An acoustic analysis of English pronunciation systems of Japanese learners Aya Kitagawa A ...

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An acoustic analysis of English pronunciation systems
of Japanese learners
Aya Kitagawa
A dissertation submitted in partial fulfilment of the requirements
for the degree of Doctor of Philosophy in Education
Waseda University
2016 January
Abstract
The purpose of this study was to offer practical implications for the learning and
teaching of pronunciation for the field of English education in Japan. The productive aspects
of learning were emphasized and two research questions were addressed: (1) which phonetic
and phonological items are easy,learnable ordifficult forJapaneselearnersof English in each
element of pronunciation; and (2) whether there is any positive, supportive relationship
between the elements ofpronunciationin the learningprocess.
Eight elements of pronunciation were targeted in this study: vowel quality, vowel
duration, plosives, fricatives, approximants, rhythm, intonation and connected speech
phenomena. The speech samples collected from Japanese learners of English, natives
speakers of British English and native speakers of American English were measured for these
elements, using different measurements, including F1, F2, F3, duration, pitch, intensity and
four spectral moments. A cluster analysis, a multivariate analysis of variance and a
discriminant analysis were carried out for each element in order to address the first research
question. The presence of supportive relationships in the learning process was investigated
for the second question -order correlation
coefficients,based onthe results ofeach element.
The results for the first research question suggested easy, learnable and difficult
items, as follows. The items that were found to be easy were the vowel quality of
, the durational vowel distinctions in the pairs, the nucleus
placement in utterances where the nucleus commonly fell on the final word, the use of a
falling tone where it was typical, the span and the level. Learnable items were the
durational distinction, VOTs of and the distinction of aspirated and unaspirated
voiceless plosives in the contrast.Difficult items contained for vowel quality,
the distinction for vowel duration, VOT of , the distinction of aspirated and
unaspirated voiceless plosives in the contrast, both voiceless fricatives , both
approximants , all four properties to produce weak vowels (i.e. pitch, intensity, duration
and vowel centralization), the nucleus placement in utterances that were long or where the
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nucleus fell on the non-final word, the use of non-falling tones where they were typical, and
three connected speech phenomena, elision, CC linking and CV linking. These results
indicate that Japanese learners of English have more difficult items to learn in order to
produce,orforuse in production,thaneasyitemsandlearnable items.
As regards the second research question, vowel quality and approximants were
found to have a supportive relationship. Vowel quality and rhythm also suggested that they
might have some relationship. It follows that these elements of pronunciation are positively
related to one another, where they support each other to develop a
system in the learning process. Approximants and fricatives were also found to have a
relationship. Referringto the articulatorybehavior and the acoustic features ofthese elements,
this relationship was interpreted as due to a similar level of difficulty. There is a need for
further examination as to whether this relationship could lead them to support one another in
the learningprocess.
Although the current study focused on Japanese learners learning English
pronunciation, comparing their performances against those of native speakers, achieving a
native-speaker level of proficiency is not the only goal of learners. This study thus offers
practical implications for both Japanese learners who use English as a foreign language,
EFL-oriented learners, and Japanese learners who use English as a lingua franca,
ELF-oriented learners, as regards five potential goals of pronunciation. Comparing the
findings ofthis studywith the targetssuggested bythese potential goals, the items thatshould
be learnedtoattaineachgoal were specified.When learnersdefine the goalthat theywill aim
for, the findings of the present study will offer them more helpful guidelines for
pronunciation inlearningand teaching.
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Acknowledgements
My many thanks go to the two professors who supervised me through this research,
Prof. Yasuyo Sawaki and Prof. Michiko Nakano. Prof. Sawaki taught me how thoroughly
research should be conducted. I am certain that this dissertation would not be what it is now
without her. Every time Ifaced difficulties in workingon this dissertation, she comforted and
guided me, and that is exactly why I was able to continue on the right track. Prof. Nakano
taughtme how important it istocultivatea broaderviewoflookingatthings,and the world.I
have learned many things from her, and this was one of the most precious times in my life.
The energy she devotes to her research has always stimulated me, and it pushed me to come
this far.Ibelieve that Icouldnot have continued mystudywithout her encouragingwords.
Ialso would like to offer sincere gratitude tothree ofthe teacherswho brought me to
this point of writing my dissertation in the field of phonetics: Prof. Yoji Tanabe, Prof. Akira
Ishihara and Dr. Michael Ashby. I vividly remember the time I learned phonetics from Prof.
Tanabe. He taught us phonetics in my first year at Waseda University, and was my
introduction to the subject. Without the warm words of encouragement that he offered me on
my graduation thesis, this academic field would have seemed like another world to me. Prof.
Ishihara also had a great influence on me.I was one of the students whose pronunciation was
severely corrected most often in his class. He was the person who definitely made me think
about the English pronunciation I would like to learn and master. The education that I
received at Waseda University guided me to University College London, where I learned the
true depth of phonetics. Dr. Ashby supervised me, and taught me what a spectrogram tells us
and how fun it is to consider. If I had not encountered these teachers, I would not have been
so fascinated byphoneticsforsucha longtime.
Needless to say, I am deeply grateful to the two deputy chairs of the committee for
this dissertation: Prof. Hiroshi Matsusaka and Prof. Tetsuo Harada. Not only did both
teachers spare much time for reading this long dissertation, but theyalso offered constructive
comments on the various issues that this study covered, ranging over phonetic and
phonological knowledge and other possible approaches to the issues. They were both helpful
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and shrewd, and at the same time, encouraging and motivating. Their words will remain in
mymind,leadingme tothe next stage ofmyresearchlife.
Lastbut notleast,no words canexpress myappreciationto everyone around me who
supported me in every moment of my life. Thanks to them, I am able to hold the complete
work that is my dissertation. All the seminar members I studied with on Thursday nights, all
the staffIhave worked with,all myfriends andallmystudents without the timethatIspent
with them, I could not have kept working on this one thing. Finally, let me extend my warm
thanksto myfamily. Itisbecause ofyour generousand warmsupport that Iamherenow.
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Table of Contents
Chapter1Introduction............................................................................................................1
1.1. The purposes ofthe research........................................................................................1
1.2. Current issues...............................................................................................................2
1.3. Research questions.......................................................................................................7
1.4. Theoreticalbackground ...............................................................................................9
1.4.1. Modelsconcerninglearningsegments ofthe secondlanguage............................9
1.4.2. Modelsconcerninglearningintonationofthesecondlanguage.........................11
1.4.3. The theoretical background ofthe firstresearchquestion..................................12
1.4.4. The theoretical background ofthe secondresearchquestion.............................16
1.5. The outline ofthe dissertation....................................................................................19
Chapter2Literaturereview .................................................................................................20
2.1. Vowels........................................................................................................................21
2.1.1. Contrastive phonetics and phonologybetweenJapaneseand English...............21
2.1.2. LearningL2 vowels............................................................................................25
2.1.3. Acoustic measurementsof vowels......................................................................28
2.1.4. The current studyand hypothesesregardingvowelqualityand duration ..........30
2.2. Plosives......................................................................................................................33
2.2.1. Contrastive phonetics and phonologybetweenJapaneseand English...............33
2.2.2. LearningL2 plosives...........................................................................................37
2.2.3. Acoustic measurementsof plosives....................................................................39
2.2.4. The current studyand hypothesesregardingplosives........................................41
2.3. Fricatives....................................................................................................................43
2.3.1. Contrastive phonetics and phonologybetweenJapaneseand English...............43
2.3.2. LearningL2 fricatives.........................................................................................44
2.3.3. Acoustic measurementsof fricatives..................................................................46
2.3.4. The current studyand hypothesesregardingfricatives.......................................49
2.4. Approximants.............................................................................................................50
2.4.1. Contrastive phonetics and phonologybetweenJapaneseand English...............50
2.4.2. LearningL2 approximants..................................................................................51
2.4.3. Acoustic measurementsof approximants...........................................................54
2.4.4. The current studyand hypothesesregardingapproximants................................57
2.5. Rhythm.......................................................................................................................59
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2.5.1. Contrastive phonetics and phonologybetweenJapaneseand English...............59
2.5.2. LearningL2 rhythm............................................................................................60
2.5.3. Acoustic measurementsof rhythm......................................................................64
2.5.4. The current studyand hypothesesregardingrhythm..........................................67
2.6. Intonation...................................................................................................................69
2.6.1. Contrastive phonetics and phonologybetweenJapaneseand English...............69
2.6.2. LearningL2 intonation.......................................................................................72
2.6.3. Acoustic measurementsof intonation.................................................................77
2.6.4. The current studyand hypothesesregardingintonation.....................................78
2.7. Connectedspeechphenomena...................................................................................84
2.7.1. Contrastive phonetics and phonologybetweenJapaneseand English...............84
2.7.2. LearningL2 connectedspeech phenomena........................................................86
2.7.3. Acoustic measurementsof connectedspeechphenomena..................................90
2.7.4. The current study and hypotheses and research question regarding connected
speech phenomena............................................................................................................91
2.8. Relationships betweentheelements ofpronunciation...............................................93
2.8.1. Application ofthetheory....................................................................................93
2.8.2. The current study and research question regarding relationships between the
elementsof pronunciation.................................................................................................94
2.9. Summaryofthe chapter.............................................................................................95
Chapter3Methodology.........................................................................................................97
3.1. Subjects......................................................................................................................97
3.2. Materials....................................................................................................................98
3.2.1. Monophthongalvowels:vowelqualityand duration........................................100
3.2.2. Consonants:plosives,fricatives and approximants..........................................102
3.2.3. Rhythm..............................................................................................................103
3.2.4. Intonation..........................................................................................................106
3.2.5. Connectedspeechphenomena..........................................................................107
3.3. Recordingand procedure.........................................................................................109
3.4. Acoustic measurementsandanalyses......................................................................110
3.4.1. Monophthongalvowels:vowelqualityand duration........................................111
3.4.2. Consonants:plosives,fricatives and approximants..........................................111
3.4.3. Rhythm..............................................................................................................113
3.4.4. Intonation..........................................................................................................114
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3.4.5. Connectedspeechphenomena..........................................................................115
3.5. Statisticalanalyses...................................................................................................116
3.5.1. Monophthongalvowels:vowelqualityand duration........................................116
3.5.2. Plosives.............................................................................................................119
3.5.3. Fricatives...........................................................................................................120
3.5.4. Approximants....................................................................................................121
3.5.5. Rhythm..............................................................................................................122
3.5.6. Intonation..........................................................................................................124
3.5.7. Connectedspeechphenomena..........................................................................128
3.5.8. Relationships betweentheelements ofpronunciation......................................129
3.5.9. Preliminaryanalyses.........................................................................................131
3.5.10. Three statisticaltests forthe analysis ofeach element ofpronunciation......135
3.5.11. A statistical test for the analysis of the relationships between the elements of
pronunciation..................................................................................................................140
3.6. Criteria oflearning...................................................................................................141
Chapter4Results.................................................................................................................143
4.1. MonophthongalVowels...........................................................................................143
4.1.1. Vowel quality....................................................................................................143
4.1.2. Vowel duration..................................................................................................155
4.2. Consonants...............................................................................................................165
4.2.1. Plosives.............................................................................................................165
4.2.2. Fricatives...........................................................................................................173
4.2.3. Approximants....................................................................................................182
4.3. Rhythm.....................................................................................................................189
4.4. Intonation.................................................................................................................202
4.5. Connectedspeechphenomena.................................................................................218
4.6. Relationships betweentheelements ofpronunciation.............................................228
Chapter5Discussion...........................................................................................................240
5.1. Vowel quality...........................................................................................................240
5.1.1. Findings.............................................................................................................240
5.1.2. Hypotheses regardingvowelquality.................................................................241
5.2. Vowel duration.........................................................................................................244
5.2.1. Findings.............................................................................................................244
5.2.2. Hypotheses regardingvowelduration..............................................................246
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5.3. Plosives....................................................................................................................250
5.3.1. Findings.............................................................................................................250
5.3.2. Hypotheses regardingplosives .........................................................................252
5.4. Fricatives..................................................................................................................254
5.4.1. Findings.............................................................................................................254
5.4.2. Hypotheses regardingfricatives........................................................................256
5.5. Approximants...........................................................................................................258
5.5.1. Findings.............................................................................................................258
5.5.2. Hypotheses regardingapproximants.................................................................260
5.6. Rhythm.....................................................................................................................261
5.6.1. Findings.............................................................................................................261
5.6.2. Hypotheses regardingrhythm...........................................................................263
5.7. Intonation.................................................................................................................266
5.7.1. Findings.............................................................................................................266
5.7.2. Hypotheses regardingintonation......................................................................270
5.8. Connectedspeechphenomena.................................................................................273
5.8.1. Findings.............................................................................................................273
5.8.2. Hypotheses regardingconnected speechphenomena.......................................275
5.9. Relationships betweentheelements ofpronunciation.............................................277
5.10. General Discussion...............................................................................................279
5.10.1. Hypotheses and models.................................................................................280
5.10.2. Researchquestions........................................................................................285
Chapter6Practicalimplications........................................................................................288
6.1. AlearninggoalofEnglishpronunciation................................................................288
6.1.1. Needto reconsidera pedagogical goalofpronunciation..................................288
6.2. Potentialpronunciation goals...................................................................................291
6.3. Pronunciation goals forEFL-orientedlearners and ELF-orientedlearners.............292
6.3.1. Vowels...............................................................................................................294
6.3.2. Plosives.............................................................................................................298
6.3.3. Fricatives...........................................................................................................300
6.3.4. Affricates...........................................................................................................302
6.3.5. Approximants....................................................................................................303
6.3.6. Nasals................................................................................................................305
6.3.7. Syllabic consonants...........................................................................................306
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6.3.8. Consonantclusters............................................................................................306
6.3.9. Rhythm..............................................................................................................308
6.3.10. Stress.............................................................................................................310
6.3.11. Intonation.......................................................................................................311
6.3.12. Connectedspeechphenomena.......................................................................316
6.4. Summaryofthe chapter...........................................................................................318
Chapter7Conclusion..........................................................................................................320
7.1. Conclusion...............................................................................................................320
7.2. Limitations...............................................................................................................323
7.3. Furtherstudies..........................................................................................................325
References..............................................................................................................................328
AppendixA:Materials...........................................................................................................351
Appendix B:Target tokens forAN subjects ..........................................................................353
Appendix C:Dendrogram for vowelquality.........................................................................357
Appendix D:Correlations between the F1 variables.............................................................358
Appendix E:Correlations between the F2 variables..............................................................359
Appendix F:Dendrogram forvowelduration .......................................................................360
Appendix G:Correlations between the variables forvowel duration....................................361
Appendix H:Dendrogram forplosives..................................................................................362
Appendix I:Correlations betweenthe variables for plosives................................................363
Appendix J:Dendrogramforfricatives.................................................................................364
Appendix K:Correlations between the variables forfricatives.............................................365
Appendix L:Dendrogramforapproximants..........................................................................366
Appendix M:Correlationbetweenthe variablesforapproximants.......................................367
Appendix N:Correlations between the variables forrhythm................................................368
Appendix O:Resultsofthe pitchpatternsforthe target utterances......................................369
Appendix P:Dendrogram forintonation...............................................................................376
Appendix Q:Correlations between the variables forintonation ...........................................377
Appendix R:Dendrogram forconnected speech phenomena................................................378
Appendix S:Correlations betweenthe variables forconnectedspeechphenomena.............379
Appendix T: Results of the rate of level agreement between the two elements of
pronunciation forthe JLsubjects...........................................................................................380
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