The relationship between the perception and production of the english contrast pair ʧand ʤ among southern vietnamese speakers of english

..

VIETNAM NATIONAL UNIVERSITY – HOCHIMINH CITY
UNIVERSITY OF SOCIAL SCIENCES & HUMANITIES
FACULTY OF ENGLISH LINGUISTICS AND LITERATURE

----------- -----------

THE RELATIONSHIP BETWEEN
THE PERCEPTION AND PRODUCTION OF THE
ENGLISH CONTRAST PAIR /t~/ AND /d2/ AMONG
SOUTHERN VIETNAMESE SPEAKERS OF ENGLISH

Submitted to the
Faculty of English Linguistics & Literature
in partial fulfillment of the Master‟s degree in TESOL

By
PHAM THI THUY TRANG
Supervised by
LE HOANG DUNG, PHD

HO CHI MINH CITY, MAY 2011


STATEMENT OF ORIGINALITY

I certify that this thesis entitled “THE RELATIONSHIP BETWEEN
THE PERCEPTION AND PRODUCTION OF THE ENGLISH CONTRAST
PAIR /t~/ AND /d2/ AMONG SOUTHERN VIETNAMESE SPEAKERS OF
ENGLISH” is my own work.

This thesis has not been submitted for the award of any degree or
diploma in any other institution.

Ho Chi Minh City, May 2011.

Phạm Thị Thùy Trang

i


ACKNOWLEDGEMENT
I would like to express my sincere gratitude to the following people who have
made writing this thesis possible for me:
First of all, I would like to express my wholehearted thanks to my thesis
supervisor, Le Hoang Dung, PHD at the University of Social Sciences and
Humanities, HCMC for his enthusiastic and valuable guidance and for his patient and
sympathetic

attitudes

towards

me.

Without

his

assistance

and

ongoing

encouragement, this thesis could not have been completed. He has given me constant
support during my thesis completion.
I would also like to thank my teacher, Nguyen Thi Kieu Thu, PHD at the
University of Social Sciences and Humanities, HCMC for her ongoing
encouragement and support during my master course.
Gratitude is also offered to my friend, Nguyen Dang Khoa, graduate student at
Australia National University for sending me valuable and precious materials without
which I could not have written the thesis.
Thanks are also due to the Board of Directors at the Pedagogy University
Language Center, Thanh Nien Language Center and Vietnam-Australia Language
School, who gave me conditions to conduct my surveys and experiments for the
thesis.
I owe many thanks to my friends and my colleagues for their support,
encouragement and assistance in data collection.
Lastly, but certainly not least, I would like to thank my dear husband, Duong
Anh Tuan, for his loving care, support and encouragement that has helped me so
much in completing this thesis.

ii


ABSTRACT
Although the recently-gained insights into the nature of second language
acquisition have proved quite beneficial to learners of English, these breakthroughs
have not borne many implications to Vietnamese adult learners, especially in the field

of pronunciation training. This can partially be attributed to the lesser significance
adult learners embrace as compared to children or young learners. Additionally, as
agreed by many researchers, phonology acquisition is considered as the least universal
aspect of language and mostly affected by the interaction of L1 and L2. Thus, the
present pronunciation training approach does not prove sufficient for Vietnamese
adult learners. In this context, this thesis attempted to explore the effects of refining
perceptual abilities on improving the pronunciation of English non-native contrast
pairs among Vietnamese adults.
In the study, it was found that L2 perception plays an important role in
language production and acts as a mediator between language input and output. The
result of the study suggests that, although high perceptual ability does not always
guarantee highly intelligible sound production, it is a prerequisite for pronunciation
improvement, at least to adult learners, whose L1 skills and knowledge has deeply
inculcated in their L2 reflection. While the parallel correlation of speech perception
and production may not be guaranteed, there exists a strong relationship between
these two processes.
Based on the findings, some suggestions were made with the hope to integrate
the new teaching approach into the textbooks. The suggestions are on how teachers
deal with pronunciation teaching in the classroom and how syllabus designers can
allocate the materials in Vietnam situation for the learners to get the most from the
current textbooks.

iii


TABLE OF CONTENT
STATEMENT OF ORIGINALITY ........................................................................................................ i
ACKNOWLEDGEMENT...................................................................................................................... ii
ABSTRACT .......................................................................................................................................... iii
TABLE OF CONTENT ........................................................................................................................ iv

LIST OF TABLES AND ABBREVIATIONS ...................................................................................... ix
TABLES ............................................................................................................................................ ix
ABBREVIATIONS ........................................................................................................................... ix
LIST OF FIGURES AND CHARTS ..................................................................................................... x
Chapter 1

INTRODUCTION ............................................................................................................ 1

1.1 RATIONALE ............................................................................................................................... 1
1.2 STATEMENT OF THE PROBLEM........................................................................................... 2
1.3 BACKGROUND TO THE STUDY ............................................................................................ 5
1.3.1 The practice of pronunciation teaching to adult learners in HCMC ...................................... 5
1.3.2 Propositions on the relationship of speech perception on speech production ....................... 6
1.4 PURPOSES OF THE STUDY .................................................................................................... 8
1.5 RESEARCH QUESTIONS ......................................................................................................... 8
1.6 SIGNIFICANCE OF THE STUDY ............................................................................................ 9
1.7 DEFINITIONS OF TERMS ........................................................................................................ 9
1.7.1 Phonological contrast ............................................................................................................ 9
1.7.2 Phoneme, phone, consonant and vowel ................................................................................. 9
1.7.3 Phonemic perception ........................................................................................................... 10
1.8 ORGANIZATION OF THE THESIS ...................................................................................... 10
Chapter 2

LITERATURE REVIEW ............................................................................................... 11

iv


2.1 THE RELATIONSHIP BETWEEN SPEECH PERCEPTION AND SPEECH PRODUCTION
.......................................................................................................................................................... 11

2.1.1 Propositions concerning perception-production relationship .............................................. 11
2.1.2 Empirical evidence of perception-production relationship.................................................. 13
2.1.2.1 Evidence from Spanish speakers of English................................................................. 14
2.1.2.2 Evidence from adult learners of French ....................................................................... 16
2.1.2.3 Evidence from bilinguals of Asian languages .............................................................. 18
2.1.3 Counter-evidence of perception-production relationship .................................................... 22
2.1.3.1 Counter-evidence from Swedish and Finnish learners of English................................ 22
2.1.3.2 Counter-evidence from Japanese speakers ................................................................... 23
2.1.4 Discussion .......................................................................................................................... 24
2.2 THE NATURE OF L2 SPEECH PERCEPTION..................................................................... 25
2.2.1 Speech Learning Model ....................................................................................................... 25
2.2.2 Perceptual Assimilation Model ........................................................................................... 27
2.2.3 Feature Competition Model ................................................................................................. 28
2.2.4 Summary ............................................................................................................................. 30
2.3 COMPARISON OF ENGLISH AND VIETNAMESE SOUND SYSTEM ............................. 31
2.3.1 Differences in syllable composition .................................................................................... 31
2.3.2 Differences in distinctive features ....................................................................................... 32
2.3.3 The contrast pair /t~/ and /d2/............................................................................................... 33
2.4 HIGH-VARIABILITY METHOD – THE ELICITATION PROCEDURES FOR
ENHANCING PHONETIC PERCEPTION .................................................................................... 34
2.5 PRINCIPAL FACTORS INFLUENCING THE PROCESS OF SPEECH ACQUISITION .... 37
2.5.1 Native L1 transference ........................................................................................................ 37
2.5.2 Exposure to the second language......................................................................................... 39
2.5.3 Motivation ........................................................................................................................... 39

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2.6 SUMMARY .............................................................................................................................. 40
Chapter 3

METHODOLOGY ..................................................................................................... 42

3.1 RESEARCH QUESTIONS ...................................................................................................... 42
3.2 RESEARCH DESIGN............................................................................................................... 42
3.2.1 Research participants ........................................................................................................... 42
CHART 3.1 The process of subject selection............................................................................... 44
3.2.2 The speakers ....................................................................................................................... 45
3.2.3 Research procedure ............................................................................................................. 45
3.2.3.1 The stimuli appraisal .................................................................................................... 47
3.2.3.2 Experimental teaching .................................................................................................. 47
3.2.3.3 The collection of perception data ................................................................................. 48
3.2.3.4 The collection of production data ................................................................................. 51
3.2.3.5 The treatment of perception and production data ......................................................... 52
3.2.3.6 The assessment of production data ............................................................................... 52
3.2.3.7 The treatment of the assessment data ........................................................................... 54
Chapter 4

DATA ANALYSIS AND FINDINGS .......................................................................... 56

4.1 DATA ANALYSIS ................................................................................................................... 56
4.1.1 The analysis of perceptual training outcomes ..................................................................... 56
4.1.2 The analysis of native listeners‟ preference judgement of the subjects‟ production ........... 60
4.1.3 The analysis of native listeners‟ identification of minimal pairs ......................................... 63
4.1.4 The relationship between the perception and production of /t~/ and /d2/ ............................ 64
4.2 Findings ...................................................................................................................................... 70
4.3 Summary ................................................................................................................................... 72
CHAPTER 5

RECOMMENDATIONS AND CONCLUSION ..................................................... 73

5.1 RECOMMENDATIONS FOR TEACHERS OF ENGLISH .................................................... 73

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5.1.1 Teacher should apply a balanced focus on both speech perception and motor skill in
pronunciation training .................................................................................................................. 73
5.1.2 Teachers should follow a systematic procedure in teaching pronunciation ........................ 74
5.2 Recommendations for syllabus designers.................................................................................. 76
5.2.1 The syllabus should provide more time allotment for the pronunciation training ............... 76
5.2.2 Syllabus designers should take into consideration specific influence of L1 on L2
acquisition .................................................................................................................................... 77
5.2.3 Syllabus designers should recognize the importance of aural input in oral production ...... 78
5.3 Limitation .................................................................................................................................. 78
5.4 Recommendation for future research ........................................................................................ 79
CONCLUSION .................................................................................................................................... 81
REFERENCES ..................................................................................................................................... 84
APPENDICES ...................................................................................................................................... 93
APPENDIX 1 SURVEY .................................................................................................................. 93
APPENDIX 2 WORD LIST FOR RECRUITMENT TEST ............................................................ 97
APPENDIX 3 LIST OF UNFAMILIAR WORDS FOR SUBJECTS.............................................. 98
APPENDIX 4 PERCEPTUAL PRETEST (and POST-TEST) (SPEAKER 4) .............................. 99
APPENDIX 5 GENERALIZATION TEST 1 (SPEAKER 6)........................................................ 100
APEENDIX 6 GENERALIZATION TEST 2 (SPEAKER 1) ....................................................... 101
APPENDIX 7 TRAINING SESSIONS .......................................................................................... 102
A. TRAINING SESSION 1 (SPEAKER 1) ............................................................................... 102
B. TRAINING SESSION 2 (SPEAKER 2)................................................................................ 103
C. TRAINING SESSION 3 (SPEAKER 3)................................................................................ 104
D. TRAINING SESSION 4 (SPEAKER 4) .............................................................................. 105

E. TRAINING SESSION 5 (SPEAKER 5) ................................................................................ 106
F. TRAINING SESSION 6 (SPEAKER 1) ................................................................................ 107

vii


G. TRAINING SESSION 7 (SPEAKER 4) ............................................................................... 108
H. TRAINING SESSION 8 (SPEAKER 3) ............................................................................... 109
APPENDIX 8 PRODUCTION TEST (Pre-test and Post-test) ..................................................... 110
APPENDIX 9 RESULT OF PERCEPTUAL TRAINING ........................................................... 111
A. Pre-training perceptual test result ......................................................................................... 111
B. Post-training perceptual test result – Group A (experimental group) .................................... 112
C. Post-training perceptual test result – Group B (control group) ............................................. 113
APPENDIX 10 RESULT OF NATIVE LISTENERS‟IDENTIFICATION OF MINIMAL PAIRS
........................................................................................................................................................ 114
A. Native listeners‟ identification test result - Group A (experimental group) ......................... 114
B. Native listeners‟ identification test result - Group B (control group) ................................... 115

viii


LIST OF TABLES AND ABBREVIATIONS
TABLES
Table 2.1 Differences between the Vietnamese and English syllables
Table 2.2 Distinctive features specifications of the Vietnamese consonants
Table 2.3 Distinctive feature specifications of the English consonants
Table 4.1 Perceptual test result at pretest phase
Table 4.2 Perceptual test result at posttest phase
Table 4.3 The two-way ANOVA test result of perceptual test scores
Table 4.4 The T-test result of perceptual test scores

Table 4.5 Native listeners‟ identification test result
Table 4.6 The T-test result of native listeners‟ identification of minimal pairs
Table 4.7 Individual Vietnamese trainee perception and production accuracy scores at
pre-test and at post-test

ABBREVIATIONS
1. L1

First language

2. L2

Second language

3. HCMC

Ho Chi Minh City

4. ESL

English as the Second Language

5. EFL

English as the Foreign Language

ix


LIST OF FIGURES AND CHARTS

FIGURES
Figure 1.1 Hewlett‟s (1990) model of phonetic and phonological processing
Figure 4.1 Percent correct perceptual identification performance for the experimental
group and the control group at the pretest, post-test and two tests of generalization
Figure 4.2 The native speakers‟ preference judgement of the subject production
Figure 4.3 (a) Vector plot of individual Vietnamese subjects‟ perceptual identification
accuracy and production identification accuracy from pretest to post-test (Subjects 15)
Figure 4.3 (b) Vector plot of individual Vietnamese subjects‟ perceptual identification
accuracy and production identification accuracy from pretest to post-test (Subjects 610)

CHARTS
Chart 3.1 The process of subject selection
Chart 3.2 The research procedure

x


Chapter 1

INTRODUCTION

This thesis reports the result of an experiment conducted to investigate the
relationship between the perception and production of the English contrast pair /t~/
and /d2/ among Southern adult Vietnamese speakers of English, with an aim to
develop new techniques for the modification of the structure of learners‟ phonetic
system, thus facilitate communication outcomes. This section takes into consideration
the rationale for the study, statement of the problem as well as presents the
background for the study. The introduction also points out purposes of the study and
introduces research questions and hypotheses.
1.1 RATIONALE

In recent years, the goal of language teaching has been pivoted around endowing
learners

with

communicative

competence.

Hymes

(1985)

proposes

that

communicative competence is exhibited through the ability to handle effectively real,
natural conversations and necessarily encompasses linguistic and pragmatic aspects.
Apart from grammatical, lexical and discourse mastery, phonological competence
remains an indispensible part at the linguistics side. The generation of acceptable
pronunciation has been acknowledged as a crucial integration of any instances of
successful communication. In fact, Garrigues (1999) essentially points out that the
foundation of effective spoken communication is good pronunciation. If a converser
utters well- and clearly-enunciated tokens, it should be much easier for their audience
interlocutors to grasp their meaning with relative ease. Otherwise, mispronunciation
stands high probability of leading to misunderstanding and, in quite a few cases,
leading to utter communication breakdown or termination. In this sense,
pronunciation has recently attracted more and more attention of language researchers
and practitioners, and has claimed more and more substantial share in EFL

curriculum. It is recognized as a fundamental skill which students should acquire,

1


primarily because it can affect accuracy, comprehension and intelligibility
(Lambacher, 1996).
Moreover, the argument justifying the emphasis of pronunciation teaching has
stretched further to the mechanism involved in working memory called the
“phonological loop” (Newton, 2009). In essence, the phonological loop is the practice
of the brain repeating the words or the phrases over and over again, either consciously
or subconsciously, to retain it in the working memory or to help it transfer to the longterm memory. As far as this concerned, a learner without a consistent and stable
pronunciation of a word cannot allot it to the long-term memory because it cannot be
held in the phonological loop. Conclusively, the phonological patterns, apart from the
grammatical structure representations, exert a substantial effect on the size of the
working memory among learners of a second language. It is thus important to
attribute substantial attention to pronunciation in the EFL classroom to help learners
quickly establish stable pronunciation and internalize the patterns and rules that work
within the language.
In consideration of the roles of intelligible pronunciation, it is proved amply
justified for ESL/ EFL learners to systematically learn to produce consistent
acceptable sounds from the very beginning of L2 learning. Also, teachers should
attach significance to the practice of pronunciation teaching and learning in EFL
classroom. Suitable remedial strategies must be planned and pondered should any
arisen issue intervene in this acquisition process.
1.2 STATEMENT OF THE PROBLEM
Communicative teaching approach and student-centred philosophy have been
introduced into Vietnam for the last ten years and with this trend, pronunciation
training has gained a larger portion in communication-oriented syllabi. However, the
influence of this movement has not extended as far as expected. It is observed that the

2


introduction of English phonological systems in the current widely-used English
textbooks may, to some extent, benefit young learners, yet it seems insufficient to
make noticeable modifications to adults‟ existent sound patterns.
On addressing the complications of training adult Vietnamese learners to
produce comprehensible English, a lot of language practitioners and teachers have
aired their deep concern about the situation. With many foreigners‟ comment that
Vietnamese and Thai speakers of English are among the most incomprehensible
speakers in Asia, Ha C. Tam (2002) admits the failure of the present communicative
teaching oriented syllabus in improving adult Vietnamese learners‟ pronunciation. In
her observation, although many of them can achieve high proficiency in other
language areas as reading and writing, just a few can make themselves easily
understood in direct interactions with foreigners. She also attributes this failure to
several phonological factors, among which mal-production of segmental components,
or discrete sounds, is the most basic aspect causing communication breakdown,
especially with learners of low levels. Also, some foreign ESL teachers in HCMC
(Guan, 2010; Douglas, 2009; Dalana, 2007) reflected on the experience of their
struggle to rectify Vietnamese adults‟ articulation and maintained that the
improvement has not been quite significant over the last ten years.
As a teacher of English in EFL context for quite a few years, the writer of this
thesis has acceptably come to the realization that the majority of Vietnamese learners,
especially those commencing to experience L2 exposure after puberty, often bewilder
native speakers by mispronouncing English sounds. Among common pronunciation
mistakes, it often remains the case that these learners, for one reason or another, either
utter one sole phonetic representation for two English contrastive sounds or distort the
sounds by replacing them with L1 alternatives. This usually occurs when the two L2
sounds are not contrastive in L1 or when an L2 sound shares some prominent features

3


with an L1 equivalent. The production of misleading phone representatives, as a
result, hinders the learners from maintaining smooth interactions and this
communication gap cannot simply be compensated by their competence in other
linguistic fields. This breakdown has also taken its toll when it comes to the issue of
vocabulary learning. So, their poor vocabulary repertoire can partly be blamed on the
failure to retrieve a consistent and stable phonetic image in the mind. By all means,
something should be done immediately to ameliorate this situation.
The poor pronunciation among Vietnamese adult learners can be partially traced
back to two factors. Firstly, it can be attributed to the largely incompatible
phonological systems in Vietnamese and English languages, which embrace different
phonetic characteristics and prominent features. In fact, it is noticed that adult learners
are the most vulnerable to non-native phonetic contrasts in L2 learning, which usually
leads to mispronunciation (e.g. Tahta et al., 1981; Flege and Hillenbrand, 1987). For
example, Japanese learners have troubles with the contrast pair /r/ - /l/ (Logan et al.,
1991) while Chinese speakers often cannot distinguish between /v/ and /w/.
Considering Vietnamese speakers, contrastive works of Nguyen D. Liem (1989),
Cheung (1986) and So & Dodd (1992) reveal that the following non-native phonetic
contrasts will cause great trouble and confusion for learners: /t~/ and /d2/, /8/ and /5/,
/n/ and /7/, /z/ and /2/, /d/ and /5/. Usually, they will produce one sole phonetic
representation for the two members of each pair. Secondly, it has been argued that
adult learners, with their specific characteristics and learning styles, should have more
speech input in order for them to produce acceptable output. Thus, special treatment
should be offered to these adult learners, especially in their dealing with certain nonnative, or novel, contrasts.
Although there have been extensive research and studies on the pronunciation
remedial strategies for adult learners on dealing with novel L2 sounds in Japan,

4


China, Korea and other Asian countries, there seem to be few investigations into the
issue in the context of Vietnam. Since Vietnamese language also embraces distinctive
features that set itself apart from English and other Asian languages, an insight into a
certain approach to rectify Vietnamese adults‟ production of certain non-native
sounds proves to be worth consideration.
1.3 BACKGROUND TO THE STUDY
1.3.1 The practice of pronunciation teaching to adult learners in HCMC
In HCMC, there exist a large number of language centers which offer a lot of
general English courses for adult learners like Thanh Nien Language center, SIFONE,
Language center of Pedagogy University, Vietnam-Australia language School, ELITE
and VUS.
Except for some minor changes, the teaching syllabi for these courses usually
conform to the available syllabi presented in certain textbooks – New English File,
New Cutting Edge, International Express, New Lifelines. Although all of these
textbooks follow modern communicative teaching philosophy and ethics, an insight
into their pronunciation syllabi reveals these two main issues. Firstly, since the books
were designed for a wide range of target markets, the treated segmental aspects are
not closely related to the problem a certain learner with a certain L1 background may
cope with. In fact, all the phones in the English sound system are tackled with equal
amount of time and focus throughout the whole textbook series. Thus, if teachers stick
to the existent syllabi, the challenging L2 sounds will not be highlighted and
sufficiently dealt with. Secondly, since these textbooks are meant to address a wide
range of target learners, adults seem not to get a lot of benefits from the presented
pronunciation teaching approach. Therefore, the textbooks and the syllabi should be
suitably adapted to match with specific learners with specific pronunciation problems.

5

Also, from her class observation, the writer of this thesis noticed that the
pronunciation teaching to adults is quite similar to other target learners. Usually, the
language input, or language exposure, does not guarantee acceptable production of
novel L2 sounds. Endowed with only one or two times listening to native speakers
before producing the sounds, the adult learners still cope with a lot of troubles and
challenges with some contrast pairs like /t~/ and /d2/, which are not contrastive in L1.
Furthermore, teachers generally concentrate mainly on training motor aspects of
phone production such as lip shape, tongue position and jaw movement rather than
provide students with audio discrimination cues between the sounds. In other words,
focus is usually shifted on the articulation phase of sound production and does not
tackle the deeper language breakdown – L2 perception.
All in all, an overview of the present teaching practice has revealed some flaws
in pronunciation training to Vietnamese adult learners. Firstly, the contemporary
prevalent teaching syllabus does not address the specific problems those learners cope
in learning L2 phonological system, or the specific sounds they characteristically have
troubles with, for example /t~/ and /d2/. Secondly, adult learners have not received
suitable remedial strategies for acquiring these novel L2 sounds. In fact, teachers
usually dedicate most of their effort on training articulatory motor skills and do not
focus much on sound perception – the input side – in their pronunciation training.
Hence, the philosophy behind this pronunciation teaching practice- the covert belief
and assumption that sound production can be improved by mere direct motor trainingshould be critically reflected and revised.
1.3.2 Propositions on the relationship of speech perception on speech production
A lot of linguists and researchers, in their studies of the nature of speech
production, draw on the impact of enhanced sound perception on refined sound
production. Actually, the linkage between speech perception and production has
6

arisen as a long-standing issue in speech science and experimental phonetics, and has
intrigued a variety of theories concerning its nature (e.g Liberman and Mattingly,
1989; Stevens and Blumstein, 1981; Diehl and Kluender, 1989). Apart from the
theoretical concern of perceptual training in the classroom practice, much of the
empirical evidence justifies the corresponding need to study the relationship between
perception and production. An increasing number of positive findings of the
relationship have supported this perceptual-based hypothesis of speech accuracy. For
example, Schneiderman, Bourdages & Champagne (1988), as studying the
effectiveness of perceptual training on speech accuracy, found that learners of French
with different L1 backgrounds, including English, Chinese, Tamil, Hindu, Turkish,
Spanish and German, achieved an encouraging progress in discriminating and
producing French words and phrases after the training. Statistical analysis also
demonstrated a significant correlation between perception and production posttraining. In much the same way, it was reported that perceptual training has
improved, though inconsistently, the intelligibility of the production output of
Japanese learners of English (Bradlow et al., 1997).
Based on this argument and evidence, the process of speech production is
closely-linked to speech perception. In this way, the amount of exposure to language
and the quality of the language stimulants in the speech perception stage greatly
influence the quality of speech production. Specifically, in training Vietnamese adult
learners to acceptably produce the non-native phonetic contrast like /t~/ and /d2/, it
may be beneficial if teachers plan some suitable strategies to improve their
perception first. Since little preliminary research has been done into the linkage
between sound perception and sound production in Vietnam context, the proposition
should be further tested before it is applied in reality.

7


1.4 PURPOSES OF THE STUDY
In consideration of insufficient empirical evidence of the relationship between

sound perception and sound production in Vietnam context, the present research was
conducted to:
(i) explore how the production of /t~/ and /d2/ among Southern Vietnamese
speakers change in correlation with the change in their perception of the two sounds;
(ii) investigate the relationship between sound perception and production with
the case of /t~/ and /d2/;
(iii) offer some possible recommendations on the current pronunciation
teaching of non-native sounds to Vietnamese adult learners.
1.5 RESEARCH QUESTIONS
Based on the purposes of the study, an experiment was designed to investigate
the relationship between speech perception and speech production in the case of /t~/
and /d2/ among Vietnamese adult learners. Since L1 background also exerts some
influence on the production of L2, the subjects taking part in the experiment were
selected within homogenous population – adult speakers with Southern Vietnamese
accent. This investigation was meant to answer the following questions.
1. How does the production of /t~/ and /d2/ among adult Southern Vietnamese
speakers change in correlation with the change in their perception of these two
sounds?
2. Might there be a positive relationship between the perception and production
of /t~/ and /d2/?

8


3. What are the methodological implications for the teaching of non-native
English sounds to adult Vietnamese learners?
1.6 SIGNIFICANCE OF THE STUDY
If the relationship between the perception and production of the contrast pair
/t~/ and /d2/among Southern Vietnamese speakers are to be proved, then this result
lends significance to the practice of pronunciation teaching in Vietnam. Firstly, it

provides a novel insight into the principles behind pronunciation teaching, at least at
segmental level. Secondly, it serves as a guideline for teachers and syllabus designers
to plan their teaching strategies for Vietnamese adult learners. Thirdly, it can serve as
a background for future studies on the issue of improving pronunciation among
Vietnamese learners.
1.7 DEFINITIONS OF TERMS
1.7.1 Phonological contrast
Gimson (1989), Nunan (1991) and Spencer (1997) share the similar view that a
phonological system (i.e. sound system) of a language is built upon the idea of sound
contrasts. By selecting one type of sound as opposed to another, one can distinguish
one word from the other. In other words, sound contrasts serve to distinguish
meanings in a language. For instance, in English, one can distinguish the words
“char” and “jar” by choosing the first consonant either as /t~/ or /d2/ and such
distinction between the sounds /t~-d2 / contributes to a contrast, /t~-d2 / is thus known
as a "contrast-pair”
1.7.2 Phoneme, phone, consonant and vowel
Crystal (1991) defines "phoneme" as the minimal unit in the sound system of a
language while a "phone" is the physical realization of a phoneme. The former thus
represents an abstract level of analysis while the latter refers to the actual articulatory

9


movement (of lips, tongue and vocal tract, etc.) and acoustic events heard in speech.
In general, there are two types of phones - consonants and vowels. Phonetically,
consonants are those sounds produced by narrowing the vocal tract so that airflow is
either completely blocked or restricted and audible friction is heard. Vowels, on the
other hand, are those sounds produced in the absence of such vocal tract constriction.
1.7.3 Phonemic perception
In defining "phonemic perception", many researchers (e.g. Ferguson, 1975; Juiesz

& Hirsch, 1972; Shvachkin, 1973) acknowledge that it includes three aspects auditory sensations, interpretation and classification of speech sounds into
meaningful contrastive categories which signify the meaning of a word Bearing the
same principle, Barton (1980) concisely defines "phonemic perception" as the
"process of discriminating and classifying speech sounds into minimal units that
signify meaning differences (1980, p.97).
1.8 ORGANIZATION OF THE THESIS
The thesis is divided into five chapters. The First chapter presents the
introduction to the thesis, which focuses on rationale of the research and problem
addressing, points out the background to the study, overviews the current practice in
L2 phonology teaching and declares the purposes of the study. The Second chapter
gives a literature review of the previous findings of the perception-production
relationship, the high-variability training approach and proposed theories of L2
speech perception. Chapter Three describes the research design. Chapter Four of the
thesis reports on the results and findings of the study while the Fifth chapter
elaborates on possible implications and recommendations drawn from the findings.

10


Chapter 2

LITERATURE REVIEW

The present study is an attempt to investigate the relationship between the
perception and production of /t~/ and /d2/ and explore possible changes to the
pronunciation teaching of non-native English sounds to Vietnamese adult learners.
Thus, the purpose of the literature review is to find out the nature of L2 sound
acquisition and how an L2 novel sound is integrated into the existent L1 phonological
system, which helps to explain why the present teaching approach is not sufficient to
rectify adult learners‟ pronunciation habit of non-native sounds. The literature review

is also meant to revise the principles and empirical evidence regarding the relationship
between speech perception and production as the background for the present study.
2.1
THE RELATIONSHIP BETWEEN SPEECH PERCEPTION AND
SPEECH PRODUCTION
This section takes into consideration the established argument, both theoretically
and empirically, in regards to the correlation between L2 perception and production.
The section focuses on the heterogeneous stances proposed by different theorists as
well as on related experimental evidence provided in the works of some renowned
researchers.
2.1.1 Propositions concerning perception-production relationship
The association between speech perception and speech production has ever been
a concern in the field of speech science, with many researchers long since divided
over the core nature of this controversial relationship. Some language theorists
postulate that the two processes- speech perception and speech production- are
directly linked and one is the causative factor of the other. For instances, the typical
argument of motor theorists (e.g., Liberman et al., 1967; Liberman and Mattingly,
1985; Liberman and Mattingly, 1989) goes that the sound perceived by listeners is
stored in the form of its respective articulatory gestures, which govern the way that
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sound is produced in later instances. Based on this theory, there exists a specific
phonetic segment that stores speech units in codes of articulatory gestures, thus
governing both speech perception and production. Articulatory gestures, admittedly,
serve as the single mediator for speech perception and production, activating the
conversion between these two processes. In other words, the interconnection between
these two processes is inextricable.
Set apart from this stance are those theorists who lend more autonomy and
separation to these two processes of speech communication. Such attitude can be

found in works of Steven and Blumstein (1981) or Diehl and Kluender (1989). These
acoustic-auditory theorists suppose that speech perception acts upon an acoustic
channel separated from the articulatory gestures regulating speech production.
However, this approach also presupposes that there exists an indirect connection
between speech perception and production due to an interaction and intermodification between acoustically-coded speech and auditory feedback mechanisms
activating during producing speech. Based on this theory, the stored information
about acoustic properties of a perceived sound is retrieved for the produced sound to
be benchmarked against. Hence, although speech perception does not exert a direct
influence on the quality of speech production, the ultimate speech outcome does very
much depend on the extent to which the listener-speaker can process the acoustic
properties of sounds.
A third theory, the direct-realist approach (Kiparsky & Menn, 1990) to speech
perception, proposes that the perceived sounds are retained, first and foremost, not
under the form of acoustically defined targets, but rather, in terms of gesturally
defined targets. At one end, listeners inadvertently perceive the articulatory gestures
of the sounds, which represent themselves as a set of distinctive gestural structures
imparted into the acoustic system. At the other end, this listener-speaker, during
speech production, will aim to achieve these articulatory gestures by employing the

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existent incorporated information. Hence, the argument of the direct-realistic
approach is that the strong cohesion between speech perception and production is
deeply-stemmed from their common communicative goal. In this way, the directrealistic approach holds a shared perspective with the motor theory about the direct
link between the two processes. Yet, this approach does not imply a specific phonetic
segment that determines the direct perception –production link. Rather, it proposes
that the link between speech perception and production is the result of the integration
of speech perception and production systems in order to achieve common
communicative goal.

Differences and disparity taken apart, these theorists have, either explicitly or
implicitly, shared the thrust of argument about the mutual impact between language
perception and production. As far as this study concerns, these stances could represent
different illustrations of different aspects and dimensions involved in the intricate
process of language perception-production. Might it be the case or not, the
relationship between the two processes is inextricable and carries significant
methodological implications. Thus, it possibly is the case that the improvement in
speech production can be fostered through perception refinement.
Concerning the present study, the theoretical propositions have provided some
guidelines for the improvement of the production of novel L2 sounds among
Vietnamese adult learners. Since the mere concentration on motor training skill does
not prove sufficient to yield significant pronunciation enhancement, the mutual
impact of speech perception and production can imply the inclusion of perceptual
development in pronunciation training.
2.1.2 Empirical evidence of perception-production relationship
In light of various theoretical works, the linkage between speech perception and
production is well-justified, yet how this relationship exposes itself in learners‟ overt

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linguistic performance is such spectrum that cannot be unfolded solely with
theoretical hypothesis. Thus, developed in parallel with the previous theoretical
stances on the issue, empirical studies of the correlative performance between
perception and production thrived in the 1980s, covering a wide range of language
spectrum and target subjects (e.g Flege & Eefing,1987; Flege, Munto & Fox, 1994).
These studies have helped provide forceful empirical facts and figures for language
researchers and practitioners to gain revealing insight into the relationship between
speech perception and production.
2.1.2.1 Evidence from Spanish speakers of English

Studies on the Spanish subjects have undoubtedly accounted for quite a
voluminous proportion in the growing body of literature on L2 perception and
production. In 1987, for instance, Flege & Eefting observed the disparity between two
groups of subjects, one consisting of adult English monolinguals, the other
comprising native English speakers, aged between 15 and 20, with about 6 years of
English exposure, who in 90% speech instances produced the English /d/ and /t/ with
a Spanish accent. The subjects in each group were due to take part in a perceptual
decision task in which they made forced-choice decision on whether the presented
auditory were English /da/ or /ta/ in the corresponding voice-onset time continuum.
Results revealed that, in correlation to their performance, the native Spanish speakers
performed a relatively poorer perceptual outcome as compared to the English
controls. Based on these findings, the researchers arrived at two conclusions - firstly,
there exists a parallel relationship between perception and production; and secondly,
the internalization of L1 may influence the construction of the perceptual
representations of L2 speech sounds. Flege & Eefting further assumed that although
the two consonants /d/ and /t/ were also contrastive in Spanish, the category boundary
of Spanish /d/ and /t/ was different from that of English. Consequently, the Spanish

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