYLW\ ZDV JUHDWHU WKDQ WKDW RI RXWVLGH YRLFHV 0RUHRYHU LW ZDV DOVR WUDQVPLWWHG WR IHWXV PRUH RIWHQ WKDQ DQ\ RWKHU YRLFHV ,Q %HQ]DTXHQ HW DO UHSRUWHG WKDW PDWHUQDO YRFDOL]DWLRQ ZDV HDVLO\ UHFRUGHG LQ XOHUR LQ WHQ SUHJQDQW ZRPHQ WHVWHG LQ WKH VWXG\ 7KH VRXQG VSHFWUXP SURGXFHG E\ SURQRXQFLQJ WKH ZRUGV RI ff ZDV FKDUDFWHUL]HG E\ SHDN LQWHQVLW\ RI WR G% 63/ DW WR +] DQG ZDV DSSUR[LPDWHO\ G% DERYH WKH LQWUDXWHULQH EDFNJURXQG QRLVH DW WKRVH IUHTXHQFLHV 5LFKDUGV HW DO f VWXGLHG WKH WUDQVPLVVLRQ RI VSHHFK LQWR WKH XWHUXV ,QWUDXWHULQH VRXQG SUHVVXUH OHYHOV RI WKH PRWKHUfV YRLFH ZHUH HQKDQFHG E\ DQ DYHUDJH RI G% LQ WKH ORZIUHTXHQF\ UDQJH ZKHUHDV H[WHUQDO PDOH DQG IHPDOH YRLFHV ZHUH DWWHQXDWHG E\ DQG G% UHVSHFWLYHO\ +RZHYHU WKHVH VWXGLHV RQO\ SURYLGHG WKH LQIRUPDWLRQ DERXW WKH H[LVWHQFH RI VSHHFK VRXQG LQ WKH LQWUDXWHULQH VRXQG HQYLURQPHQW 7KH XQGHUVWDQGDELOLW\ RI VSHHFK UHFRUGHG IURP ZLWKLQ WKH XWHUXV LV DQRWKHU FULWLFDO LVVXH IRU RXU XQGHUVWDQGLQJ RI HDUO\ VSHHFK DQG ODQJXDJH GHYHORSPHQW )HWDO LGHQWLILFDWLRQ RI LWV PRWKHUnV YRLFH DQG LWV DELOLW\ WR IRUP PHPRULHV RI HDUO\ H[SRVXUH WR VSHHFK DUH LQ SDUW GHSHQGHQW RQ WKH LQWHOOLJLELOLW\ RI WKH VSHHFK PHVVDJH

PAGE 41

&XUUHQWO\ WZR SXEOLVKHG VWXGLHV DGGUHVV WKH SHUFHSWLELOLW\ RI VSHHFK UHFRUGHG IURP LQVLGH WKH XWHUXV 4XHUOHX HW DO Ef UHFRUGHG WKH YRLFHV RI ILYH SUHJQDQW ZRPHQ DQG YRLFHV RI RWKHU PDOH DQG IHPDOH WDONHUV ZLWK D PRGLILHG PLFURSKRQH SRVLWLRQHG E\ WKH KHDG RI WKH IHWXV 6L[ OLVWHQHUV ZHUH DEOH WR UHFRJQL]H DERXW b RI WKH )UHQFK SKRQHPHV 1R VLJQLILFDQW GLIIHUHQFH ZDV QRWHG EHWZHHQ WKH PDOH DQG IHPDOH YRLFH DQG WKH PRWKHUfV YRLFH ZDV QRW EHWWHU SHUFHLYHG DOWKRXJK PRUH LQWHQVH 7KH UHFRJQLWLRQ RI YRZHOV ZDV FRUUHODWHG ZLWK WKHLU VHFRQG IRUPDQW 7KH LQWRQDWLRQ SDWWHUQV ZKLFK IUHTXHQFLHV ZHUH UDQJLQJ IURP WR +] ZHUH SHUIHFWO\ ZHOO GLVFULPLQDWHG FRPSDUHG WR OLQJXLVWLF PHDQLQJ ,Q D PRUH UHFHQW VWXG\ FRQGXFWHG E\ *ULIILWKV HW DO f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f JHQGHU RI WKH WDONHU PDOH RU IHPDOHf DQG LQWHQVLW\ OHYHO RU G%f )RU UHFRUGLQJV PDGH DW WKH PDWHUQDO IODQN WKHUH ZDV QR VLJQLILFDQW GLIIHUHQFH EHWZHHQ PDOH DQG IHPDOH WDONHUV ,QWHOOLJLELOLW\ VFRUHV LQFUHDVHG ZLWK LQFUHDVHG VWLPXOXV OHYHO IRU WDONHUV DQG DW ERWK UHFRUGLQJ VLWHV +RZHYHU LQWHOOLJLELOLW\ VFRUHV ZHUH VLJQLILFDQWO\ ORZHU IRU IHPDOHV WKDQ IRU PDOHV ZKHQ WKH UHFRUGLQJV ZHUH PDGH LQ WHUR

PAGE 42

$Q DQDO\VLV RI WKH IHDWXUH LQIRUPDWLRQ IURP UHFRUGLQJV LQVLGH DQG RXWVLGH WKH XWHUXV VKRZHG WKDW YRLFLQJ LQIRUPDWLRQ LV EHWWHU WUDQVPLWWHG LQ XOHUR WKDQ SODFH RU PDQQHU LQIRUPDWLRQ 9RLFLQJ UHIHUV WR WKH SUHVHQFH RU DEVHQFH RI YRFDO IROG YLEUDWLRQV HJ V YV ]f SODFH RI DUWLFXODWLRQ UHIHUV WR WKH ORFDWLRQ RI WKH PDMRU DLUIORZ FRQVWULFWLRQ GXULQJ SURGXFWLRQ HJ ELODELDO YV DOYHRODUf DQG PDQQHU UHIHUV WR WKH ZD\ WKH VSHHFK VRXQG LV SURGXFHG HJ SORVLYH YV JOLGHf 0LOOHU DQG 1LFHO\ f UHSRUWHG WKDW ORZSDVV ILOWHULQJ RI VSHHFK VLJQDOV UHVXOWHG LQ D JUHDWHU ORVV RI PDQQHU DQG SODFH LQIRUPDWLRQ WKDQ RI YRLFLQJ LQIRUPDWLRQ 7KH\ FRQFOXGHG WKDW WKH KLJKHU IUHTXHQF\ LQIRUPDWLRQ LQ WKH VSHHFK VLJQDO LV FULWLFDO IRU DFFXUDWH LGHQWLILFDWLRQ RI PDQQHU DQG SODFH RI DUWLFXODWLRQ 7KH ILQGLQJV RI *ULIILWKV HW DO f DUH FRQVLVWHQW ZLWK WKRVH RI 0LOOHU DQG 1LFHO\ f LQ WKDW WUDQVPLVVLRQ LQWR WKH XWHUXV FDQ EH PRGHOHG DV D ORZSDVV ILOWHU 7KH SRRUHU LQ 8WHUR UHFHSWLRQ RI SODFH DQG PDQQHU LQIRUPDWLRQ LV DVVRFLDWHG ZLWK WKH JUHDWHU KLJK IUHTXHQF\ DWWHQXDWLRQ 9RLFLQJ LQIRUPDWLRQ IURP WKH PDOH WDONHU ZKLFK LV FDUULHG E\ ORZIUHTXHQF\ HQHUJ\ ZDV ODUJHO\ SUHVHUYHG LQ WHUR 7KH MXGJHV HYDOXDWHG WKH PDOH WDONHUnV YRLFH HTXDOO\ ZHOO UHJDUGOHVV RI WUDQVGXFHU VLWH 6SHHFK RI WKH IHPDOH WDONHU FDUULHG OHVV ZHOO LQWR WKH XWHUXV 7KH IXQGDPHQWDO IUHTXHQF\ RI WKH IHPDOH WDONHU ZDV KLJKHU WKDQ WKDW RI WKH PDOH WDONHU 7KXV LW LV XQGHUVWDQGDEOH WKDW YRLFLQJ LQIRUPDWLRQ IURP WKH PDOH ZRXOG FDUU\ EHWWHU LQWR WKH XWHUXV WKDQ WKDW IURP WKH IHPDOH 0DOH DQG IHPDOH WDONHU LQWHOOLJLELOLW\ VFRUHV DYHUDJHG DSSUR[LPDWHO\ b DQG b UHVSHFWLYHO\ ZKHQ UHFRUGHG IURP ZLWKLQ WKH XWHUXV $OWKRXJK WKHVH UHVXOWV UHIOHFW WKH SHUFHSWLELOLW\ RI WKH VSHHFK HQHUJLHV SUHVHQW LQ WKH DPQLRWLF IOXLG WKH\ GR QRW VSHFLI\ ZKDW VSHHFK HQHUJ\ PLJKW EH SUHVHQW DW WKH IHWDO LQQHU HDU 0HDVXUHV RI DFRXVWLF

PAGE 43

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fV SUHIHUHQFHV IRU D SDUWLFXODU DFRXVWLFDO VLJQDO /HFDQXHW DQG 6FKDDO f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

PAGE 44

%XVQHO f 7KH KHDUWUDWH DFFHOHUDWLRQ FKDQJHV WR DXGLWRU\ VWLPXODWLRQ DUH W\SLFDOO\ DVVRFLDWHG ZLWK VRFDOOHG fVWDUWOLQJf RU GHIHQVLYH UHVSRQVH ZKLOH GHFHOHUDWLRQ FKDQJHV DUH fRULHQWLQJf RU DWWHQWLYH UHVSRQVH %HUJ DQG %HUJ f ([SHULPHQWV KDYH VKRZQ WKDW UHSHWLWLRQ DW D VKRUW LQWHUYDO HYHU\ VHFRQGVf RI D WR G% 63/ DFRXVWLF VWLPXOXV OHG WR WKH GLVDSSHDUDQFH RI D FDUGLDF GHFHOHUDWLRQ UHVSRQVH WKDW KDG EHHQ LQGXFHG E\ WKH ILUVW SUHVHQWDWLRQ RI WKH VWLPXOXV LQGLFDWLQJ DQ KDELWXDWLRQ /HFDQXHW HW DO f +DELWXDWLRQ LV GHILQHG DV WKH GHFUHPHQW LQ UHVSRQVH DIWHU UHSHDWHG SUHVHQWDWLRQ RI D VWLPXOXV +DELWXDWLRQ LV HVVHQWLDO IRU WKH HIILFLHQW IXQFWLRQLQJ DQG VXUYLYDO RI WKH RUJDQLVP HQDEOLQJ LW WR LJQRUH IDPLOLDU VWLPXOL DQG DWWHQG WR QHZ VWLPXOL +DELWXDWLRQ UHSUHVHQWV RQH RI WKH VLPSOHVW \HW PRVW HVVHQWLDO OHDUQLQJ SURFHVVHV WKH LQGLYLGXDO SRVVHVVHV DQG XQGHUOLHV PXFK RI RXU IXQFWLRQLQJ DQG GHYHORSPHQW +HSSHU f 8VLQJ D FODVVLFDO KDELWXDWLRQ GLVKDELWXDWLRQ SURFHGXUH .LVLOHYVN\ DQG 0XLU f REWDLQHG D VLJQLILFDQW GHFUHPHQW RI ERWK IHWDO FDUGLDF DFFHOHUDWLRQ DQG PRYHPHQW UHVSRQVHV WR D FRPSOH[ QRLVH DW G% 63/f IROORZHG E\ D UHFRYHU\ RI WKHVH UHVSRQVHV ZKHQ WULJJHUHG E\ D QRYHO YLEURDFRXVWLF VWLPXOXV 7KH IHWXVHV ZHUH EHWZHHQ DQG ZHHNV JHVWDWLRQ GXULQJ WKH H[SHULPHQW +DELWXDWLRQ LQ WHUR UHODWHV QRW RQO\ WR WKH UHFHSWLRQ RI WKH VHQVRU\ PHVVDJH EXW DOVR LWV LQWHJUDWLRQ DW ORZHU OHYHOV RI WKH FHQWUDO QHUYRXV V\VWHP 7KHUHIRUH WKH IHWXV LQ WHUR LV FDSDEOH RI OHDUQLQJ 4XHUOHX HW DO f /HFDQXHW HW DO f VWXGLHG WKH DXGLWRU\ GLVFULPLQDWLYH FDSDFLWLHV RI WKH QHDUWHUP IHWXV E\ XVLQJ KDELWXDWLRQGLVKDELWXDWLRQ RI KHDUWUDWH GHFHOHUDWLRQ UHVSRQVHV ,Q RQH VWXG\ /HFDQXHW *UDQLHU'HIHUUH DQG %XVQHO f IHWXVHV DW WR ZHHNV JHVWDWLRQ GLVSOD\HG D WUDQVLW KHDUWUDWH GHFHOHUDWLRQ UHVSRQVH ZKHQ WKH\ ZHUH H[SRVHG WR

PAGE 45

WKH UHSHDWHG SUHVHQWDWLRQ HYHU\ VHFRQGf RI D SDLU RI )UHQFK V\OODEOHV ED DQG EL RU EL DQG ED VSRNHQ E\ D IHPDOH WDONHU DW G% 63/ 5HYHUVLQJ WKH RUGHU RI WKH SDLUHG V\OODEOHV DIWHU SUHVHQWDWLRQV DOVR UHOLDEO\ LQGXFHG WKH VDPH W\SH RI UHVSRQVH 7KLV ZDV REVHUYHG LQ IHWXVHV LQ WKH %$%,%,%$ FRQGLWLRQ DQG LQ IHWXVHV LQ WKH %,%$%$%, FRQGLWLRQ 5HVSRQVH UHFRYHU\ VXJJHVWHG WKDW IHWXVHV GLVFULPLQDWHG EHWZHHQ WKH WZR VWLPXOL 7KH GLVFULPLQDWLRQ WKDW RFFXUUHG PD\ KDYH EHHQ SHUIRUPHG RQ WKH EDVLV RI D SHUFHSWXDO GLIIHUHQFH LQ ORXGQHVV LQWHQVLW\f EHWZHHQ WKH ED DQG EL VLQFH WKH HTXDOL]DWLRQ RI WKHVH V\OODEOHV ZDV SUHVHQWHG ZLWK 63/ QRW KHDULQJ OHYHO 7KLV LQWHQVLW\ DGMXVWPHQW PDNHV EL ORXGHU WKDQ ED IRU DXGLW OLVWHQHUV 6LPLODUO\ 6KDKLGXOODK DQG +HSSHU f IRXQG WKDW IHWXVHV DW ZHHNV JHVWDWLRQ KDG WKH DELOLW\ WR GLVFULPLQDWH EHWZHHQ EDED DQG ELEL ,Q DQRWKHU H[SHULPHQW /HFDQXHW HW DO f WKH DELOLW\ RI QHDUWHUP IHWXVHV WR GLVFULPLQDWH GLIIHUHQW VSHDNHUV SURGXFLQJ WKH VDPH VHQWHQFH ZDV VWXGLHG 7KH KHDUWUDWH UHVSRQVHV RI IHWXVHV EHWZHHQ WR ZHHNV JHVWDWLRQ ZHUH UHFRUGHG EHIRUH GXULQJ DQG DIWHU VWLPXODWLRQ WR WKH VHQWHQFH f'LFN D GX ERQ WKf 'LFN KDV VRPH JRRG WHDf 7KH VHQWHQFH ZDV VSRNHQ E\ HLWKHU D PDOH WDONHU PLQLPXP IXQGDPHQWDO IUHTXHQF\ )R +]f RU D IHPDOH WDONHU PLQLPXP ) +]f DQG GHOLYHUHG WKURXJK D ORXGVSHDNHU FP DERYH WKH PRWKHUfV DEGRPHQ DW WKH VDPH OHYHO G% 63/f 7KH IHWXVHV ZHUH H[SRVHG WR WKH ILUVW YRLFH SUHVHQWDWLRQ PDOH RU IHPDOHf DQG IROORZHG E\ WKH RWKHU YRLFH RU WKH VDPH YRLFH FRQWURO FRQGLWLRQf DIWHU IHWDO KHDUWUDWH UHVSRQVH UHWXUQHG WR EDVHOLQH 7KH UHVXOWV GHPRQVWUDWHG WKDW LQ WKH ILUVW V DIWHU SUHVHQWDWLRQ RI WKH LQLWLDO YRLFH WKH YRLFH PDOH RU IHPDOHf LQGXFHG D KLJK DQG VLPLODU SURSRUWLRQ RI KHDUW UDWH GHFHOHUDWLRQ FKDQJHV b WR WKH PDOH YRLFH b WR WKH IHPDOH YRLFHf FRPSDUHG WR D JURXS RI QRQ

PAGE 46

VWLPXODWHG VXEMHFWV b RI GHFHOHUDWLRQ DQG b RI DFFHOHUDWLRQf :LWKLQ WKH ILUVW V IROORZLQJ WKH YRLFH FKDQJH b RI WKH IHWXVHV H[SRVHG WR WKH RWKHU YRLFH GLVSOD\HG D KHDUWUDWH GHFHOHUDWLRQ UHVSRQVH ZKHUHDV b RI WKH IHWXVHV LQ WKH FRQWURO FRQGLWLRQ GLVSOD\HG KHDUWUDWH DFFHOHUDWLRQ FKDQJH 7KH DXWKRUV SRLQWHG RXW WKDW QHDUWHUP IHWXVHV PLJKW SHUFHLYH D GLIIHUHQFH EHWZHHQ WKH YRLFH FKDUDFWHULVWLFV RI WZR VSHDNHUV DW OHDVW ZKHQ WKH\ DUH KLJKO\ FRQWUDVWHG IRU )R DQG WLPEUH 7KH UHVXOWV FDQQRW EH JHQHUDOL]HG IRU DOO PDOH DQG IHPDOH YRLFHV RU IRU DOO VSHDNHUV VLQFH YRLFHV ZLWK H[WUHPHO\ ORZ )R ZHUH XVHG LQ WKH VWXG\ /HFDQXHW *UDQLHU'HIHUUH DQG %XVQHO /HFDQXHW f +HSSHU HW DO f VWXGLHG WKH DELOLW\ RI IHWXVHV WR GLVFULPLQDWH EHWZHHQ D VWUDQJH IHPDOHfV YRLFH DQG WKH PRWKHUfV YRLFH E\ PHDVXUHPHQW RI WKH QXPEHU RI IHWDO PRYHPHQWV GXULQJ D PLQXWH VSHHFK SUHVHQWDWLRQ 7KH UHVXOWV VKRZHG WKDW IHWXVHV DW ZHHNV JHVWDWLRQ GLG QRW GLVFULPLQDWH EHWZHHQ WKHLU PRWKHUfV YRLFH DQG WKDW RI D VWUDQJHU ZKHQ WDSH UHFRUGLQJV ZHUH SOD\HG WR WKHP YLD DQ DLUFRXSOHG ORXGVSHDNHU SODFHG RQ WKH DEGRPHQ +RZHYHU WKH IHWXVHV ZHUH DEOH WR GLVFULPLQDWH EHWZHHQ WKHLU PRWKHUfV YRLFH UHFRUGHG RQ WDSH DQG SOD\HG WR WKHP RYHU WKH ORXGVSHDNHU DQG WKH PRWKHUfV YRLFH SURGXFHG QDWXUDOO\ OHVV PRYHPHQWV ZHUH QRWHG LQ UHVSRQVH WR WKH PRWKHUfV GLUHFW VSHDNLQJ YRLFH ZKHQ FRPSDUHG WR D WDSH UHFRUGLQJ RI KHU YRLFH $FFRUGLQJ WR WKH DXWKRUV GLVFULPLQDWLRQ PD\ EH GXH WR WKH SUHVHQFH RI LQWHUQDOO\ WUDQVPLWWHG FRPSRQHQWV RI VSHHFK ZKLFK WKH IHWXV SHUFHLYHV ZKHQ WKH PRWKHU LV VSHDNLQJ EXW WKDW DUH QRW SUHVHQW ZKHQ WKH WDSH UHFRUGLQJ RI WKH PRWKHUfV YRLFH LV SOD\HG 7KH SRVVLELOLW\ RI SUHQDWDO UHFRJQLWLRQ RI D IDPLOLDU FKLOGfV UK\PH ZDV VWXGLHG E\ 'H&DVSHU HW DO f 6HYHQWHHQ SUHJQDQW ZRPHQ UHFLWHG D FKLOGfV UK\PH DORXG WKUHH WLPHV D GD\ IURP WKHLU UG WR WK ZHHN RI SUHJQDQF\ )HWDO KHDUWUDWH UHVSRQVH ZDV

PAGE 47

XVHG WR DVVHVV GLIIHUHQWLDO IHWDO UHVSRQVLYHQHVV WR WKH WDUJHW UK\PH YHUVXV D QRYHO UK\PH 'XULQJ WKH WK ZHHN RI JHVWDWLRQ HDFK IHWXV ZDV VWLPXODWHG WR RQH UK\PH IRU VHFRQGV WKURXJK D ORXGVSHDNHU SODFHG RYHU WKH PRWKHUfV DEGRPHQ 7KH ILUVW UK\PH ZDV IROORZHG E\ V RI VLOHQFH DQG WKHQ WKH RWKHU UK\PH ZDV SUHVHQWHG IRU V 6WLPXOXV OHYHO IRU ERWK UK\PHV ZDV VHW DW G% 63/ &DUH ZDV WDNHQ GXULQJ IHWDO WHVWLQJ WR NHHS WKH PRWKHU XQDZDUH RI ZKLFK UK\PH ZDV EHLQJ SUHVHQWHG VR WKDW VKH FRXOG QRW LQDGYHUWHQWO\ FXH KHU IHWXV 7KH UHVXOWV VKRZHG WKDW IHWDO KHDUW UDWHV VLJQLILFDQWO\ GHFUHDVHG IURP SUHVWLPXOXV OHYHOV ZKHQ WKH WDUJHW UK\PH ZDV SUHVHQWHG DQG VLJQLILFDQWO\ LQFUHDVHG RYHU SUHVWLPXOXV OHYHOV ZKHQ WKH QRYHO UK\PH ZDV SUHVHQWHG UHJDUGOHVV RI SUHVHQWDWLRQ RUGHU 7KLV GLIIHUHQWLDO KHDUWUDWH FKDQJH LPSOLHG WKDW WKH IHWXV GLVFULPLQDWHG WKH WZR UK\PHV 0RUHRYHU VLQFH WKHVH UK\PHV ZHUH FRXQWHUEDODQFHG DFURVV IHWXVHV WKH GLIIHUHQW SDWWHUQV RI KHDUWUDWH UHVSRQGV FRXOG QRW EH DWWULEXWHG WR DQ\ XQLTXH DFRXVWLF DWWULEXWHV RI RQH UK\PH 7KHUH LV QRZ D JURZLQJ ERG\ RI GDWD VKRZLQJ WKDW IHWXVHV SHUFHLYH DFRXVWLFDO VWLPXOL 1HDUWHUP IHWXVHV FDQ GLVFULPLQDWH EHWZHHQ WZR FRPSOH[ VWLPXOL VXFK DV V\OODEOHVf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

PAGE 48

DXGLWRU\ H[SHULHQFH SOD\V D PDMRU UROH LQ WKH GHYHORSPHQW RI KXPDQ QHZERUQ DXGLWRU\ SUHIHUHQFHV DQG FDSDELOLWLHV )LIHU /HDQXHW f ,W KDV EHHQ VKRZQ WKDW PDWHUQDO KHDUWEHDW 6DON f DQG UHFRUGLQJV RI LQWUDXWHULQH QRLVHV 5RVQHU DQG 'RKHUW\ f FDQ FDOP D UHVWOHVV EDE\ DQG VHUYHV DV D SRWHQW UHLQIRUFHU GXULQJ RSHUDQW FRQGLWLRQLQJ QRQQXWULWLYH VXFNLQJ SURFHGXUHV 'H&DVSHU DQG 6LJDIRRV f ,QGHHG LQWUDXWHULQH FDUGLDF UK\WKPV DUH SRWHQW UHLQIRUFHV IRU WR GD\ROG QHZERUQV D ILQGLQJ WKDW VXJJHVWV WKDW SUHQDWDO DXGLWRU\ H[SHULHQFH DIIHFWV SRVWQDWDO EHKDYLRU 1RQQXWULWLYH VXFNLQJ SURFHGXUHV PDGH LW SRVVLEOH WR REMHFWLI\ QHZERUQfV GLVFULPLQDWLYH DELOLWLHV DQG WR WHVW WKH QHZERUQfV SUHIHUHQFH IRU D JLYHQ VWLPXOXV 7KH KXPDQ YRLFH HVSHFLDOO\ WKDW RI LWV PRWKHU LV OLNHO\ WR KDYH LQFUHDVHG VDOLHQFH IRU WKH IHWXV UHODWLYH WR RWKHU DXGLWRU\ VWLPXOL 0RWKHUfV YRLFH LQ WKH IHWDO VRXQG HQYLURQPHQW GLIIHUV IURP RWKHU VRXQGV LQ LWV LQWHQVLW\ YDULDELOLW\ DQG RWKHU PXOWLPRGDO FKDUDFWHULVWLFV 0RWKHUfV YRLFH KDV EHHQ UHSRUWHG WR EH WKH PRVW LQWHQVH DFRXVWLF VLJQDO PHDVXUHG LQ WKH DPQLRWLF HQYLURQPHQW 4XHUOHX HW DO D %HQ]DTXHQ HW DK 5LFKDUGV HW DK f 7KH QDWXUH RI WKH PDWHUQDO YRLFH PD\ SURPRWH JUHDWHU IHWDO UHVSRQVLYHQHVV WR PRWKHUfV YRLFH WKDQ DQ\ RWKHU SUHQDWDO VRXQG 7KH HDUOLHVW HYLGHQFH IRU GLIIHUHQWLDO UHVSRQVLYHQHVV WR PDWHUQDO YRLFH FDPH IURP ZRUN ZLWK ROGHU LQIDQWV 0LOOV DQG 0HOXLVK f 7KH H[SHULPHQWV GHPRQVWUDWHG D GLIIHUHQWLDO VHQVLWLYLW\ WR WKH PDWHUQDO YRLFH LQ WR GD\ROG LQIDQWV 7KH DPRXQW RI WLPH VSHQW VXFNLQJ DQG QXPEHU RI VXFNV SHU PLQXWH ZHUH LQFUHDVHG DIWHU D EULHI SUHVHQWDWLRQ RI KLVKHU PRWKHUfV YRLFH ,Q D ODWHU VWXG\ XVLQJ PRQWKROG LQIDQWV 0HKOHU HW DK f VXFNV ZHUH UHLQIRUFHG ZLWK HLWKHU D PRWKHUfV RU D VWUDQJHUfV YRLFH LQWRQDWHG RU PRQRWRQH $ VLJQLILFDQW LQFUHDVH LQ VXFNLQJ

PAGE 49

ZDV RQO\ REVHUYHG ZKHQ PRWKHUfV YRLFH ZDV QRUPDOO\ LQWRQDWHG 7KH UROH RI LQWRQDWLRQ LQ UHFRJQLWLRQ RI WKH PRWKHUfV YRLFH ZDV VXJJHVWHG $OWKRXJK WKHVH SURFHGXUHV FOHDUO\ GHPRQVWUDWH WKDW LQIDQWV UHVSRQG GLIIHUHQWLDOO\ WR WKHLU PRWKHUfV QRUPDO YRLFH WKH GLIIHUHQFHV LQ UHVSRQGLQJ GR QRW QHFHVVDULO\ LQGLFDWH D SUHIHUHQFH IRU KHU YRLFH )LIHU f 7KH VWXG\ E\ 'H&DVSHU DQG )LIHU f XVLQJ WZR GLIIHUHQW QRQQXWULWLYH VXFNLQJ SURFHGXUHV ZDV WKH ILUVW WR SURYLGH GLUHFW H[SHULPHQWDO HYLGHQFH WKDW QHRQDWHV SUHIHU WKHLU PRWKHUfV YRLFH 8VLQJ D WHPSRUDO GLVFULPLQDWLRQ SURFHGXUH WR GD\ROG LQIDQWV ZHUH REVHUYHG IRU D PLQXWH EDVHOLQH SHULRG LQ ZKLFK QRQUHZDUGHG VXFNV RQ D QRQQXWULWLYH QLSSOH ZHUH UHFRUGHG 7KH PHGLDQ WLPH RI WKH LQWHUEXUVW LQWHUYDOV ,%,Vf ZDV FDOFXODWHG DQG XVHG WR VHW WKH FRQWLQJHQF\ IRU WKH WHVWLQJ )RU RI WKH LQIDQWV WHVWHG VXFNLQJ EXUVWV WKDW HQGHG ,%,V VKRUWHU WKDQ WKH EDVHOLQH PHGLDQ ,%, P,%,f WXUQHG RQ D WDSH UHFRUGLQJ RI WKH LQIDQWfV PRWKHU UHDGLQJ D FKLOGUHQfV VWRU\ :KHUHDV VXFNLQJ EXUVWV WKDW HQGHG ,%,V HTXDO WR RU ORQJHU WKDQ WKH P,%, WXUQHG RQ D WDSH UHFRUGLQJ RI DQRWKHU LQIDQWfV PRWKHU UHDGLQJ WKH VDPH VWRU\ )RU WKH RWKHU ILYH LQIDQWV WKH ,%,VWRU\ FRQWLQJHQF\ ZDV UHYHUVHG 7KH UHVXOWV VKRZHG WKDW RI WKH LQIDQWV VKLIWHG WKHLU RYHUDOO PHGLDQV VLJQLILFDQWO\ LQ WKH GLUHFWLRQ QHFHVVDU\ WR WXUQ RQ WKH UHFRUGLQJ RI LWV PRWKHUfV YRLFH $OVR WKH LQIDQWV WXUQHG RQ WKH UHFRUGLQJ RI WKHLU PRWKHUfV YRLFH PRUH RIWHQ DQG IRU D ORQJHU WRWDO SHULRG RI WLPH WKDQ WKH XQIDPLOLDU IHPDOH YRLFH ,Q WKH VHFRQG SURFHGXUH ZKLFK LQYROYHG D VLJQDO GLVFULPLQDWLRQ SDUDGLJP WKH SUHVHQFH RU DEVHQFH RI D V )O] WRQH VLJQDOHG WKH DYDLODELOLW\ RI WKH GLIIHUHQW YRLFHV DQG WKH YRLFHV UHPDLQHG RQ IRU WKH GXUDWLRQ RI WKH VXFNLQJ EXUVW )RU RI WKH LQIDQWV WHVWHG VXFNLQJ RQ WKH QLSSOH GXULQJ WKH WRQH UHVXOWHG LQ WKH FHVVDWLRQ RI WKH WRQH DQG

PAGE 50

WXUQHG RQ D UHFRUGLQJ RI WKHLU RZQ PRWKHUfV YRLFH UHDGLQJ D FKLOGUHQfV VWRU\ ZKHUHDV VXFNLQJ GXULQJ VLOHQFH WXUQHG RQ D UHFRUGLQJ RI DQRWKHU ZRPDQ UHDGLQJ WKH VDPH VWRU\ )RU WKH RWKHU HLJKW LQIDQWV WKH VLJQDOVWRU\ FRQWLQJHQF\ ZDV UHYHUVHG $JDLQ HYLGHQFH RI QHZERUQVf SUHIHUHQFH IRU WKHLU RZQ PRWKHUfV YRLFH ZDV REWDLQHG ,QIDQWV VKRZHG D VLJQLILFDQWO\ JUHDWHU SUREDELOLW\ RI VXFNLQJ GXULQJ WKH VLJQDO WRQH RU VLOHQFHf WKDW OHG WR WKH SUHVHQWDWLRQ RI WKH PDWHUQDO YRLFH UHFRUGLQJ 6LQFH LW LV SRVVLEOH WKDW SUHIHUHQFH IRU WKH PRWKHUfV YRLFH FRXOG EH JHQHUDWHG YHU\ IDVW E\ WKH QHZERUQfV LQLWLDO SRVWQDWDO FRQWDFW ZLWK WKH PRWKHU VHYHUDO VXEVHTXHQW VWXGLHV KDYH DWWHPSWHG WR UXOH RXW WKH HIIHFW RI SRVWQDWDO DXGLWRU\ H[SHULHQFH )LIHU f IDLOHG WR ILQG DQ\ HYLGHQFH WKDW SUHIHUHQFH LQ QHZERUQV IRU PDWHUQDO YRLFH ZDV UHODWHG WR HLWKHU SRVWQDWDO DJH YV GD\ROGVf RU PHWKRG RI IHHGLQJ ERWWOHIHG YV EUHDVWIHGf $QRWKHU VWXG\ VKRZHG WKDW GD\ROG QHZERUQV GLG QRW SUHIHU LWV IDWKHUfV YRLFH WR WKDW RI DQRWKHU PDOHfV YRLFH HYHQ WKRXJK WKHVH QHZERUQV KDG WR KRXUV RI SRVWQDWDO FRQWDFW ZLWK WKHLU IDWKHUV 'H&DVSHU DQG 3UHVFRWW f 7KLV VWXG\ DOVR GHWHUPLQHG WKDW WKH DEVHQFH RI D SUHIHUHQFH IRU WKH SDWHUQDO YRLFH ZDV QRW GXH WR WKH LQDELOLW\ RI QHZERUQV WR GLVFULPLQDWH EHWZHHQ SDLUV RI PDOH YRLFHV )XUWKHUPRUH WKH DXWKRUV FRPSDUHG WKH SUHIHUHQFH EHWZHHQ DQ DLUERUQH YHUVLRQ RI WKRVH PRWKHUfV YRLFH DQG WKHLU fLQWUDXWHULQHf ORZSDVV ILOWHUHG YHUVLRQ 8VLQJ WRQHVLOHQFH GLVFULPLQDWLYH UHVSRQGLQJ SURFHGXUHV WR GD\ROG LQIDQWV ZHUH JLYHQ D FKRLFH RI KHDULQJ WKHLU PRWKHUfV YRLFH RU RWKHU IHPDOHfV YRLFHf HLWKHU XQILOWHUHG RU ORZSDVV ILOWHUHG DW +] 6SHQFH DQG 'H&DVSHU f ,QIDQWV VKRZHG QR SUHIHUHQFH IRU HLWKHU WKH XQILOWHUHG RU ORZSDVV ILOWHUHG YHUVLRQ RI WKHLU PRWKHUfV YRLFH ZKHUHDV LQIDQWV SUHIHUUHG WKH XQILOWHUHG YHUVLRQ RI WKH QRQPDWHUQDO YRLFH WR WKH ILOWHUHG QRQPDWHUQDO YRLFH $FFRUGLQJ WR WKH DXWKRUV VLQFH WKHUH LV DSSDUHQWO\ OLWWOH

PAGE 51

SUHQDWDO H[SHULHQFH ZLWK WKH ORZIUHTXHQF\ IHDWXUHV RI RWKHU IHPDOH YRLFHV EXW FRQVLGHUDEOH SRVWQDWDO H[SHULHQFH ZLWK WKHLU IXOO VSHFWUDO FKDUDFWHULVWLFV WKH QHZERUQV SUHIHUUHG WKH PRUH IDPLOLDU YHUVLRQ RI WKH IHPDOH VWUDQJHUfV YRLFH ,Q FRQWUDVW ERWK WKH ILOWHUHG DQG XQILOWHUHG YHUVLRQV RI PDWHUQDO YRLFH FRQWDLQHG WKH QHFHVVDU\ ORZIUHTXHQF\ IHDWXUHV IRU PDWHUQDO YRLFH UHFRJQLWLRQ VR WKH LQIDQWV VKRZHG QR SUHIHUHQFH )LQDOO\ )LIHU DQG 0RRQ f XVLQJ D PRGLILHG YHUVLRQ RI WKH fLQWUDXWHULQHf PRWKHUfV YRLFH PL[HG RU QRW PL[HG ZLWK PDWHUQDO FDUGLRYDVFXODU VRXQGV IRXQG WKDW GD\ROG QHZERUQV SUHIHUUHG D ORZSDVV ILOWHUHG YHUVLRQ RI WKH PDWHUQDO YRLFH WR DQ XQILOWHUHG YHUVLRQ ZKHQ ),] ZDV WKH FXWRII IUHTXHQF\ 7KHUHIRUH LW LV SRVVLEOH WKDW WKH LQIDQWV LQ WKH SUHYLRXV VWXG\ 6SHQFH DQG 'H&DVSHU f GLG QRW VKRZ D SUHIHUHQFH IRU WKH ILOWHUHG PDWHUQDO YRLFH EHFDXVH LW ZDV PRUH VLPLODU WR WKHLU SRVWQDWDO UDWKHU WKDQ WKHLU SUHQDWDO H[SHULHQFH ZLWK WKH PDWHUQDO YRLFH 1HZERUQVf SUHQDWDO IDPLOLDULW\ ZLWK PDWHUQDO YRLFH PD\ H[SODLQ WKH ILQGLQJV E\ +HSSHU HW DO f 8VLQJ DQ DQDO\VLV RI IHWDO PRYHPHQWV +HSSHU HW DO GHPRQVWUDWHG WKDW WR GD\ROG QHZERUQV GLVFULPLQDWHG QRUPDO VSHHFK IURP fPRWKHUHVHf VSHHFK RI WKHLU PRWKHUVf YRLFH EXW QRW EHWZHHQ QRUPDO LQWRQDWHG DQG RQH RI fPRWKHUHVHf RI D VWUDQJH IHPDOHfV YRLFH 1HZERUQV KRZHYHU GLVFULPLQDWHG WKH PDWHUQDO YRLFH IURP D VWUDQJH IHPDOH YRLFH 7DNHQ WRJHWKHU WKHVH UHVXOWV VXJJHVW WKDW SUHQDWDO DXGLWRU\ H[SHULHQFH GHWHUPLQHV DW OHDVW VRPH RI WKH LQIDQWfV HDUO\ DXGLWRU\ SUHIHUHQFHV 7KLV SUHQDWDO HIIHFW ZDV GHPRQVWUDWHG PRUH GLUHFWO\ E\ WKH VWXG\ FRQGXFWHG E\ 'H&DVSHU DQG 6SHQFH f 6L[WHHQ SUHJQDQW ZRPHQ UHFLWHG RQH RI WKH WKUHH FKLOGUHQfV VWRULHV DORXG WZLFH HDFK GD\ GXULQJ WKH ILQDO ZHHNV RI WKHLU SUHJQDQFLHV $IWHU ELUWK WKH QHZERUQV DYHUDJH DJH RI KRXUVf ZHUH WHVWHG XVLQJ WKH QRQQXWULWLYH ,%, FRQWLQJHQW VXFNLQJ SURFHGXUH )RU

PAGE 52

HLJKW RI WKH LQIDQWV LQ WKH SUHQDWDO JURXS VXFNLQJ EXUVWV IROORZLQJ ,%,V P,%, WXUQHG RQ D UHFRUGLQJ RI D ZRPDQ HLWKHU WKH LQIDQWfV RZQ PRWKHU RU WKH PRWKHU RI DQRWKHU LQIDQWf UHDGLQJ WKH VWRU\ WKDW WKH LQIDQWfV PRWKHU KDG UHDG ZKLOH SUHJQDQW 6XFNLQJ EXUVWV ZKLFK IROORZHG ,%,V P,%, WXUQHG RQ D UHFRUGLQJ RI WKDW VDPH ZRPDQ UHDGLQJ D QRYHO VWRU\ )RU WKH RWKHU HLJKW LQIDQWV LQ WKH SUHQDWDO JURXS WKH ,%,VWRU\ FRQWLQJHQF\ ZDV UHYHUVHG $GGLWLRQDOO\ D FRQWURO JURXS LQIDQWVf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f JHQHUDOL]HG IURP PDWHUQDO WR QRQPDWHUQDO YRLFH ,W LPSOLHV WKDW WKH QHZERUQ UHWDLQV WZR GLIIHUHQW NLQGV RI DFRXVWLF LQIRUPDWLRQ IURP SUHQDWDO H[SHULHQFH LQIRUPDWLRQ DERXW VSHFLILF FKDUDFWHULVWLFV RI WKH PRWKHUfV YRLFH SHUKDSV IXQGDPHQWDO IUHTXHQF\f DQG PRUH JHQHUDO FKDUDFWHULVWLFV WKDW DUH QRW QHFHVVDULO\ PRWKHUVSHFLILF VXFK DV LQWRQDWLRQ FRQWRXUV DQG RU WHPSRUDO FKDUDFWHULVWLFV 7KHVH VWXGLHV SURYLGH VWURQJ HYLGHQFH WKDW WKH ODWHWHUP KXPDQ IHWXV LV DEOH WR SURFHVV VRPH DVSHFWV RI YRFDO VWLPXODWLRQ SUHVHQWHG E\ WKH PRWKHU DQG UHWDLQ VRPH RI WKDW LQIRUPDWLRQ IRU DW OHDVW VHYHUDO GD\V DIWHU ELUWK ,W UHPDLQV XQFOHDU KRZHYHU ZKLFK VSHFLILF DVSHFWV RI SUHQDWDO DXGLWRU\ VWLPXODWLRQ ZHUH UHVSRQVLEOH IRU SRVWQDWDO DXGLWRU\ SUHIHUHQFHV

PAGE 53

%HFDXVH H[WHUQDO ORZIUHTXHQF\ VRXQG LV WUDQVPLWWHG LQWR WKH XWHUXV ZLWK OLWWOH DWWHQXDWLRQ DQG EHFDXVH KLJKIUHTXHQF\ VRXQG LV DWWHQXDWHG WKH IHWXV FDQ RQO\ GHWHFW WKH ORZIUHTXHQF\ FRPSRQHQWV RI SDVVDJH SUHVHQWHG E\ WKH PRWKHU ,W DSSHDUV WKDW WKHVH QHZERUQV FRXOG QRW PHUHO\ GHSHQG RQ VHJPHQWDO LQIRUPDWLRQ SKRQHWLF FRPSRQHQWV RI VSHHFK LH WKH VSHFLILF FRQVRQDQWV DQG YRZHOV PDNLQJ XS WKH ZRUGVf ZKLFK WKH\ H[SHULHQFHG SUHQDWDOO\ DV WKH EDVLV IRU WKHLU SRVWQDWDO UHFRJQLWLRQ VLQFH VHJPHQWDO LQIRUPDWLRQ LV FDUULHG E\ WKRVH IUHTXHQFLHV WKDW DSSHDU WR EH PRVW DWWHQXDWHG LQ WHUR IUHTXHQFLHV DERYH +]f ,Q FRQWUDVW WKH VXSUDVHJPHQWDO LQIRUPDWLRQ LQWRQDWLRQ IUHTXHQF\ YDULDWLRQ VWUHVV DQG UK\WKPf FRQWDLQHG LQ WKH PDWHUQDO YRLFH DQG LQ WKH VWRULHV UHFLWHG E\ WKH PRWKHU LV DYDLODEOH WR WKH IHWXV ZLWK YHU\ OLWWOH DWWHQXDWLRQ 7KH K\SRWKHVLV DERXW WKH UROH RI VXSUDVHJPHQWDO LQIRUPDWLRQ LQ IHWDO DXGLWRU\ SHUFHSWLRQ KDV EHHQ LQYHVWLJDWHG &RRSHU DQG $VOLQ f ,Q DQ HIIRUW WR WHVW ZKHWKHU SUHQDWDOO\ DYDLODEOH VXSUDVHJPHQWDO LQIRUPDWLRQ ZRXOG EH VXIILFLHQW WR LQGXFH D SRVWQDWDO SUHIHUHQFH WKH DXWKRUV KDG SUHJQDQW ZRPHQ VLQJ WKH O\ULFV RI WKH WXQH WR f0DU\ +DG $ /LWWOH /DPEf XVLQJ WKH V\OODEOH fDf LQVWHDG RI WKH DFWXDO ZRUGV RI WKH PHORG\ &RRSHU DQG $VOLQ f (DFK ZRPDQ VDQJ WKH PHORG\ PLQXWHV GDLO\ VWDUWLQJ RQ WKH WK GD\ SULRU WR KHU GXH GDWH 7KH QHZERUQV RI WKHVH PRWKHUV ZHUH WHVWHG EHWZHHQ DQG KRXUV DIWHU ELUWK PHDQ DJH KRXUV ROGf XVLQJ WKH ,%, SURFHGXUH )RU WKH VHYHQ LQIDQWV LQ WKH SUHQDWDO JURXS VXFNLQJ EXUVWV WKDW HQGHG ,%,V P,%, WXUQHG RQ D UHFRUGLQJ RI f0DU\ +DG $ /LWWOH /DPEf VXQJ E\ D SURIHVVLRQDO IHPDOH VLQJHU XVLQJ fODf LQVWHDG RI WKH ZRUGVf ZKHUHDV VXFNLQJ EXUVWV WKDW HQGHG ,%,V P,%, WXUQHG RQ D UHFRUGLQJ RI WKH VDPH VLQJHU VLQJLQJ fRYH 6RPHERG\ DOVR ZLWK fODf LQVWHDG RI WKH ZRUGV 7KHVH WZR PHORGLHV ZHUH VXQJ LQ WKH VDPH NH\ DQG FRQWDLQHG WKH

PAGE 54

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f 8VLQJ WKH D RU ,nOO VLJQDO GLVFULPLQDWLRQ SURFHGXUH 0RRQ DQG )LIHU f 0RRQ HW DO f GHPRQVWUDWHG WKDW GD\ROG QHZERUQV ZKRVH PRWKHUV ZHUH PRQROLQJXDO VSHDNHUV RI 6SDQLVK RU (QJOLVK SUHIHUUHG WKHLU PRWKHUfV ODQJXDJH WR WKH RWKHU RQH 'HPRQVWUDWLRQ RI D SUHIHUHQFH IRU WKH QDWLYH ODQJXDJH DW VXFK DQ HDUO\ DJH IDYRUV DQ LQWHUSUHWDWLRQ RI WKH VWXG\ E\ 0HKOHU HW DO f LQ WHUPV RI D SUHQDWDO IDPLOLDUL]DWLRQ ,Q WKH ODWWHU VWXGLHV XVLQJ D QRQFRQWLQJHQW KDELWXDWLRQ GLVKDELWXDWLRQ RI KLJKDPSOLWXGH VXFNLQJ SURFHGXUH 0HKOHU HW DO f GHPRQVWUDWHG WKDW GD\ROG QDWLYH )UHQFK QHZERUQV FRXOG GLVFULPLQDWH D UHFRUGLQJ RI D ZRPDQ VSHDNLQJ 5XVVLDQ IURP WKH VDPH ZRPDQ VSHDNLQJ )UHQFK EXW GLG QRW GLIIHUHQWLDOO\ UHVSRQG WR (QJOLVK IURP ,WDOLDQ UHFRUGLQJV $OVR GD\ROGV RI QRQ)UHQFK SDUHQWV GLG QRW UHVSRQG GLIIHUHQWLDOO\ WR HLWKHU 5XVVLDQ RU )UHQFK UHFRUGLQJV 7KXV YHU\ \RXQJ LQIDQWV VHHP WR UHTXLUH VRPH

PAGE 55

H[SHULHQFH ZLWK D ODQJXDJH LQ RUGHU WR UHVSRQG GLIIHUHQWLDOO\ WR ODQJXDJHV 7KLV LQWHUSUHWDWLRQ LV VWUHQJWKHQHG E\ DGGLWLRQDO GDWD 0HKOHU HW DO f VKRZLQJ WKDW QDWLYH (QJOLVK PRQWKROGV DOVR GLG QRW UHVSRQG GLIIHUHQWLDOO\ WR 5XVVLDQ RU )UHQFK EXW HDVLO\ GLVFULPLQDWHG (QJOLVK IURP ,WDOLDQ 7KXV LW ZDV QRW PHUHO\ WKH \RXQJ DJH RI WKH QHZERUQV WKDW UHVXOWHG LQ WKHLU IDLOXUH WR UHVSRQG GLIIHUHQWLDOO\ WR QRUPDWLYH ODQJXDJHV 3UHQDWDO PDWHUQDO VSHHFK LV RQH OLNHO\ VRXUFH RI QDWLYH ODQJXDJH H[SHULHQFH IRU WKH QHZERUQV )LQDOO\ 0HKOHU HW DO f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fV QDWLYH ODQJXDJH 7KH LQIDQWfV SUHQDWDO H[SHULHQFH ZLWK PDWHUQDO VSHHFK PD\ LQ ODUJH SDUW GHWHUPLQH WKH HDUO\ SRVWQDWDO SHUFHSWXDO VDOLHQFH RI D VSHFLILF PRWKHUfV VSHHFK DQG QDWLYH VSHHFK

PAGE 56

6SHHFK 3HUFHSWLRQ 6SHHFK 3HUFHSWLRQ LQ ,QIDQF\ 7KHUH DUH WZR FKDUDFWHUL]DWLRQV RI LQIDQWVf fLQLWLDO VWDWHf UHJDUGLQJ VSHHFK SHUFHSWLRQ 2QH DUJXHV WKDW LQIDQWV HQWHU WKH ZRUOG HTXLSSHG ZLWK VSHFLDOL]HG VSHHFK VSHFLILF PHFKDQLVPV HYROYHG IRU WKH SHUFHSWLRQ RI VSHHFK DQG WKDW LQIDQWV DUH ERUQ ZLWK D fVSHHFK PRGXOHf WR GHFRGH WKH FRPSOH[ DQG LQWULFDWH VSHHFK VLJQDOV )RGHU 0HKOHU DQG 'XSRX[ f 7KH RWKHU KROGV WKDW LQIDQWV EHJLQ OLIH ZLWKRXW VSHFLDOL]HG PHFKDQLVPV GHGLFDWHG WR VSHHFK DQG WKDW LQIDQWVf LQLWLDO UHVSRQVLYHQHVV WR VSHHFK FDQ EH DWWULEXWHG WR WKHLU PRUH JHQHUDO VHQVRU\ DQG FRJQLWLYH DELOLWLHV $VOLQ .XKO -XVF]\N f ,Q IDFW WKH FDSDFLW\ RI QHZERUQV WR GLVWLQJXLVK PLQLPDO VSHHFK FRQWUDVWV LV UHPDUNDEOH $VOLQ 3LVRQL DQG -XVF]\N $VOLQ .XKO 0HKOHU DQG 'XSRX[ f (LPDV HW DO f ZHUH WKH ILUVW WR GHPRQVWUDWH WKDW KXPDQ LQIDQWV DV \RXQJ DV RQH PRQWK ROG FDQ GLVFULPLQDWH VXEWOH DFRXVWLF SURSHUWLHV LQ D FDWHJRULFDO PDQQHU WKDW GLIIHUHQWLDWH IRU (QJOLVKVSHDNLQJ DGXOWV WKH VWRSFRQVRQDQWYRZHO V\OODEOHV ,EDO IURP SD ZKLFK DUH GLIIHUHQW LQ YRLFH RQVHW WLPH 927f ,Q WKHLU VWXG\ FRPSXWHUn JHQHUDWHG V\QWKHWLFf VSHHFK GLIIHULQJ RQO\ 927 ZDV SUHVHQWHG LQ SDLUV WR LQIDQWV IRU WHVWLQJ ZLWK WKH KLJKDPSOLWXGH VXFNLQJ SURFHGXUH 2QO\ RQH RI WKHVH 927 SDLUV VSDQQHG WKH ERXQGDU\ EHWZHHQ (QJOLVKVSHDNLQJ DGXOWVf SKRQHPLF FDWHJRULHV IRU ,EDO DQG SD 7KLV EHWZHHQFDWHJRU\ 927 SDLU ZDV GLVFULPLQDWHG E\ WKH LQIDQWV ZKHUHDV VHYHUDO RWKHU ZLWKLQFDWHJRU\ SDLUV ZHUH QRW GLVFULPLQDWHG HYHQ WKRXJK WKH 927 GLIIHUHQFH EHWZHHQ HDFK SDLU ZDV LGHQWLFDO VHFRQGf 6LQFH WKHQ WKHUH LV JURZLQJ ERG\ RI HYLGHQFH WKDW QHDUO\ DOO VSHHFK FRQWUDVWV SKRQHWLF FRQWUDVWVf XVHG LQ DQ\ RI WKH ZRUOGfV QDWXUDO

PAGE 57

ODQJXDJHV FDQ EH GLVFULPLQDWHG E\ PRQWKV RI DJH $VOLQ 3LVRQL DQG -XVF]\N $VOLQ .XKO -XVF]\N f 7KHUH DUH DOVR LQGLFDWLRQV WKDW GXULQJ WKH HDUO\ VWDJHV WKH PHFKDQLVPV WKDW XQGHUOLH VSHHFK SURFHVVLQJ E\ LQIDQWV PD\ EH D SDUW RI PRUH JHQHUDO DXGLWRU\ SURFHVVLQJ FDSDFLWLHV $VOLQ 3LVRQL DQG -XVF]\N $VOLQ .XKO -XVF]\N f 3ULRU WR PRQWKV RI DJH LQIDQWV DUH SHUIRUPLQJ WKHLU DQDO\VLV RI VSHHFK VRXQGV VROHO\ RQ WKH EDVLV RI DFRXVWLF GLIIHUHQFHV 7KHVH DFRXVWLF GLIIHUHQFHV DUH VXIILFLHQW WR SHUPLW FDWHJRULFDO SHUFHSWLRQ MXVW DV VLPLODU DFRXVWLF PHFKDQLVPV SUHVXPDEO\ VXSSRUW WKH SURFHVVLQJ RI QRQVSHHFK FRQWUDVWV E\ LQIDQWV -XVF]\N HW DO f DQG WKH SURFHVVLQJ RI VSHHFK FRQWUDVWV E\ QRQKXPDQV .XKO DQG 0LOOHU f &KDUDFWHULVWLF RI 6SHHFK 6SHHFK VLJQDOV KDYH QXPHURXV GLVWLQFWLYH DFRXVWLF SURSHUWLHV RU DWWULEXWHV WKDW DUH XVHG LQ WKH HDUOLHVW VWDJHV RI SHUFHSWXDO DQDO\VLV 7KH DYHUDJH LQWHQVLW\ RI QRUPDO VSHHFK PHDVXUHG DW D GLVWDQFH RI FHQWLPHWHU IURP WKH VSHDNHUfV OLSV LV DERXW G% LQWHQVLW\ OHYHO ,/f DQG LQGLYLGXDO YDULDWLRQ EHWZHHQ VSHDNHUV LV DERXW s G% 'XQQ DQG :KLWH f ,I WKH SDXVHV VLOHQW LQWHUYDOVf DUH H[FOXGHG WKH H[SHULPHQWDO GDWD LQGLFDWHG WKDW WKHVH OHYHOV ZRXOG EH LQFUHDVHG G% )OHWFKHU f /RXG VSHHFK PD\ UHDFK G% ,/ ZKLOH VRIW VSHHFK PD\ EH DV ORZ DV G% ,Q WKH FRXUVH RI RUGLQDU\ FRQYHUVDWLRQ WKH G\QDPLF UDQJH RI VSHHFK LV DERXW G% )OHWFKHU f ,Q D PRUH UHFHQW VWXG\ &R[ DQG 0RRUH f WKH PHDQ VRXQG SUHVVXUH OHYHO DW PHWHU IRU D PDOH WDONHU VSHDNLQJ ZLWK QRUPDO YRFDO HIIRUW ZDV G% DQG IRU D IHPDOH WDONHU ZDV G% 7KH DYHUDJH VSHFWUD ZHUH VLPLODU LQ WKH UDQJH IURP WR +] EHWZHHQ PDOH DQG IHPDOH WDONHUV

PAGE 58

,QWHUHVWLQJO\ WKH FRPSDULVRQ RI ORQJWHUP DYHUDJH VSHHFK VSHFWUD RYHU ODQJXDJHV VKRZHG WKDW WKH VSHFWUXP ZDV VLPLODU IRU DOO ODQJXDJHV DOWKRXJK WKHUH ZHUH PDQ\ VPDOO GLIIHUHQFHV %\UQH HW DO f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f 7KH IUHTXHQF\ UDQJH RI VSHHFK H[WHQGV IURP +] WR VHYHUDO WKRXVDQG +HUW] ZKLOH WKH IUHTXHQFLHV LPSRUWDQW WR WKH VSHHFK VLJQDO DUH ZLWKLQ WKH WR +] UDQJH %RUGHQ DQG +DUULV f 7KH KXPDQ YRLFH LV FRPSRVHG RI PDQ\ IUHTXHQFLHV 7KH ORZHVW IUHTXHQF\ LV WKH IXQGDPHQWDO IUHTXHQF\ RI WKH YRLFH GULYHQ E\ WKH YLEUDWLRQ RI WKH YRFDO IROGV 7KH IXQGDPHQWDO IUHTXHQF\ LV FRQVWDQWO\ FKDQJLQJ GXULQJ DUWLFXODWLRQ DQG YDULHV FRQVLGHUDEO\ IURP RQH SHUVRQ WR DQRWKHU 7KH IXQGDPHQWDO IUHTXHQF\ RI D ORZSLWFKHG PDOH YRLFH LV DERXW +] ZKLOH D ZRPDQ ZLWK D KLJKSLWFKHG YRLFH PD\ VSHDN DW D IXQGDPHQWDO IUHTXHQF\ RI DERXW +] 2Q DYHUDJH WKH DYHUDJH IHPDOH YRLFH FRUUHVSRQGV WR PLGGOH & RU +] ZKHUHDV WKH PDOH YRLFH LV DERXW DQ RFWDYH ORZHU )OHWFKHU f 7KH HQHUJ\ LQ YRZHOV LV FRQFHQWUDWHG PDLQO\ LQ WKH KDUPRQLF VRXQGV RI WKH IXQGDPHQWDO IUHTXHQF\ ZKLFK IRU HDFK YRZHO LV GLYLGHG LQWR VHYHUDO W\SLFDO IUHTXHQF\ UHJLRQV FDOOHG IRUPDQWV ZKRVH FHQWHU IUHTXHQF\ GHSHQGV RQ WKH VKDSH RI WKH YRFDO WUDFW

PAGE 59

UHVRQDQFH RI WKH YRFDO WUDFWf ,Q DGGLWLRQ WR WKH IXQGDPHQWDO IUHTXHQF\ )Rf IRXU IRUPDQWV DUH XVXDOO\ UHFRJQL]HG WKH ORZHVW WZR IRUPDQWV )L DQG )f DUH VWURQJHU WKDQ WKH RWKHU WZR DQG RFFXU DW IUHTXHQFLHV W\SLFDO IRU HDFK YRZHO 7KH ORZHVW WKUHH IRUPDQWV DUH WKH PRVW LPSRUWDQW IRU FRUUHFW UHFRJQLWLRQ RI (QJOLVK YRZHOV 7KH IUHTXHQF\ UDQJH RI WKHVH IRUPDQWV ILWV IDLUO\ ZHOO ZLWKLQ WKH +] UDQJH ZKLFK LV WKH VWDQGDUG EDQGZLGWK XVHG LQ WKH WHOHSKRQH LQGXVWU\ %RUGHQ DQG +DUULV .HQW f ,I WKH IXQGDPHQWDO IUHTXHQF\ LV UDLVHG E\ DQ RFWDYH WKH IRUPDQW YDOXHV LQFUHDVH E\ RQO\ SHUFHQW 3HWHUVRQ DQG %DUQH\ f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f ,Q FRQWUDVW WR DFRXVWLF SKRQHWLFV WKDW LGHQWLILHV VSHHFK VRXQGV LQ WHUPV RI DFRXVWLF SDUDPHWHUV IUHTXHQF\ FRPSRVLWLRQ UHODWLYH LQWHQVLW\ DQG GXUDWLRQ FKDQJHVf WUDGLWLRQDO SKRQHWLFV GHVFULEHV VSHHFK VRXQGV LQ WHUPV RI WKH ZD\ WKH\ DUH SURGXFHG 7KH PDLQ GLYLVLRQV DUH YRLFLQJ SODFH DQG PDQQHU f9RLFLQJf LV UHODWHG WR YRFDO IROG YLEUDWLRQ HJ YRLFHG RU YRLFHOHVV f3ODFHf LV UHODWHG WR WKH ORFDWLRQ RI WKH PDMRU DLUIORZ FRQVWULFWLRQ RI WKH YRFDO WUDFW GXULQJ DUWLFXODWLRQ HJ ELODELDO ODELRGHQWDO OLQJXLGHQWDO DOYHRODU SDODWDO RU YHODU f0DQQHUf LV UHODWHG WR WKH GHJUHH RI QDVDO RUDO RU SKDU\QJHDO FDYLW\

PAGE 60

FRQVWUXFWLRQ HJ YRZHOV VWRSV SORVLYHVf QDVDOV IULFDWHV DIIULFDWHV OLTXLGV RU JOLGHV 7KXV 3RO LQ WKH ZRUG fEHVWf LV D YRLFHG ELODELDO VWRS SORVLYHf %RUGHQ DQG +DUULV f ,QWHOOLJLELOLW\ RI 6SHHFK 7KH DELOLW\ WR XQGHUVWDQG VSHHFK LV WKH PRVW LPSRUWDQW PHDVXUDEOH DVSHFW RI KXPDQ DXGLWRU\ IXQFWLRQ 6SHHFK FDQ EH GHWHFWHG DV D VLJQDO DV VRRQ DV WKH PRVW LQWHQVH SRLQW RI LWV VSHFWUXP H[FHHGV WKH HDUnV SXUH WRQH WKUHVKROG DW WKH IUHTXHQF\ FRQFHUQHG 7KLV LQWHQVLW\ LV FDOOHG WKH VSHHFK GHWHFWLRQ WKUHVKROG RU WKUHVKROG RI GHWHFWDELOLW\ (JDQ 6FKLOO f $W WKLV LQWHQVLW\ OHYHO D OLVWHQHU LV MXVW DEOH WR GHWHFW WKH SUHVHQFH RI VSHHFK VRXQGV DERXW b RI WKH WLPH :KHQ WKH LQWHQVLW\ LV LQFUHDVHG E\ VRPH G% WKH VXEMHFWV EHJLQ WR XQGHUVWDQG VRPH ZRUGV DQG FDQ UHSHDW KDOI RI WKH VSHHFK PDWHULDO SUHVHQWHG WKLV LV WKH VSHHFK UHFHSWLRQ WKUHVKROG RU WKUHVKROG RI SHUFHSWLELOLW\ (JDQ +DZNLQV DQG 6WHYHQV 6FKLOO f 7KH VSHHFK UHFHSWLRQ WKUHVKROG RI VSRQGHH ZRUGV WZR V\OODEOHVf ZKLFK LV FRQVLGHUDEO\ ORZHU WKDQ RQHV\OODEOH ZRUGV LV DW DERXW G% 63/ 'DYLV 3HQRUG f +RZHYHU RQO\ DIWHU WKH DYHUDJH LQWHQVLW\ RI VSHHFK KDV UHDFKHG EHWZHHQ WR G% 63/ DUH SHUFHQW RI PRQRV\OODELF ZRUGV XQGHUVWRRG .U\WHU )UHQFK DQG 6WHLQEHUJ 'DYLV (JDQ f 6SHHFK LQWHOOLJLELOLW\ RU VSHHFK GLVFULPLQDWLRQ H[SUHVVHG LQ WHUPV RI SHUFHQWDJH FRUUHFW LV XVHG WR GHVFULEH KRZ PXFK VSHHFK VRXQG FDQ EH XQGHUVWRRG 7KH IDFWRUV DIIHFWLQJ VSHHFK LQWHOOLJLELOLW\ DUH QXPHURXV 7KHVH LQFOXGH SK\VLFDO IDFWRUV UHODWHG WR WKH VSHHFK VWLPXOL VXFK DV OHYHO RI SUHVHQWDWLRQ IUHTXHQF\ FRPSRVLWLRQ GLVWRUWLRQ DQG VLJQDO WR QRLVH UDWLR

PAGE 61

)UHQFK DQG 6WHLQEHUJ f XVHG QRQVHQVH PRQRV\OODEOHV RI WKH FRQVRQDQW YRZHOFRQVRQDQW &9&f W\SH DV ZRUG PDWHULDO LQ WKHLU VWXGLHV DQG H[DPLQHG LQWHOOLJLELOLW\ DIWHU ORZSDVV DQG KLJKSDVV ILOWHULQJ 7KH\ IRXQG WKDW ZKHQ LQWHQVLW\ ZDV LQFUHDVHG GLVFULPLQDWLRQ LPSURYHG XS WR D FHUWDLQ OLPLW DIWHU ZKLFK LW UHPDLQHG ODUJHO\ FRQVWDQW HYHQ LI LQWHQVLW\ ZDV IXUWKHU LQFUHDVHG 2SWLPDO LQWHQVLW\ ZLWK GLIIHUHQW ILOWHU VHWWLQJV SURYHG WR EH DSSUR[LPDWHO\ WKH VDPH ZLWKLQ D UDQJH RI G% 7KH RSWLPDO LQWHQVLW\ ZDV G% 63/ $W WKLV OHYHO ZKHQ DOO IUHTXHQFLHV DERYH +] ZHUH SDVVHG WKURXJK WKH ILOWHU b RI &9& V\OODEOHV ZHUH UHFRJQL]HG FRUUHFWO\ +RZHYHU ZKHQ RQO\ WKH IUHTXHQFLHV EHORZ +] ZHUH SUHVHQWHG FRUUHFW LGHQWLILFDWLRQ RI WKH &9& V\OODEOHV GHFOLQHG WR b 7KH )UHQFK DQG 6WHLQEHUJ VWXG\ FOHDUO\ GHPRQVWUDWHG WKH LPSRUWDQFH RI WKH KLJK IUHTXHQFLHV IRU FRUUHFW LGHQWLILFDWLRQ RI &9& V\OODEOHV )XUWKHUPRUH ZKHQ LQWHOOLJLELOLW\ VFRUHV ZHUH SORWWHG DV D IXQFWLRQ RI FXWRIIIUHTXHQF\ RI DW RSWLPDO LQWHQVLW\ OHYHOV WKH ORZSDVV DQG KLJKSDVV FXUYHV LQWHUVHFWHG DW +] ZKHUH WKH LQWHOOLJLELOLW\ VFRUH ZDV b ,W ZDV VDLG WKDW WKH FURVVRYHU SRLQW GLYLGHG WKH IUHTXHQF\ VFDOH LQWR WZR HTXLYDOHQW SDUWV WKH IUHTXHQFLHV DERYH WKH FURVV ZHUH DV LPSRUWDQW DV WKH IUHTXHQFLHV EHORZ WKH FURVVRYHU IUHTXHQF\ 7KH W\SH RI VSHHFK PDWHULDO GLVWLQFWO\ DIIHFWV WKH LQWHOOLJLELOLW\ RI ILOWHUHG VSHHFK +LUVK 5H\QROGV DQG -RVHSK f 7KH VSHHFK PDWHULDOV LQ WKHLU VWXG\ LQFOXGHG QRQVHQVH V\OODEOHV PRQRV\OODELF ZRUGV &HQWUDO ,QVWLWXWH IRU WKH 'HDI $XGLWRU\ 7HVW : f GLV\OODELF ZRUGV VSRQGHHV LDPEV DQG WURFKHHVf DQG SRO\V\OODELF ZRUGV 7KH LQSXW VSHHFK OHYHO IRU DOO ILOWHU FRQGLWLRQV ZDV G% 63/ 7KH\ IRXQG WKDW QRQVHQVH PRQRV\OODEOHV DQG PRQRV\OODEOH ZRUGV VXIIHUHG PRVW LQ LQWHOOLJLELOLW\ GXULQJ IUHTXHQF\ ILOWHULQJ :KHQ WKH FXWRII IUHTXHQF\ KLJKSDVV ILOWHUf ZDV OHVV WKDQ +] WKH

PAGE 62

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b 7KH KLJKHU FURVVRYHU IUHTXHQF\ +]f ZLWK ORZHU LQWHOOLJLELOLW\ VFRUH bf LQ WKH )UHQFK DQG 6WHLQEHUJ f FXUYHV PD\ EH GXH WR WKH KLJK UHMHFWLRQ UDWH RI WKH ILOWHUV +LUVK HW DO f DOVR VWXGLHG QRLVHPDVNLQJ HIIHFWV RQ WKH LQWHOOLJLELOLW\ RI GLIIHUHQW W\SHV RI VSHHFK PDWHULDOV 7KH LQWHOOLJLELOLW\ RI HDV\ VSHHFK PDWHULDO LQFUHDVHG PRUH UDSLGO\ DV D IXQFWLRQ RI VLJQDOWRQRLVH 61f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

PAGE 63

3ROODFN f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fV HDU SURGXFHG E\ WKH WHVW V\VWHP WR WKH RUWKRWHOHSKRQLF UHIHUHQFH V\VWHP DERXW G% 63/f JDYH RQO\ SHUFHQW GLVFULPLQDWLRQ HYHQ WR XQILOWHUHG VSHHFK :LWK ORZSDVV DQG KLJKSDVV ILOWHULQJ WKH LQWHOOLJLELOLW\ LPSURYHG FRQWLQXRXVO\ ZLWK LQFUHDVLQJ LQWHQVLW\ XS WR D G% RUWKRWHOHSKRQLF JDLQ ZLWK GLIIHUHQW ILOWHU VHWWLQJV HYHQ WKRXJK WKH ULVH RI WKH FXUYHV EHWZHHQ RUWKRWHOHSKRQLF JDLQ RI DQG G% ZDV IDLUO\ VOLJKW 7KH LQWURGXFWLRQ RI EDFNJURXQG QRLVH UHVXOWHG LQ VKLIWLQJ RSWLPDO LQWHQVLW\ IURP G% RUWKRWHOHSKRQLF JDLQ )UHQFK DQG 6WHLQEHUJ f WR WKH WR G% OHYHO 7KH 3ROODFN f VWXG\ DOVR GHPRQVWUDWHG WKDW WKH FRQWULEXWLRQ WR WKH LQWHOOLJLELOLW\ RI WKH KLJKHU VSHHFK IUHTXHQFLHV DORQH ZDV VPDOO :KHQ D KLJKSDVV ILOWHU ZLWK D +] FXWRII ZDV XVHG LQWHOOLJLELOLW\ ZDV RQO\ b DW PD[LPDO JDLQ +RZHYHU WKHVH VDPH IUHTXHQFLHV PDGH DQ DSSUHFLDEOH GLIIHUHQFH LQ LQWHOOLJLELOLW\ ZKHQ WKH ORZ IUHTXHQF\ VRXQGV ZHUH DOVR SDVVHG DW WKH VDPH WLPH :KHQ WKH FXWRII IUHTXHQF\ RI ORZ SDVV ILOWHU ZDV H[WHQGHG IURP +] WR +] WKH LQWHOOLJLELOLW\ ZDV LPSURYHG IURP b WR b ,W ZDV VXJJHVWHG WKDW WKH FRQWULEXWLRQ WR LQWHOOLJLELOLW\ RI D JLYHQ EDQG RI VSHHFK IUHTXHQFLHV ZDV QRW LQGHSHQGHQW RI WKH FRQWULEXWLRQ EHLQJ PDGH DW WKH VDPH WLPH

PAGE 64

E\ RWKHU EDQGV RI IUHTXHQFLHV 7KHUH ZDV DQ LQWHUDFWLRQ DPRQJ WKH FRQWULEXWLRQV RI WKH YDULRXV EDQGV 6LPLODUO\ WKH FRQWULEXWLRQ WR LQWHOOLJLELOLW\ RI YHU\ ORZ VSHHFK IUHTXHQFLHV ZDV DOVR VPDOO 1R ZRUGV ZHUH UHFRJQL]HG ZKHQ WKH IUHTXHQFLHV EHORZ +] DORQH ZHUH KHDUG +RZHYHU ZKHQ KLJKSDVV FXWRII IUHTXHQF\ ZDV GHFUHDVHG IURP +] WR +] WKH LQWHOOLJLELOLW\ ZDV LPSURYHG IURP b WR b $ VWXG\ RI WKH HIIHFWV RI QRLVH DQG IUHTXHQF\ ILOWHULQJ RQ WKH SHUFHSWXDO FRQIXVLRQV RI (QJOLVK FRQVRQDQWV UHYHDOHG WKDW QRLVH DQG ORZSDVV ILOWHULQJ HQVXUHG PRUH KRPRJHQHRXV DQG ZHOOGHILQHG UHVXOWV ZKHUHDV WKH PLVWDNHV IURP KLJKSDVV ILOWHULQJ ZHUH PRUH LQGHILQLWH 0LOOHU DQG 1LFHO\ f 1RQVHQVH FRQVRQDQWYRZHO &9f V\OODEOHV ZHUH XVHG DV WKH WHVW PDWHULDO 7KH FRQVRQDQWV ZHUH VSRNHQ LQLWLDOO\ EHIRUH WKH YRZHO D 7KH UHVXOWV VKRZHG WKDW YRLFLQJ DQG QDVDOLW\ PDQQHU RI DUWLFXODWLRQf ZHUH PXFK OHVV DIIHFWHG E\ D UDQGRP PDVNLQJ QRLVH WKDQ ZHUH WKH RWKHU IHDWXUHV $IIULFDWLRQ DQG GXUDWLRQ PDQQHU RI DUWLFXODWLRQf ZHUH VRPHZKDW VXSHULRU WR SODFH EXW IDU LQIHULRU WR YRLFLQJ DQG QDVDOLW\ 9RLFLQJ DQG QDVDOLW\ ZHUH GLVFULPLQDEOH DW 61 UDWLR DV SRRU DV G% ZKHUHDV WKH SODFH RI DUWLFXODWLRQ ZDV KDUG WR GLVWLQJXLVK DW 61 UDWLR OHVV WKDQ G% DQ G% GLIIHUHQFH LQ HIILFLHQF\ $IWHU ORZSDVV ILOWHULQJ FXWRII IUHTXHQF\ UDQJHG IURP +] WR +]f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

PAGE 65

IUHTXHQF\ UDQJHG IURP +] WR +]f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f DQG IROORZLQJ ILOWHULQJ GLVWRUWLRQ RI VSHHFK :DQJ 5HHG DQG %LOJHU f E\ VHTXHQWLDO LQIRUPDWLRQ DQDO\VLV 6,1)$f ZKLFK VHTXHQWLDOO\ LGHQWLILHV IHDWXUHV ZLWK D KLJK SURSRUWLRQ RI WUDQVPLWWHG LQIRUPDWLRQ FRQWULEXWLQJ WR FRQVRQDQW SHUFHSWLRQ 1RQVHQVH V\OODEOHV ZHUH XVHG DV WHVW PDWHULDOV LQ WKHLU VWXGLHV 7KH VWLPXOL UHSUHVHQWHG DOO SKRQRORJLFDOO\ SHUPLVVLEOH FRQVRQDQWYRZHO &9f DQG YRZHO FRQVRQDQW 9&f V\OODEOHV ZKLFK ZHUH IRUPHG E\ FRPELQJ RQH RI FRQVRQDQWV ZLWK WKH YRZHOVL DRUX :DQJ DQG %LOJHU f GHPRQVWUDWHG WKDW DUWLFXODWRU\ DQG SKRQRORJLFDO IHDWXUHV FRXOG DFFRXQW IRU D ODUJH SURSRUWLRQ RI WUDQVPLWWHG LQIRUPDWLRQ 7KH SDUWLFXODU IHDWXUHV ZKLFK UHVXOWHG LQ KLJK OHYHOV RI SHUIRUPDQFH YDULHG VLJQLILFDQWO\ IURP RQH V\OODEOH VHW WR DQRWKHU DQG LQ VRPH FDVHV YDULHG ZLWKLQ V\OODEOH VHWV DV D

PAGE 66

IXQFWLRQ RI OLVWHQLQJ FRQGLWLRQV 9RLFH DQG QDVDO IHDWXUHV ZHUH ZHOO SHUFHLYHG ERWK LQ QRLVH DQG LQ TXLHW DQG WKH\ ZHUH LGHQWLILHG DV SHUFHSWXDOO\ LPSRUWDQW LQ HYHU\ V\OODEOH VHW ZKHUH WKH\ ZHUH GLVWLQFWLYH 7KH IHDWXUH URXQG Z DQG KZf ZDV DOVR ZHOO SHUFHLYHG ERWK LQ QRLVH DQG LQ TXLHW 2WKHU IHDWXUHV VXFK DV IULFDWLRQ DQG SODFH DSSHDUHG WR KDYH GLIIHUHQW SHUFHSWXDO LPSRUWDQFH GHSHQGLQJ XSRQ WKH OLVWHQLQJ FRQGLWLRQ 8QGHU ILOWHULQJ FRQGLWLRQV WKHUH ZHUH GLIIHUHQWLDO HIIHFWV RI KLJKSDVV DQG ORZSDVV ILOWHULQJ RQ IHDWXUH UHFRJQLWLRQ :DQJ 5HHG DQG %LOJHU f /RZSDVV ILOWHULQJ FXWRII IUHTXHQF\ UDQJHG IURP +] WR +]f SURGXFHG V\VWHPDWLF FKDQJHV LQ WKH LPSRUWDQFH RI GLIIHUHQW IHDWXUHV ZKHUHDV KLJKSDVV ILOWHULQJ FXWRII IUHTXHQF\ UDQJHG IURP +] WR +]f SURGXFHG OHVV FRQVLVWHQW FKDQJHV LQ IHDWXUHV UHFRJQLWLRQ :KHQ WKH ORZSDVV FXWRII ZDV ORZHUHG IURP WR +] VLELODQFH VL ,]O 6, W6 ,=DQG G=f PDQQHU RI DUWLFXODWLRQf TXLFNO\ ORVW LWV SHUFHSWLELOLW\ 7KH KLJKSDVV ILOWHULQJ KDG OLWWOH HIIHFW RQ WKH UHFRJQLWLRQ RI VLELODQFH 7KH KLJK FURVVRYHU SRLQW RI WKH IXQFWLRQV DW +] LQGLFDWHG WKDW FXHV IRU VLELODQW VRXQG OD\ LQ WKH KLJKIUHTXHQF\ UHJLRQ RI WKH VSHFWUXP DERYH +] +LJK N ,JO ,6 ,W6, ,n/O ,G=, UM Z DQG Mf DQG DQWHULRU S W ,EO ,G ,I ,V ,YO ,]O ,PO ,QL O DQG ,Gf IHDWXUHV SODFH RI DUWLFXODWLRQf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f

PAGE 67

7KH SDWWHUQV RI FRQVRQDQW FRQIXVLRQV JHQHUDWHG E\ VXEMHFWV ZLWK VHQVRULQHXUDO KHDULQJ ORVV ZHUH OLNH WKRVH JHQHUDWHG E\ QRUPDO KHDULQJ VXEMHFWV LQ UHVSRQVH WR WKH DSSURSULDWH ILOWHULQJ GLVWRUWLRQ RI VSHHFK %LOJHU DQG :DQJ :DQJ 5HHG DQG %LOJHU f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fV YRLFH ZDV PRUH LQWHOOLJLEOH WKDQ D IHPDOH WDONHUfV YRLFH ZKHQ WKH UHFRUGLQJV ZHUH PDGH LQ XOHUR )XUWKHUPRUH DQ DQDO\VLV RI WKH IHDWXUH LQIRUPDWLRQ WUDQVPLVVLRQ IURP UHFRUGLQJV LQVLGH DQG RXWVLGH WKH XWHUXV UHYHDOHG WKDW YRLFLQJ LQIRUPDWLRQ LV EHWWHU WUDQVPLWWHG LQ WHUR WKDQ SODFH RU PDQQHU LQIRUPDWLRQ 7KH ILQGLQJV DUH TXLWH VLPLODU WR WKRVH RI VWXGLHV FRQGXFWHG E\ 0LOOHU DQG 1LFHO\ f DQG :DQJ HW DO f LQ WKDW WUDQVPLVVLRQ LQWR WKH XWHUXV FDQ EH PRGHOHG DV D ORZSDVV ILOWHU :KLOH WKH UHVXOWV RI *ULIILWKV HW DO f VWXG\ RQO\ UHIOHFW WKH SHUFHSWLELOLW\ RI WKH VSHHFK HQHUJLHV SUHVHQW LQ WKH DPQLRWLF IOXLG WKH\ GR QRW VSHFLI\ ZKDW VSHHFK HQHUJ\ PLJKW EH SUHVHQW DW WKH OHYHO RI IHWDO LQQHU HDU 0HDVXUHPHQWV RI DFRXVWLF WUDQVPLVVLRQ WR WKH IHWDO LQQHU HDU DUH TXLWH OLPLWHG DW SUHVHQW 7KH SXUSRVH RI FXUUHQW VWXG\ ZDV WR HYDOXDWH WKH LQWHOOLJLELOLW\ RI H[WHUQDOO\ JHQHUDWHG VSHHFK XWWHUDQFHV WUDQVPLWWHG WR DQG UHFRUGHG DW WKH IHWDO VKHHS LQQHU HDU LQ WHUR

PAGE 68

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f 7KH VHFRQG SRUWLRQ RI WKH VWXG\ LQYROYHG SOD\LQJ WKH UHFRUGLQJV WR D MXU\ RI QRUPDO KHDULQJ DGXOWV VR VSHHFK LQWHOOLJLELOLW\ FRXOG EH HYDOXDWHG 6XUJHU\ (LJKW WLPHPDWHG SUHJQDQW HZHV FDUU\LQJ IHWXVHV DW JHVWDWLRQDO DJHV IURP GD\V ZHUH SUHSDUHG IRU VXUJHU\ WHUP LV GD\Vf )URP WKLV JURXS VSHHFK VWLPXOL UHFRUGHG IURP RQO\ RQH DQLPDO ZHUH XVHG LQ WKLV VWXG\ 5HFRUGLQJV IURP WKLV DQLPDO ZHUH MXGJHG E\ WKH H[SHULPHQWHU WR KDYH WKH EHVW ILGHOLW\ 6SHHFK VLJQDOV SURGXFHG IURP D

PAGE 69

ORXGVSHDNHU ZHUH UHFRUGHG ZLWK DQ DLU PLFURSKRQH D K\GURSKRQH SODFHG LQ WKH XWHUXV RI SUHJQDQW VKHHS DQG DQ HOHFWURGH VHFXUHG WR WKH URXQG ZLQGRZ RI WKH IHWXV 7KH $QLPDO 8VH 3URWRFRO LQ WKLV VWXG\ ZDV DSSURYHG E\ WKH ,QVWLWXWLRQDO $QLPDO &DUH DQG 8VH &RPPLWWHH ,$&8&f RI WKH 8QLYHUVLW\ RI )ORULGD ,Q SUHSDUDWLRQ IRU PHDVXUHPHQWV RI IHWDO FRFKOHDU PLFURSKRQLF &0f HZHV ZHUH IDVWHG DQHVWKHWL]HG DQG PDLQWDLQHG RQ D PL[WXUH RI R[\JHQ DQG KDORWKDQH bf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f ZLWK WKH LQVXODWLRQ UHPRYHG IURP RQH HQG 7KH XQLQVXODWHG HQG ZDV UROOHG LQWR D PP GLDPHWHU EDOO DQG SODFHG LQVLGH WKH URXQG ZLQGRZ QLFKH SRVLWLYH HOHFWURGHf $IWHU YHULI\LQJ WKH LPSHGDQFH RI WKH URXQG ZLQGRZ HOHFWURGH NILf WKH EXOOD ZDV UHILOOHG ZLWK DPQLRWLF IOXLG DQG VHDOHG RYHU ZLWK PHWK\OPHWKDFU\ODWH $GGLWLRQDO &RRQHU ZLUH HOHFWURGHV ZHUH VXWXUHG WR WLVVXH RYHUO\LQJ WKH EXOOD QHJDWLYH HOHFWURGHf DQG WR WLVVXH DW D UHPRWH VLWH JURXQG HOHFWURGHf 7KH VNLQ RYHU WKH EXOOD ZDV VXWXUHG DQG WKH HOHFWURGHV ZHUH FDUHIXOO\ VHFXUHG WR WKH IHWXV ZLWK VLON WKUHDG 7KH IHWXV ZDV UHWXUQHG WR WKH XWHUXV DQG WKH XWHUXV DQG DEGRPHQ ZHUH FORVHG ZLWK FODPSV (OHFWURGH

PAGE 70

ZLUHV SDVVHG WKURXJK WKH LQFLVLRQV DQG ZHUH FRQQHFWHG WR D ELRORJLFDO DPSOLILHU *UDVV ,QVWUXPHQWV &R PRGHO 3 ,. 4XLQF\ 0$f 5HFRUGLQJ 6SHHFK 6WLPXOL 7KH DQHVWKHWL]HG HZH ZDV SODFHG VXSLQH RQ D VWUHWFKHU DQG WUDQVSRUWHG WR D VRXQG WUHDWHG ERRWK ,QGXVWULDO $FRXVWLFV &R PRGHO *'&/ %URQ[ 1
PAGE 71

)LJXUH 6FKHPDWLF GUDZLQJ VKRZLQJ WKH DPLQDO DQG WKH VHWXS RI GHYLFHV IRU VWLPXOXV JHQHUDWLRQ VWLPXOXV PHDVXUHPHQW DQG UHFRUGLQJ LQ DLU LQ WKH XWHUXV DQG IURP WKH IHWDO LQQHU HDU FRFKOHDU PLFURSKRQLFf Y2

PAGE 72

ZLUHV 7KH HOHFWULFDO LQWHUIHUHQFH SURGXFHV D YROWDJH RXWSXW IURP WKH ELRORJLFDO DPSOLILHU WKDW PLPLFV WKH WUXH ELRORJLF SRWHQWLDO %HFDXVH HOHFWURPDJQHWLF HQHUJ\ WUDYHOV DW WKH VSHHG RI OLJKW ZKHUHDV DFRXVWLF HQHUJ\ WUDYHOV DW WKH VSHHG RI VRXQG PVf XQFRQWDPLQDWHG &0 RFFXUUHG DSSUR[LPDWHO\ PV DIWHU WKH RQVHW RI WKH VWLPXOXV ,I WKLV RQVHW GHOD\ ZDV QRW SUHVHQW LQ WKH UHFRUGLQJ WKHQ PHDVXUHPHQWV ZHUH UHSHDWHG DIWHU DSSURSULDWH HTXLSPHQW DGMXVWPHQW DQG RU JURXQGLQJ 7KH SUHVHQFH RI DQ RQVHW GHOD\ FRQILUPHG WKDW WKH UHFRUGHG ZDYHIRUP ZDV ELRHOHFWULF UDWKHU WKDQ HOHFWURPDJQHWLF *HUKDUGW HW DO f %HIRUH UHFRUGLQJ VSHHFK VWLPXOL &0V )LJXUH f ZHUH YHULILHG E\ XVLQJ WRQH EXUVWV DQG N+]f $Q HYRNHG SRWHQWLDO DYHUDJLQJ FRPSXWHU 7XFNHU'DYLV 7HFKQRORJLHV *DLQHVYLOOH )/f GHOLYHUHG VWLPXOL WR WKH ORXGVSHDNHU 7RQH EXUVWV ZHUH GHOLYHUHG WR WKH HZHfV IODQN DW LQWHQVLW\ OHYHOV WKDW ZHUH FDSDEOH RI SURGXFLQJ &0 UHVSRQVHV 7ZHQW\ VWLPXOL ZHUH GHOLYHUHG DQG DYHUDJHG IRU HDFK &0 UHVSRQVH 6WLPXOXV GXUDWLRQ RU PVf VZHHS WLPH RU PVf DQG ILOWHULQJ )O] RU +]f YDULHG ZLWK VWLPXOXV IUHTXHQF\ DQG N+]f 7KH UDWH RI VWLPXODWLRQ ZDV V DQG WKH ULVHIDOO WLPH ZDV PV 7KH VSHHFK VWLPXOL ZHUH GHOLYHUHG WR WKH IODQN RI SUHJQDQW HZHV DW WZR LQWHQVLW\ OHYHOV DQG G% 63/f )LUVW WKH VLJQDOV ZHUH VLPXOWDQHRXVO\ GHWHFWHG ZLWK D PLFURSKRQH ORFDWHG RYHU WKH DEGRPHQ DQG HOHFWURGHV SODFHG RQ WKH IHWDO URXQG ZLQGRZ LQ WHUR 7KH RXWSXWV IURP WKH PLFURSKRQH DQG LQQHU HDU &0f ZHUH UHFRUGHG RQ WZR VHSDUDWH FKDQQHOV RI D '$7 WDSH UHFRUGHU 621< &RUSRUDWLRQ W\SH =$(6 -DSDQf 7KHQ WKH VDPH VSHHFK VWLPXOL ZHUH UHSHDWHG DQG UHFRUGHG ZLWK D K\GURSKRQH SODFHG LQ WKH XWHUXV DQG HOHFWURGHV SODFHG RQ WKH IHWDO URXQG ZLQGRZ H[ WHUR 7KH IHWDO H[WHUQDO FDQDO DQG PLGGOH HDU FDYLW\ ZHUH FOHDUHG RI IOXLGV GXULQJ H[ WHUR PHDVXUHPHQW $W WKH FRPSOHWLRQ RI DOO

PAGE 73

+] G% +] G% +] G% )LJXUH &0 UHVSRQVHV REWDLQHG IURP D IHWDO VKHHS ([DPSOHV RI &0V HYRNHG E\ DLUERUQH SXUH WRQHV DW DQG N+] DQG DW VWLPXOXV OHYHOV LQGLFDWHG XQGHU HDFK ZDYHIRUP 7KH DSSDUHQW RQVHW ODWHQF\ UHSUHVHQWV WKH DFRXVWLF WUDYHOWLPH IURP WKH ORXGVSHDNHU WR WKH IHWDO LQQHU

PAGE 74

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f 6SHHFK 6WLPXOL 7ZR VHWV RI VWLPXOL ZHUH XVHG YRZHOFRQVRQDQWYRZHO 9&9f QRQVHQVH V\OODEOHV DQG FRQVRQDQWYRZHOFRQVRQDQW &9&f ZRUGV VSRNHQ E\ PDOH DQG IHPDOH WDONHUV DQG ZRUGV EDVHG RQ WKH *ULIILWKV ZRUG OLVWV f (DFK VWLPXOXV LWHP ZDV SUHVHQWHG LQ D

PAGE 75

7DEOH 3HUFHSWXDO WHVWV 3HUFHSWXDO DXGLR &' &RQWHQWV 1XPEHU RI MXGJHV $ 9&9 % &9& & &9& &9& ( &9& ) &9&

PAGE 76

FDUULHU SKUDVH f0DUN WKH ZRUG 7KHO QRQVHQVH V\OODEOHV & S W N E G J I Y V ] P Q 6 W6f VSRNHQ E\ ERWK D PDOH DQG D IHPDOH WDONHU ZHUH SUHFHGHG DQG IROORZHG E\ WKH YRZHO D HJ DJDf 7KH PHDQ IXQGDPHQWDO IUHTXHQFLHV ZHUH DQG +] IRU WKH PDOH DQG IHPDOH WDONHUV UHVSHFWLYHO\ 6L[W\IRXU LWHPV ZHUH UHFRUGHG DW HDFK RI FRQGLWLRQV DPRQJ JHQGHU RI WDONHU PDOH DQG IHPDOHf VWLPXOXV OHYHOV DQG G% 63/f DQG UHFRUGLQJ ORFDWLRQV DLU XWHUXV &0 H[ WHUR DQG &0 LQ WHURf 3URFHGXUHV 7KH ZRUG OLVW VSRNHQ E\ ERWK PDOH DQG IHPDOH WDONHUV ZHUH SOD\HG WKURXJK WKH ORXGVSHDNHU YLD D FDVVHWWH WDSH UHFRUGHU DW WZR GLIIHUHQW DLUERUQH OHYHOV PHDVXUHG DW WKH PDWHUQDO IODQN DQG G% 63/ G% UH S3Df 7KH RXWSXWV IURP WKH DLU PLFURSKRQH WKH K\GURSKRQH DQG WKH IHWXV LQQHU HDU &0f H[ WHUR DQG LQ 8WHUR ZHUH UHFRUGHG RQ '$7 WDSHV 2QH VHW RI UHFRUGLQJV ZLWK WKH EHVW TXDOLW\ VRXQG IURP RQH IHWXV ZDV FKRVHQ IRU FRQVWUXFWLQJ SHUFHSWXDO WDSHV )LUVW VSHHFK VWLPXOL ZHUH GLJLWL]HG DQG UHSURGXFHG YLD D FRPSXWHU SURJUDP &RRO (GLW 6\QWULOOLXP 6RIWZDUH &RUSRUDWLRQ 3KRHQL[ $=f ZLWK N+] VDPSOLQJ UDWH DQG ELW UHVROXWLRQ 7KH DPSOLWXGHV RI WKH VSHHFK VWLPXOL ZHUH DGMXVWHG WR WKH VDPH UHODWLYH YROWDJH OHYHOV 6HFRQG HDFK V\OODEOH LWHP ZLWK D FDUULHU SKUDVH ZDV VDYHG DV DQ LQGLYLGXDO ILOH 7KHQ D FRPSXWHU SURJUDP ZDV XVHG WR UDQGRPL]H DQG FRXQWHUEDODQFH WKH VSHHFK VWLPXOL DPRQJ JHQGHU RI WDONHU PDOH DQG IHPDOHf VWLPXOXV OHYHOV DQG G% 63/f DQG UHFRUGLQJ ORFDWLRQV DLU XWHUXV &0 H[ WHUR DQG &0 LQ WHURf )LQDOO\ VL[ GLIIHUHQW SHUFHSWXDO DXGLR FRPSDFW GLVFV &'Vf ZHUH FUHDWHG 2QH FRQWDLQHG UDQGRPL]HG UHFRUGLQJV RI QRQVHQVH LWHPV QRQVHQVH V\OODEOHV UHFRUGHG

PAGE 77

XQGHU FRQGLWLRQVf 7KH ILYH RWKHU &'V FRQWDLQHG UHFRUGLQJV RI PRQRV\OODELF ZRUGV HDFK YHUVLRQ FRQVLVWHG RI ZRUGV ZRUGV UHFRUGHG XQGHU FRQGLWLRQV WKH VDPH ZRUG RFFXUUHG QR PRUH WKDQ WLPHV LQ HDFK YHUVLRQf $ VHFRQG VLOHQFH LQWHUYDO VHSDUDWHG HDFK WHVW LWHP 7KH UHFRUGLQJV ZHUH XVHG WR FRQGXFW D SHUFHSWXDO WHVW RI VSHHFK LQWHOOLJLELOLW\ 7KH WHVW UHTXLUHG JURXSV RI MXGJHV WR OLVWHQ WR WKH XWWHUDQFHV LQ WKH FDUULHU SKUDVH DQG PDUN RQ SDSHU ZKDW WKH\ KHDUG 7KH MXGJHVf UHVSRQVHV SURYLGHG WKH EDVLV IRU GHWHUPLQLQJ LQWHOOLJLELOLW\ VFRUHV SHUFHQW FRUUHFWf DVVRFLDWHG ZLWK WKH 9&9 QRQVHQVH LWHPV DQG WKH &9& ZRUGV )RU WKH 9&9 QRQVHQVH LWHPV WKH MXGJHV ILOOHG LQ D EODQN LQ D DBD IUDPH ZLWK WKH YRZHO VHW WR D )RU H[DPSOH LI D MXGJH KHDUG f0DUN WKH ZRUG DSDf KH RU VKH ZRXOG KDYH WR ZULWH D fSf LQ WKH EODQN WR EH FRUUHFW )RU WKH &9& ZRUGV HDFK MXGJH VHOHFWHG KLV RU KHU UHVSRQVH IURP D FORVHG VHW RI VL[ PRQRV\OODEOH ZRUGV WKDW GLIIHUHG LQ HLWKHU WKH LQLWLDO RU ILQDO FRQVRQDQW )RU H[DPSOH RQH VWLPXOXV LWHP ZDV f0DUN WKH ZRUG EDWf DQG WKH UHVSRQVH OLVW LQFOXGHG fEDWFK EDVK EDW EDVV EDFN EDGJHf 7R EH FRUUHFW WKH MXGJH ZRXOG KDYH WR PDUN WKH ZRUG fEDWf (DFK YHUVLRQ RI SHUFHSWXDO DXGLR &'V ZHUH SOD\HG WR D JURXS RI MXGJHV FRPSULVLQJ QRUPDO KHDULQJ \RXQJ DGXOWV $OO WHVWLQJ ZHUH FRQGXFWHG LQ D VSHFLDOO\ GHVLJQHG OLVWHQLQJ ODERUDWRU\ ZKLFK DFFRPPRGDWHG XS WR SHRSOH DW RQH WLPH 7KH SHUFHSWXDO DXGLR &' ZHUH SOD\HG RYHU HDUSKRQHV +6 DQG +6 621
PAGE 78

G% 5(/$7,9( )LJXUH 7KH IUHTXHQF\ UHVSRQVHV RI WZR W\SHV RI HDUSKRQHV 621< +6 GRW OLQHf DQG +6 VROLG OLQHf XVHG IRU WKH SHUFHSWXDO WHVWV 2Q 21

PAGE 79

WHVW ZDV SUHFHGHG E\ D EULHI SUDFWLFH VHVVLRQ XVLQJ D YHUVLRQ RI SHUFHSWXDO DXGLR &' GLIIHUHQW IURP WKH UHDO WHVWLQJ &' WR HQVXUH WKDW VXEMHFWV XQGHUVWRRG WKH SHUFHSWXDO WHVWV 'DWD $QDO\VHV 6WDWLVWLFDO $QDO\VHV ,QWHOOLJLELOLW\ FRQVRQDQW FRQIXVLRQ PDWULFHV DQG VSHFWUDO DQDO\VHV RI UHFRUGHG VSHHFK VLJQDOV ZHUH DVVHVVHG 7KH VSHHFK LQWHOOLJLELOLW\ VFRUHV SHUFHQW FRUUHFWf ZHUH GHULYHG IURP WKH MXGJHVf UHVSRQVHV WR WKH SHUFHSWXDO DXGLR &'V IRU WKH 9&9 QRQVHQVH V\OODEOHV DQG &9& ZRUGV E\ JHQGHU LQWHQVLW\ OHYHO DQG UHFRUGLQJ ORFDWLRQ 0XOWLIDFWRU DQDO\VLV RI YDULDQFH $129$f ZDV SHUIRUPHG RQ WKH GDWD RI WKH 9&9 QRQVHQVH V\OODEOHV DQG &9& ZRUGV VHSDUDWHO\ 7KH LQGHSHQGHQW YDULDEOHV LQFOXGHG WKUHH IDFWRUV JHQGHU RI WKH WDONHU PDOH DQG IHPDOHf VRXQG SUHVVXUH OHYHO RI WKH DLUERUQH VWLPXOXV DQG G%f DQG ORFDWLRQ RI UHFRUGLQJ DLU XWHUXV &0 IURP H[ WHUR IHWXV DQG &0 IURP LQ WHUR IHWXVf 7KH GHSHQGHQW YDULDEOHV ZHUH SHUFHQWDJH RI FRUUHFW LGHQWLILFDWLRQ RI QRQVHQVH V\OODEOHV DQG PRQRV\OODELF ZRUGV SHUFHSWXDO VFRUHVf ,Q RUGHU WR PHHW WKH YDULDQFH DVVXPSWLRQV IRU VWDWLVWLFDO DQDO\VLV WKH SHUFHQW LQWHOOLJLELOLW\ GDWD ZKLFK DUH ELQRPLDO YDULDEOHV 7KRUQWRQ DQG 5DIILQ f ZHUH WUDQVIRUPHG XVLQJ DQ DUFVLQH IXQFWLRQ [DUFVLQ[9bff WR QRUPDOL]H WKH YDULDQFH SULRU WR IXUWKHU DQDO\VLV :LQHU %URZQ DQG 0LFKHOV f

PAGE 80

,QIRUPDWLRQ $QDO\VHV 'DWD ZHUH SUHVHQWHG LQ WKH IRUP RI D [ LWHP FRQIXVLRQ PDWUL[ IRU HDFK FRQGLWLRQ $ WRWDO RI PDWULFHV IRU 9&9 QRQVHQVH V\OODEOHV ZHUH FROOHFWHG 6HTXHQWLDO ,QIRUPDWLRQ $QDO\VLV 6,1)$ :DQJ f RI SHUFHSWXDO SDWWHUQ ZDV SHUIRUPHG 6,1)$ LV DSSOLHG WR WKH HUURU PDWULFHV LQ RUGHU WR HYDOXDWH WKH DPRXQW RI IHDWXUH LQIRUPDWLRQ UHFHLYHG 6,1)$ DOORZV IRU WKH SDUWLWLRQLQJ RI WKH FRQWLQJHQW LQIRUPDWLRQ WUDQVPLWWHG DQG UHFHLYHG IRU SDUWLFXODU IHDWXUHV RI WKH VWLPXOL HJ YRLFLQJ PDQQHU DQG SODFHf )URP WKHVH UHVXOWV D UHODWLYH PHDVXUH RI SHUIRUPDQFH PD\ EH FDOFXODWHG WKH UDWLR RI WKH ELWV RI LQIRUPDWLRQ UHFHLYHG WR WKH ELWV VHQW ZLWK WKH HIIHFWV RI RWKHU IHDWXUHV KHOG FRQVWDQWf 7KH GDWD IURP DOO FRQGLWLRQV ZHUH DQDO\]HG XVLQJ 6,1)$ $FRXVWLF $QDO\VHV $FRXVWLF DQDO\VHV RI ILYH YRZHOV ,,, ,9 OHL DH $f VHOHFWHG IURP WKH *ULIILWKVf ZRUGV OLVW &9&f ZHUH SHUIRUPHG DFURVV WKH UHFRUGLQJ FRQGLWLRQV G% VWLPXOL RI ERWK PDOH DQG IHPDOH VSHDNHUV UHFRUGHG LQ DLU LQ WKH XWHUXV &0 IURP H[ XOHUR IHWXV DQG &0 IURP LQ WHUR IHWXVf 7KH IXQGDPHQWDO IUHTXHQF\ )f DQG WKH ILUVW WKUHH IRUPDQW IUHTXHQFLHV )f ) DQG )f DQG WKHLU UHODWLYH LQWHQVLW\ OHYHOV ZHUH PHDVXUHG E\ XVLQJ D VLJQDOn SURFHVVLQJ FRPSXWHU SURJUDP &RRO (GLW 6\QWULOOLXP 6RIWZDUH &RUSRUDWLRQ 3KRHQL[ $=f (DFK UHDOWLPH VSHHFK ZDYHIRUP ZDV GLJLWL]HG ZLWK N+] VDPSOLQJ UDWH DQG ELW UHVROXWLRQ $Q DYHUDJH PV VHJPHQW ZDV VHOHFWHG DURXQG WKH VWHDG\VWDWH SRUWLRQ RI HDFK YRZHO 7KH ) DQG IRUPDQWV )f ) DQG )f RI HDFK VHJPHQW ZHUH PHDVXUHG E\ YLVXDO LQVSHFWLRQ RI WKH FRUUHVSRQGLQJ )RXULHU WUDQVIRUP VSHFWUXP XVLQJ +DPPLQJ ZLQGRZ ZLWK

PAGE 81

)RXULHU VL]H IROORZHG E\ VPRRWKLQJ /HH 3RWDPLDQRV DQG 1DUD\DQDQ f $FFRUGLQJ WR WKH YDOXHV PHDVXUHG E\ 3HWHUVRQ DQG %DUQH\ f DQG +LOOHQEUDQG HW DO f ) DQG IRUPDQWV IUHTXHQFLHV )f ) DQG )f ZHUH HVWLPDWHG 7KH UHODWLYH LQWHQVLW\ OHYHOV ZHUH DOVR FDOFXODWHG E\ VXEWUDFWLQJ WKH EDFNJURXQG QRLVH YDOXH IURP WKH SHDN YDOXH XQGHU GLIIHUHQW UHFRUGLQJ FRQGLWLRQV 7ZRIDFWRU UHSHDWHG PHDVXUHV $129$V ZHUH SHUIRUPHG RQ WKH GDWD RI UHODWLYH LQWHQVLW\ OHYHOV RI ) )f ) DQG ) DFURVV WKH UHFRUGLQJ ORFDWLRQV IRU HDFK YRZHO

PAGE 82

&+$37(5 5(68/76 $1' ',6&866,21 2QH KXQGUHG DQG WKLUW\QLQH MXGJHV FRPSOHWHG WKH SHUFHSWXDO WHVWV %HFDXVH WKH VSHHFK VWLPXOL ZHUH FRPSOHWHG UDQGRPL]HG DQG FRXQWHUEDODQFHG DFURVV JHQGHU RI WDONHUV PDOH DQG IHPDOHf VWLPXOXV OHYHOV DQG G% 63/f DQG UHFRUGLQJ ORFDWLRQV DLU XWHUXV &0 H[ XOHUR DQG &0 LQ WHURf OHDUQLQJ HIIHFWV ZHUH PLQLPL]HG ,QWHOOLJLELOLW\ 7KH VSHHFK LQWHOOLJLELOLW\ VFRUHV SHUFHQW FRUUHFWf GHULYHG IURP WKH MXGJHVf UHVSRQVHV WR WKH SHUFHSWXDO DXGLR FRPSDFW GLVFV &'Vf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b ORZHU WKDQ UHFRUGLQJV IURP HLWKHU WKH DLU RU K\GURSKRQH ORFDWLRQV 7KH LQWHOOLJLELOLW\ VFRUHV UHFRUGHG IURP WKH LQQHU HDU RI WKH IHWXV LQ WHUR DUH DERXW b SRRUHU WKDQ WKH VFRUHV UHFRUGHG IURP WKH IHWDO &0 H[ WHUR 6HFRQG IURP FDVXDO LQVSHFWLRQ RI WKH WZR )LJXUHV WKHUH DSSHDU WR EH D VOLJKW JHQGHU DQG OHYHO HIIHFWV SULPDULO\ IRU WKH 9&9 OLVWV

PAGE 83

)LJXUH 0HDQ SHUFHQW LQWHOOLJLELOLW\ RI 9&9 QRQVHQVH VWLPXOL VSRNHQ E\ D PDOH DQG D IHPDOH WDONHU UHFRUGHG LQ DLU LQ WKH XWHUXV IURP WKH IHWDO &0 H[ WHUR DQG IURP IHWDO &0 LQ WHUR DW WZR DLUERUQH VWLPXOXV OHYHOV %DUV HTXDO WKH VWDQGDUG HUURU RI WKH PHDQ

PAGE 84

$,5 87(586 &0(; &0,1 7(67 &21',7,21

PAGE 85

)LJXUH 0HDQ SHUFHQW LQWHOOLJLELOLW\ RI &9& ZRUGV VSRNHQ E\ D PDOH DQG D IHPDOH WDONHU UHFRUGHG LQ DLU LQ WKH XWHUXV IURP WKH IHWDO &0 H[ WHUR DQG IURP IHWDO &0 LQ WHUR DW WZR DLUERUQH VWLPXOXV OHYHOV %DUV HTXDO WKH VWDQGDUG HUURU RI WKH PHDQ

PAGE 86

B  ’ XL A $,5 87(586 &0(; &0,1 7(67 &21',7,21

PAGE 87

*HQGHU DQG OHYHO HIIHFWV DUH PRUH SURQRXQFHG IURP UHFRUGLQJV RI WKH &0 WKDQ IURP UHFRUGLQJV LQ DLU RU LQ WKH XWHUXV 6XPPDULHV RI WKH PHDQV DQG VWDQGDUG GHYLDWLRQV IRU LQWHOOLJLELOLW\ E\ JHQGHU VWLPXOXV OHYHO DQG ORFDWLRQ WKDW FRQWULEXWHG WR WKHVH ILJXUHV DUH SUHVHQWHG LQ 7DEOHV DQG 7KH UHVXOWV RI D WKUHHIDFWRU UHSHDWHG PHDVXUH $129$ DUH VXPPDUL]HG IRU 9&9 VWLPXOL DQG JLYHQ LQ 7DEOHV 7KHUH ZDV D VLJQLILFDQW WKUHHZD\ LQWHUDFWLRQ DPRQJ JHQGHU VWLPXOXV OHYHO DQG ORFDWLRQ ) S f 7KH PDLQ HIIHFWV ZHUH VLJQLILFDQW IRU HDFK RI WKH WKUHH IDFWRUV ORFDWLRQ ) S f JHQGHU )L S f DQG VWLPXOXV OHYHO )L S f 7KH UHVXOWV RI WKH SRVW KRF PXOWLSOH FRPSDULVRQ WHVW 1HZPDQ.HXOVf DUH SUHVHQWHG LQ 7DEOH 1RW DOO RI WKH SDLUHG UHVXOWV ZHUH LQFOXGHG LQ WKLV WDEOH 1RWH WKDW LQWHOOLJLELOLW\ LQ DOO FDVHV ZDV VLJQLILFDQWO\ JUHDWHU S f IRU &0 H[ WHUR WKDQ IRU &0 LQ WHUR $OVR LQWHOOLJLELOLW\ RI WKH QRQVHQVH V\OODEOHV 9&9f ZDV EHWWHU DW KLJKHU SUHVHQWDWLRQ OHYHOV WKDQ DW ORZHU SUHVHQWDWLRQ OHYHOV :KHQ ERWK VWLPXOXV OHYHOV ZHUH FRPSDUHG VWDWLVWLFDO VLJQLILFDQFH S f ZDV DWWDLQHG IRU WKH PDOH YRLFH UHFRUGHG LQ WKH XWHUXV IURP &0 H[ WHUR DQG IURP &0 LQ WHUR DV ZHOO DV IRU WKH IHPDOH YRLFH UHFRUGHG IURP &0 LQ WHUR 7KH $129$ UHVXOWV IRU &9& ZRUGV 7DEOH f VKRZHG D VLJQLILFDQW WKUHHZD\ LQWHUDFWLRQ DPRQJ JHQGHU VWLPXOXV OHYHO DQG ORFDWLRQ ) S f 7KLV ZDV VLPLODU WR WKH UHVXOWV IRU WKH QRQVHQVH V\OODEOHV 9&9f 7KH PDLQ HIIHFWV ZHUH VLJQLILFDQW IRU ORFDWLRQ )LV S f DQG VWLPXOXV OHYHO )L S f EXW QRW IRU JHQGHU )L S f 7KH UHVXOWV RI WKH SRVW KRF PXOWLSOH FRPSDULVRQ WHVW 1HZPDQ.HXOVf DUH JLYHQ LQ 7DEOH LQ ZKLFK QRW DOO RI

PAGE 88

7DEOH 9&9 VWLPXOXV LQWHOOLJLELOLW\ VFRUHV IRU HDFK WDONHU VWLPXOXV OHYHO DQG UHFRUGLQJ VLWH ,Q $LU ,Q 8WHUXV &0H[ WHUR &0Q WHUR 0DOH WDONHU G% G% G% G% G% G% G% G% 0HDQ bf b b b b b b b b 6' bf b b b b b b b b 1R FRUUHFW 1 f 6' 1R RI MXGJHV )HPDOH WDONHU 0HDQ bf b b b b b b b b 6' bf b b b b b b b b 1R FRUUHFW 1 f 6' 1R RI MXGJHV

PAGE 89

7DEOH &9& VWLPXOXV LQWHOOLJLELOLW\ VFRUHV IRU HDFK WDONHU VWLPXOXV OHYHO DQG UHFRUGLQJ VLWH ,Q $LU ,Q 8WHUXV &0H[ WHUR &0cm WHUR 0DOH WDONHU G% G% G% G% G% G% G% G% 0HDQ bf b b b b b b b b 6' bf b b b b b b b b 1R FRUUHFW 1 f 6' 1R RIMXGJHV )HPDOH WDONHU 0HDQ bf b b b b b b b b 6' bf b b b b b b b b 1R FRUUHFW 1 f 6' 1R RI MXGJHV

PAGE 90

7DEOH $129$ VXPPDU\ WDEOH IRU 9&9 VWLPXOL 6RXUFH 6XP RI 6TXDUHV GI 0HDQ 6TXDUHV ) SYDOXH /RFDWLRQ (UURU /RFDWLRQf *HQGHU (UURU *HQGHUf /HYHO (UURU /HYHOf /RFDWLRQ [ *HQGHU (UURU /RFDWLRQ [ *HQGHUf /RFDWLRQ [ /HYHO (UURU /RFDWLRQ [ /HYHOf *HQGHU [ /HYHO (UURU *HQGHU [ /HYHOf /RFDWLRQ [ *HQGHU [ /HYHO (UURU /RFDWLRQ [ *HQGHU [ /HYHOf

PAGE 91

7DEOH 3RVW KRF PXOWLSOH FRPSDULVRQV 1HZPDQ.HXOV WHVWf IRU 9&9 VWLPXOL &RQGLWLRQV $0+ $0/ 80+ 80/ ;0+ ;0/ ,0+ ,0/ $)+ $)/ 8)+ 8)/ ;)+ ;)/ ,)+ ,)/ $0+ $0/ 80+ rr 80/ r rr ;0+ rr rr ;0/ rr rr rr ,0+ rr rr rr ,0/ rr rr rr rr $)+ rr $)/ rr 8)+ rr rr 8)/ rr rr ;)+ rr rr rr ;)/ rr rr rr ,)+ rr rr rr rr ,)/ rr rr rr rr 1RWH $ ,Q $LU 8 ,Q 8WHUXV ; &0H[ WHUR &0LQ WHUR 0 0DOH ) )HPDOH + G% / G% S! r S rr S n2

PAGE 92

7DEOH $129$ VXPPDU\ WDEOH IRU &9& VWLPXOL 6RXUFH 6XP RI 6TXDUHV GI 0HDQ 6TXDUHV ) SYDOXH /RFDWLRQ (UURU /RFDWLRQf *HQGHU (UURU *HQGHUf /HYHO (UURU /HYHOf /RFDWLRQ [ *HQGHU (UURU /RFDWLRQ [ *HQGHUf /RFDWLRQ [ /HYHO (UURU /RFDWLRQ [ /HYHOf *HQGHU [ /HYHO (UURU *HQGHU [ /HYHOf /RFDWLRQ [ *HQGHU [ /HYHO (UURU /RFDWLRQ [ *HQGHU [ /HYHOf

PAGE 93

7DEOH 3RVW KRF PXOWLSOH FRPSDULVRQV 1HZPDQ.HXOV WHVWf IRU &9& VWLPXOL &RQGLWLRQV $0+ $0/ 80+ 80/ ;0+ ;0/ ,0+ ,0/ $)+ $)/ 8)+ 8)/ ;)+ ;)/ ,)+ ,)/ $0+ $0/ r 80+ r 80/ rr rr ;0+ rr rr ;0/ rr rr ,0+ rr rr ,0/ rr rr rr rr $)+ rr $)/ rr rr 8)+ rr rr 8)/ rr ;)+ rr rr ;)/ rr rr ,)+ rr rr rr rr ,)/ rr rr rr rr rr 1RWH $ ,Q $LU 8 ,Q 8WHUXV ; &0H[ WHUR &0P WHUR 0 0DOH ) )HPDOH + G% / G% S! r S rr S

PAGE 94

WKH SDLUHG UHVXOWV ZHUH LQFOXGHG ,W LV QRWHG WKDW LQWHOOLJLELOLW\ ZDV VLJQLILFDQWO\ JUHDWHU S f IRU &0 H[ WHUR WKDQ IRU &0 LQ WHUR H[FHSW IRU WKH PDOH YRLFH UHFRUGHG DW G% 63/ S f $OVR LQWHOOLJLELOLW\ RI WKH ZRUGV &9&f ZDV EHWWHU DW KLJKHU SUHVHQWDWLRQ OHYHOV WKDQ DW ORZHU SUHVHQWDWLRQ OHYHOV H[FHSW IRU WKH PDOH YRLFH UHFRUGHG LQ DLU :KHQ ERWK VWLPXOXV OHYHOV ZHUH FRPSDUHG VWDWLVWLFDO VLJQLILFDQFH S f ZDV DFKLHYHG IRU WKH PDOH YRLFH UHFRUGHG LQ DLU S f LQ WKH XWHUXV DQG IURP &0 LQ WHUR DV ZHOO DV IRU WKH IHPDOH YRLFH UHFRUGHG LQ DLU DQG IURP &0 LQ WHUR )LJXUHV VLPSOLILHV WKRVH GDWD SUHVHQWHG LQ )LJXUH E\ FRPELQLQJ OHYHOV )RU 9&9 VWLPXOL WKH DYHUDJH LQWHOOLJLELOLW\ VFRUHV IRU WKH PDOH YRLFH UHFRUGHG LQ DLU LQ WKH XWHUXV IURP IHWDO &0 H[ WHUR DQG IURP IHWDO &0 LQ WHUR ZHUH b b b DQG b UHVSHFWLYHO\ )RU WKH IHPDOH YRLFH UHFRUGHG LQ DLU LQ WKH XWHUXV IURP IHWDO &0 H[ WHUR DQG IURP IHWDO &0 LQ 8WHUR WKH LQWHOOLJLELOLW\ VFRUHV ZHUH b b b DQG b UHVSHFWLYHO\ $ WZRIDFWRU UHSHDWHG PHDVXUHV $129$ LQGLFDWHG VLJQLILFDQW LQWHUDFWLRQ EHWZHHQ JHQGHU DQG ORFDWLRQ ) b S f DQG PDLQ HIIHFWV IRU JHQGHU )L S f DQG ORFDWLRQ ) S f 7KH SRVW KRF PXOWLSOH FRPSDULVRQ WHVW 1HZPDQ.HXOVf LQGLFDWHG WKDW WKH LQWHOOLJLELOLW\ VFRUHV RI WKH PDOH YRLFH ZHUH VLJQLILFDQWO\ KLJKHU S f WKDQ WKDW RI WKH IHPDOH YRLFH DW DOO IRXU UHFRUGLQJ ORFDWLRQV $OVR IRU ERWK PDOH DQG IHPDOH WDONHUV WKH LQWHOOLJLELOLW\ VFRUHV UHFRUGHG LQ DLU ZHUH VLJQLILFDQWO\ KLJKHU S f WKDQ WKDW RI HDFK RI WKH RWKHU WKUHH UHFRUGLQJ ORFDWLRQV 7KH VFRUHV UHFRUGHG LQ WKH XWHUXV ZHUH VLJQLILFDQWO\ KLJKHU S f WKDQ WKDW RI UHFRUGLQJV IURP &0 H[ WHUR DQG &0 LQ WHUR 7KH VFRUHV UHFRUGHG IURP &0 H[ WHUR ZHUH VLJQLILFDQWO\ KLJKHU S f WKDQ WKDW IURP &0 LQ WHUR

PAGE 95

)LJXUH 0HDQ SHUFHQW LQWHOOLJLELOLW\ RI 9&9 QRQVHQVH VWLPXOL VSRNHQ E\ D PDOH DQG D IHPDOH WDONHU UHFRUGHG LQ DLU LQ WKH XWHUXV IURP WKH IHWDO &0 H[ WHUR DQG IURP IHWDO &0 LQ WHUR ZKHQ FRPELQLQJ WZR DLUERUQH VWLPXOXV OHYHOV %DUV HTXDO WKH VWDQGDUG HUURU RI WKH PHDQ

PAGE 96

+ M &2 2 BO B /8 $,5 87(586 &0(; &0,1 7(67 &21',7,21

PAGE 97

6LPLODUO\ )LJXUHV FODULILHV WKRVH GDWD SUHVHQWHG LQ )LJXUH E\ FRPELQLQJ OHYHOV )RU &9& ZRUGV WKH DYHUDJH LQWHOOLJLELOLW\ VFRUHV IRU WKH PDOH YRLFH UHFRUGHG LQ DLU LQ WKH XWHUXV IURP IHWDO &0 H[ WHUR DQG IURP IHWDO &0 LQ WHUR ZHUH b b b DQG b UHVSHFWLYHO\ )RU WKH IHPDOH YRLFH UHFRUGHG LQ DLU LQ WKH XWHUXV IURP IHWDO &0 H[ WHUR DQG IURP IHWDO &0 LQ WHUR WKH LQWHOOLJLELOLW\ VFRUHV ZHUH b b b DQG b UHVSHFWLYHO\ $ WZRIDFWRU UHSHDWHG PHDVXUHV $129$ LQGLFDWHG VLJQLILFDQW LQWHUDFWLRQ EHWZHHQ JHQGHU DQG ORFDWLRQ ) S f DQG PDLQ HIIHFWV IRU ORFDWLRQ )LV S f EXW QRW IRU JHQGHU )L S f $ SRVW KRF PXOWLSOH FRPSDULVRQ WHVW 1HZPDQ.HXOVf LQGLFDWHG WKDW IRU ERWK PDOH DQG IHPDOH WDONHUV WKH LQWHOOLJLELOLW\ VFRUHV UHFRUGHG LQ DLU ZHUH VLJQLILFDQWO\ KLJKHU S f WKDQ WKDW RI HDFK RI WKH RWKHU WKUHH UHFRUGLQJ ORFDWLRQV 7KH VFRUHV UHFRUGHG LQ WKH XWHUXV ZHUH VLJQLILFDQWO\ KLJKHU S f WKDQ WKDW RI UHFRUGLQJV IURP &0 H[ WHUR DQG &0 LQ WHUR 7KH VFRUHV UHFRUGHG IURP &0 H[ WHUR ZHUH VLJQLILFDQWO\ KLJKHU S f WKDQ WKDW IURP &0 LQ WHUR 7KHUH ZHUH QR VWDWLVWLFDO GLIIHUHQFHV S f EHWZHHQ WKH PDOH YRLFH DQG WKH IHPDOH YRLFH DFURVV UHFRUGLQJ ORFDWLRQV H[FHSW ZKHQ UHFRUGHG LQ DLU S f $V UHSRUWHG DERYH VSHHFK 9&9 DQG &9& VWLPXOLf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

PAGE 98

)LJXUH 0HDQ SHUFHQW LQWHOOLJLELOLW\ RI &9& ZRUGV VSRNHQ E\ D PDOH DQG D IHPDOH WDONHU UHFRUGHG LQ DLU LQ WKH XWHUXV IURP WKH IHWDO &0 H[ XOHUR DQG IURP IHWDO &0 LQ WHUR ZKHQ FRPELQLQJ WZR DLUERUQH VWLPXOXV OHYHOV %DUV HTXDO WKH VWDQGDUG HUURU RI WKH PHDQ

PAGE 99

‘ FYF ’ 0DOH 8S [ :N +L ,S , ‘ ‘ LOO +, ‘ $,5 87(586 &0(; &0,1 7(67 &21',7,21 RR -

PAGE 100

ZHOO GHVFULEHG LQ KXPDQV 4XHUOHX HW DO D 5LFKDUGV HW DO f DQG VKHHS $UPLWDJH %DOGZLQ DQG 9LQFH 9LQFH HW DO *HUKDUGW $EUDPV DQG 2OLYHU f 7KH DEGRPHQ ZDOO XWHUXV DQG DPQLRWLF IOXLGV FDQ EH FKDUDFWHUL]HG DV D ORZSDVV ILOWHU ZLWK D KLJKIUHTXHQF\ FXWRII DW +] DQG D UHMHFWLRQ UDWH RI DSSUR[LPDWHO\ G% SHU RFWDYH )RU IUHTXHQFLHV EHORZ +] VRXQG SUHVVXUHV SDVVLQJ WKURXJK WR WKH IHWXV DUH XQDWWHQXDWHG DQG LQ VRPH FDVHV DUH HQKDQFHG $ERYH +] VRXQG SUHVVXUHV DUH LQFUHDVLQJO\ DWWHQXDWHG E\ XS WR G% *HUKDUGW $EUDPV DQG 2OLYHU f 7KXV WKH VSHHFK VLJQDOV ZRXOG EH DOWHUHG DV WKH\ SDVVHG WKURXJK WLVVXHV RI WKH HZH LQWR WKH XWHUXV $GGLWLRQDOO\ WKH VSHFWUDO FRQWHQWV RI H[WHUQDO VRXQGV DUH IXUWKHU PRGLILHG E\ WKH URXWH RI VRXQG WUDQVPLVVLRQ LQWR WKH IHWDO LQQHU HDU 6RXQG SUHVVXUHV SDVV WKURXJK WKH IHWDO KHDG E\ D ERQH FRQGXFWLRQ SDWKZD\ *HUKDUGW HW DO f )RU WR +] DQ DLUERUQH VLJQDO ZRXOG EH UHGXFHG E\ G% EHIRUH UHDFKLQJ WKH IHWDO LQQHU HDU )RU WKURXJK +] WKH VLJQDO ZRXOG EH UHGXFHG E\ G% *HUKDUGW HW DO f 7KHUHIRUH WKH UHFRUGLQJV RI VSHHFK IURP &0 LQ WHUR ZRXOG EH IXUWKHU GHJUDGHG DQG OHVV LQWHOOLJLEOH WKDQ WKH UHFRUGLQJV LQ DLU DQG LQ WKH XWHUXV 7KH SUHVHQW ILQGLQJV UHYHDO EHWWHU LQWHOOLJLELOLW\ IRU VSHHFK LQ WKH XWHUXV WKDQ KDV EHHQ SUHYLRXVO\ IRXQG 4XHUOHX HW DO E *ULIILWKV HW DO f 4XHUOHX HW DO Ef IRXQG WKDW DERXW b RI )UHQFK SKRQHPHV UHFRUGHG ZLWKLQ WKH XWHUXV RI SUHJQDQW ZRPHQ ZHUH UHFRJQL]HG ,Q *ULIILWKV HW DO HYDOXDWHG WKH LQWHOOLJLELOLW\ RI VSHHFK VWLPXOL 9&9 QRQVHQVH V\OODEOHV DQG &9& ZRUGVf UHFRUGHG ZLWKLQ WKH XWHUXV RI D SUHJQDQW VKHHS 7KH LQWHOOLJLELOLW\ VFRUHV ZHUH DSSUR[LPDWHO\ b DQG b IRU WKH PDOH DQG IHPDOH WDONHUV UHVSHFWLYHO\ +RZHYHU WKH UHVXOWV IURP WKH FXUUHQW VWXG\ VKRZHG WKDW WKH LQWHOOLJLELOLW\ VFRUHV DYHUDJHG DFURVV WKH VWLPXOXV W\SHV DQG LQWHQVLW\ OHYHOV ZHUH

PAGE 101

DSSUR[LPDWHO\ b DQG b IRU WKH PDOH DQG IHPDOH YRLFHV UHFRUGHG LQ WKH XWHUXV UHVSHFWLYHO\ 7KH ORZHU LQWHOOLJLELOLW\ RI VSHHFK DFKLHYHG E\ 4XHUOHX HW DO Ef KDV EHHQ H[SODLQHG E\ WKH ORFDWLRQ RI WKH WUDQVGXFHU ZLWKLQ WKH XWHUXV *ULIILWKV HW DO f DQG E\ WKH W\SH RI WUDQVGXFHU $ PRGLILHG PLFURSKRQH XVHG LQ 4XHUOHXfV VWXG\ ZDV SRVLWLRQHG DW WKH FURZQ RI WKH IHWDO KHDG SRWHQWLDOO\ FORVHU WR YDVFXODU EHGV DQG EHWWHU DEOH WR SLFN XS PDWHUQDO KHDUW VRXQGV ,Q ERWK WKH SUHVHQW VWXG\ DQG WKH VWXG\ E\ *ULIILWKV HW DO f D K\GURSKRQH SRVLWLRQHG E\ WKH IHWDO QHFN ZDV XVHG 7KH DEVHQFH RI GHWHFWDEOH KHDUW VRXQGV LQ WKH UHFRUGLQJV IURP WKHVH WZR VWXGLHV VXSSRUWV WKDW WKH K\GURSKRQH SODFHPHQW UHVXOWV LQ OHVV YDVFXODU QRLVH +RZHYHU WKH UHFRUGLQJV ZLWKLQ WKH XWHUXV LQ WKH FXUUHQW VWXG\ VKRZHG PXFK KLJKHU LQWHOOLJLELOLW\ VFRUHV WKDQ WKDW LQ *ULIILWKVf VWXG\ f DOWKRXJK ERWK VHWV RI GDWD ZHUH REWDLQHG XVLQJ WKH VDPH VSHHFK VWLPXOL 9&9 QRQVHQVH V\OODEOH DQG &9& ZRUGVf VSRNHQ E\ PDOH DQG IHPDOH VSHDNHUV 7KH GLVFUHSDQF\ FRXOG UHVXOW IURP WKH KLJKHU VWLPXOXV OHYHOV DQG G% 63/ YV DQG G% 63/f DQG EHWWHU SHUFHSWXDO WHVWLQJ FRQGLWLRQ HDUSKRQH YV VRXQG ILHOGf XVHG LQ WKH FXUUHQW VWXG\ *ULIILWKV HW DO f DOVR GHPRQVWUDWHG WKDW WKH PDOH WDONHUfV YRLFH ZDV PRUH LQWHOOLJLEOH WKDQ WKH IHPDOH WDONHUfV YRLFH IRU ERWK 9&9 DQG &9& VWLPXOL ZKHQ UHFRUGHG ZLWKLQ WKH XWHUXV DOWKRXJK WKH LQWHOOLJLELOLW\ VFRUHV IRU ERWK WDONHUV ZHUH QRW VLJQLILFDQW GLIIHUHQW UHJDUGOHVV RI VWLPXOXV W\SH ZKHQ UHFRUGHG LQ DLU 7KH UHVXOWV RI WKH SUHVHQW GDWD LQGLFDWHG WKDW WKH LQWHOOLJLELOLW\ VFRUHV RI WKH PDOH YRLFH ZHUH VLJQLILFDQWO\ KLJKHU WKDQ WKDW RI WKH IHPDOH YRLFH DFURVV DOO IRXU UHFRUGLQJ ORFDWLRQV LQ DLU LQ WKH XWHUXV IURP &0 H[ WHUR DQG IURP &0 LQ WHURf IRU 9&9 QRQVHQVH V\OODEOHV EXW QRW IRU &9& ZRUGV 7KH GLIIHUHQFHV RI LQWHOOLJLELOLW\ VFRUHV IRU 9&9 QRQVHQVH V\OODEOHV EHWZHHQ WKH PDOH

PAGE 102

WDONHU DQG WKH IHPDOH WDONHU ZHUH b LQ DLU b IRU PDOH DQG b IRU IHPDOHf b LQ WKH XWHUXV b IRU PDOH DQG b IRU IHPDOHf b IURP &0 H[ WHUR b IRU PDOH DQG b IRU IHPDOHf DQG b IURP &0 LQ WHUR b IRU PDOH DQG b IRU IHPDOHf :KHQ OLVWHQLQJ WR WKH IHPDOH VSHDNHUfV RULJLQDO WDSH LW LV GLIILFXOW IRU LQYHVWLJDWRUV WR GLVWLQJXLVK WKH FRQVRQDQW Y IURP E 7ZHQW\QLQH RXW RI MXGJHV UHVSRQGHG 9&9 VWLPXOXV LWHP DYD DV DED LQ WKH DLU FRQGLWLRQ IRU WKH IHPDOH WDONHU 7KH XQFOHDU SURQXQFLDWLRQ RI WKH FRQVRQDQW O?O DFFRXQWHG IRU WKH GHFUHDVHV LQ WKH LQWHOOLJLELOLW\ RI WKH IHPDOH WDONHU LQ DLU DQG WKHUHIRUH IRU WKH RWKHU UHFRUGLQJ ORFDWLRQV 7KH GLIIHUHQFHV LQ WKH LQWHOOLJLELOLW\ VFRUHV EHWZHHQ WKH PDOH DQG WKH IHPDOH WDONHUV UDQJHG IURP b &0 LQ WHURf WR b &0 H[ 8WHURf 7KHVH GLIIHUHQFHV ZHUH TXLWH VPDOO H[FHSW b IRU &0 H[ WHURf UHODWLYH WR WKH LWHP SHUFHSWXDO WHVW 9&9 LWHPVf 7KXV WKH GLIIHUHQFHV EHWZHHQ WDONHU JHQGHU PD\ QRW EH FOLQLFDOO\ VLJQLILFDQW DOWKRXJK WKH\ DUH VWDWLVWLFDOO\ VLJQLILFDQW 7KRUQWRQ DQG 5DIILQ f VWXGLHG WKH ELQRPLDO FKDUDFWHULVWLFV RI VSHHFK GLVFULPLQDWLRQ LQWHOOLJLELOLW\f VFRUHV DQG SRLQWHG RXW WKH UHODWLRQ EHWZHHQ PHDVXUHPHQW HUURU DQG VDPSOH VL]H QXPEHU RI WHVW LWHPf $V VDPSOH VL]H ZDV UHGXFHG YDULDELOLW\ LQ VFRUHV LQFUHDVHG DQG WKH IDUWKHU WKH VFRUH IURP b RU b WKH OHVV FRQILGHQFH RQH FDQ KDYH LQ WKH VSHFLILF YDOXH 7KH DXWKRUV KDYH SURYLGHG FRQILGHQFH LQWHUYDOV DQG H[SHFWHG UDQJHV RI VFRUHV EDVHG RQ HYDOXDWLRQV RI VXEMHFWV ZLWK &,' $XGLWRU\ 7HVW : PRQRV\OODELF ZRUGVf )RU H[DPSOH D OLVWHQHU ZKR PDNHV D VFRUH RI b PD\ YDU\ EHWZHHQ DQG b RQ D LWHP OLVW DQG VWLOO EH ZLWKLQ H[SHFWHG YDULDWLRQ b FRQILGHQFH LQWHUYDOf ZKLOH WKH H[SHFWHG UDQJH RI YDULDWLRQ IRU D LWHP OLVW LV HYHQ JUHDWHU DW WR b )RU WKH VXEMHFW ZLWK D VFRUH RI b WKH UDQJH RI YDULDWLRQ IRU LWHPV LV IURP WR b DQG IRU LWHPV LV WR b

PAGE 103

7KH &0 LV DQ $& UHFHSWRU SRWHQWLDO SURGXFHG SULPDULO\ E\ WKH RXWHU KDLU FHOOV RI WKH RUJDQ RI &RUWL GXULQJ DFRXVWLF VWLPXODWLRQ DQG PLPLFV WKH DFRXVWLF LQSXW LQ DPSOLWXGH DQG IUHTXHQF\ RYHU D UHPDUNDEO\ ZLGH UDQJH *XOLFN *HVFKHLGHU DQG )ULVLQD f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fPLFURSKRQHf WKH RYHUDOO LQWHOOLJLELOLW\ IURP &0 H[ WHUR UHFRUGLQJV ZDV RQO\ b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f 7KXV KLJKIUHTXHQF\ FRPSRQHQWV RI VSHHFK ZRXOG EH

PAGE 104

DWWHQXDWHG LQ WKH UHFRUGLQJV IURP &0 H[ WHUR LI IOXLG UHPDLQHG LQ WKH PLGGOH HDU FDYLW\ )LQDOO\ WKH &0 SURGXFHG E\ DQ\ SDUWLFXODU SXUH WRQH KDV LWV PD[LPXP VHQVLWLYLW\ DW D VSHFLILF SODFH DORQJ WKH FRFKOHDU EDVLODU PHPEUDQH *XOLFN *HVFKHLGHU DQG )ULVLQD f +RQUXELD DQG :DUG f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f DQG VWLPXOXV W\SHV 9&9 DQG &9& VWLPXOLf WKH\ ZHUH b DQG b IRU WKH PDOH DQG IHPDOH YRLFHV UHFRUGHG LQ DLU :LWKLQ WKH XWHUXV VFRUHV ZHUH b DQG b IRU WKH PDOH DQG WKH IHPDOH YRLFHV UHVSHFWLYHO\ 7KH GHFOLQH LQ LQWHOOLJLELOLW\ ZDV RQO\ b IRU WKH PDOH VSHDNHU DQG b IRU WKH IHPDOH VSHDNHU IURP LQ DLU UHFRUGLQJV WR LQ WKH XWHUXV UHFRUGLQJV 7KH UHGXFWLRQ RI LQWHOOLJLELOLW\ UHIOHFWHG WKH ILOWHU HIIHFW SURGXFHG E\ WKH PDWHUQDO DEGRPHQ XWHUXV DQG DPQLRWLF IOXLG

PAGE 105

,Q FRQWUDVW WKH PHDQ LQWHOOLJLELOLW\ VFRUHV UHFRUGHG IURP &0 LQ WHUR DYHUDJHG DFURVV WZR OHYHOV DQG VWLPXOXV W\SHV IRU WKH PDOH DQG IHPDOH YRLFHV ZHUH b DQG b UHVSHFWLYHO\ )RU &0 H[ WHUR VFRUHV ZHUH b DQG b IRU WKH PDOH DQG WKH IHPDOH WDONHUV 7KXV WKH UHGXFWLRQ LQ LQWHOOLJLELOLW\ UHFRUGLQJV PDGH IURP &0 H[ WHUR WR &0 LQ 8WHUR ZDV b IRU WKH PDOH VSHDNHU DQG b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f RI WKH QRQVHQVH V\OODEOHV DQG PRQRV\OODELF ZRUGV PD\ KDYH SURGXFHG LPSURYHG LQWHOOLJLELOLW\ IRU WKH IHPDOH WDONHU ZKHQ UHFRUGHG LQ WKH XWHUXV DQG IURP WKH IHWDO LQQHU HDU $QG HDUOLHU VWXG\ ZLWK VKHHS WKDW VKRZHG D JHQGHU HIIHFW XVHG ORZHU OHYHOV RI VWLPXOXV SUHVHQWDWLRQV *ULIILWKV HW DO f 6HFRQG LQ WKH &0 LQ WHUR UHFRUGLQJ FRQGLWLRQ WKH JHQGHU HIIHFW RQ WKH LQWHOOLJLELOLW\ RI VSHHFK VWLPXOL ZDV PLQLPL]HG EHFDXVH WKH FXWRII IUHTXHQF\ RI WKH

PAGE 106

ORZSDVV ILOWHU ERQH FRQGXFWLRQ URXWH LQWR WKH IHWDO LQQHU HDUf ZDV IXUWKHU ORZHUHG ZKHQ FRPSDUHG WR WKH XWHUXV UHFRUGLQJ FRQGLWLRQ *HUKDUGW HW DK f 7KH KLJKIUHTXHQF\ FRPSRQHQW RI VSHHFK WKDW FXHG WKH JHQGHU HIIHFW RQ WKH LQWHOOLJLELOLW\ RI VSHHFK ZDV HOLPLQDWHG ZKHQ WUDQVPLWWHG LQWR WKH IHWDO LQQHU HDU LQ WHUR &RQVRQDQW )HDWXUH 7UDQVPLVVLRQ &RQVRQDQW FRQIXVLRQ PDWULFHV ZHUH FRQVWUXFWHG IURP WKH UHVSRQVHV RI DOO VXEMHFWV WR WKH 9&9 QRQVHQVH V\OODEOHV IRU HDFK UHFRUGLQJ FRQGLWLRQ 7KH\ DUH SUHVHQWHG LQ 7DEOHV WR IRU WKH PDOH WDONHU DW HDFK RI WKH IRXU UHFRUGLQJ ORFDWLRQV DLU XWHUXV &0 H[ WHUR DQG &0 LQ WHURf DQG DW HDFK RI WKH VWLPXOXV OHYHOV DQG G% 63/f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b LQ WKH UHFRUGLQJV PDGH LQ DLU LQ WKH XWHUXV DQG IURP &0 H[ WHUR IRU ERWK PDOH DQG IHPDOH WDONHUV DW G% 63/ ,W GURSSHG VOLJKWO\ WR b DQG b LQ &0 LQ WHUR DW G% 63/ IRU WKH PDOH DQG IHPDOH WDONHUV

PAGE 107

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG LQ DLU DW G% 63/ 6WLPXOXV 5HVSRQVH E S OLW KL t ,NO ,% 0 V ,]O ,PO Q ,6 KVL ,EO S G KL J N ,IO ,YO V ,]P ,QL ,6 WV V2 9f

PAGE 108

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG LQ DLU DW G% 63/ 5HVSRQVH 6WLPXOXV ,EO S G W ,JO N ,9 0 V ] P Q 6 W6 E S G W J N ,9 1 V ] P Q 6 ,WV 92 2Y

PAGE 109

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG LQ WKH XWHUXV DW G% 63/ 6WLPXOXV E S G ,W ,JO 0 ,IO ,YO ,V ,]O ,PO ,QL 6, ,W6 5HVSRQVH ,EO S ,G ,WO ,JO 0 : ,YO ,V ,]O ,PO ,QL ,6 ,WV

PAGE 110

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG LQ WKH XWHUXV DW G% 63/ 5HVSRQVH 6WLPXOXV E S G W J N ,IO Y V ,]O P Q ,6 WV E S G 1 N 0 0 V ,]O P Q V WV 92 RR

PAGE 111

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG IURP &0H[ WHUR DW G% 63/ 6WLPXOXV 5HVSRQVH K 9 ,G Z J N ,IO 0 V ,]O P Q ,6 WV E ,SO GM O?J N : 0 V ,]O ,PO Q V WV 62 62

PAGE 112

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG IURP &0H[ WHUR DW G% 63/ 6WLPXOXV 5HVSRQVH OE ,SO ,G ,W J ,NO ,II 0 ,VO ,]O ,PO Q ,6 WV Z S ,G KL b IN,II 0 ,VO ,]O ,PO ,QL ,6 LWV R R

PAGE 113

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG IURP &0P WHUR DW G% 63/ 5HVSRQVH 6WLPXOXV E S G W J N ,IO ,YO V ,]O PO Q 6 W6 E S G W J N ,WO 0 V ,]P ,QL ,6 ,W6,

PAGE 114

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU PDOH WDONHU UHFRUGHG IURP &0P WHUR DW G% 63/ 5HVSRQVH 6WLPXOXV E S G W 'G Y V ,]O P Q V WV E S L GL W J N P 0 V ] P Q V WV

PAGE 115

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG LQ DLU DW G% 63/ 6WLPXOXV 5HVSRQVH ,EO ,SO ,GO ,W J ,NO ,I Y ,V ,]O ,PO ,QL ,6, ,W6, ,EO S G 0 N ,IO 0 ,VO ,],PO ,QL ,6 LWV

PAGE 116

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG LQ DLU DW G% 63/ 5HVSRQVH 6WLPXOXV E ,SO G W J N I 0 ,V ,W, ,PO ,QL 6 W6 OE ,SO ,G ,W J N II Y ,V ,]O ,PO ,QL 6 WV

PAGE 117

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG LQ WKH XWHUXV DW G% 63/ 5HVSRQVH 6WLPXOXV E S G W N ,IO 0 V ,],PO ,QL ,6 W6 E S ,G W J N ,IO 0 V ,]O ,PO ,QL V WV R

PAGE 118

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG LQ WKH XWHUXV DW G% 63/ 5HVSRQVH 6WLPXOXV OE ,SO IGI IW LV 0 0 IDI ,WP Q ,6 WV E S IGI IW !V N ,% 0 IVI ]P Q V WV R 2Q

PAGE 119

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG IURP &0H[ WHUR DW G% 63/ 5HVSRQVH 6WLPXOXV OE S ,GKL ,V ,NO ,6 ,YO ,V OE g ,G,6 g ,NO ,6 ,YO ,V ,]O PO Q ,6 ,W6, O]O ,PO Q ,6 W6 R

PAGE 120

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG IURP &0H[ WHUR DW G% 63/ 6WLPXOXV 5HVSRQVH ,EO ,SO ,G KL : ,N ,9 0 ,V ,]O ,PO Q ,6 WV ,EO ,SO ,G KL JL 'HO ,9 0 V ,],PO OU?O 6, ,WV R RR

PAGE 121

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG IURP &0]nZ WHUR DW G% 63/ 5HVSRQVH 6WLPXOXV OE S ,G ,W J ,N ,W 0 ,V ,]O ,PO ,QL ,6, $6 0 S G 1 LJL ,N ,9 0 V ,]PO ,QL ,6 ,WV R 62

PAGE 122

7DEOH &RQVRQDQW FRQIXVLRQ PDWUL[ IRU IHPDOH WDONHU UHFRUGHG IURP &0LQ WHUR DW G% 63/ 5HVSRQVH 6WLPXOXV ,EO S G W J N ^ 0 V ] ,PO 0 6 W6 E S G W J N IU Y V ] P Q 6 W6

PAGE 123

,OO UHVSHFWLYHO\ ,Q FRQVWUDVW IRU WKH PDOH YRLFH UHFRUGHG DW G% 63/ FRUUHFW LGHQWLILFDWLRQV RI 6 DQG $6 ZHUH b DQG b IURP &0 H[ XOHUR DQG b DQG b IURP &0 LQ WHUR UHVSHFWLYHO\ DOWKRXJK ERWK FRQVRQDQWV ZHUH SHUIHFWO\ LGHQWLILHG bf LQ DLU DQG LQ WKH XWHUXV FRQGLWLRQV )RU WKH IHPDOH YRLFH UHFRUGHG DW G% 63/ FRUUHFW LGHQWLILFDWLRQ RI 6 DQG W6 ZHUH b DQG b IURP &0 H[ WHUR DQG b DQG b IURP &0 LQ WHUR UHVSHFWLYHO\ ZKLOH 6 ZDV b LGHQWLILHG DQG W6 ZDV b LGHQWLILHG ERWK LQ DLU DQG LQ WKH XWHUXV FRQGLWLRQV )XUWKHU DQDO\VHV RI WKH FRQVRQDQW IHDWXUH WUDQVPLVVLRQ XQGHU GLIIHUHQW UHFRUGLQJ FRQGLWLRQV ZHUH PDGH XVLQJ D VSHFLDO FRPSXWHU SURJUDP %HFDXVH WKH IHDWXUHV RI YRLFLQJ PDQQHU DQG SODFH DUH VWURQJO\ LQWHUGHSHQGHQW WKH VHTXHQWLDO LQIRUPDWLRQ DQDO\VLV 6,1)$f ZKLFK VHTXHQWLDOO\ LGHQWLILHV IHDWXUHV ZLWK D KLJK SURSRUWLRQ RI WUDQVPLWWHG LQIRUPDWLRQ ZDV DSSOLHG WR SDUWLDO RXW WKH HIIHFWV RI WKH IHDWXUHV RQ HDFK RWKHU :DQJ DQG %LOJHU :DQJ f 6,1)$ IRFXVHV RQ WKH WUDQVPLWWHG LQIRUPDWLRQ DVVRFLDWHG ZLWK D JLYHQ VWLPXOXVUHVSRQVH FRQIXVLRQ PDWUL[ DQG LGHQWLILHV WKH FRQWULEXWLRQV RI YDULRXV SKRQRORJLFDO IHDWXUHV WR WKH WUDQVPLWWHG LQIRUPDWLRQ 7KH UHVXOWV RI 6,1)$ DUH JLYHQ LQ 7DEOH ZKLFK FRQWDLQV WKH SHUFHQWDJH RI FRQWLQJHQW YRLFLQJ PDQQHU DQG SODFH LQIRUPDWLRQ UHFHLYHG ELWV UHFHLYHG ELWV VHQWf IRU HDFK WDONHU DQG UHFRUGLQJ ORFDWLRQ IRU G% DQG G% VWLPXOL 7KH 6,1)$ UHVXOWV DUH JUDSKLFDOO\ GLVSOD\HG LQ )LJXUH $ QXPEHU RI SRLQWV FDQ EH PDGH IURP LQVSHFWLRQ RI )LJXUH )LUVW DOO WKUHH IHDWXUHV YRLFLQJ PDQQHU DQG SODFH DSSHDUHG WR EH ZHOO WUDQVPLWWHG LQ UHFRUGLQJV PDGH LQ DLU UHJDUGOHVV RI WDONHU JHQGHU DQG VWLPXOXV OHYHOV 6HFRQG YRLFLQJ LQIRUPDWLRQ UHFHLYHG IURP LQ WKH XWHUXV UHFRUGLQJV ZDV VOLJKWO\ UHGXFHG DERXW b IRU WKH IHPDOH WDONHU EXW QRW DW

PAGE 124

7DEOH &RQGLWLRQDO SHUFHQWDJH RI YRLFLQJ PDQQHU DQG SODFH LQIRUPDWLRQ UHFHLYHG RI ELWV VHQWf IRU HDFK WDONHU UHFRUGLQJ ORFDWLRQ DQG VWLPXOXV OHYHO FRQGLWLRQ IRU WKH QRQVHQVH V\OODEOHV 9&9f &RQGLWLRQ /RFDWLRQ 7DONHU /HYHO G%f ,Q $LU ,Q 8WHUXV &0H[ WHUR &0LQ WHUR 0DOH )HPDOH 0DOH )HPDOH 0DOH )HPDOH 0DOH )HPDOH ,QIRUPDWLRQ 9RLFLQJ 0DQQHU 3ODFH

PAGE 125

)LJXUH &RQGLWLRQDO SHUFHQWDJH RI YRLFLQJ PDQQHU DQG SODFH LQIRUPDWLRQ UHFHLYHG IRU D PDOH 0f DQG D IHPDOH )f WDONHU LQ DLU $f LQ WKH XWHUXV 8f IURP WKH IHWDO &0 H[ XOHUR ;f DQG IURP WKH IHWDO &0 LQ XOHUR ,f DW G% +f DQG G% /f 63/

PAGE 126

&21',7,21 ;)+ 6,1)$ ‘ 9RLFLQJ ’ 0DQQHU (=, 3ODFH f§,, f§,; f§

PAGE 127

DOO IRU WKH PDOH WDONHU DFURVV WKH VWLPXOXV OHYHOV +RZHYHU PDQQHU DQG SODFH LQIRUPDWLRQ ZHUH UHGXFHG DERXW b DQG b UHVSHFWLYHO\ IRU ERWK PDOH DQG IHPDOH WDONHUV ZKHQ UHFRUGHG LQ WKH XWHUXV DQG DYHUDJHG DFURVV VWLPXOXV OHYHOV 7KLUG LQIRUPDWLRQ DERXW DOO WKUHH IHDWXUHV GHFUHDVHG IURP K\GURSKRQH UHFRUGLQJV ZLWKLQ WKH XWHUXV WR UHFRUGLQJV IURP IHWDO &0 H[ XOHUR DQG WR WKDW IURP &0 LQ WHUR +RZHYHU YRLFLQJ LQIRUPDWLRQ DSSHDUHG WR EH EHWWHU SUHVHUYHG WKDQ PDQQHU DQG SODFH LQIRUPDWLRQ IRU ERWK PDOH DQG IHPDOH WDONHUV 9RLFLQJ LQIRUPDWLRQ UHFHLYHG IURP &0 H[ WHUR DQG &0 LQ WHUR ZDV UDQJHG IURP b WR b IRU WKH PDOH WDONHU DQG IURP b WR b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f D SDQHO RI XQWUDLQHG LQGLYLGXDOV MXGJHG WKH LQWHOOLJLELOLW\ RI VSHHFK UHFRUGHG LQ WHUR IURP D SUHJQDQW VKHHS 7KH VDPH 9&9 DQG &9& VWLPXOL ZHUH XVHG DV WKH SUHVHQW VWXG\ $Q DQDO\VLV 6,1)$f RI WKH IHDWXUH LQIRUPDWLRQ IURP UHFRUGLQJV LQVLGH DQG RXWVLGH WKH XWHUXV VKRZHG WKDW YRLFLQJ LQIRUPDWLRQ LV EHWWHU WUDQVPLWWHG LQ XOHUR WKDQ SODFH RU PDQQHU LQIRUPDWLRQ 7KH FXUUHQW VWXG\ FRQILUPHG WKH ILQGLQJV UHJDUGLQJ YRLFLQJ LQIRUPDWLRQ LQVLGH WKH XWHUXV )XUWKHUPRUH WKH UHVXOWV RI 6,1)$ IURP WKH SUHVHQW VWXG\ LQGLFDWHG WKDW YRLFLQJ LQIRUPDWLRQ ZDV DFFXUDWHO\ SHUFHLYHG LQ WKH IHWDO LQQHU HDU &0 UHFRUGLQJVf H[ WHUR DQG LQ XOHUR DQG WKH PDOH YRLFLQJ LQIRUPDWLRQ ZDV EHWWHU SUHVHUYHG WKDQ WKDW RI WKH

PAGE 128

IHPDOH 0DLPHU DQG SODFH LQIRUPDWLRQ ZHUH QRW UHFHLYHG DV ZHOO DV YRLFLQJ LQIRUPDWLRQ E\ WKH IHWDO LQQHU HDU WKHUH ZHUH UHPDUNDEOH UHGXFWLRQV LQ &0 UHFRUGLQJV HVSHFLDOO\ IRU WKH IHPDOH YRLFH 0LOOHU DQG 1LFHO\ f UHSRUWHG WKDW ORZSDVV ILOWHULQJ RI VSHHFK VLJQDOV UHVXOWHG LQ D JUHDWHU ORVV RI PDQQHU DQG SODFH LQIRUPDWLRQ WKDQ RI YRLFLQJ LQIRUPDWLRQ 7KH\ FRQFOXGHG WKDW WKH KLJKHU IUHTXHQF\ LQIRUPDWLRQ LQ WLUH VSHHFK VLJQDO LV FULWLFDO IRU DFFXUDWH LGHQWLILFDWLRQ RI PDQQHU DQG SODFH RI DUWLFXODWLRQ :DQJ HW DO f KDG WKH VDPH FRQFOXVLRQ RQ FRQVRQDQW IHDWXUH UHFRJQLWLRQ RI ORZSDVV ILOWHULQJ VSHHFK E\ XVLQJ 6,1)$ 7KH ILQGLQJV RI ERWK *ULIILWKV HW DO f DQG WKH FXUUHQW VWXG\ DUH FRQVLVWHQW ZLWK WKRVH RI 0LOOHU DQG 1LFHO\ f DQG :DQJ HW DO f LQ WKDW WUDQVPLVVLRQ LQWR WKH XWHUXV FDQ EH PRGHOHG DV D ORZSDVV ILOWHU 7KH SRRUHU LQ XOHUR UHFHSWLRQ RI SODFH DQG PDQQHU LQIRUPDWLRQ LV DVVRFLDWHG ZLWK WKH JUHDWHU KLJKIUHTXHQF\ DWWHQXDWLRQ 0RUHRYHU WKH VSHFWUDO FRQWHQWV RI H[WHUQDO VSHHFK VLJQDOV DUH IXUWKHU PRGLILHG E\ WKH URXWH RI ERQH FRQGXFWLRQ WKURXJK WKH IHWDO VNXOO WR WKH LQQHU HDU *HUKDUGW HW DO f )RU ORZ IUHTXHQFLHV DQG +] DQ DLUERUQH VLJQDO ZRXOG EH UHGXFHG E\ G% WR UHDFK WKH IHWDO LQQHU HDU LQ WHUR )RU WKURXJK +] WKH VLJQDO ZRXOG EH UHGXFHG E\ G% *HUKDUGW HW DO f 7KXV WKH KLJKIUHTXHQF\ FRPSRQHQWV RI VSHHFK ZRXOG EH DWWHQXDWHG RQFH DJDLQ ZKHQ WUDQVPLWWHG WKURXJK WKH VNXOO LQWR WKH IHWDO LQQHU HDU LQ XOHUR 0DQQHU DQG SODFH LQIRUPDWLRQ ZHUH ORVW WR D JUHDW GHJUHH LQ WKH UHFRUGLQJV IURP &0 LQ XOHUR VLQFH KLJKIUHTXHQF\ LQIRUPDWLRQ ZDV DWWHQXDWHG PRVW DIWHU WUDQVPLVVLRQ IURP DLU WKURXJK WKH PDWHUQDO DEGRPHQ XWHUXV DQG IHWDO KHDG WR WKH IHWDO LQQHU HDU

PAGE 129

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n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f0DUN WKH ZRUG ODVKf 7KH DPSOLWXGHV RI HDFK UHFRUGLQJ ZHUH DGMXVWHG WR WKH VDPH UHODWLYH YROWDJH OHYHO RQ WKH VSHFWURJUDSKLF DQDO\VLV 7KH FRQWUDVW EHWZHHQ YRLFHG DQG YRLFHOHVV SRUWLRQV RI WKH SKUDVH LV DSSDUHQW WR VRPH GHJUHH LQ DOO HLJKW VSHFWURJUDPV 7KH KLJKIUHTXHQF\ QRLVH DVVRFLDWHG ZLWK WKH UHOHDVH RI WKH IULFDWLYH

PAGE 130

)LJXUH 6SHFWURJUDSKLF UHFRUGLQJV RI f0DUN WKH ZRUG ODVKf VSRNHQ E\ $ WKH PDOH WDONHU UHFRUGHG LQ DLU % WKH IHPDOH WDONHU UHFRUGHG LQ DLU & WKH PDOH WDONHU UHFRUGHG LQ WKH XWHUXV WKH IHPDOH WDONHU UHFRUGHG LQ WKH XWHUXV ( WKH PDOH WDONHU UHFRUGHG IURP WKH IHWDO &0 H[ WHUR ) WKH IHPDOH WDONHU UHFRUGHG IURP WKH IHWDO &0 H[ WHUR WKH PDOH WDONHU UHFRUGHG IURP WKH IHWDO &0 LQ WHUR + WKH IHPDOH WDONHU UHFRUGHG IURP WKH IHWDO &0 LQ WHUR

PAGE 131

)UHmW f +] )LJXUH $

PAGE 132

)LJXUH % &RQWLQXHG

PAGE 133

’$!FKO ‘%!63* +L )LJXUH & &RQWLQXHG

PAGE 134

)LJXUH &RQWLQXHG

PAGE 135

)LJXUH ( &RQWLQXHG

PAGE 136

)UHT&+] )LJXUH ) &RQWLQXHG

PAGE 137

! ’$!FKO ‘%!63* 7LQH VHF! )LJXUH &RQWLQXHG

PAGE 138

)LJXUH + &RQWLQXHG

PAGE 139

,6 LV XQGHWHFWDEOH LQ WKH &0 LQ XOHUR VSHFWURJUDPV IRU ERWK WDONHUV FRQVLVWHQW ZLWK WKH ORZSDVV ILOWHULQJ RI WKH PDWHUQDO WLVVXHV IOXLGV DQG IHWDO VNXOO $FRXVWLF PHDVXUHPHQWV IRU WKH &9& ZRUGV FRQWDLQLQJ RQH RI WKH ILYH YRZHOV L H DV $f ZHUH SHUIRUPHG )RU HDFK RI WKH YRZHOV L DV DQG $ ILYH &9& ZRUGV ZHUH VHOHFWHG IRU VSHFWUDO DQDO\VHV )RU WKH YRZHO OHL IRXU &9& ZRUGV ZHUH DQDO\]HG 7KH PHDQV RI WKH IXQGDPHQWDO IUHTXHQF\ )Rf DQG WKH ILUVW WKUHH IRUPDQW IUHTXHQFLHV )L ) DQG )f RI WKH PDOH DQG IHPDOH VSHDNHUV DYHUDJHG DFURVV HDFK RI WKH ILYH YRZHOV DUH SUHVHQWHG LQ 7DEOH )RU WKH SXUSRVH RI FRPSDULVRQ 7DEOH DOVR LQFOXGHV WKH YDOXHV REWDLQHG IURP WZR ODUJH VWXGLHV RI YRZHO IRUPDQW IUHTXHQFLHV D FODVVLF SDSHU E\ 3HWHUVRQ DQG %DUQH\ f DQG D UHFHQW UHSOLFDWLRQ E\ +LOOHQEUDQG HW DO f 7KHUH ZHUH FOHDU VLPLODULWLHV LQ WKH SUHVHQW GDWD WR WKH GDWD IURP 3HWHUVRQ DQG %DUQH\ f DQG IURP +LOOHQEUDQG HW DO f 7R HYDOXDWH WKH FKDUDFWHULVWLFV RI YRZHO WUDQVPLVVLRQ XQGHU GLIIHUHQW UHFRUGLQJ FRQGLWLRQV WKH UHODWLYH LQWHQVLW\ OHYHOV RI )R )L ) DQG ) ZHUH FDOFXODWHG E\ VXEWUDFWLQJ WKH EDFNJURXQG QRLVH OHYHO IURP WKH SHDN DPSOLWXGHV RI )R )L ) DQG ) IRU ERWK WKH PDOH DQG IHPDOH VSHDNHUV DFURVV WKH ILYH YRZHOV 7DEOH FRQWDLQV WKH PHDQV DQG VWDQGDUG GHYLDWLRQV RI UHODWLYH LQWHQVLW\ OHYHOV RI )R )L ) DQG ) IRU YRZHO OLO SURGXFHG E\ WKH PDOH DQG IHPDOH WDONHUV XQGHU GLIIHUHQW UHFRUGLQJ FRQGLWLRQV 7KHVH GDWD DUH DOVR GLVSOD\HG LQ )LJXUH 9RZHO OLO KDV D ORZ ) IUHTXHQF\ +] IRU WKH PDOH VSHDNHU DQG +] IRU IHPDOHf DQG D KLJK ) IUHTXHQF\ +] IRU PDOH DQG +] IRU IHPDOHf DV ZHOO DV D KLJK ) IUHTXHQF\ +] IRU PDOH DQG ),] IRU IHPDOHf )URP DQ LQVSHFWLRQ RI )LJXUH D JHQHUDO WUDQVPLVVLRQ SDWWHUQ IRU YRZHO ,,, FDQ EH GUDZQ ,Q WKH DLU UHFRUGLQJ FRQGLWLRQ )R )L ) DQG ) ZHUH ZHOO LGHQWLILHG IRU ERWK PDOH DQG IHPDOH WDONHUV )RU WKH

PAGE 140

7DEOH $YHUDJH IXQGDPHQWDO IUHTXHQFLHV )Rf DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )L ) )f IRU ILYH YRZHOV SURGXFHG E\ HDFK WDONHU DQG UHFRUGHG LQ DLU 7KH VHFRQG URZ LQFOXGHV WKH YDOXH IURP 3HWHUVRQ DQG %DUQH\ f 7KH WKLUG URZ LV IURP +LOOHQEUDQG HW DO f L LX V DV )R 0DOH f f )HPDOH f f ) 0DOH f f )HPDOH f f ) 0DOH f f )HPDOH f f I 0DOH f f )HPDOH f f

PAGE 141

7DEOH 0HDQ DQG VWDQGDUG GHYLDWLRQ 6'f RI UHODWLYH LQWHQVLW\ OHYHOV G%f RI IXQGDPHQWDO IUHTXHQF\ )Rf DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )L ) )f IRU YRZHO ,nOO SURGXFHG E\ HDFK WDONHU DW GLIIHUHQW UHFRUGLQJ ORFDWLRQV LQ WKH G% FRQGLWLRQ 0DOH &RQGLWLRQ DONHU ,,, ,Q $LU ,Q 8WHUXV &0H[ WHUR &0P WHUR )R 0HDQ 6' )L 0HDQ 6' I 0HDQ 6' I 0HDQ 6' )HPDOH WDONHU ,,, )R 0HDQ 6' )L 0HDQ 6' I 0HDQ 6' I 0HDQ 6'

PAGE 142

)LJXUH 0HDQ RI LQWHQVLW\ OHYHOV G% UHODWLYHf RI IXQGDPHQWDO IUHTXHQF\ )Rf DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )L ) DQG )f IRU YRZHO ,,, SURGXFHG E\ ERWK WDONHUV UHFRUGHG DW GLIIHUHQW ORFDWLRQV DW G% 63/ %DUV HTXDO RQH VWDQGDUG GHYLDWLRQ 0DOH WDONHU UHVXOWV XSSHU SDQHO IHPDOH WDONHU UHVXOWV ORZHU SDQHO

PAGE 143

G% 5HODWLYHf G% 5HODWLYHf )250$17 )250$17

PAGE 144

IHPDOH WKH LQWHQVLW\ OHYHOV RI ) DQG ) ZHUH G% KLJKHU WKDQ WKDW RI PDOH +RZHYHU )L RI WKH PDOH WDONHU ZDV G% JUHDWHU WKDQ WKDW RI WKH IHPDOH 1RZ FRQVLGHULQJ WKH OHYHOV LQ WKH XWHUXV )R )L ) DQG ) ZHUH ZHOO UHSUHVHQWHG IRU ERWK WDONHUV ZLWK WKH H[FHSWLRQ WKDW ) IRU WKH PDOH WDONHU ZDV RQO\ DERXW G% DERYH QRLVH IORRU 7KH GURS LQ OHYHOV DV D IXQFWLRQ RI IRUPDQW IUHTXHQF\ LV SUHGLFWHG EDVHG XSRQ WUDQVPLVVLRQ ORVV DW KLJKHU IUHTXHQFLHV )URP &0 H[ XOHUR DQG LQ 8WHUR UHFRUGLQJV )R DQG ) IRU PDOH DQG )R RQO\ IRU IHPDOH ZHUH SUHVHUYHG ) DQG ) )L DOVR IRU IHPDOHf PHUJHG LQ WKH EDFNJURXQG QRLVH ,W ZDV DOVR QRWHG WKDW WKH LQWHQVLW\ OHYHO RI )R IURP &0 LQ XOHUR ZDV JUHDWHU WKDQ WKDW IURP &0 H[ WHUR IRU ERWK WDONHUV HVSHFLDOO\ IRU WKH PDOH WDONHU 7KH H[SODQDWLRQ LV WKDW ORZ IUHTXHQF\ VLJQDOV OHVV WKDQ +] )R ZHUH +] IRU WKH PDOH WDONHU DQG +] IRU IHPDOHf ZRXOG EH HQKDQFHG ZKHQ WUDQVPLWWHG LQWR WKH XWHUXV 9LQFH HW DO *HUKDUGW $EUDPV DQG 2OLYHU f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

PAGE 145

7ZR VHSDUDWH WZRIDFWRU UHSHDWHG PHDVXUHV $129$ ZHUH DSSOLHG WR WKH GDWD GHULYHG IURP YRZHO L DFFRUGLQJ WR WKH WDONHU JHQGHU )RU WKH PDOH WDONHU WKH UHVXOWV LQGLFDWHG VLJQLILFDQW LQWHUDFWLRQ EHWZHHQ IRUPDQW )R )L ) DQG )f DQG UHFRUGLQJ ORFDWLRQ ) S f PDLQ HIIHFWV IRU IRUPDQW ) S f DQG ORFDWLRQ ) S f 7KH SRVW KRF PXOWLSOH FRPSDULVRQ WHVW 1HZPDQ .HXOVf LQGLFDWHG WKDW WKH LQWHQVLW\ OHYHOV RI )R )L ) DQG ) PHDVXUHG LQ DLU FRQGLWLRQ ZHUH VLJQLILFDQWO\ JUHDWHU S f WKDQ WKRVH UHFRUGHG LQ WKH XWHUXV IURP &0 H[ XOHUR DQG IURP &0 LQ WHUR H[FHSW WKDW RI )R PHDVXUHG LQ WKH XWHUXV S f ,Q WKH XWHUXV FRQGLWLRQ WKH LQWHQVLW\ OHYHOV RI )R DQG )L ZHUH JUHDWHU S IRU )L IURP &0 H[ WHUR S f WKDQ WKDW IURP &0 H[ WHUR DQG IURP &0 LQ WHUR EXW QRW ) DQG ) S f ,Q WKH &0 FRQGLWLRQV RQO\ )R IURP &0 H[ WHUR ZDV VLJQLILFDQWO\ GLIIHUHQW S f IURP &0 LQ WHUR WKHUH ZHUH QR GLIIHUHQFH S f IRU WKH ILUVW WKUHH IRUPDQW IUHTXHQFLHV )RU WKH IHPDOH WDONHU WKH UHVXOWV LQGLFDWHG VLJQLILFDQW LQWHUDFWLRQ EHWZHHQ IRUPDQW )R )L ) DQG )f DQG UHFRUGLQJ ORFDWLRQ )A S f PDLQ HIIHFWV IRU IRUPDQW ) S f DQG ORFDWLRQ ) S f 7KH SRVW KRF PXOWLSOH FRPSDULVRQ WHVW 1HZPDQ.HXOVf LQGLFDWHG WKDW WKH LQWHQVLW\ OHYHOV RI )R )L ) DQG ) PHDVXUHG LQ DLU FRQGLWLRQ ZHUH VLJQLILFDQWO\ JUHDWHU S f WKDQ WKRVH UHFRUGHG LQ WKH XWHUXV IURP &0 H[ WHUR DQG IURP &0 LQ WHUR H[FHSW WKDW RI )PHDVXUHG LQ WKH XWHUXV S f ,Q WKH XWHUXV UHFRUGLQJ FRQGLWLRQ WKH LQWHQVLW\ OHYHOV RI )R )_ ) DQG ) ZHUH JUHDWHU S f WKDQ WKDW IURP &0 H[ WHUR DQG IURP &0 LQ WHUR &RPSDULQJ FRQGLWLRQV RI &0 H[ WHUR DQG &0 LQ WHUR WKHUH ZHUH QR GLIIHUHQFH S f IRU WKH LQWHQVLW\ OHYHOV RI WKH IXQGDPHQWDO IUHTXHQF\ DQG WKH ILUVW WKUHH IRUPDQW IUHTXHQFLHV

PAGE 146

7KH H[SODQDWLRQ IRU WKH ODFN RI VLJQLILFDQW GLIIHUHQFHV LV EHFDXVH PRVW OHYHOV IRU ) DQG ) ZHUH LQGLVWLQJXLVKDEOH IURP WKH QRLVH IORRU 7DEOH FRQWDLQV WKH PHDQV DQG VWDQGDUG GHYLDWLRQV RI UHODWLYH LQWHQVLW\ OHYHOV RI )R )L ) DQG ) UHFRUGHG LQ GLIIHUHQW ORFDWLRQV IRU WKH YRZHO +SURGXFHG E\ WKH PDOH DQG IHPDOH WDONHUV 7KH GDWD DUH DOVR GLVSOD\HG LQ )LJXUH 9RZHO VLPLODU WR YRZHO L KDV D ORZ ) IUHTXHQF\ +] IRU WKH PDOH VSHDNHU DQG +] IRU IHPDOHf DQG D KLJK ) IUHTXHQF\ +] IRU PDOH DQG +] IRU IHPDOHf DV ZHOO DV D KLJK ) IUHTXHQF\ +] IRU PDOH DQG +] IRU IHPDOHf IDLUO\ FORVH WR ) IUHTXHQF\ 7KH UHVXOWV IURP VSHFWUDO DQDO\VHV DQG VWDWLVWLFDO DQDO\VHV $129$f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f DQG D UHODWLYH ORZ ) IUHTXHQF\ +] IRU PDOH DQG +] IRU IHPDOHf DV ZHOO DV D KLJK ) IUHTXHQF\ +] IRU PDOH DQG +] IRU IHPDOHf )URP DQ LQVSHFWLRQ RI )LJXUH D JHQHUDO FKDUDFWHULVWLF RI WUDQVPLVVLRQ IRU WKH YRZHO OHL FDQ EH GHULYHG ,Q WKH DLU UHFRUGLQJ FRQGLWLRQ )R )_ ) DQG ) ZHUH ZHOO LGHQWLILHG IRU ERWK PDOH DQG IHPDOH WDONHUV DQG IRU WKH IHPDOH WKH LQWHQVLW\ OHYHOV RI ) DQG ) ZHUH DERXW G% DQG G% KLJKHU WKDQ WKDW RI

PAGE 147

7DEOH 0HDQ DQG VWDQGDUG GHYLDWLRQ 6'f RI UHODWLYH LQWHQVLW\ OHYHOV G%f RI IXQGDPHQWDO IUHTXHQF\ )f DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )L ) )f IRU YRZHO SURGXFHG E\ HDFK WDONHU DW GLIIHUHQW UHFRUGLQJ ORFDWLRQV LQ WKH G% FRQGLWLRQ 0DOH &RQGLWLRQ WDONHU +, ,Q $LU ,Q 8WHUXV &0H[ WHUR &0LQ WHUR )R 0HDQ 6' ) 0HDQ 6' I 0HDQ 6' I 0HDQ 6' )HPDOH WDONHU ,,, )R 0HDQ 6' ) 0HDQ 6' I 0HDQ 6' )M 0HDQ 6'

PAGE 148

)LJXUH 0HDQ RI LQWHQVLW\ OHYHOV G% UHODWLYHf RI IXQGDPHQWDO IUHTXHQF\ )Rf DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )L ) DQG )f IRU YRZHO SURGXFHG E\ ERWK WDONHUV UHFRUGHG DW GLIIHUHQW ORFDWLRQV DW G% 63/ %DUV HTXDO RQH VWDQGDUG GHYLDWLRQ 0DOH WDONHU UHVXOWV XSSHU SDQHO IHPDOH WDONHU UHVXOWV ORZHU SDQHO

PAGE 149

G% 5HODWLYHf G% 5HODWLYHf )250$17 )250$17

PAGE 150

7DEOH 0HDQ DQG VWDQGDUG GHYLDWLRQ 6'f RI UHODWLYH LQWHQVLW\ OHYHOV G%f RI IXQGDPHQWDO IUHTXHQF\ )Rf DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )L ) )f IRU YRZHO H SURGXFHG E\ HDFK WDONHU DW GLIIHUHQW UHFRUGLQJ ORFDWLRQV LQ WKH G% FRQGLWLRQ 0DOH &RQGLWLRQ WDONHU H ,Q $LU ,Q 8WHUXV &0H[ WHUR &0Q WHUR )R 0HDQ 6' ) 0HDQ 6' I 0HDQ 6' )M 0HDQ 6' )HPDOH WDONHU H )R 0HDQ 6' ) 0HDQ 6' I 0HDQ 6' I 0HDQ 6'

PAGE 151

)LJXUH 0HDQ RI LQWHQVLW\ OHYHOV G% UHODWLYHf RI IXQGDPHQWDO IUHTXHQF\ )Rf DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )L ) DQG )f IRU YRZHO ,( Hf SURGXFHG E\ ERWK WDONHUV UHFRUGHG DW GLIIHUHQW ORFDWLRQV DW G% 63/ %DUV HTXDO RQH VWDQGDUG GHYLDWLRQ 0DOH WDONHU UHVXOWV XSSHU SDQHO IHPDOH WDONHU UHVXOWV ORZHU SDQHO

PAGE 152

G% 5HODWLYHf G% 5HODWLYHf )250$17 )250$17

PAGE 153

WKH PDOH UHVSHFWLYHO\ 7KH IHPDOH WDONHUfV KLJKHU LQWHQVLW\ OHYHOV RI ) DQG ) WKDQ WKH PDOH LQ DLU UHVXOWHG LQ KLJKHU OHYHOV RI ) DQG ) PHDVXUHG LQ WKH XWHUXV DQG IHWDO LQQHU HDU ,Q WKH XWHUXV )R )L ) DQG ) ZHUH DOVR ZHOO UHFHLYHG IRU ERWK WDONHUV )URP &0 H[ WHUR UHFRUGLQJV )R )L DQG ) IRU ERWK WDONHUV ZHUH WUDQVPLWWHG LQWR WKH IHWDO LQQHU HDU EXW ) PHUJHG LQ WKH EDFNJURXQG QRLVH )URP &0 LQ WHUR UHFRUGLQJV )R )M DQG ) ZHUH SUHVHUYHG IRU WKH IHPDOH WDONHU EXW RQO\ )R DQG ) ZHUH UHFHLYHG IRU WKH PDOH WDONHU VLQFH ) ZDV FORVH WR WKH OHYHO RI EDFNJURXQG QRLVH 7KXV OH FRXOG EH HDVLO\ LGHQWLILHG LQ WKH XWHUXV UHFRUGLQJV IRU ERWK WDONHUV DQG FRXOG EH UHFRJQL]HG IURP &0 H[ WHUR EHFDXVH ) ZDV ZHOO SHUFHLYHG IRU ERWK WDONHUV )ORZHYHU LWV LGHQWLILFDWLRQ PLJKW EH PDGH IURP &0 LQ WHUR UHFRUGLQJV IRU WKH IHPDOH WDONHU EXW PLJKW QRW EH IRU WKH PDOH EHFDXVH ) ZDV QRW ZHOO SHUFHLYHG LQ WKH IHWDO LQQHU HDU LQ WHUR 7ZR VHSDUDWH WZRIDFWRU UHSHDWHG PHDVXUHV $129$ ZHUH DSSOLHG WR WKH GDWD IRU WKH YRZHO H IRU ERWK WKH PDOH DQG IHPDOH WDONHU )RU WKH PDOH WDONHU WKH UHVXOWV LQGLFDWHG VLJQLILFDQW LQWHUDFWLRQ EHWZHHQ IRUPDQW )R )L ) DQG )f DQG UHFRUGLQJ ORFDWLRQ )L S f PDLQ HIIHFWV IRU IRUPDQW )! S f DQG ORFDWLRQ )! S f 7KH SRVW KRF PXOWLSOH FRPSDULVRQ WHVW 1HZPDQ.HXOVf VKRZHG WKDW WKH LQWHQVLW\ OHYHOV RI )R )L ) DQG ) PHDVXUHG LQ DLU FRQGLWLRQ ZHUH VLJQLILFDQWO\ JUHDWHU S f WKDQ WKRVH UHFRUGHG LQ WKH XWHUXV IURP &0 H[ WHUR DQG IURP &0 LQ WHUR H[FHSW WKDW RI )R PHDVXUHG LQ WKH XWHUXV S f ,Q WKH XWHUXV FRQGLWLRQ WKH LQWHQVLW\ OHYHOV RI )R )L ) DQG ) ZHUH JUHDWHU S S IRU ) &0 H[ 8WHURf WKDQ WKDW IURP &0 H[ WHUR DQG IURP &0 LQ WHUR ,Q WKH &0 FRQGLWLRQV RQO\ ) S f DQG )L S f IURP &0 H[ WHUR ZHUH VLJQLILFDQWO\ GLIIHUHQW IURP &0 LQ WHUR

PAGE 154

)RU WKH IHPDOH WDONHU WKH UHVXOWV LQGLFDWHG VLJQLILFDQW LQWHUDFWLRQ EHWZHHQ IRUPDQW )R )L ) DQG )f DQG UHFRUGLQJ ORFDWLRQ ) S f PDLQ HIIHFWV IRU IRUPDQW A S f DQG ORFDWLRQ )A S f 7KH SRVW KRF PXOWLSOH FRPSDULVRQ WHVW 1HZPDQ.HXOVf LQGLFDWHG WKDW WKH LQWHQVLW\ OHYHOV RI )R )L ) DQG ) PHDVXUHG LQ DLU FRQGLWLRQ ZHUH VLJQLILFDQWO\ JUHDWHU S S IRU ) LQ WKH XWHUXVf WKDQ WKRVH UHFRUGHG LQ WKH XWHUXV IURP &0 H[ XOHUR DQG IURP &0 LQ WHUR EXW QRW WKDW RI )R DQG ) PHDVXUHG LQ WKH XWHUXV S f ,Q WKH XWHUXV UHFRUGLQJ FRQGLWLRQ WKH LQWHQVLW\ OHYHOV RI )R )_ ) DQG ) ZHUH JUHDWHU S f WKDQ WKDW IURP &0 H[ WHUR DQG IURP &0 LQ WHUR %HWZHHQ WKH FRQGLWLRQV RI &0 H[ WHUR DQG &0 LQ WHUR RQO\ )L S f DQG ) S f IURP &0 H[ WHUR ZHUH VLJQLILFDQWO\ GLIIHUHQW IURP &0 LQ WHUR 7DEOH FRQWDLQV WKH PHDQV DQG VWDQGDUG GHYLDWLRQV RI UHODWLYH LQWHQVLW\ OHYHOV RI )R )L ) DQG ) UHFRUGHG LQ GLIIHUHQW ORFDWLRQV IRU WKH YRZHO DV SURGXFHG E\ WKH PDOH DQG IHPDOH WDONHUV 7KH GDWD DUH DOVR JUDSKLFDOO\ GLVSOD\HG LQ )LJXUH )RU WKH YRZHO $ WKH GDWD DUH GLVSOD\HG LQ 7DEOH DQG )LJXUH 6LPLODU WR WKH YRZHO ,G YRZHOV DV DQG ,$KDYH KLJK ) IUHTXHQFLHV ORZ ) IUHTXHQFLHV +]f DQG KLJK ) IUHTXHQFLHV 7KH VSHFWUDO DQDO\VHV DQG VWDWLVWLFDO DQDO\VHV $129$f FOHDUO\ VKRZHG WKH VLPLODULWLHV RI FKDUDFWHULVWLFV RI WUDQVPLVVLRQ LQWR WKH XWHUXV DQG LQWR WKH IHWDO LQQHU HDU LQ 8WHUR DPRQJ WKH YRZHOV ,G DV DQG $ )RU ERWK YRZHO DV DQG $ LQ WKH XWHUXV UHFRUGLQJV )R )L ) DQG ) ZHUH ZHOO UHFHLYHG IRU ERWK WDONHUV )URP &0 H[ WHUR UHFRUGLQJV )R )L DQG ) IRU ERWK WDONHUV ZHUH WUDQVPLWWHG LQWR WKH IHWDO LQQHU HDU EXW ) ZDV FORVH WR WKH OHYHO RI EDFNJURXQG QRLVH )URP &0 LQ WHUR UHFRUGLQJV )R )L DQG ) RI WKH YRZHO DV ZHUH SUHVHUYHG IRU WKH IHPDOH WDONHU EXW RQO\ )R DQG ) ZHUH UHFHLYHG IRU WKH PDOH WDONHU VLQFH ) ZDV FORVH WR WKH OHYHO RI EDFNJURXQG QRLVH )RU WKH YRZHO$ )R )L DQG ) ZHUH SUHVHUYHG IRU ERWK WDONHUV

PAGE 155

7DEOH 0HDQ DQG VWDQGDUG GHYLDWLRQ 6'f RI UHODWLYH LQWHQVLW\ OHYHOV G%f RI IXQGDPHQWDO IUHTXHQF\ )Rf DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )L ) )f IRU YRZHO ,HHO SURGXFHG E\ HDFK WDONHU DW GLIIHUHQW UHFRUGLQJ ORFDWLRQV LQ WKH G% FRQGLWLRQ &RQGLWLRQ 0DOH WDONHU DV ,Q $LU ,Q 8WHUXV &0H[ WHUR &0LQ WHUR )R 0HDQ 6' )M 0HDQ 6' ) 0HDQ 6' ) 0HDQ 6' )HPDOH WDONHU DV )R 0HDQ 6' )L 0HDQ 6' ) 0HDQ 6' ) 0HDQ 6'

PAGE 156

)LJXUH 0HDQ RI LQWHQVLW\ OHYHOV G% UHODWLYHf RI IXQGDPHQWDO IUHTXHQF\ )Rf DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )L ) DQG )f IRU YRZHO r SURGXFHG E\ ERWK WDONHUV UHFRUGHG DW GLIIHUHQW ORFDWLRQV DW G% 63/ %DUV HTXDO RQH VWDQGDUG GHYLDWLRQ 0DOH WDONHU UHVXOWV XSSHU SDQHO IHPDOH WDONHU UHVXOWV ORZHU SDQHO

PAGE 157

G% 5HODWLYHf G% 5HODWLYHf )250$17 )250$17

PAGE 158

7DEOH 0HDQ DQG VWDQGDUG GHYLDWLRQ 6'f RI UHODWLYH LQWHQVLW\ OHYHOV G%f RI IXQGDPHQWDO IUHTXHQF\ )Rf DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )W ) )f IRU YRZHO $ SURGXFHG E\ HDFK WDONHU DW GLIIHUHQW UHFRUGLQJ ORFDWLRQV LQ WKH G% FRQGLWLRQ 0DOH &RQGLWLRQ WDONHU $ ,Q $LU ,Q 8WHUXV &0H[ WHUR &0LQ WHUR )R 0HDQ 6' )W 0HDQ 6' I 0HDQ 6' I 0HDQ 6' )HPDOH WDONHU $ )R 0HDQ 6' )W 0HDQ 6' I 0HDQ 6' I 0HDQ 6'

PAGE 159

)LJXUH 0HDQ RI LQWHQVLW\ OHYHOV G% UHODWLYHf RI IXQGDPHQWDO IUHTXHQF\ )Rf DQG ILUVW WKUHH IRUPDQW IUHTXHQFLHV )M ) DQG )f IRU YRZHO $ $f SURGXFHG E\ ERWK WDONHUV UHFRUGHG DW GLIIHUHQW ORFDWLRQV DW G% 63/ %DUV HTXDO RQH VWDQGDUG GHYLDWLRQ 0DOH WDONHU UHVXOWV XSSHU SDQHO IHPDOH WDONHU UHVXOWV ORZHU SDQHO

PAGE 160

G% 5HODWLYHf G% 5HODWLYHf )250$17 )250$17

PAGE 161

EXW ) ZDV RQO\ G% DERYH WKH OHYHO RI EDFNJURXQG QRLVH LQ WKH &0 LQ WHUR UHFRUGLQJ FRQGLWLRQ 7KXV DV DQG $ FRXOG EH ZHOO LGHQWLILHG LQ WKH XWHUXV UHFRUGLQJV IRU ERWK WDONHUV DQG DOVR FRXOG EH UHFRJQL]HG IURP &0 H[ WHUR EHFDXVH ) ZDV ZHOO SHUFHLYHG G% DERYH WKH QRLVH IORRUf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f )URP DLU WKURXJK WKH PDWHUQDO WLVVXHV DQG IOXLGV LQWR WKH XWHUXV VRXQGV DUH DWWHQXDWHG E\ G% LQ WKH ORZIUHTXHQF\ UDQJH +]f DQG G% IRU KLJKHU IUHTXHQFLHV +]f 7R UHDFK WKH IHWDO LQQHU HDU WKH VSHFWUDO FRQWHQWV RI DLUERUQH VRXQGV DUH IXUWKHU PRGLILHG E\ WKH ERQH FRQGXFWLRQ URXWH WKURXJK WKH IHWDO KHDG )RU ORZ IUHTXHQFLHV IURP WR +] DLUERUQH VRXQGV ZRXOG EH UHGXFHG E\ G% WR UHDFK WKH IHWDO LQQHU HDU )RU IUHTXHQFLHV IURP WR +] VRXQGV ZRXOG EH UHGXFHG E\ G% ,Q JHQHUDO ORZIUHTXHQF\

PAGE 162

7DEOH 6XPPDU\ RI DFRXVWLF DQDO\VHV RI YRZHOV $UWLFXODWLRQ )RUPDQW )UHTXHQF\ 6WLPXOXV 3UHVHQW DW ) 9RZHO 7RQJXH 3RVLWLRQ )L I ,Q 8WHUXV &0 LQ WHUR 1 )URQW +LJK /RZ +LJK
PAGE 163

FRPSRQHQWV RI H[WHUQDO VRXQGV DUH ZHOO SHUFHLYHG DW WKH OHYHO RI IHWDO LQQHU HDU ZKLOH KLJK IUHTXHQF\ FRPSRQHQWV DUH UHGXFHG WR D JUHDW GHJUHH EHIRUH UHDFKLQJ WKH IHWDO LQQHU HDU 7KH GDWD IURP WKH FXUUHQW VWXG\ FOHDUO\ VKRZHG WKDW WKH IXQGDPHQWDO IUHTXHQF\ )Rf DQG WKH ILUVW WKUHH IRUPDQWV )L ) DQG )f RI DOO ILYH YRZHOV ZHUH ZHOO SUHVHUYHG LQ WKH XWHUXV UHFRUGLQJV IRU ERWK WKH PDOH DQG IHPDOH WDONHUV 7KHVH UHVXOWV DUH FRQVLVWHQW ZLWK WKH KLJK LQWHOOLJLELOLW\ VFRUHV REWDLQHG LQ WKLV VWXG\ 4XHUOHX HW DO Ef DOVR IRXQG WKDW ) KDG FULWLFDO HIIHFW RQ WKH UHFRJQLWLRQ RI )UHQFK YRZHOV UHFRUGHG ZLWKLQ WKH XWHUXV 7KH DFRXVWLF FXHV QHFHVVDU\ IRU WKH SHUFHSWLRQ RI YRZHOV OLH LQ WKH SDWWHUQV RI IRUPDQWV 7KH ILUVW WZR ORZHVW IUHTXHQF\ IRUPDQWV DUH XVXDOO\ UHTXLUHG WR LGHQWLI\ WKH YRZHOV *HQHUDOO\ WZR IRUPDQWV DUH UHTXLUHG IRU IURQW YRZHOV ZKLFK KDYH D KLJK ) IUHTXHQF\ L V DQG DV $ LV D FHQWUDO YRZHOf $ VLQJOH IRUPDQW FDQ EH XVHG WR DSSUR[LPDWH WKH EDFN YRZHOV ZKLFK KDYH D ORZ ) IUHTXHQF\ X 8 R 2 DQG ODf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f ,Q WKH SUHVHQW VWXG\ WKH VSHFWUDO DQDO\VHV RI YRZHOV IURP WKH &0 UHFRUGLQJV LQGLFDWHG WKDW IXQGDPHQWDO IUHTXHQF\ )Rf DQG ORZIUHTXHQF\ IRUPDQWV ) DQG ) +]f ZHUH ZHOO SUHVHUYHG LQ WKH IHWDO LQQHU HDU LQ WHUR )RU YRZHOV L DQG +, WKDW KDYH KLJK IUHTXHQF\ VHFRQG IRUPDQWV ),]f RQO\ )R DQG ) ZHUH SHUFHLYHG LQ WKH UHFRUGLQJV

PAGE 164

IURP &0 LQ XOHUR :KHUHDV IRU YRZHOV OHL DV DQG $ WKDW KDYH ORZ IUHTXHQF\ VHFRQG IRUPDQWV +]f )R )L DQG ) ZHUH DOO SHUFHLYHG LQ WKH UHFRUGLQJV IURP &0 LQ WHUR 7KXV YRZHOV ^OHL DV DQG ,$f ZLWK ORZ IUHTXHQF\ VHFRQG IRUPDQWV +]f PLJKW EH HDVLO\ LGHQWLILHG IURP &0 LQ WHUR UHFRUGLQJV %HFDXVH ) RI DOO ILYH YRZHOV ZHUH KLJKHU WKDQ +] ) RIL LV HYHQ DERYH +]f WKH WKLUG IRUPDQWV ZHUH QRW SUHVHUYHG LQ WKH IHWDO LQQHU HDU LQ 8WHUR 7KH LGHQWLILFDWLRQ RI YRZHOV LQ WKH UHFRUGLQJV IURP &0 LQ WHUR IRU ERWK PDOH DQG IHPDOH VSHDNHUV PLJKW EH HDV\ EHFDXVH WKH\ DUH YRLFHG UHODWLYH KLJK LQ LQWHQVLW\ DQG KDYH SURPLQHQW IRUPDQW IUHTXHQFLHV

PAGE 165

&+$37(5 6800$5< $1' &21&/86,216 7KLV VWXG\ KDG WZR GLVWLQFW FRPSRQHQWV 7KH ILUVW LQYROYHG UHFRUGLQJ VSHHFK SURGXFHG WKURXJK D ORXGVSHDNHU ZLWK DQ DLU PLFURSKRQH D K\GURSKRQH SODFHG ,Q WKH XWHUXV RI D SUHJQDQW VKHHS DQG DQ HOHFWURGH VXUJLFDOO\ VHFXUHG WR WKH URXQG ZLQGRZ RI WKH IHWXV H[ WHUR DQG LQ WHUR FRFKOHDU PLFURSKRQLF &0f 7KH VSHHFK VWLPXOL FRQVLVWHG RI WZR VHSDUDWH OLVWV 9RZHO&RQVRQDQW9RZHO 9&9f QRQVHQVH V\OODEOHV DQG &RQVRQDQW 9RZHO &RQVRQDQW &9&f PRQRV\OODEOH ZRUGV VSRNHQ E\ D PDOH DQG D IHPDOH WDONHU 7KH\ ZHUH SUHVHQWHG DW WZR DLUERUQH LQWHQVLW\ OHYHOV DQG G% 63/ 3HUFHSWXDO DXGLR &'V ZHUH FRQVWUXFWHG IURP RQH UHFRUGLQJ ZLWK WKH EHVW TXDOLW\ VRXQG 7KH VHFRQG SRUWLRQ RI WKH VWXG\ LQYROYHG SOD\LQJ WKH UHFRUGLQJV WR D JURXS RI QRUPDO KHDULQJ DGXOWV 1 f RYHU HDUSKRQHV 7KH LQWHOOLJLELOLW\ RI VSHHFK ZDV HYDOXDWHG IURP WKH MXGJHVf UHVSRQVHV WR WKH VSHHFK VWLPXOL XQGHU GLIIHUHQW UHFRUGLQJ FRQGLWLRQV 7KH VSHHFK 9&9 QRQVHQVH V\OODEOHV DQG &9& ZRUGVf LQWHOOLJLELOLW\ VFRUHV DV D IXQFWLRQ RI UHFRUGLQJ ORFDWLRQ DORQH GHFUHDVHG IURP WKH DLU WR WKH XWHUXV ORFDWLRQV DQG IXUWKHU GHFUHDVHG IURP WKH &0 H[ WHUR WR WKH &0 LQ WHUR FRQGLWLRQV ,QWHOOLJLELOLW\ ZDV VLJQLILFDQWO\ KLJKHU IRU WKH UHFRUGLQJV LQ DLU WKDQ LQ WKH XWHUXV DQG VLJQLILFDQWO\ KLJKHU IRU WKH UHFRUGLQJV IURP &0 H[ WHUR WKDQ IURP &0 LQ WHUR ,Q DGGLWLRQ WKH LQWHOOLJLELOLW\ VFRUHV RI WKH PDOH YRLFH ZHUH VLJQLILFDQWO\ KLJKHU WKDQ WKDW RI WKH IHPDOH

PAGE 166

YRLFH DFURVV DOO IRXU UHFRUGLQJ ORFDWLRQV IRU 9&9 QRQVHQVH V\OODEOHV EXW QRW IRU &9& ZRUGV 7KH UHVXOWV DOVR VKRZHG VWLPXOXV OHYHO HIIHFW RQ WKH LQWHOOLJLELOLW\ 2YHUDOO ZKHQ WKH PHDQ LQWHOOLJLELOLW\ VFRUHV ZHUH DYHUDJHG DFURVV WZR VWLPXOXV OHYHOV DQG G% 63/f DQG VWLPXOXV W\SHV 9&9 DQG &9& VWLPXOLf WKH\ ZHUH b DQG b IRU WKH PDOH DQG IHPDOH YRLFHV UHFRUGHG ZLWKLQ WKH XWHUXV UHVSHFWLYHO\ :KHUHDV WKH PHDQ LQWHOOLJLELOLW\ VFRUHV UHFRUGHG IURP &0 LQ XOHUR DYHUDJHG DFURVV WZR OHYHOV DQG VWLPXOXV W\SHV IRU WKH PDOH DQG IHPDOH YRLFHV ZHUH b DQG b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f )RU IUHTXHQFLHV OHVV WKDQ +] H[WHUQDO VRXQG SDVVHV WKURXJK WKH XWHUXV WR WKH IHWXV ZLWK OLWWOH UHGXFWLRQ LQ VRXQG SUHVVXUH DQG LQ VRPH LQVWDQFHV WKH SUHVVXUH LV JUHDWHU ZLWKLQ WKH XWHUXV WKDQ LW LV RXWVLGH WKH DEGRPHQ $ERYH +] VRXQG SUHVVXUH DWWHQXDWLRQ RFFXUV DW D UDWH RI DSSUR[LPDWHO\ G% SHU RFWDYH DQG UHDFKHV DERXW G% IRU +] *HUKDUGW $EUDPV DQG 2OLYHU f 7KXV H[WHUQDO VSHHFK VLJQDOV ZRXOG EH VKDSHG E\ WKH WLVVXHV DQG IOXLGV RI SUHJQDQF\ EHIRUH UHDFKLQJ WKH IHWDO KHDG 0RUHRYHU VRXQG WUDQVPLVVLRQ SURSHUWLHV WKURXJK WKH IHWDO KHDG WR WKH LQQHU HDU E\ ERQH FRQGXFWLRQ IXUWKHU PRGLILHG WKH VWLPXOXV *HUKDUGW HW DO *HUKDUGW HW DO f 7KLV LQIOXHQFH FRXSOHG WR WKH DWWHQXDWLRQ RI VRXQG SUHVVXUHV SURYLGHG E\ WKH WLVVXHV DQG IOXLGV RI SUHJQDQF\ UHVXOW LQ

PAGE 167

VRPH LVRODWLRQ RI WKH IHWXV IURP H[WHUQDO VRXQGV )HWDO VKHHS SUREDEO\ GHWHFW ORZ IUHTXHQF\ VRXQG SURGXFHG RXWVLGH LWV PRWKHU ZLWK D ORVV RI WR G% IRU DQG +] UHVSHFWLYHO\ )RU IUHTXHQFLHV IURP WR +] WKH IHWXV LV LVRODWHG E\ G% *HUKDUGW HW DO f 7KHUHIRUH WKH UHFRUGLQJV RI H[WHUQDO VSHHFK IURP &0 LQ WHUR ZRXOG EH GHJUDGHG WR D JUHDWHU GHJUHH IRU WKH KLJKIUHTXHQF\ FRPSRQHQWV RI VSHHFK UDWKHU WKDQ WKH ORZIUHTXHQF\ FRPSRQHQWV ,QWHOOLJLELOLW\ ZRXOG EH H[SHFWHG WR IROORZ 7KH SUHVHQW ILQGLQJV VKRZHG PXFK EHWWHU LQWHOOLJLELOLW\ RI VSHHFK UHFRUGHG ZLWKLQ WKH XWHUXV WKDQ SUHYLRXVO\ IRXQG 4XHUOHX HW DO E *ULIILWKV HW DO f 4XHUOHX HW DO Ef IRXQG WKDW DERXW b RI )UHQFK SKRQHPHV UHFRUGHG ZLWKLQ WKH XWHUXV RI SUHJQDQW ZRPHQ ZHUH UHFRJQL]HG *ULIILWKV HW DO f VKRZHG WKH LQWHOOLJLELOLW\ RI VSHHFK VWLPXOL UHFRUGHG ZLWKLQ WKH XWHUXV RI D SUHJQDQW VKHHS ZDV b DQG b IRU WKH PDOH DQG IHPDOH WDONHUV UHVSHFWLYHO\ +RZHYHU IURP WKH FXUUHQW VWXG\ WKH LQWHOOLJLELOLW\ ZDV b DQG b IRU WKH PDOH DQG IHPDOH YRLFHV UHFRUGHG LQ WKH XWHUXV UHVSHFWLYHO\ 7KH GLVFUHSDQF\ PLJKW EH DFFRXQWHG IRU E\ WKH KLJKHU VWLPXOXV OHYHOV DQG WKH XVH RI HDUSKRQHV &RQVRQDQW IHDWXUH WUDQVPLVVLRQ ZDV DQDO\]HG XVLQJ 6,1)$ 7KH UHVXOWV FRQILUPHG WKH ILQGLQJV WKDW YRLFLQJ LQIRUPDWLRQ LV ZHOO UHWDLQHG LQVLGH WKH XWHUXV *ULIILWKV HW DO f )XUWKHUPRUH WKH SUHVHQW VWXG\ GHPRQVWUDWHG WKDW YRLFLQJ LQIRUPDWLRQ LV DOVR DFFXUDWHO\ UHSUHVHQWHG LQ WKH IHWDO LQQHU HDU &0 UHFRUGLQJVf LQ WHUR 0DQQHU DQG SODFH LQIRUPDWLRQ ZHUH QRW PDLQWDLQHG DV ZHOO DV YRLFLQJ LQIRUPDWLRQ DW WKH IHWDO LQQHU HDU 7KHVH UHVXOWV DUH FRQVLVWHQW ZLWK WKRVH RI 0LOOHU DQG 1LFHO\ f DQG :DQJ HW DO f LQ ZKLFK ORZSDVV ILOWHULQJ RI VSHHFK VLJQDOV UHVXOWHG LQ D JUHDWHU ORVV RI PDQQHU DQG SODFH LQIRUPDWLRQ WKDQ RI YRLFLQJ LQIRUPDWLRQ 7KH\ FRQFOXGHG WKDW WKH

PAGE 168

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f DQG WKH ILUVW WKUHH IRUPDQWV )L ) DQG )f RI DOO ILYH YRZHOV ,,, +, OHL V $f ZHUH ZHOO SUHVHUYHG LQ WKH XWHUXV UHFRUGLQJV IRU ERWK WKH PDOH DQG IHPDOH WDONHUV 7KH\ ZHUH DOVR UHIOHFWHG LQ WKH UHVXOWV RI KLJK LQWHOOLJLELOLW\ VFRUHV REWDLQHG LQ WKLV VWXG\ 4XHUOHX HW DO Ef QRWHG WKDW ) KDG D FULWLFDO HIIHFW RQ WKH UHFRJQLWLRQ RI )UHQFK YRZHOV UHFRUGHG ZLWKLQ WKH XWHUXV ,W LV ZHOO NQRZQ WKDW WKH DFRXVWLF FXHV QHFHVVDU\ IRU WKH LGHQWLILFDWLRQ RI YRZHOV OLH LQ WKH SDWWHUQV RI WKH IRUPDQWV 7KH ILUVW WZR ORZHVW IUHTXHQF\ IRUPDQWV ) DQG )f DUH XVXDOO\ UHTXLUHG WR LGHQWLI\ WKH YRZHOV *HQHUDOO\ WZR IRUPDQWV DUH UHTXLUHG IRU IURQW YRZHOV ZKLFK KDYH D KLJK ) IUHTXHQF\ L 8 OHL DQG DH $ LV D FHQWUDO YRZHOf D VLQJOH IRUPDQW )Lf FDQ EH XVHG WR DSSUR[LPDWH WKH EDFN YRZHOV ZKLFK KDYH D ORZ ) IUHTXHQF\ $L ,8 OR ,2, DQG Df ) LV PRUH LPSRUWDQW IRU IURQW YRZHOV WKDQ IRU EDFN YRZHOV %RUGHQ DQG +DUULV f 7KH GDWD IURP WKH &0 UHFRUGLQJV LQGLFDWHG WKDW IXQGDPHQWDO IUHTXHQF\ )Rf DQG ORZIUHTXHQF\ IRUPDQWV )L DQG ) +]f ZHUH ZHOO UHSUHVHQWHG LQ WKH IHWDO LQQHU HDU LQ WHUR )RU YRZHOV L DQG + WKDW KDYH KLJKIUHTXHQF\ ) +]f RQO\ )R DQG ) ZHUH SHUFHLYHG LQ UHFRUGLQJV IURP &0 LQ WHUR ZKHUHDV IRU YRZHOV OHL DH DQG ,$, WKDW

PAGE 169

KDYH ORZIUHTXHQF\ ) +]f )R )L DQG ) ZHUH DOO SHUFHLYHG LQ UHFRUGLQJ IURP &0 LQ XOHUR 7KXV YRZHOV V DV DQG $f ZLWK ORZIUHTXHQF\ ) +]f PLJKW EH HDV\ LGHQWLILHG IURP &0 LQ WHUR UHFRUGLQJV %HFDXVH ) RI DOO ILYH YRZHOV ZHUH KLJKHU WKDQ +] ) RI L LV HYHQ DERYH +]f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b DQG b UHVSHFWLYHO\ ZKHQ UHFRUGHG IURP WKH IHWDO &0 LQ WHUR 7KH\ UHSUHVHQW WKH VSHHFK HQHUJLHV UHFHLYHG E\ WKH IHWDO LQQHU HDU LQ WHUR ZKLFK DUH XQGHUHVWLPDWHG E\ XVLQJ URXQG ZLQGRZ HOHFWURGH SODFHPHQWV 7KH LPSOLFDWLRQV RI WKLV UHVHDUFK UHODWH WR WKHRULHV UHJDUGLQJ WKH SUHQDWDO IXQFWLRQDO GHYHORSPHQW RI DXGLWRU\ SDWKZD\V DQG WR WKH IRXQGDWLRQV IRU WKH ODWHU DFTXLVLWLRQ RI VSHHFK DQG ODQJXDJH &RRSHU DQG $VOLQ 4XHUOHX HW DO 5XEHQ $EUDPV *HUKDUGW DQG $QWRQHOOL f ,W KDV EHHQ SRVWXODWHG WKDW SUHQDWDO VHQVRU\ DQG OHDUQLQJ H[SHULHQFHV KHOS WR RUJDQL]H KLJKHU FRUWLFDO IXQFWLRQ DQG SURYLGH WKH IRXQGDWLRQ IRU IXWXUH OHDUQLQJ DELOLWLHV )LIHU DQG 0RRQ +HSSHU 6PRWKHUPDQ DQG 5RELQVRQ f :KHQ GLVFXVVLQJ WKH FRQFHSW RI LQQDWH DELOLWLHV RQH VKRXOG WDNH LQWR DFFRXQW WKH IDFW WKDW D QHRQDWH LV QRW ZLWKRXW H[SHULHQFH ZLWK VSHHFK VWLPXOL

PAGE 170

$33(1',; $ 68%-(&7 5(63216( 6+((7 9&9 1RQVHQVH 6\OODEOHV DBEBD DSD D G DO DBWD D J D DBNBD ODIMDO DBYBD DBVBD DB]D ODP D DBQBD DB6D DW6 D &9& :RUGV EDVV ORVV ZLFN GXII EDWFK ODZV ZLWK GXWK EDGJH ORGJH ZLW GXPE EDW ORJ ZLJ GRYH EDVK ORQJ ZLWFK GXE EDFN ORE ZLOO GXJ FXS GLP GXQJ ILW FXE GLG GXY ILE FXG GLOO GXJ ILJ FRPH GLS GXG ILOO FXII GLJ GXQ ILQ FXW GLQ GXE IL]] OHDVK WRVV ODJ PDQ OHDYH WDONV ODVK PDW OLHJH WDOO ODWK PDG OHDFK WRJ ODFN PDFN OHDG WRQJ ODVV PDVV OHDS WDM ODXJK PDWK

PAGE 171

EDVH SDQ SHDFK SLWFK ED\V SDVV SHDV SLS ED\HG SDFN SHDO SLJ EHLJH SDWK SHDW SLFN EDNH SDG SHDN SLOO EDWKH SDW SHDFH SLW SXV KDV ZHDYH VDVK SXWW KDJ ZHDQ VDFN SXII KDYH ZHHN VDG SXFN KDOI ZHHG VDS (0( KDWK ZHnUH VDJ SXE KDVK ZHDO VDW VKHDWK VLQ VXG WDP VKHDYH VLOO VXS WDJ VKHDI VLS VXE WDS VKHLN VLFN VXP WDQJ VKHDWKH VLQJ VXQ WDQ VKHHQ VLW VXQJ WDE WHDU UHG VROG ZLJ WHHWK ZHG KROG ULJ WHHWKH GHDG FROG JLJ WHHO OHG WROG ELJ WHDVH VKHG JROG 3LJ WHDP IHG PROG GLJ WKLFN WLQ PDUN WDOH FKLFN NLQ SDUN JDOH NLFN ILQ GDUN PDOH OLFN VKLQ EDUN EDOH VLFN WKLQ ODUN SDOH SLFN SLQ VKDUN UDLO IHHO WLOO SHDO VDPH HHO NLOO ]HDO WDPH SHHO KLOO IHHO VKDPH NHHO PLOO UHHO JDPH UHHO ZLOO YHDO ODPH KHHO ELOO VHDO FDPH

PAGE 172

WKHQ ILQ FKLQ ]HH WHQ ZLQ JLQ WKHH IHQ SLQ WLQ GHH KHQ GLQ VLQ NQHH GHQ VLQ VKLQ VHH SHQ WLQ WKLQ OHH WHQW ULS VKRS YRUH SHQW OLS SRS IRU EHQW FKLS WRS JRUH GHQW WLS ORS ZRUH UHQW GLS FRS URDU ZHQW KLS KRS ORUH ILH GLS QHVW UXVW WK\ ]LS ZHVW JXVW YLH J\S EHVW EXVW OLH VKLS UHVW OXVW WKLJK QLS MHVW MXVW KLJK OLS YHVW GXVW UDW PD\ PDW WKH\ EDW JD\ YDW ED\ IDW QD\ WKDW ZDY

PAGE 173

$33(1',; % 5$: '$7$ )520 68%-(&7 5(63216( )2506 7KH IROORZLQJ WDEOHV FRQWDLQ WKH LQGLYLGXDO UHVSRQVHV QXPEHU RI FRUUHFW UHVSRQVHVf WR 9&9 $f DQG &9& %f VWLPXOL XQGHU UHFRUGLQJ FRQGLWLRQV /HWWHU &RGHV $ ,Q $LU 8 ,Q 8WHUXV ; &0H[ XOHUR &0LQ WHUR 0 0DOH ) )HPDOH + G% / G%

PAGE 174

$ 9&9 1RQVHQVH 6\OODEOHV &RQGLWLRQV 6XEMHFWV $0+ $0/ 80+ 80/ ;0+ ;0/ ,0+ ,0/ $)+ $)/ 8)+ 8)/ ;)+ ;)/ ,)+ ,)/

PAGE 175

&RQGLWLRQV 6XEMHFWV $0+ $0/ 80+ 80/ ;0+ ;0/ ,0+ ,0/ $)+ $)/ 8)+ 8)/ ;)+ ;)/ )+ ,)/

PAGE 176

EMH 7 % &9& :RUGV &RQGLWLRQV $0+ $0/ 80+ 80/ ;0+ ;0/ ,0+ ,0/ $)+ $)/ 8)+ 8)/ ;)+

PAGE 177

7HVW &RQGLWLRQV 6XEMHFWV $0+ $0/ 80+ 80/ ;0+ ;0/ ,0+ ,0/ $)+ $)/ 8)+ 8)/ ;)+ ;)/ ,)+ ,)/

PAGE 178

W\H ,)/ &RQGLWLRQV $0+ $0/ 80+ 80/ ;0+ ;0/ ,0+ ,0/ $)+ $)/ 8)+ 8)/ ;)+ ;)/

PAGE 179

EMH 7 &RQGLWLRQV $0+ $0/ 80+ 80/ ;0+ ;0/ ,0+ ,0/ $)+ $)/ 8)+ 8)/ ;)+ ;)/

PAGE 180

7HVW 6XEMHFWV &RQGLWLRQV $0+ $0/ 80+ 80/ ;0+ ;0/ ,0+ ,0/ $)+ $)/ 8)+ 8)/ ;)+ ;)/ ,)+ ,)/

PAGE 181

$33(1',; & 5$: '$7$ )520 $&2867,& $1$/<6(6 2) 92:(/6 7KH IROORZLQJ WDEOHV FRQWDLQ WKH YDOXHV RI VSHFWUDO DQDO\VHV RI YRZHOV XQGHU GLIIHUHQW UHFRUGLQJ ORFDWLRQV IRU PDOH DQG IHPDOH VSHDNHUV $ ,Q DLU % ,Q WKH XWHUXV & &0H[ WHURn &0LQ WHUR

PAGE 182

$ ,Q $LU 0DOH )RUPDQW +]f 6WLPXOXV /HYHO G%f 1RLVH /HYHO G%f 5HODWLYH G% 9RZHO :RUG ) ) I I )R ) I I )R ) I I ) ) I I 1 OHDYH SHDN VKHHQ WHHWKH SHHO 9 ZLJ GLJ ILOO SLFN VLQJ OHL OHG WHQ UHQW QHVW cHO EDW ODVK PDW SDVV KDWK GXPE FXII GXQ SXS VXG f}M R

PAGE 183

)HPDOH )RUPDQW )O]f 6WLPXOXV /HYHO G%f 1RLVH /HYHO G%f 5HODWLYH G% 9RZHO :RUG )R ) I ) )f ) I I ) ) I I )R ) I I c OHDYH SHDN VKHHQ WHHWKH SHHO L ZLJ GLJ ILOO SLFN VLQJ V OHG WHQ UHQW QHVW DH EDW ODVK PDW SDVV KDWK $ GXPE FXII GXQ SXS VXG

PAGE 184

% ,Q 8WHUXV 0DOH )RUPDQW +]f 6WLPXOXV /HYHO G%f 1RLVH /HYHO G%f 5HODWLYH G% 9RZHO :RUG ) ) I I )f ) I ) ) ) I I ) ) I I ,,, OHDYH SHDN VKHHQ WHHWKH SHHO P ZLJ GLJ ILOO SLFN VLQJ H OHG WHQ UHQW QHVW DG EDW ODVK PDW SDVV KDWK ,$, GXPE FXII GXQ SXS VXG

PAGE 185

)HPDOH )RUPDQW +]f 6WLPXOXV /HYHO G%f 1RLVH /HYHO G%f 5HODWLYH G% 9RZHO :RUG ) ) I ) ) ) I I ) ) I I ) ) I I OLW OHDYH SHDN VKHHQ WHHWKH SHHO P ZLJ GLJ ILOO SLFN VLQJ V OHG WHQ UHQW QHVW DV EDW ODVK PDW SDVV KDWK $GXPE FXII GXQ SXS VXG

PAGE 186

Be!B & &0H[ WHUR )RUPDQW +]f 6WLPXOXV /HYHO G%f 1RLVH /HYHO G%f 5HODWLYH G% ) I I )f ) I I )f ) I I )f ) I I E

PAGE 187

)HPDOH )RUPDQW ),]f 6WLPXOXV /HYHO G%f 1RLVH /HYHO G%f 5HODWLYH G% 9RZHO :RUG )f ) I ) )R ) I I )R ) I I )f ) I I L OHDYH SHDN VKHHQ WHHWKH SHHO 9 ZLJ GLJ ILOO SLFN VLQJ ,V OHG WHQ UHQW QHVW DH EDW ODVK PDW SDVV KDWK $ GXPE FXII GXQ SXS VXG

PAGE 188

' &0 LQ WHUR 0DOH )RUPDQW +]f 6WLPXOXV /HYHO G%f 1RLVH /HYHO G%f 5HODWLYH G% 9RZHO :RUG )f ) I ) )R ) I I ) ) I I ) ) I I P OHDYH SHDN VKHHQ WHHWKH SHHO WY ZLJ GLJ ILOO SLFN VLQJ H OHG WHQ UHQW QHVW DH EDW ODVK PDW SDVV KDWK $ GXPE FXII GXQ SXS VXG R 2V

PAGE 189

) )RUPDQW +]f 6WLPXOXV /HYHO G%f 1RLVH /HYHO G%f 5HODWLYH G% ) I I )f ) I I ) ) I I )f ) I I

PAGE 190

5()(5(1&(6 $EUDPV 5 0 *HUKDUGW t $QWRQHOOL 3 f )HWDO KHDULQJ 'HYHORSPHQWDO 3V\FKRELRORJ\ $EUDPV 5 0 *HUKDUGW *ULIILWKV 6 )OXDQJ ; t $QWRQHOOL 3 f ,QWUDXWHULQH VRXQG LQ VKHHS -RXUQDO RI 6RXQG DQG 9LEUDWLRQ $EUDPV 5 0f *ULIILWKV 6 )OXDQJ ; 6DLQ /DQJIRUG t *HUKDUGW f )HWDO PXVLF SHUFHSWLRQ WKH UROH RI VRXQG WUDQVPLVVLRQ 0XVLF 3HUFHSWLRQ $EUDPV 5 0 +XWFKLQVRQ $ $ 0F7LQHPDQ 0 t 0HUZLQ ( f (IIHFWV RI FRFKOHDU DEODWLRQ RQ ORFDO FHUHEUDO JOXFRVH XWLOL]DWLRQ LQ IHWDO VKHHS $PHULFDQ -RXUQDO RI 2EVWHWULFV DQG *\QHFRORJ\ $LMPDQG ( +DUULV 0 t 'DOORV 3 f 'HYHORSPHQWDO FKDQJHV LQ IUHTXHQF\ PDSSLQJ RI WKH JHUELO FRFKOHD FRPSDULVRQ RI WZR FRFKOHD ORFDWLRQV +HDULQJ 5HVHDUFK $UPLWDJH 6 ( %DOGZLQ % $ t 9LQFH 0 $ f 7KH IHWDO VRXQG HQYLURQPHQW RI VKHHS 6FLHQFH $VOLQ 5 1 f 9LVXDO DQG DXGLWRU\ GHYHORSPHQW LQ LQIDQF\ ,Q 2VRIVN\ (Gf +DQGERRN RI ,QIDQW 'HYHORSPHQW &QG (GLWLRQf 1HZ
PAGE 191

%HQ]DQTXHQ 6 *DJQRQ 5 +XQVH & t )RUHPDQ f 7KH LQWUDXWHULQH VRXQG HQYLURQPHQW RI WKH KXPDQ IHWXV GXULQJ ODERU $PHULFDQ -RXUQDO RI 2EVWHWULFV DQG *\QHFRORJ\ %HUJ : t %HUJ 0 f 3V\FKRSK\VLRORJLFDO GHYHORSPHQW LQ LQIDQF\ 6WDWH VWDUWOH DQG DWWHQWLRQ ,Q 2VRIVN\ (Gf +DQGERRN RI ,QIDQW 'HYHORSPHQW QG (GLWLRQf 1HZ
PAGE 192

'H&DVSHU $ t 6LJDIRRV $ f 7KH LQWUDXWHULQH KHDUWEHDW D SRWHQW UHLQIRUFHU IRU QHZERUQV ,QIDQW %HKDYLRU DQG 'HYHORSPHQW 'H&DVSHU $ t 6SHQFH 0 f 3UHQDWDO PDWHUQDO VSHHFK LQIOXHQFHV QHZERUQVf SHUFHSWLRQ RI VSHHFK VRXQGV ,QIDQW %HKDYLRU DQG 'HYHORSPHQW 'XQQ + t :KLWH 6 f 6WDWLVWLFDO PHDVXUHPHQWV RQ FRQYHUVDWLRQDO VSHHFK 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD (FKWHOHU 6 0 $LMPDQG ( t 'DOORV 3 f 'HYHORSPHQWDO DOWHUDWLRQV LQ WKH IUHTXHQF\ PDS RI WKH PDPPDOLDQ FRFKOHD 1DWXUH (JDQ 3 f $UWLFXODWLRQ WHVWLQJ PHWKRGV /DU\QJRVFRSH (LPDV 3 6LTXHODQG ( 5 -XVF]\N 3 t 9LJRULWR f 6SHHFK SHUFHSWLRQ LQ LQIDQWV 6FLHQFH )LIHU : 3 f 1HRQDWDO SUHIHUHQFH IRU PRWKHUfV YRLFH ,Q .UDVQHJRU 1 $ %ODVV ( 0 +RIHU 0 $ t 6PRWKHUPDQ : 3 (GVf 3HULQDWDO 'HYHORSPHQW $ 3VYFKRELRORJLFDO 3HUVSHFWLYH 2UODQGR )/ $FDGHPLF 3UHVV ,QF )ODUFRXUW %UDFH -RYDQRYLFK 3XEOLVKHUV )LIHU : 3 t 0RRQ & 0 f $XGLWRU\ H[SHULHQFH LQ WKH IHWXV ,Q 6PRWKHUPDQ : 3 t 5RELQVRQ 6 5 (GVf %HKDYLRU RI WKH )HWXV :HVW &ROGZHOO 17HOIRUG 3UHVV )LIHU : 3 t 0RRQ & 0 f 3V\FKRELRORJ\ RI QHZERUQ DXGLWRU\ SUHIHUHQFHV 6HPLQDUV LQ 3HULQDWRORJ\ )LIHU : 3 t 0RRQ & 0 f 7KH UROH RI PRWKHUfV YRLFH LQ WKH RUJDQL]DWLRQ RI EUDLQ IXQFWLRQ LQ WKH QHZERUQ $FWD 3DHGLDWU 6WRFNKROPf 6XSSO )LIHU : 3 t 0RRQ & 0 f 7KH HIIHFWV RI IHWDO H[SHULHQFH ZLWK VRXQG ,Q /HFDQXHW -3 )LIHU : 3 .UDVQHJRU 1 $ t 6PRWKHUPDQ : 3 (GVf )HWDO 'HYHORSPHQW $ 3VYFKRELRORJLFDO 3HUVSHFWLYH 1HZ -HUVH\ /DZUHQFH (UOEDXP $VVRFLDWHV ,QF )LWFK 5 + 0LOOHU 6 t 7DOODO 3 f 1HXURELRORJ\ RI VSHHFK SHUFHSWLRQ $QQXDO 5HYLHZ RI 1HXURVFLHQFH )OHWFKHU + f 6SHHFK DQG +HDULQJ LQ &RPPXQLFDWLRQ 1HZ
PAGE 193

)RZOHU & $ f /LVWHQHUV GR KHDU VRXQGV QRW WRQJXHV 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD )UHQFK 1 5 t 6WHLQEHUJ & f )DFWRUV JRYHUQLQJ WKH LQWHOOLJLELOLW\ RI VSHHFK VRXQG 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD *DJQRQ 5 %HQ]DTXHQ 6 t +XQVH & f 7KH IHWDO VRXQG HQYLURQPHQW GXULQJ YLEURDFRXVWLF VWLPXODWLRQ LQ ODERU HIIHFW RQ IHWDO KHDUW UDWH UHVSRQVH 2EVWHWULF t *\QHFRORJ\ *HOPDQ 6 5 :RRG 6 6SHOODF\ : 1 t $EUDPV 5 0 f )HWDO PRYHPHQWV LQ UHVSRQVH WR VRXQG VWLPXODWLRQ $PHULFDQ -RXUQDO RI 2EVWHWULFV DQG *\QHFRORJ\ *HUKDUGW f &KDUDFWHULVWLFV RI WKH IHWDO VKHHS VRXQG HQYLURQPHQW 6HPLQDUV LQ 3HULQDWRORJ\ *HUKDUGW f 3UHQDWDO DQG SHULQDWDO ULVNV RI KHDULQJ ORVV 6HPLQDUV LQ 3HULQDWRORJ\ -f *HUKDUGW t $EUDPV 5 0 f )HWDO KHDULQJ &KDUDFWHUL]DWLRQ RI WKH VWLPXOXV DQG UHVSRQVH 6HPLQDUV LQ 3HULQDWRORJ\ *HUKDUGW $EUDPV 5 0 t 2OLYHU & & f 6RXQG HQYLURQPHQW RI WKH IHWDO VKHHS $PHULFDQ -RXUQDO RI 2EVWHWULFV DQG *\QHFRORJ\ *HUKDUGW +XDQJ ; $UULQJWRQ ( 0HL[QHU $EUDPV 5 0 t $QWRQHOOL 3 f )HWDO VKHHS LQ XOHUR KHDU WKURXJK ERQH FRQGXFWLRQ $PHULFDQ -RXUQDO RI 2WRODU\QJRORJ\ *HUKDUGW 2WWR 5 $EUDPV 5 0 &ROLH %XUFKILHOG t 3HWHUV $ 0 f &RFKOHDU PLFURSKRQLFV UHFRUGHG IURP IHWDO DQG QHZERUQ VKHHS $PHULFDQ -RXUQDO RI 2WRODU\QJRORJ\ *ULIILWKV f 5K\PLQJ PLQLPDO FRQWUDVWV D VLPSOLILHG GLDJQRVWLF DUWLFXODWLRQ WHVW 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD *ULIILWKV 6 %URZQ : 6 *HUKDUGW $EUDPV 5 0 t 0RUULV 5 f 7KH SHUFHSWLRQ RI VSHHFK VRXQGV UHFRUGHG ZLWKLQ WKH XWHUXV RI D SUHJQDQW VKHHS 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD *ULPZDGH & :DONHU : t :RRG & f 6HQVRU\ VWLPXODWLRQ RI WKH KXPDQ IHWXV $XVWUDOLDQ -RXUQDO RI 0HQWDO 5HWDUGDWLRQ

PAGE 194

*XOLFN : / *HVFKHLGHU $ t )ULVLQD 5 f +HDULQJ 3K\VLRORJLFDO $FRXVWLFV 1HXUDO &RGLQJ DQG 3VYFKRDFRXVWLFV 1HZ
PAGE 195

-RKDQVVRQ % :HGHQEHUJ ( t :HVWHQ % f 0HDVXUHPHQW RI WRQH UHVSRQVH E\ WKH KXPDQ IRHWXV $ SUHOLPLQDU\ UHSRUW $FWD 2WRODU\QJRORJ\ 6WRFNKROPf -XVF]\N 3 : f 'HYHORSPHQWDO VSHHFK SHUFHSWLRQ ,Q /DVV 1 (Gf 3ULQFLSOHV RI ([SHULPHQWDO 3KRQHWLFV 6W /RXLV 02 0RVE\
PAGE 196

/HFDQXHW -3 *UDQLHU'HIHUUH & t %XVQHO 0& f 3UHQDWDO IDPLOLDUL]DWLRQ ,Q %RQQLHF 3/ t 'ROLWVN\ 0 (GVf /DQJXDJH %DVHV 'LVFRXUVH %DVHV 6RPH $VSHFWV RI &RQWHPQRUDUY )UHQFK/DQJXDJH 3V\FKROLQJXLVWLFV 5HVHDUFK $PVWHUGDP 1HWKHUODQGV -RKQ %HQMDPLQV 3XEOLVKLQJ &RPSDQ\ /HFDQXHW -3 *UDQLHU'HIHUUH & t %XVQHO 0& f +XPDQ IHWDO DXGLWRU\ SHUFHSWLRQ ,Q /HFDQXHW -3 )LIHU : 3 .UDVQHJRU 1 $ t 6PRWKHUPDQ : 3 (GVf )HWDO 'HYHORSPHQW $ 3VYFKRELRORJLFDO 3HUVSHFWLYH 1HZ -HUVH\ /DZUHQFH (UOEDXP $VVRFLDWHV ,QF /HFDQXHW -3 *UDQLHU'HIHUUH & -DFTXHW $< t %XVQHO 0& f 'HFHOHUDWLYH FDUGLDF UHVSRQVLYHQHVV WR DFRXVWLF VWLPXODWLRQ LQ WKH QHDU WHUP IHWXV 2XDWHUOY -RXUQDO RI ([SHULPHQWDO 3V\FKRORJ\ E /HFDQXHW -3 *UDQLHU'HIHUUH & -DFTXHW $< &DSSRQL t /HGUR / f 3UHQDWDO GLVFULPLQDWLRQ RI D PDOH DQG D IHPDOH YRLFH XWWHULQJ WKH VDPH VHQWHQFH (DUO\ 'HYHORSPHQW DQG 3DUHQWLQJ f /HFDQXHW -3 t 6FKDDO % f )HWDO VHQVRU\ FRPSHWHQFLHV (XURSHDQ -RXUQDO RI 2EVWHWULF t *\QHFRORJ\ DQG 5HSURGXFWLYH %LRORJ\ /HH 6 3RWDPLDQRV $ t 1DUD\DQDQ 6 f $FRXVWLFV RI FKLOGUHQfV VSHHFK GHYHORSPHQWDO FKDQJHV RI WHPSRUDO DQG VSHFWUDO SDUDPHWHUV 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD /LEHUPDQ $ 0 f 2Q WKH ILQGLQJ WKDW VSHHFK LV VSHFLDO $PHULFDQ 3V\FKRORJLVW /LEHUPDQ $ 0 t 0DWWLQJO\ f 7KH PRWRU WKHRU\ RI VSHHFK SHUFHSWLRQ UHYLVHG &RJQLWLRQ /LSSH : 5 t 5XEHO ( : f 'HYHORSPHQW RI WKH SODFH SULQFLSOH WRQRWRSLF RUJDQL]DWLRQ 6FLHQFH /LSSH : 5 t 5XEHO ( : f 2QWRJHQ\ RI WRQRWRSLF RUJDQL]DWLRQ RI EUDLQ VWHP DXGLWRU\ QXFOHL LQ WKH FKLFNHQ LPSOLFDWLRQV RI GHYHORSPHQW RI WKH SODFH SULQFLSOH -RXUQDO RI &RPSDUDWLYH 1HXURORJ\ 0DUW\ 5 f 'YHORSSPHQW SRVWQDWDO GHV USRQVHV VHQVRULHOOHV GX FRUWH[ FUEUDO FKH] HW OH ODSLQ $UFKLYHV Gf$QDWRPLH 0LFURVFRSLDXH HW GH 0RUSKRORJLH ([SULPHQWDOH

PAGE 197

0HKOHU %HUWRQFLQL %DUULHUH 0f t -DVVLN*HUVFKHQIHOG f ,QIDQW UHFRJQLWLRQ RI PRWKHUfV YRLFH 3HUFHSWLRQ 0HKOHU t 'XSRX[ ( f :KDW ,QIDQWV .QRZ 7KH 1HZ &RJQLWLYH 6FLHQFH RI (DUO\ 'HYHORSPHQW 7UDQVODWHG E\ 6RXWKJDWH 3f &DPEULGJH 0$ %ODFNZHOO 0HKOHU -XVF]\N 3 /DPEHUWH +DOVWHG 1 %HUWRQFLQL t $PLHO7LVRQ & f $ SUHFXUVRU RI ODQJXDJH DFTXLVLWLRQ LQ \RXQJ LQIDQWV &RJQLWLRQ 0LOOHU $ t 1LFHO\ 3 ( f $Q $QDO\VLV RI SHUFHSWXDO FRQIXVLRQV DPRQJ VRPH (QJOLVK FRQVRQDQWV 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD 0LOOV 0 1RUWRQ 6 t 5XEHO ( : f 'HYHORSPHQW RI DFWLYH DQG SDVVLYH PHFKDQLFV LQ WKH PDPPDOLDQ FRFKOHD $XGLWRU\ 1HXURVFLHQFH 0LOOV 0 t 5XEHO ( : f 'HYHORSPHQW RI WKH FRFKOHDU DPSOLILHU 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD 0LOOV 0 t 0HOKXLVK ( f 5HFRJQLWLRQ RI PRWKHUfV YRLFH LQ HDUO\ LQIDQF\ 1DWXUH 0RRQ & 0 &RRSHU 5 3 t )LIHU : 3 f 7ZRGD\ROGV SUHIHU WKHLU QDWLYH ODQJXDJH ,QIDQW %HKDYLRU DQG 'HYHORSPHQW 0RRQ & 0 t )LIHU : 3 f 6\OODEOHV DV VLJQDOV IRU GD\ROG LQIDQWV ,QIDQW %HKDYLRU DQG 'HYHORSPHQW 1RUWKHUQ / t 'RZQV 0 3 f +HDULQJ LQ &KLOGUHQ WK (GLWLRQf %DOWLPRUH 0' :LOOLDPV t :LONLQV 2KDOD f 6SHHFK SHUFHSWLRQ LV KHDULQJ VRXQGV QRW WRQJXHV 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD 3HFN ( f 'HYHORSPHQW RI KHDULQJ SDUW ,, HPEU\RORJ\ -RXUQDO RI $PHULFDQ $FDGHPLF RI $XGLRORJ\ 3HQURG 3 f 6SHHFK GLVFULPLQDWLRQ WHVWLQJ ,Q .DW] &(GO +DQGERRN RI &OLQLFDO $XGLRORJ\ UG (GLWLRQf %DOWLPRUH 0' :LOOLDPV t :LONLQV 3HWHUV $ 0 $EUDPV 5 0 *HUKDUGW t *ULIILWKV 6 Df 7UDQVPLVVLRQ RI DLUERUQH VRXQG IURP +] LQWR WKH DEGRPHQ RI VKHHS -RXUQDO RI /RZ )UHTXHQF\ 1RLVH DQG 9LEUDWLRQ

PAGE 198

3HWHUV $ 0 *HUKDUGW $EUDPV 5 0 t /RQJPDWH $ Ef 7KUHH GLPHQVLRQDO LQWUDDEGRPLQDO VRXQG SUHVVXUHV LQ VKHHS SURGXFHG E\ DLUERUQH VWLPXOL $PHULFDQ -RXUQDO RI 2EVWHWULF DQG *\QHFRORJ\ 3HWHUVRQ ( t %DUQH\ + / f &RQWURO PHWKRGV XVHG LQ D VWXG\ RI WKH YRZHOV 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD 3LFNOHV 2 f $Q ,QWURGXFWLRQ WR WKH 3K\VLRORJ\ RI +HDULQJ QG (GLWLRQf 6DQ 'LHJR &$ $FDGHPLF 3UHVV ,QF 3ROODFN f (IIHFWV RI KLJK SDVV DQG ORZ SDVV ILOWHULQJ RQ WKH LQWHOOLJLELOLW\ RI VSHHFK LQ QRLVH 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD 3XMRO 5 t +LOGLQJ f $QDWRP\ DQG SK\VLRORJ\ RI WKH RQVHW RI DXGLWRU\ IXQFWLRQ $FWD 2WRORDUYQJRORJY 6WRFNKROPf 3XMRO 5 /DYLJQH5HELOODUG 0 t /HQRLU 0 f 'HYHORSPHQW RI VHQVRU\ DQG QHXUDO VWUXFWXUHV LQ WKH PDPPDOLDQ FRFKOHD ,Q 5XEHO ( : 3RSSHU $ 1 t )D\ 5 5 (GVf 'HYHORSPHQW RI $XGLWRU\ 6\VWHP 1HZ
PAGE 199

5LFKDUGV 6 )UHQW]HQ % *HUKDUGW 0F&DQQ 0 ( t $EUDPV 5 0 f 6RXQG OHYHOV LQ WKH KXPDQ XWHUXV 2EVWHWULFV t *\QHFRORJ\ 5RPDQG 5 f 7RQRWRSLF HYROXWLRQ GXULQJ GHYHORSPHQW +HDULQJ 5HVHDUFK 5RPDQG 5 t 5RPDQG 05 f 0\HOLQDWLRQ NLQHWLFV RI VSLUDO JDQJOLRQ FHOOV -RXUQDO RI &RPSDUDWLYH 1HXURORJ\ 5RVQHU % 6 t 'RKHUW\ 1 ( f 7KH UHVSRQVH RI QHRQDWHV WR LQWUDXWHULQH VRXQGV 'HYHORSPHQWDO 0HGLFLQH DQG &KLOG 1HXURORJ\ 5XEHO ( : f 2QWRJHQ\ RI VWUXFWXUH DQG IXQFWLRQ LQ WKH YHUWHEUDWH DXGLWRU\ V\VWHP ,Q -DFREVRQ 0 (Gf +DQGERRN RI 6HQVRU\ 3K\VLRORJ\ 'HYHORSPHQW RI 6HQVRU\ 6\VWHPV I9RO ; 1HZ
PAGE 200

6FKLOO + $ f 7KUHVKROG IRU VSHHFK ,Q .DW] (G +DQGERRN RI &OLQLFDO $XGLRORJ\ UG (GLWLRQf %DOWLPRUH 0' :LOOLDPV t :LONLQV 6FKZHLW]HU / t &DQW 1 % f 'HYHORSPHQW RI WKH FRFKOHDU LQQHUYDWLRQ RI WKH GRUVDO FRFKOHDU QXFOHXV RI WKH KDPVWHU -RXUQDO RI &RPSDUDWLYH 1HXURORJ\ 6KDKLGXOODK 6 t +HSSHU 3 f 7KH GHYHORSPHQWDO RULJLQV RI IHWDO UHVSRQVLYHQHVV WR DQ DFRXVWLF VWLPXOXV -RXUQDO RI 5HSURGXFWLYH DQG ,QIDQW 3V\FKRORJ\ 6KDKLGXOODK 6 t +HSSHU 3 f )UHTXHQF\ GLVFULPLQDWLRQ E\ WKH IHWXV (DUO\ +XPDQ 'HYHORSPHQW 6PRWKHUPDQ : 3 t 5RELQVRQ 6 5 f 7UDFLQJ GHYHORSPHQWDO WUDMHFWRULHV LQWR WKH SUHQDWDO SHULRG ,Q /HFDQXHW -3 )LIHU : 3 .UDVQHJRU 1 $ t 6PRWKHUPDQ : 3 (GVf )HWDO 'HYHORSPHQW $ 3VYFKRELRORJLFDO 3HUVSHFWLYH 1HZ -HUVH\ /DZUHQFH (UOEDXP $VVRFLDWHV ,QF 6SHQFH 0 t 'H&DVSHU $ f 3UHQDWDO ([SHULHQFH ZLWK ORZIUHTXHQF\ PDWHUQDOYRLFH VRXQGV LQIOXHQFH QHRQDWDO SHUFHSWLRQ RI PDWHUQDO YRLFH VDPSOHV ,QIDQW %HKDYLRU DQG 'HYHORSPHQW 6WDUU $ $POLH 5 1 0DUWLQ : + t 6DQGHUV 6 f 'HYHORSPHQW RI DXGLWRU\ IXQFWLRQ LQ QHZERUQ LQIDQWV UHYHDOHG E\ DXGLWRU\ EUDLQVWHP SRWHQWLDOV 3HGLDWULFV f 7KRUQWRQ $ 5 t 5DIILQ 0 0 f 6SHHFKGLVFULPLQDWLRQ VFRUHV PRGHOHG DV D ELQRPLDO YDULDEOH -RXUQDO RI 6SHHFK DQG +HDULQJ 5HVHDUFK 9LQFH 0 $ $UPLWDJH 6 ( %DOGZLQ % $ 7RQHU t 0RRUH % & f 7KH VRXQG HQYLURQPHQW RI WKH IRHWDO VKHHS %HKDYLRXU 9LQFH 0 $ %LOOLQJ $ (f %DOGZLQ % $ 7RQHU 1 t :HOOHU & f 0DWHUQDO YRFDOL]DWLRQV DQG RWKHU VRXQGV LQ WKH IHWDO ODPEnV VRXQG HQYLURQPHQW (DUO\ +XPDQ 'HYHORSPHQW :DONHU *ULPZDGH t :RRG & f ,QWUDXWHULQH QRLVH D FRPSRQHQW RI WKH IHWDO HQYLURQPHQW $PHULFDQ -RXUQDO RI 2EVWHWULF DQG *\QHFRORJ\ :DOVK ( t 0F*HH f 'HYHORSPHQW RI DXGLWRU\ FRGLQJ LQ WKH FHQWUDO QHUYRXV V\VWHP LPSOLFDWLRQV IRU LQ XOHUR KHDULQJ 6HPLQDUV LQ 3HULQDWRORJ\ f

PAGE 201

:DQJ 0 f 6,1)$ PXOWLYDULDWH XQFHUWDLQW\ DQDO\VLV IRU FRQIXVLRQ PDWULFHV %HKDYLRU 5HVHDUFK 0HWKRGV DQG ,QVWUXPHQWDWLRQ :DQJ 0 t %LOJHU 5 & f &RQVRQDQW FRQIXVLRQV LQ QRLVH D VWXG\ RI SHUFHSWXDO IHDWXUHV 7KH -RXUQDO RI WKH $FRXVWLFDO 6RFLHW\ RI $PHULFD :DQJ 0 5HHG & 0 t %LOJHU 5 & f $ FRPSDULVRQ RI WKH HIIHFWV RI ILOWHULQJ DQG VHQVRULQHXUDO KHDULQJ ORVV RQ SDWWHUQV RI FRQVRQDQW FRQIXVLRQV -RXUQDO RI 6SHHFK DQG +HDULQJ 5HVHDUFK :LONLQV : t :DNHILHOG f %UDLQ HYROXWLRQ DQG QHXUROLQJXLVWLF SUHFRQGLWLRQV %HKDYLRUDO DQG %UDLQ 6FLHQFHV :LQHU % %URZQ 5 t 0LFKHOV 0 f 6WDWLVWLFDO 3ULQFLSOHV LQ ([SHULPHQWDO 'HVLJQ UG (GLWLRQf 1HZ
PAGE 202

%,2*5$3+,&$/ 6.(7&+ ;LQ\DQ +XDQJ ZDV ERUQ RQ -XO\ LQ %HLMLQJ &KLQD ZKHUH KH ZDV UDLVHG DQG HGXFDWHG +H REWDLQHG KLV 0' GHJUHH IURP %HLMLQJ 0HGLFDO 8QLYHUVLW\ LQ DQG VWDUWHG KLV UHVLGHQF\ LQ RWRODU\QJRORJ\KHDG DQG QHFN VXUJHU\ DW WKH 7KLUG 7HDFKLQJ +RVSLWDO %HLMLQJ 0HGLFDO 8QLYHUVLW\ ZKHUH KH ZDV KRQRUHG DV 'RFWRU RI WKH
PAGE 203

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

PAGE 204

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

PAGE 205

/'