An Ultrasound and Acoustic Study of

Turkish Rounded/Unrounded Vowel Pairs

by

Milica Radisic

A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Graduate Department of Linguistics University of Toronto

© Copyright by Milica Radisic 2014 An Ultrasound and Acoustic Study of

Turkish Rounded/Unrounded Vowel Pairs

Doctor of Philosophy; 2014

Milica Radisic

Linguistics Department, University of Toronto

Abstract

This dissertation grew out of a phonology course paper on the adaption of Turkish words in Serbian. The focus of the paper was on the Turkish vowels /ɯ y œ/. Noticeably, in contrast to vowels /y œ/, the back vowel /ɯ/ showed variable patterns of adaptation. The conclusion drawn from the paper was that the vowel /ɯ/ was different from other vowels. Interestingly, the Turkish vowel inventory is a crowded vowel system with three rounded/unrounded vowel pairs, two front vowel pairs (/i y/ and /e œ/), and one back vowel pair (/ɯ u/). And, while phonetic research has largely focused on front vowel pairs in other languages, I emphasize on the importance of the back vowel pair.

The dissertation examines the phonetics of Turkish vowels to determine acoustic and articulatory properties of vowels produced in different contexts. Four experiments were done, two describing vowels in isolation and two describing vowels in four different consonantal contexts, based on place of articulation.

First, I discuss the theory behind acoustics and articulation, by outlining theories of coarticulation and describing how the vowel /ɯ/ differs from other vowels. Then, I present methodology used in the dissertation.

Chapters 4 and 5 present results of articulation and acoustic experiments on vowels in isolation, while Chapter 6 and 7 present results of the articulation and acoustic experiments on vowels in consonantal contexts. Chapter 8 discusses the main findings.

ii The study discovered that the three rounded/unrounded vowel pairs are true pairs, as they do not articulatorily differ much in tongue height and frontness. Since they differ most consistently in F2, this confirms the non-linear relationship between articulation and acoustics. Both high back vowels /ɯ u/ are more prone to coarticulation in F2 than other vowels. Context variability, short duration, and absence of visual cues can explain why /ɯ/ behaves like no other vowel in loanword adaptations.

The dissertation enriches phonetic research by investigating the back vowel pair, by examining front rounded/unrounded vowel pairs in contexts, and by using quantitative ultrasound methodology. Also, it contributes to loanword research by accounting for loanword adaption of the back unrounded vowel /ɯ/.

iii Acknowledgments

First of all, I would like to thank my thesis supervisor, Keren Rice, for her enormous encouragement and support.

I am also thankful to the other two members of my committee, Alexei Kochetov and Yoonjung Kang, for their advice and helpful comments. I am also very grateful to Mary Hsu for her always present positive attitude.

Without a huge support from my family this dissertation would not have been accomplished.

iv TABLE OF CONTENTS

Chapter 1: Introduction 1

1.1 About the Topic: From Vowels in Loanwords to Rounded/Unrounded Vowel Pairs 1

1.2 Turkish Sound Inventory 7

1.3 Goals, Contributions, and Structure of the Dissertation 10

1.3.1 Goals 10

1.3.2 Contributions 11

1.3.3 Structure of the Dissertation 15

Chapter 2: Literature Review 17

2.1 The Theory 18

2.1.1 Acoustics and Articulation – General 18

2.1.2 Models of Articulation and Acoustics 21

2.1.2.1 High/Low, Front/Back Model 21

2.1.2.2 Palatal/Dorsal/Pharyngeal/Labial Model 24

2.1.2.3 Tubes, Nodes and Antinodes 25

2.2 Articulatory and Acoustic Studies on Rounded/Unrounded Vowel Pairs 29

2.2.1 High Front Rounded/Unrounded Pair 29

2.2.2 Mid Front Rounded/Unrounded Pairs 35

2.2.3 High Back Rounded/Unrounded Pair 40

2.2.4 Mid Back Rounded/Unrounded Pairs 43

2.2.5 Summary 46

2.2.6 Back or Central? 47

2.2.7 Comparing High Back and High Central Unrounded Vowels: /ɯ/ and /ɨ/ 49

2.3 High Back Unrounded Vowel /ɯ/ 51

v 2.3.1 The Place of Articulation of /ɯ/: Back or Central 52

2.3.2 Duration of /ɯ/: Is It Shorter than Other Turkish Vowels? 54

2.3.3 /ɯ/ in Loanwords 56

2.4 Coarticulation 60

2.4.1 Defining Coarticulation 60

2.4.2 Directionality of Coarticulation

61

2.4.3 Universality of Coarticulation 62

2.4.4 Domain of Coarticulation 64

2.4.5 Unit of Coarticulation 64

2.4.6 Time and Coarticulation 65

2.4.7 English Vowels and Coarticulation 66

2.4.8 Vowel Perception and Coarticulation 68

2.4.9 Reduced Vowels 69

2.4.10 Schwa 70

2.5 Research Questions and Predictions 72

2.6 Summary 78

Chapter 3: Experimental Methodology 79

3.1 Recording Articulation Using Ultrasound Imaging 79

3.2 A Short Overview of the Previous Ultrasound Studies on Vowels 82

3.2.1 Overall Tongue Contour/Shape 83

3.2.2 Using Coefficients 86

3.2.3 Measuring Real Distances in mm 87

3.3 Articulatory and Acoustic Measurements Used in the Study 88

vi 3.4 Equipment and Procedure 91

3.5 Participants 92

3.6 Stimuli 93

3.7 Analysis 94

3.7.1 Tongue Height and Tongue Frontness 97

3.7.2 Anteriority Index (AI) 98

3.7.3 Constriction Location and Constriction Degree 100

3.8 Statistical Analysis 102

3.9 Summary 104

Chapter 4: Experiment 1: Articulation of Sustained Vowels in Isolation 105

4.1 Tongue Shape 106

4.2 Tongue Height 116

4.3 Tongue Frontness 119

4.4. Anteriority Index 121

4.5 Summary and Discussion of the Articulatory Data 124

4.6 Constriction Location and Constriction Degree 132

4.7 Conclusion 137

Chapter 5: Experiment 2: Acoustics of Sustained Vowels in Isolation 139

5.1 F1 140

5.2 F2 143

5.3 F3 145

5.4 Summary and Discussion of the Acoustic Data 148

5.5 Articulation and Acoustics 153

5.6 Conclusion 159

vii

Chapter 6: Experiment 3: C-to-V Coarticulation with Vowel /ɯ/ - Articulation 161

6.1 Tongue Shape 163

6.2 Tongue Height 165

6.3 Tongue Frontness 168

6.4 Anteriority Index 171

6.5 Summary of the Articulation Data 175

6.6 Conclusion 181

Chapter 7: Experiment 4: C-to-V Coarticulation – Acoustics 182

7.1 C-to-V Coarticulation with Vowel /ɯ/ 184

7.1.1 F1 184

7.1.2 F2 187

7.1.3 F3 189

7.1.4 Summary of the Acoustic Data 192

7.1.5 Discriminant Analysis 198

7.1.6 Summary 200

7.2 C-to-V Coarticulation with Vowel /u/ 202

7.2.1 F1 202

7.2.2 F2 205

7.2.3 F3 208

7.2.4 Summary 209

7.2.5 Comparing the Vowel /ɯ/ and the Vowel /u/ 212

7.3 C-to-V Coarticulation with Vowel /i/ 213

7.3.1 F1 213

viii 7.3.2 F2 216

7.3.3 F3 218

7.3.4 Summary 221

7.4 C-to-V Coarticulation with Vowel /y/ 225

7.4.1 F1 225

7.4.2 F2 228

7.4.3 F3 230

7.4.4 Summary 232

7.4.5 Comparing the Vowel /i/ and the Vowel /y/ 236

7.4.6 Comparing the /i y/ Pair and the /ɯ u/ Pair 236

7.5 C-to-V Coarticulation with Vowel /e/ 237

7.5.1 F1 237

7.5.2 F2 240

7.5.3 F3 243

7.5.4 Summary 245

7.6 C-to-V Coarticulation with Vowel /œ/ 248

7.6.1 F1 248

7.6.2 F2 249

7.6.3 F3 252

7.6.4 Summary 254

7.6.5 Comparing the Vowel /e/ and the Vowel /œ/ 259

7.6.6 Comparing the /e œ/ Pair and the /i y/ Pair 259

7.7 C-to-V Coarticulation with Vowel /o/ 260

7.7.1 F1 260

ix 7.7.2 F2 263

7.7.3 F3 266

7.7.4 Summary 267

7.8 C-to-V Coarticulation with Vowel /a/ 272

7.8.1 F1 272

7.8.2 F2 275

7.8.3 F3 277

7.8.4 Summary 279

7.9 Vowels in Isolation and in Context: Contextualization and Centralization 283

7.10 Same Consonantal Contexts with Different Vowels 286

7.11 Duration 291

7.12 Preliminary Results with Real Words 293

7.13 Conclusion 294

Chapter 8: Discussion and Conclusion 296

8.1 Reviewing the Goals and the Contributions 296

8.2 Vowels in Isolation 298

8.3 Vowels in Context 308

8.4 The Vowel /ɯ/ 313

8.5 Summary 321

References 322

x List of Tables

Chapter 2

Table 1 27

Table 2 30

Table 3 34

Table 4 36

Table 5 38

Table 6 41

Table 7 44

Table 8 46

Table 9 48

Table 10 48

Table 11 50

Table 12 56

Table 13 58

Chapter 3

Table 1 93

Chapter 4

Table 1 131

Table 2 131

Table 3 131

Table 4 132

Chapter 5

Table 1 153

xi Table 2 154

Table 3 155

Table 4 156

Table 5 157

Table 6 157

Chapter 6

Table 1 162

Table 2 180

Table 3 180

Chapter 7

Table 1 183

Table 2 192

Table 3 198

Table 4 200

Table 5 209

Table 6 221

Table 7 232

Table 8 245

Table 9 255

Table 10 267

Table 11 279

Table 12 289

Chapter 8

Table 1 300

xii Table 2 301

Table 3 303

Table 4 307

Table 5 309

xiii List of Figures

Chapter 1

Figure 1 1

Figure 2 1

Figure 3 8

Figure 4 8

Figure 5 10

Chapter 2

Figure 1 21

Figure 2 24

Figure 3 26

Chapter 3

Figure 1 81

Figure 2 84

Figure 3 89

Figure 4 92

Figure 5 96

Figure 6 98

Figure 7 99

Figure 8 101

Chapter 4

Figure 1 107

Figure 2 109

Figure 3 111

xiv Figure 4 113

Figure 5 115

Figure 6 117

Figure 7 118

Figure 8 119

Figure 9 120

Figure 10 122

Figure 11 123

Figure 12 126

Figure 13 127

Figure 14 128

Figure 15 129

Figure 16 130

Figure 17 133

Figure 18 134

Figure 19 136

Chapter 5

Figure 1 140

Figure 2 142

Figure 3 143

Figure 4 145

Figure 5 146

Figure 6 147

Figure 7 149

xv Figure 8 151

Figure 9 152

Figure 10 155

Figure 11 157

Chapter 6

Figure 1 163

Figure 2 164

Figure 3 165

Figure 4 166

Figure 5 168

Figure 6 169

Figure 7 171

Figure 8 172

Figure 9 174

Figure 10 175

Figure 11 176

Figure 12 177

Figure 13 178

Figure 14 179

Chapter 7

Figure 1 185

Figure 2 186

Figure 3 187

Figure 4 188

xvi Figure 5 190

Figure 6 191

Figure 7 194

Figure 8 196

Figure 9 203

Figure 10 204

Figure 11 206

Figure 12 207

Figure 13 208

Figure 14 210

Figure 15 214

Figure 16 215

Figure 17 216

Figure 18 217

Figure 19 219

Figure 20 220

Figure 21 223

Figure 22 226

Figure 23 227

Figure 24 228

Figure 25 229

Figure 26 231

Figure 27 234

Figure 28 238

xvii Figure 29 239

Figure 30 241

Figure 31 242

Figure 32 243

Figure 33 244

Figure 34 246

Figure 35 249

Figure 36 250

Figure 37 251

Figure 38 253

Figure 39 254

Figure 40 257

Figure 41 261

Figure 42 262

Figure 43 264

Figure 44 265

Figure 45 266

Figure 46 270

Figure 47 273

Figure 48 274

Figure 49 275

Figure 50 276

Figure 51 278

Figure 52 281

xviii Figure 53 284

Figure 54 286

Figure 55 287

Figure 56 288

Figure 57 289

Figure 58 291

Chapter 8

Figure 1 306

xix CHAPTER 1

INTRODUCTION

1.1 What Prompted the Thesis

Although this dissertation is a study on the phonetic properties of the Turkish vowels in context, I would like start by explaining what prompted me to look at the Turkish vowels. A few years ago, I did a phonology paper on the patterns of adaptation of Turkish loanwords into

Serbian. There are a large number of well-established Turkish loanwords in Serbian as a result of a five century Turkish occupation of Serbian territory, from the 14th to the 19th century. The focus of the paper was the adaptation of vowels. Figure 1 and 2 illustrate Turkish and Serbian vowel inventories, respectively.

ɯ

œ

Figure 1. Turkish vowels Figure 2. Serbian vowels

The Turkish vowel system /i y e œ ɯ u o a/ (Figure 1, based on IPA1999) differs from the

Serbian vowel system /i e u o a/ (Figure 2, based on IPA1999 and Miletić 1933) in that

Turkish has three extra vowels that Serbian does not have /y œ ɯ/ (e.g. Zimmer and Orgun

1999)1. Thus, while Turkish actively employs rounding to distinguish between vowel pairs of the same frontness and height, Serbian does not.

1 Different studies use different symbols to represent Turkish vowels. See section 1.2 for discussion. For convenience, I choose to represent Turkish vowels based on Zimmer and Orgun 1999 (IPA). 1 How does the Serbian sound system deal with these three extra vowels? Generally, there are two different adaptation patterns. One adaptation pattern is straightforward – Turkish front rounded vowels /y œ/ are adapted as Serbian back rounded vowels /u ɔ/, as in (1)

(Radisic 2008)2.

Turkish Serbian Turkish Serbian

1 /kyp/ [tɕup] ‘jug’ b. /bœrek/ [burek] ‘pie’ a.

/kynk/ [tɕunak] ‘drain pipe’ /bœrek/ [bubreg] ‘kidney’

c. /dœrt/ [dort] ‘road’

/kœʃe/ [tɕoʃe] ‘corner’

In 1a, Turkish /y/ is adapted as Serbian [u]3. In 1b and 1c, Turkish /œ/ is adapted either as

Serbian [u] or [o], depending on whether there is an adjacent labial consonant present or not.

Assuming features for roundness, height and backness, the features marking rounded/unrounded and high/low are preserved at the expense of the features front/back. We can say that the adaptation of /y/ is phonological in nature. The phonological view of loanword adaptation argues that borrowers identify phonemic categories, “operating on the mental representation of an L2 (second language) sounds” (LaCharité and Paradis 2005:223). This presupposes that borrowers are familiar with L2 phonology, and are, in fact, bilingual speakers of both the native and the L2 language (e.g. LaCharité and Paradis 2005, Paradis and

LaCharité 1997). Thus, in our case, Serbian borrowers tap into the Turkish phonological

2 Following common practice, I use slashed brackets for the loanwords input, although it is not certain whether Serbian borrowers had access to the underlying form of Turkish words. 3 Consonantal changes/adaptations will not be addressed in this study. 2 system, and manipulate phonological features of the Turkish vowel /y/ during the adaptation process.

On the other hand, the adaptation of /œ/ is the result of the interplay of phonological and phonetic factors. In particular, high rounded vowels are, generally, articulated with more rounded lips than mid vowels. High vowels are generally more close – produced with a raised jaw, while mid rounded vowels are more open - produced with a lowered jaw (e.g. Kaun 1995,

Linker 1982). The close vowel allows for more rounded lips. Due to a coarticulation effect, a labial consonant, produced with a narrow constriction at the lips, influences the mid vowel, so that the vowel is articulated with a more narrow lip constriction than when produced in isolation. The phonetic view of loanword adaptation argues that borrowers pay attention to the acoustic and visual signal. In this case, an L2 phoneme is adapted based on its surface representation, which can be influenced by surrounding sounds (e.g. Peperkamp and Dupoux

2003, Vendelin and Peperkamp 2004). In our case, Serbian borrowers are aware of and take into account the acoustic and visual effect that a labial consonant exerts on the vowel /œ/, interpreting it as the high vowel [u]. There is evidence that roundedness is prominent in

Turkish, in the sense that a rounded vowel in a word spreads its roundedness to other non- adjacent vowels in the same word, as the presence of vowel harmony and an articulatory study on Turkish shows (Boyce 1988, 1989). While the phonological and phonetic approaches present opposite strategies in loanword adaptation, there is enough evidence to support a mixed account of loanword adaptation, according to which borrowers sometimes focus more on phonemic categories, and sometimes more on phonetics, but rarely use one or the other exclusively (e.g. Dohlus 2005; Heffernan 2005; Kang 2010; Yip 2002). Thus, the pattern of adaptation of the vowel /œ/ in Serbian is best explained by using reference to both phonology and phonetics.

3 Based on the patterns of adaptation described above, we might expect the Turkish /ɯ/ to be generally adapted as Serbian [i], since both are unrounded and high, and differ in the front/back dimension; we might or might not expect some phonetic variation similar to that found with the adaptation of the Turkish /œ/. However, this expectation is not met; /ɯ/ is adapted as all five Serbian vowels [i e u o a], depending on the word (2).

Turkish Serbian

2 a. /bahʃɯʃ/ [bakʃiʃ] ‘tip’

b. /barɯm/ [barem] ‘at least’ * [barim]

c. /jastɯk/ [jastuk] ‘pillow’ * [jastik]

d. /tɕadɯr/ [tɕador] ‘tent’ * [tɕadir]

e. /satɯr/ [satara] ‘meat cleaver’ * [satira]

Examples, 2 a-e show that the Turkish vowel /ɯ/ is adapted in Serbian: as [i] (2a), [e] (2b), [u]

(2c), [o] (2d) and [a] (2e). If the adaptation of the unrounded /ɯ/ had followed the same pattern as the adaptation of the rounded /y œ/, /ɯ/ in these words would have been adapted as

[i], with the preservation of the rounding and height features. However, this is not the case, as is clearly shown by the unattested forms in the right hand column. Thus, the pattern of adaptation of /ɯ/ differs from the patterns we have seen with the two rounded vowels /y œ/, and it can hardly be explained as purely, or mostly, phonological in nature.

Moreover, the adaptation of /ɯ/ differs in yet another way from the adaptation of /y œ/; namely /ɯ/, and no other vowel, is often deleted next to /r/ (3).

(3) Turkish Serbian Turkish Serbian a. /kaldɯˈrɯm/ [kaldrma] d. /tœrˈpu/ [turpija] ‘file’ *[trpija]

‘cobblestone’

4 b. /ˈsɯrtʃa/ [srtʃa] ‘broken e. /tyrkiˈje/ [turska] ‘Turkey’ *[trska]

glass’ c. /baˈkɯr/ [bakar] ‘copper’ f. /derˈviʃ/ [derviʃ] *[drviʃ]

In 3a-b, the vowel /ɯ/ next to /r/ is deleted; in 3c, the vowel /ɯ/ next to the word-final /r/ is not deleted; in 3d-f, other vowels, such as /œ y e/ next to /r/, are not deleted either. Deletion does not depend on whether the Turkish vowel /ɯ/ is stressed or not, as 3a shows. This situation is yet another clue that /ɯ/ is somehow different from the other two adapted vowels

/y œ/ (and other Turkish vowels in general). It has been noticed in a number of languages that consonant clusters (predominantly those having liquids as the second element) frequently contain a non-phonological vowel in between – a so-called svarabhakti vowel, whose acoustic properties can match the acoustic properties of the mid central schwa (e.g. for German,

Jannedy et al. 2008; for Spanish, Colantoni and Steele 2005, Ramírez 2006; for a cross- linguistic overview, Hall 2003, 2006). Serbian allows more complex consonant clusters than

Turkish, and, also, has a syllabic /r/, such as in the word /kərəv/ ‘blood’. It is then possible that

Serbian borrowers perceive /ɯ/ as a svarabhakti vowel because of its acoustic properties, and do not acknowledge it as a full-fledged vowel with phonological status.

These findings raised some interesting questions: Why does the pattern of adaptation of the unrounded /ɯ/ differ from the patterns of adaptation of the two rounded vowels /y œ/? And how can this pattern of adaptation best be explained? Is the vowel /ɯ/ particularly susceptible to the influence of surrounding consonants, more so than other Turkish vowels? If so, then its articulation and/or perception might vary substantially from one consonantal environment to another in Turkish. Is the Turkish vowel /ɯ/ very short, shorter than other Turkish vowels? If

5 so, then it might be perceived by Serbian borrowers as the svarabhakti vowel, a vowel which appears preceding and/or following Serbian syllabic /r/.

A review of the literature revealed that there is a disagreement among scholars on two of the phonetic properties of the vowel /ɯ/ in Turkish, its place of articulation and its duration.

First, some scholars claim that /ɯ/ is the shortest Turkish vowel, while others do not agree

(more about this in section 2.3.2). Second, some scholars claim that /ɯ/ is a central vowel, while others claim that it is back (more about this in section 2.3.1).

Further literature review revealed that there were no phonetic studies done on the vowel /ɯ/ in consonantal contexts, in Turkish or other languages; nor were there studies on such a complex vowel system with three rounded/unrounded vowel pairs. Turkish has three pairs of rounded/unrounded vowels, which is not very common. Cross-linguistically we can say that, in that sense, Turkish has a crowded vowel inventory. While some phonetic studies have been done on the high front rounded/unrounded vowel pair /i y/ in different languages, there are comparatively fewer studies done on the mid pairs /e ø/ and /ɛ œ/, while the back rounded/unrounded pairs /ɯ u/, /ɤ o/ and /ʌ ɔ/ have been rather neglected in phonetic research.

Moreover, the effect of different consonantal contexts on high back rounded/unrounded vowels has not been given full attention. How does a vowel system with both back and front rounded/unrounded pairs pattern phonetically, in various contexts? Only a member of one of these pairs shows unexpected and puzzling behaviour in loanword adaptation, and that member happens to belong to the back vowel pair. Is there something special about this pair compared to the front pairs, or is there something special about this vowel compared to the other two unrounded members? And, if so, what is it?

Answers to these questions can be pursued only if the vowel /ɯ/ is studied as an integral part of a vowel inventory, in this case the Turkish vowel system. There are other,

6 more specific, reasons for doing a study on the whole vowel system. First, in a crowded vowel system like Turkish, with four vowels of the same height (high vowels), how much variability is one vowel allowed? If one vowel exhibits considerable variability, does it mean that other vowels of the same height are more restricted in their variability? Second, since patterns of adaptation differ between the front rounded /y œ/ on the one hand, and the back unrounded

/ɯ/, on the other, is there also a difference in the amount of variability these vowels exhibit in different consonantal contexts? Third, are all unrounded vowels equally prone to coarticulation, and are all rounded vowels less susceptible to it?

In order to test whether loanword adaption can be explained by exceptional coarticulation susceptibility and shortness of the vowel /ɯ/, and in order to determine the actual place of articulation of the vowel /ɯ/, in comparison to the other Turkish vowels, I undertook an articulation and acoustic study of the Turkish vowels in different consonantal contexts.

1.2 Turkish Sound Inventory

The Turkish phonological vowel system is of primary importance to the current study simply because the study is about the phonetics of Turkish vowels. In order to understand the phonetics, it is important to discuss the Turkish vowel inventory, as there are conflicting accounts on the exact nature of Turkish vowels. This section thus presents the vowel system.

The consonantal inventory is also presented here, since some of the experiments (namely, experiments 3 and 4, on coarticulation) contain stimuli with vowels in four consonantal contexts that differ in place of articulation.

Turkish belongs to the Altaic/Turkic language family, and is spoken predominantly in

Turkey, but also in several Balkan countries (e.g. Greece, Bosnia) and Uzbekistan (Lewis

7 2001). The consonant and vowel phonemic inventories are shown in Figures 3 and 4, respectively. Vowels and consonants are presented following Zimmer and Orgun (1999).

Labial Coronal Dorsal Glottal Consonants Labio- Post- Bilabial Dental Alveolar Palatal Velar dental alveolar Stop p b t d c ɟ k g Fricative f v s z ʃ ʒ γ h Affricate tʃ dʒ Nasal m n ɾ Tap Approximant j Lateral ɫ l Approximant Figure 3. Turkish consonants Turkish has a medium-size consonant inventory, with four major places of articulation for stops and fricatives. Some studies argue that palatal stops [c ɟ] and the lateral [l] are allophones of the stops /k g/ and the lateral /ɫ/, respectively (e.g. Swift 1963), because they occur only preceding front vowels in Turkish native words; in words of foreign origin, /c ɟ l/ contrast with

/k g ɫ/.

ɯ

œ

Figure 4. Turkish vowels

For my study, the vowels are of primary interest. According to Zimmer and Orgun’s (1999) vowel classification, Turkish has high front vowels /i y/, mid front vowels /e œ/ and high back vowels /ɯ u/. This vowel classification is based on acoustic data, and presented in the classic

8 form of the acoustic quadrilateral, where both mid front Turkish vowels have similar F1 values4. By convention, the acoustic quadrilateral, so frequently used in phonetics, represents

F1 values on an inverted y-axis and F2 values on an inverted x-axis. F1 values are inversely proportional to tongue/vowel height, and F2 values reflect tongue/vowel frontness. The only low vowel /a/ is front-central. The data is based on a speaker of standard Turkish, from

Istanbul (North West of Turkey).

Turkish vowels have, however, been described in different ways. For instance, according to Kiliç and Öğüt (2004), Turkish has the low front rounded/unrounded pair /ɛ œ/, the mid low back vowel /ɔ/, and the low back unrounded vowel /ɑ/ (5 speakers from South and

South East of Turkey). However, in most studies, the articulation of vowels is not described in detail, and, traditionally, the symbols used are the Turkish orthography symbols i ü e ı u ö o a.

Thus, if a study labels a vowel ı, we cannot tell whether the authors actually subscribe to it as being articulatorily back or central. Moreover, some authors tend to call /ɯ/ central, and what they mean is, in fact, central “acoustically”, i.e. having its F2 values midway in-between /i/ and /u/ (Esling 1994, Ergenç 1989, Selen 1979, as cited in Kiliç and Öğüt 2004). Thus, we need to be careful about the label “central”. In the present study, the label central refers only to articulatory properties.

Turkish also has four long vowels /aː eː iː uː/, which have the same vowel quality

(except length) as the short corresponding vowels (Underhill 1976).

The dominant phonological process in Turkish is vowel harmony, where front vowels combine with front vowels /i y e œ/, back with back /ɯ u o a/, and high vowels /i y ɯ u/ agree in roundedness with high vowels. Since high rounded and unrounded vowels do not mix, /ɯ/ can occur in the same word only with /ɯ/ and /a/ (e.g. Clements and Sezer 1982; Lewis 2001;

4 More about F1 and F2 in section 2.1. 9 Underhill 1976; Yavas 1980). This eliminates the phonetic influence (coarticulation effect) of rounded and front vowels on /ɯ/. Thus, /a/ is phonologically back.

From the phonological perspective, the Turkish vowel system is generally represented as high front vowels /i y/, high back vowels /ɯ u/, front non-high vowels /e œ/ and back non- high vowels /a o/.

Vowels Front Back High i y ɯ u Non-high e œ a o Figure 5. Turkish vowels based on vowel harmony

Thus, phonologically, Turkish has two levels of height, high and non-high, where /a/ is not treated as a low vowel, and where there is no difference between mid-high and mid-low vowels; also, Turkish has two levels of frontness, front and back, and two levels of rounding.

In sum, while phonological studies agree on the nature of Turkish vowels, based mostly on the evidence from vowel harmony, phonetic studies do not agree on the nature of some vowels, including /ɯ/ and /a/. As the vowels /ɯ/ and /a/ are phonologically back, are they also phonetically back?

1.3 Goals, Contributions, and Structure of the Dissertation

1.3.1 Goals

The immediate goal of this work is to investigate the phonetic nature of the three Turkish rounded/unrounded vowel pairs /i y/, /e œ/, and /ɯ u/. Further, using the Turkish vowel system as a representative of a vowel system crowded with rounded/unrounded vowel pairs, the study particularly focuses on the back rounded/unrounded vowel pair /ɯ u/ and the vowel /ɯ/.

Through this investigation, the answers to the following questions are sought. In a complex vowel system like Turkish, do rounded members of vowel pairs /y œ u/ phonetically

10 differ in the same way from their unrounded counterparts /i e ɯ/? In other words, do pair members differ only in lip rounding? Or, do the members of the rounded/unrounded vowel pairs differ in other ways as well, such as tongue fronting and/or height? If so, does this apply to all pairs, or to only some of them? Does their backness play a crucial role, or their height?

For instance, does the back vowel pair /ɯ u/ differ from the front vowel pairs /i y/ and /e œ/, or do the high vowel pairs /i y/ and /ɯ u/ differ from the mid vowel pair /e œ/? Or, do all these three pairs differ from each other?

I look for the answers to these and other questions using two different phonetic methods, acoustics and articulation, and examining vowels produced in isolation and in context.

1.3.2 Contributions

This study makes contributions to several areas of phonetics, phonology and loanword adaptation.

First, the thesis studies in detail the acoustics and articulation of a complex/crowded vowel system consisting of three rounded/unrounded vowel pairs. Some studies have been done on rounded/unrounded vowels, but very few on back pairs. Most of these studies have been done on the high front pair in four European languages (Dutch, Finnish, French, German) and Chinese (for an overview of studies, see Wood 1979, 1982), and it has been noticed that

/y/ has a tendency to be articulated lower and less front than /i/. Also, /ø/ is lower and less front than /e/ in Dutch, and the mid low rounded/unrounded pair /ɛ œ/ is not a true pair, and differs qualitatively from both the high pair and the mid high pair (Raphael et al. 1978). Such research has not been done on back rounded/unrounded vowel pairs. Should we expect that the

11 rounded /u/ will be lower and less front than the unrounded /ɯ/, because the front pairs differ this way?

Turkish is a typologically rare language with respect to the number of high vowels, 4, and the number of rounded/unrounded vowel pairs, 3. The most common vowel system is a 5- vowel system /i e a o u/ (e.g. Maddieson 1984). In the high/low dimension, it is most common to have three vowel contrasts, high, mid and low, while in the front/back dimension, it is most common to have two vowel contrasts, front and back. The most common high vowels are /i u/.

Thus, the front vowel is usually unrounded and the back vowel is usually rounded. One of the explanations for this is that /i/ and /u/ are most distinct acoustically, with /i/ having the largest distance between F1 and F2 values and /u/ the smallest. There are languages which contrast up to four vowels in the high/low dimension, such as English with 4 unrounded front vowels of different height /i ej ɛ æ/5. Also, there are languages that contrast up to three vowels in the front/back dimension, such as Nimborean (Papuan language family), with 3 high unrounded vowels, front, central and back, /i ɨ ɯ/ (Ladefoged and Maddieson 1996), or Norwegian, with

3 high rounded vowels /y ʉ u/ (Ladefoged 2005).

The UPSID database (Maddieson and Precoda 1992) contains only five languages, besides Turkish6, which contrast front rounded/unrounded vowels and back rounded/unrounded vowels /i y u ɯ/, which is 1.1% (5 out of the 451 languages represented): Chuvash and Yakut

(Altaic, spoken in Russian Federation), Highland or Quiotepec Chinantec (Oto-Manguean, spoken in Mexico), Korean (isolate, spoken in Korea) and Naxi (Sino-Tibetan, spoken in

China). Therefore, although it is not frequent for languages to have four high vowels, two rounded /u y/ and two unrounded /i ɯ/, these five languages belong to four language families,

5 English also has /ɪ/, and /i/ and /ɪ/ differ somewhat in that /i/ has a higher F1. However, it is generally assumed that another dimension, such as tenseness or length, is the primary property that distinguishes best between the two vowels. For a detailed discussion, see, for example, Maddieson and Ladefoged (1985). 6 UPSID lists Turkish as “Osmanli”, and describes the four vowels as “lowered” variations of those vowels. 12 and to three separate language areas – Europe, South America and Asia - so it does not seem to be a genetic (shared by the majority of the members of the same language family, as they evolved from the common ancestor language) or areal (shared by the majority of neighbouring languages, whose language families might differ) feature, but rather an individual development. Of these 5 languages, only Yakut has also a mid low front rounded/unrounded pair /ɛ œ/7 8. In sum, the present study is the first in-depth phonetic study of a typologically unusual vowel system with three rounded/unrounded vowel pairs, front and back.

Second, the study contributes to a better understanding of back rounded/unrounded vowel pairs. There are no in-depth studies of the back rounded/unrounded vowel pairs, in comparison to the front rounded/unrounded vowel pairs, although high back vowel pairs occur more frequently than front (UPSID, 9.1% vs. 5.8% of the 451 included languages). The reason is, most likely, related to speaker availability – front rounded/unrounded vowel pairs are common in European languages, including French, German, and Dutch, while back rounded/unrounded vowel pairs do not occur in European languages. Moreover, in a number of Asian languages, including Turkish, the literature is not quite clear with respect to whether there is such a pair, or whether there is the back rounded /u/ and the central unrounded /ɨ/ instead (see Kiliç and Öğüt 2004 and section 1.2). Are these unrounded vowels really phonetically back, or central? If the literature on front vowels finds that the unrounded

7 In his survey of front rounded vowels, Maddieson (Haspelmath et al. 2005) argues that front rounded vowels are concentrated mostly among European and Asian languages (29/37 languages), while the remaining 8 languages ”are widely scattered, and the reports are not always sufficiently detailed to be relied on with confidence”: 4 in Americas, 3 in the Pacific region and 1 in Africa (2005:50). Thus, front rounded vowels most likely are an areal feature – they spread from one language to another: “It seems likely that the hearing of sounds of this sort in some languages of the area may have given further support to phonetically natural processes in other languages, with the end result being the addition of front rounded vowels to the inventory of more of the languages” (2005:51). However, it would not be so easy to connect Breton here, for example, which is Indo-European and spoken in France (UPSID, Maddieson and Precoda 1992). See also George et al. (1999) on the discussion of Proto-Altaic languages: Do the similarities arise because of the genetic or the areal influence? 8 There is some disagreement about the Korean vowel system. For more information, see, for example, Ahn and Iverson (2004), Lee (1999), Yang (1996). 13 counterpart is more front and higher, should we expect the same relationship to hold with the back vowel pair? And if /ɯ/ is more front, and articulated without lip rounding, does this explain why it is often treated as a central vowel, because, acoustically, its F2 comes close to a central vowel F2? Is there anything about that vowel that makes it special, compared to the other five Turkish vowels that belong to rounded/unrounded pairs? For example, is it shorter?

Is it more malleable, and more prone to the influence of the surrounding sounds? How does it compare to /u/ in these respects? Or, is /ɯ/ phonologically unmarked, and as such, more prone to the spreading of features from adjacent consonants?

Third, this thesis is the first to look at the adaptation patterns of the high back unrounded vowels in different languages. Four different adaptation patterns were found for /y/ in the literature. In loans from French into several languages, /y/ is adapted in various ways, primarily as /i/ in Fula, Kinyarwanda, Lingala and Spanish; /y/ is adapted equally as /u/ and /i/ in Moroccan Arabic (Paradis and Prunet 2000). Another pattern of adaptation, named

“unpacking”, is found in the adaptation of German and French vowels in Japanese (Dohlus

2004, 2010), as well as in Vietnamese and Fon, where /y/ becomes /wi/ (Barker 1969 and

Gbéto 2000, data from Dohlus 2010). Little work has been done on the adaptation of mid front round vowels. Dohlus found that German mid rounded vowels /ø œ/ are adapted as /e/ in

Japanese, the same French vowels are adapted as /u/ in Japanese, as /ə/ in Vietnamese, and as

/ɛ/ in Fon (data from Dohlus 2010). However, there are no studies that deal with the adaptation of the back unrounded vowels.

I examined Turkish vowels in loanwords in languages that differ genetically, including

Serbian, Bulgarian, (Slavic), Greek (Greek), Albanian (Albanian), Romanian (Romance) (all these languages are from the Indo-European language family) and Hungarian (Uralic family)

(all languages belong to the same language area). Some of these languages have different

14 vowel inventories, and some the same. On the one hand, languages with the same vowel system have different adaptation patterns. For instance, in Greek, which has the same vowels as Serbian, /i e a u o/, the same three extra vowels are adapted based on their height and roundedness in the following way: /y/  [u], /ø/  [o], /ɯ/  [i]. Thus, when looking only at

Serbian, we might assume that /ɯ/ is somehow phonetically different from the other vowels, for instance, more prone to coarticulation; however, the Greek pattern of adaptation seems to contradict that, as Greek borrowers treat /ɯ/ straightforwardly as other vowels. Does this mean that /ɯ/ is not by its nature more prone to coarticulation or more malleable than other vowels?

Does it rather mean that coarticulation is variously perceived in different languages? On the other hand, there are languages which contain some form of a mid central or a mid back unrounded vowel; they have a clear pattern of /ɯ/ adaptation. Loanwords are dealt in more detail in section 2.3.3.

The fourth major contribution of my thesis is to phonetic methodology. Although vowels have been studied using various articulatory methods (x-ray, MRI, ultrasound, EMA), most of the studies have looked at front rounded/unrounded pairs. With respect to back unrounded vowels, one MRI study has been done on Korean (Yang 1992), and another on

Turkish (Kiliç and Öğüt 2004), focusing on four vowels in isolation. Both studies are quantitative. The present study provides quantitative measurements (Tongue Height and

Frontness, and Anteriority Index) and statistical analysis, where applicable, using ultrasound imaging of the tongue.

1.3.3 The Structure of the Dissertation

The thesis is divided into eight chapters. Chapter 2 gives theoretical background on rounded/unrounded vowel pairs and a summary of phonetic acoustic and articulatory studies

15 on rounded/unrounded vowel pairs. The theory behind coarticulation is also presented, and there is a separate section on the issues surrounding /ɯ/. Chapter 2 ends with several hypotheses addressed through the experiments. Chapter 3 describes the experimental set-up in detail. In Chapters 4, 5, 6 and 7, acoustic and ultrasound experiments are presented, with vowels in isolation (Chapter 4 and 5) and in context (Chapter 6 and 7). Chapter 8 discusses the main findings from the previous four chapters, and connects the finding with the larger questions the thesis asks; it also concludes the dissertation.

16 CHAPTER 2

LITERATURE REVIEW

As discussed in Chapter 1, this study has a twofold goal: to determine the phonetic properties of the three rounded/unrounded vowel pairs in Turkish, with special emphasis on the back rounded/unrounded vowel pair /ɯ u/ and, in particular, to determine the phonetic properties of the Turkish vowel /ɯ/. These two goals are accomplished by investigating the articulation and acoustics of Turkish vowels in isolation and in different consonantal contexts. Although the focus is on the six Turkish vowels that comprise the three pairs, the other two vowels /o a/ are included in the study, since vowels are treated as a system.

Since the study investigates the acoustic and articulatory properties of Turkish vowels, it is valuable to present background on acoustic and articulatory theory, and discuss the relationship between them when it comes to vowels. For instance, if /i/ is articulated with the front part of the tongue raised (articulation), and this is manifested as low F1 and high F2 formants (acoustics), it is important to understand theoretically what “low” and “high” mean, and how articulation relates to acoustics. Section 2.1 reviews general acoustic and articulatory theory behind the production of sounds, with emphasis on vowels and, specifically, rounded/unrounded vowel pairs. It also explains concepts such as formants (F1, F2, F3), nodes and antinodes.

In addition to understanding the theory, it is important to examine some of the studies that have been done on the articulation and acoustics of vowels. Section 2.2 summarizes relevant studies done on the articulation and acoustics of rounded/unrounded vowel pairs.

Section 2.3 focuses specifically on the high back unrounded vowel, and the problems and questions that surround it, as there is some indication that it behaves in a peculiar way.

17 As the study aims at describing vowels in their “pure” form, unaffected by the environment, as well as when they are affected by the environment (coarticulation), section 2.4 outlines coarticulation theories, focusing on issues relevant to the topic in question, and presents some studies done on coarticulation of vowels which are of immediate use for the study. Finally, combining theoretical knowledge with empirical, we can better predict the outcome of the current study, and explain the results (section 2.5). Section 2.6 summarizes

Chapter 2.

2.1 The Theory

This section gives an overview of articulation and acoustic theory, with a focus on vowel production.

2.1.1 Acoustics and Articulation – General

Speech is an act of communication that in its simplest form consists of a speaker and a listener. When it comes to sounds, the most basic question linguists ask is what the speaker does with his/her speech organs in order to produce speech sounds that the listener can identify in a particular manner. The listener identifies the sounds predominantly on the basis of the acoustic information coming from the physical properties of the speech sound wave produced by the speaker; visual cues can also be important in sound identification (e.g. Johnson et al.

2007, Johnson and Mackenzie 2006, Winters 2000). For example, when the listener hears /i/, the speaker’s speech organs must be positioned in order to produce sound waves of particular frequencies that the listener identifies as /i/, and not, for instance, as /e/ or /u/. Thus, articulation and acoustics are necessarily connected in a speech act. If we record and analyze the movements of the tongue and the lips in order to describe how vowels are articulated, we

18 would be focusing only on the speaker’s part of the speech chain, and neglecting the hearer.

Alternitavely, if we record the speech sound waves, analyze them and describe acoustic properties of speech sounds, we would again be focusing only on one part of the speech chain, the receiving end, and neglecting the speaker.

Thus, articulation and acoustics are connected, and if we have information about one of them, we can, to a certain extent, make inferences about the other: based on acoustic theory, we can make inferences as to what is happening in the vocal tract, and, vice versa, based on what is happening in the vocal tract we can make some predictions about the acoustic outcome.

Acoustic and articulatory recordings both began to be used for speech sound research at the end of the 19th century (Kühnert and Nolan 1999, Wood 1982). Acoustic recording became more popular and developed more quickly, since it is more convenient for the researcher and the participant - it requires only a simple recording device and a microphone, compared to the expensive machines, complicated to manipulate, that are typical for articulatory studies. For these reasons, researchers have mostly relied on acoustic recording and have inferred articulatory data from it.

Yet inferring what is happening with speech organs, although sometimes straightforward, can, in some instances, prove to be ambiguous. In particular, one acoustic property of the speech sound wave can refer to more than one articulatory event. This is, for instance, the case with rounded/unrounded vowel pairs. To take a particular example, constriction at the lips lowers F1, and, since /y/ has a constriction at the lips, and /i/ does not, we might expect the rounded /y/ to have lower F1 than the unrounded /i/. If in a particular language we find the opposite - /y/ F1 is higher than /i/ F1 - can we infer what is happening with the speech organs that causes this unexpected result? Is the lip constriction area the same

19 for both vowels? Is /y/ articulated with the tongue body lower than /i/? Or, is it a combination of the two?

As an answer to such questions we can make speculations like those above. Or we can record the production of vowels using an articulatory method and see what is really happening with the speech organs. Articulatory methods differ, and some of them give more satisfactory answers than others, depending on what is being studied. For instance, MRI and x-ray give a more complete video image of the whole oral cavity, including the lips, while the possibilities of ultrasound are more limited for this purpose (see section 3.1. for discussion of ultrasound).

But, in choosing the articulatory method for speech recording, we frequently need to make a trade off between a complete image of the oral and pharyngeal cavity and the lip aperture

(MRI) and a less complete image of speech articulators (ultrasound), based on the convenience of the recording and analysis.

By combining acoustic and articulatory studies we can study the relationships that hold between the position and shape of the speech organs and the acoustic properties of the speech sound waves thus produced. For instance, we can answer questions like: If /i/ is articulated with the front part of the tongue raised, and the listener does not normally see what is happening in the oral cavity, which property of the acoustic signal tells the listener what articulatory organ is active and in which manner? Is there one specific property in the acoustic signal that can be directly related to a particular articulatory property, i.e. is there a simple one to one correspondence? Or, can a property of a speech sound wave relate to more than one, or a combination of articulatory properties of a sound? Several models have been developed, and the two major ones will be discussed in the next section.

20 2.1.2 Models of Articulation and Acoustics

Acoustic theory as part of physics, and acoustics and articulation as part of linguistics has aimed at explaining acoustics and articulation and the relationships that hold between them.

Two major articulatory models have emerged: the “High/Low, Front/Back Model” (Bell 1867) and the “Palatal/Dorsal/Pharyngeal/Labial Model”9 (very useful and detailed information about their origins and history can be found in Wood 1982). These are presented in turn.

2.1.2.1 High/Low, Front/Back Model

According to the High/Low, Front/Back Model, vowels are best described along these two dimensions. For instance, /u/ is back and high, i.e. /u/ has backed tongue body position and

“the tongue body is in a raised or high position” (Stevens 1998: 277), while /a/ is front and low, i.e. /a/ has “front tongue body position” (277) and “the tongue body is low in the mouth cavity” (274).

Figure 1. The “High/Low, Front/Back Model” (adapted from Wood 1982:4)

9 The names for these models given in quotes are my own. Wood (1982) calls the first The Tongue Arch Model and the second The Ancient Palatal-Labiovelar-Pharyngeal-Jaw Type of Model. 21 According to the High/Low, Front/Back Model, the tongue moves in two dimensions, up/down and front/back, as illustrated with two arrows intersecting in the quadrilateral in Figure 1. The single double-sided arrow represents articulation at the lips.

Labels such as “more back”, “more front”, “lower” and “higher” which are used to characterize vowels make sense only in reference to another vowel. Thus, /u/ is articulated with the tongue body placed more back than /i/; or, /u/ is articulated with the tongue body placed higher than /o/. We can, in this way, compare two or more vowels. Thus, we can, for instance, compare /u/ and /o/ and say that, although both are back vowels, /u/ is higher than

/o/.

The reference vowel is usually /ə/, being the most central with respect to the front/back dimension and the most mid with respect to the high/low dimension. Another reason why /ə/ is commonly used as a reference vowel is because the oral cavity during the articulation of this vowel resembles a simple uniform tube, closed at one end (the glottis) and open at the other end (the lips), whose acoustic properties (frequencies) can be easily calculated using a formula well-known in physics..

The oral cavity during the production of /ə/ resembles a “uniform tube”, because the cross- section is roughly the same at any point. The tongue is in the neutral position for this vowel, i.e. it is neither raised nor lowered and resembles a uniform tube. We can compare the articulation of other vowels with respect to /ə/. For example, the high back vowel /u/ is produced with the back part of the tongue relatively raised compared to /ə/, and the low back vowel /ɑ/ is produced with the back part of the tongue relatively lowered compared to /ə/.

This particular position of the speech organs during the production of /ə/ creates a tube of a special shape, and its shape makes sound waves of certain frequencies more intense than

22 others. Of these intensified frequencies – formants - only the lowest three (the first formant –

F1; the second formant – F2; the third formant – F3) are recognized as important for speech sounds, due to the properties of the human auditory system.

In the High/Low, Front/Back Model, in order to describe vowels, we need to measure the highest point of the tongue (high/low dimension) and the location of that highest point

(front/back dimension). The first articulatory property, the height of the tongue, is acoustically mostly reflected in the first formant (F1), with high vowels having lower F1 than low vowels.

The second articulatory property, the frontness of the tongue, is acoustically mostly reflected in F2, with higher F2 representing a front vowel, and a lower F2 representing a back vowel.

Additionally, the shape of the lips plays an important role - some vowels are articulated with an additional constriction at the lips (apart from the tongue), while other are not. This constriction can be made either with protrusion/rounding of the lips, or without. In the first, more common case (e.g. Ladefoged and Maddieson 1996), elongating the tube in front of the tongue constriction lowers all three formants (the longer the tube, the lower the frequencies), and making a constriction has the same effect (lip constriction is located at the place where the air volume velocity in the tube is maximal for F1, F2 and F3 – antinode; section 2.1.2.3). In the second case, there is no elongation, and it is only the constriction that lowers the formants.

The common term for this second type of vowel is “compressed lips” vowels. It is argued that the Japanese high back vowel /u/ and the Swedish high front vowel /ʉ/ are articulated with compressed lips (e.g. Ladefoged and Maddieson 1996: 295-296).

It should also be noted that, if a vowel is articulated with lip constriction, this does not necessarily entail that the lip aperture will be smaller than with a vowel without lip constriction. For example, it was found that, in Iaii (Austronesian), /ɔ/ and /ɤ/ have the same lip aperture, and the difference in lip shape is accomplished “with the different degrees of Lip

23 Height and Width that balance each other out” (Maddieson and Anderson 1995: 175). Lip constriction in this case does not decrease formant values.

2.1.2.2 Palatal/Doral/Pharyngeal/Labial Model

According to the Palatal/Dorsal/Pharyngeal/Labial Model (e.g. Wood 1982), vowels are best described with constriction location and constriction degree, where constriction location involves one or more of palatal, dorsal, pharyngeal and labial places of articulation. For example, /u/ is dorsal and labial with narrow constriction, i.e. /u/ has two constrictions, at the lips and at the dorsum/soft palate, and the tongue constriction is narrow, while /a/ is pharyngeal with wide constriction, i.e. with /a/ the tongue is backed towards the pharyngeal wall and the constriction is wide. This is illustrated in Figure 2.

i u

a

Figure 2. Labial, palatal, velar and pharyngeal places of articulation for vowels.

According to the Palatal/Dorsal/Pharyngeal/Labial Model, the tongue moves in three directions: /i e/ - palatal, /u o/ - velar, and /ɑ a/ - pharyngeal. The lips are also an active articulator, representing the labial place of articulation of rounded vowels.

24 These measurements are acoustically reflected in F1 as narrow/wide constriction, with a vowel with wider constriction representing higher F1, and in F2 as a shorter/longer cavity in front of the constriction, with a vowel with the longer cavity representing lower F2.

2.1.2.3 Tubes, Nodes and Antinodes

Two major acoustic models have emerged that connect articulation to acoustics: the Tube

Model (e.g. Fant 1960, Stevens 1998) and The Perturbation Theory (e.g. Chiba and Kajiyama

1941; Fant 1980, Stevens 1998). Both work quite well in explaining the acoustics of vowels.

However, one is preferred over the other depending on the context: the Tube Model is preferred when the constriction is narrower in the vocal tract, because it relies on front and back tubes, which can be coupled or not, while the Perturbation Theory is preferred when there are multiple constrictions (Johnson 1997).

The Tube Model infers the relevant three formants for a vowel based on the individual frequencies of the two tubes created when the constriction is made in the vocal tract – the back and the front tube. As the front tube (in front of the constriction) gets smaller, 8 cm and farther away from the glottis, F2 gets higher. For example, the articulation of the vowel /u/ can be represented as consisting of 2 tubes, tube 1 and tube 2, with different cross-section, i.e. constriction areas. These two tubes are minimally coupled, i.e. they almost do not influence each other.

The Perturbation Model infers the formants based on the location of constriction and nodes and antinodes. The three formant frequencies can change based on the location and degree of constriction. A constriction made at certain points of the uniform tube, called nodes, increases the frequency of a particular formant. Nodes are locations in the tube where sound waves of a certain frequency reach minimum volume velocity and maximum pressure. A constriction made at a node increases the frequency of a particular formant. Antinodes are the

25 opposite. A constriction made at an antinode decreases the frequency of a particular formant.

Antinodes are locations in the uniform tube where sound waves of a certain frequency reach maximum volume velocity and minimum pressure. F1 has one node (at the glottis) and one antinode (at the lips). F2, additionally, has one more antinode and one more node in between.

And F3 additionally has, in between these, one more node and one more antinode than F2.

Since all three formants have the same extreme node and antinode, the constriction near or at the lips (antinode for all formants) will lower the frequency of all three formants, while the constriction near or at the glottis (node) will raise all three formants. This is illustrated in

Figure 3.

N A N A N A

Figure 3. Nodes and antinodes (N – node; A – antinode)

Figure 3 shows the oral cavity as a tube, with the lips on the right hand side. F1, F2 and F3 reach maximum velocity, i.e. antinodes as points indicated with symbol A. Thus, for F1, there is one antinode, at the lips, for F2 there are two antinodes, and for F3 there are three antinodes. Nodes are not indicated, but are located at the points of minimum velocity.

Moreover, if the tube (oral cavity) is shorter (front vowels), the frequency of a sound wave is higher; and vice versa, if the tube is longer, the frequency of a sound wave is lower.

Thus, if two vowels are produced in absolutely the same manner, except that one has a constriction at the front, and, thus, a smaller cavity/tube in front of the constriction, for

26 instance /i/, and the other vowel has a constriction more at the back, and, thus, a larger cavity/tube in front of the constriction, for instance /ɯ/, then the vowel which is articulated with the front part of the tongue will have higher F2 than the vowel articulated with the back part of the tongue. Also, if a vowel is produced with protruded lips the tube is elongated, which, as a consequence lowers all three formants. Thus, if there are two vowels with all properties the same, except that one vowel is articulated with protruded lips, such as /y/, and the other is not, such as /i/, the former vowel will exhibit lower frequency with respect to the latter.

In sum, although the two models for vowel production differ in which articulatory properties they emphasize, at the acoustic plane they converge: front vowels equal vowels with a shorter cavity in front of the constriction, which is reflected as high F2; high vowels equal vowels with a narrower constriction, which is reflected as low F1.

So far, I have focused mostly on F1 and F2. The information obtained from F1 and F2 alone is enough for the listener to identify some vowels. For example, in the most common vowel system of 5 vowels, such as the one for Serbian, /i e u o a/, F1 and F2 are sufficient to discriminate all vowels, as shown in Table 1.

Table 1. F1 and F2 categorize vowels in a 5-vowel system F1 F2 low mid high low mid high /i/ /u/ /e/ /o/ /a/

27 The table shows that in the common five vowel system, F1 and F2 successfully distinguish the vowels in the following way: /i/ low F1/high F2 (shaded cells), /u/ low F1/lowF2, /e/ mid

F1/high F2, /o/ mid F1/low F2, /a/ high F1/high F2. However, additional information is required for some other vowels. Such is the case with vowel systems that have rounded/unrounded vowel pairs. For instance, both the unrounded /i/ and the rounded /y/ have similar low F1 and high F2 values. In an ideal case, the listeners would still be able to distinguish these two vowels with only F1 and F2, since the lip constriction should lower all three formants (at the lip antinode), so /y/ would have lower F1 and F2 than /i/. However, the situation is not that simple. The cross-section of the lip aperture can be the same with both vowels, with one vowel having more lip width, and less lip height than the other vowel. Or, one vowel may have a wider constriction than the other. Thus, the listener would do better if she had another acoustic property at her disposal, such as F3. F3 can be lowered with the lip constriction, elongation of the tube and a tongue constriction at one of the other two antinodes.

F3 can be raised with a tongue constriction made at one of the three nodes. For rounded/unrounded vowel pairs, we would expect F3 to be lower for the rounded than the unrounded member, if the two vowels do not differ otherwise. If they also differ in the location of the tongue constriction, there is a possibility that F3 can be raised as well.

According to Wood (1982), languages that have the high front rounded/unrounded pair /i y/ tend to have their constriction in the prepalatal region, which is close to the mid F3 antinode, which, in turn, lowers F3.

The speaker tends to make acoustic properties of the sounds such that the listener can more easily identify the sounds. So, in case of vowels, for instance, the constriction point for

/i/ will be located in such a place in the oral cavity that the difference between F1 and F2 is large. Or, /u/ is articulated with two simultaneous constrictions, which together make the

28 difference between F1 and F2 small. That is why, from the acoustic point of view, some vowels are more frequent than other. The majority of languages have /i/ and /u/, while /y/ and

/ɯ/ are less frequent because they do not have such extreme formant values (e.g. Ladefoged and Maddieson 1996).

The next section reviews several studies done on rounded/unrounded vowels in order to determine how the theory behind these vowel pairs compares to what is really found in languages.

2.2 Articulatory and Acoustic Studies of Rounded/Unrounded Vowel Pairs

In this section, a review is given of acoustic and articulatory studies on vowels, with the focus on rounded/unrounded vowel pairs.

Rounded/unrounded pairs have been studied, more acoustically and less articulatorily, in several languages. Most studies have focused on front vowel pairs, probably, as pointed out earlier, because of the accessibility of speakers of languages with the contrast.

The following sections summarize several acoustic studies, done on different languages, on high front rounded/unrounded pair (Section 2.2.1), mid front rounded/unrounded pairs (Section 2.2.2), high back rounded/unrounded pair (Section 2.2.3) and mid back rounded/unrounded pairs (Section 2.2.4). Some issues regarding phonetic properties of the vowel /ɯ/ are presented separately (Section 2.2.5). Finally, relevant issues with respect to coarticulation are presented (Section 2.2.6).

2.2.1 High Front Rounded/Unrounded Pair

Table 2 summarizes several acoustic studies done on the high front rounded/unrounded vowel pair in different languages.

29 Table 2. High front rounded/unrounded vowel pair Languages Speaker(s) and Stimuli F1 (Hz) F2 (Hz) F3 (Hz) /i/ /y/ /i/ /y/ /i/ /y/ French 10 male, real words - various10 1 295 302 2029 1797 (Gendrot and Adda-Decker 2004) German, North 4 male, nonsense syllables – 2 309 301 1986 1569 2960 1934 (Strange et al. 2004) unspecified Dutch 50 male, real words - /hVt/ 3 294 305 2208 1730 2766 2208 (Pols et al. 1973) Swedish 24 male, isolation/sustained11 4 255 260 2190 2060 3150 2675 (Fant et al. 1969) Korean 10 male, real words - /hVda/ 5 341 338 2219 2114 3047 2729 (Yang 1996) Estonian 1 male, isolation/sustained 6 254 254 1881 1780 2980 2156 (Eek and Meister 1994) Hungarian 4 male, real words - various 7 260 280 2250 1800 (Tarnóczy 1964) Finnish 1 male, real words – unspecified 8 250 240 2000 1700 (IIvonen and Huhe 2005) Mongolian 1 male, real words - unspecified 9 300 290 2300 2000 (IIvonen and Huhe 2005) Iaai 2 male, real words - various 10 300 280 2150 1670 (Maddieson and Anderson 1995) Note: Shaded cells represent languages where F1 is higher for the rounded vowel.

10 “various”/”unspecified”: the authors did not provide the word list and/or they collapsed results for different consonantal contexts 11 “sustained”: vowels were produced in isolation for a longer period of time 30 Table 2 gives an overview of the acoustics properties of the high front rounded/unrounded vowel pair in 10 languages, belonging to 5 language families: Indo-European (Dutch, French,

German, Swedish), Uralic (Estonian, Finnish, Hungarian), Korean (isolate), Austronesian (Iaii) and Altaic (Mongolian) (language specifications follow Ethnologue)12.

The following issues refer to all studies mentioned in sections 2.2.1-2.2.4. All speakers that contributed to the results presented here were male (some studies also included female speakers, but, for the sake of consistency, the results here are given only for male speakers).

The studies generally differ in the following two ways: the number of speakers differs, ranging from 1 to 50, and the speech stimuli differ, from isolated, sustained vowels in the arguably neutral /hVt/ context to nonsense syllables and various real words where the vowel is surrounded by different consonants. One of the disadvantages of some of the studies is that the authors do not provide all the necessary information about the stimuli. For example, Strange et al. (2004) characterize their stimuli as “nonsense syllables”, with information about the consonants surrounding vowels missing. Also, in the case of Hungarian, the results were based on various real words where different consonantal contexts were collapsed.

If the vowels were uttered in isolation, i.e. there are no preceding and following consonants, then the vowels are “pure” in the sense that their production is not affected by the environment. Such vowels are rarely found in normal speech, but form the basis of articulation. If the vowels are uttered in context, i.e. surrounded by consonants, then vowel production can be influenced by surrounding consonants – coarticulation (section 2.4 deals with coarticulation). Suffice it to say here that it is difficult to make an exact and reliable comparison between the studies mentioned, as the vowels are sometimes analyzed in their pure form and sometimes when affected by the environment.

12 A representative sample of phonetic studies is included. 31 However, in spite of the differences, the results show that the relationship between /i/ and /y/ across languages has commonalities. First, all these studies have in common the fact that F2 and F3 values of the rounded member /y/ are consistently lower than F2 and F3 of the unrounded member /i/. Thus, the studies confirm that rounded vowels have lower F2 and F3.

(There are studies where F3 was not measured – blank cells in Table 2.) On the other hand, there was no such consistency with F1 – F1 can be lower for /y/ than /i/ (Finnish, German,

Iaai, Korean, Mongolian), the same for /y/ and /i/ (Estonian) or higher for /y/ than /i/ (Dutch,

French, Hungarian, Swedish). Sometimes the difference is so small as to be almost negligible

(probably not statistically significant), such as 5Hz for Swedish, for example. Thus, based on these acoustic studies, we have to conclude that another articulatory property – the one that raises F1 - can combine with lip constriction in some languages, and that is why, in some languages, rounded vowels end up having the same or higher F1 than their unrounded counterparts.

We would expect F2 to be lower for the rounded member of the pair, /y/, since F2 reflects the length of the oral cavity in front of the tongue constriction (whether caused by the placement of the tongue or the shape of the lips, or both), and/or the presence or absence of the additional constriction at the lips. F2 is lower if that portion of the oral cavity is longer, and/or if there is an additional constriction at the lips. The data from these 10 languages agrees. Moreover, articulatory studies indicate that /y/ is less front than /i/ (German, EMA -

Hoole 1999, Dutch; EMG - Raphael et al. 1978; Chinese, Dutch, English, French, German and

Swedish, x-ray - Wood 1982). Thus, we can indeed expect that lower F2 for /y/ is due to both articulatory properties mentioned above - a shorter oral cavity with /y/ and an additional lip constriction with /y/. The differences in F2 range from around 100-450Hz.

32 F3 is usually mentioned only with reference to the presence or absence of lip constriction - one of the F3 antinodes is located at the lips, and the constriction at that point lowers F3. Thus, we would expect F3 to be lower for /y/ than for /i/. The data confirm this.

We know that /y/ is articulated with a constriction at the lips; this is, acoustically, consistently reflected as lower F3. According to Wood (1982), lip rounding lowers F3 (about 1000Hz) more than F2 (abut 500Hz) if the tongue is also raised in the prepalatal region. However, we should also bear in mind that F3 has 2 more antinodes and 3 nodes, and a constriction at any of these points can cause a change in F3. The differences in F3 range from around 300-

1000Hz.

F1 should also be expected to be lower with /y/ than with /i/. F1 reflects the narrowness of the constriction, with lower F1 indicating a more constricted articulation. This can be achieved with the tongue or with the lips. With rounded vowels like /y/, lips can be more constricted than with unrounded vowels like /i/. A note of caution here is needed. Although the vowel is rounded, it does not necessarily mean that it has a smaller constriction area than its unrounded counterpart. This has been noticed, for example, for the Iaai mid back vowel pair

(section 2.2.4). According to Wood, the lips are “moderately closed” with /y/, unlike with /u/, where the lips are more rounded and closed. This might indicate that the difference in lip aperture is smaller between /i/ and /y/ than between /i/ and /u/. Additionally, the articulatory studies introduced above found that /y/ has a lower tongue body compared to /i/, which means a less constricted articulation, which would raise F1. Thus, F1 values in such cases most likely are the result of the interplay of the lip constriction and the tongue constriction. For example, in the case of Iaai, where /y/ F1 is lower than /i/ F1, the constriction at the lips can be the principal contributing factor. In the case of Hungarian, where /y/ F1 is higher, a wider constriction at the tongue can be the principal contributing factor. In the case of Estonian,

33 where F1 is the same for /i/ and /y/, the lowering of F1 at the lip constriction and the raising of

F1 at the tongue constriction cancel each other out. F1 values range from around 0-20Hz.

Different stimuli can also influence F1, due to the effects that the preceding and/or following consonants can have. In the case of Swedish and Estonian (higher F1 for /y/ and no difference in F1, respectively), where isolated vowels are used as stimuli, it cannot be said that the surrounding context somehow causes /y/ F1 to raise. However, sometimes several studies have been done on the same languages, and the results for F1 differ. This is the case with

Dutch, as shown in Table 3.

Table 3. Three studies on Dutch Language Speakers and Stimuli F1 (Hz) F2 (Hz) F3 (Hz) /i/ /y/ /i/ /y/ /i/ /y/ Dutch 50 male, real words /hVt/ 294 305 2208 1730 2766 2208 (Pols et al., 1973) Dutch, Southern Standard 1 male, nonce words /əpVp/ 242 277 2006 1691 2902 2111 (Raphael et al. 1978) Dutch, Northern Standard 20 male, real words /sVs/ 278 259 2162 1734 2665 2205 (Adank et al. 2004) Dutch, Southern Standard 20 male, real words /sVs/ 278 265 2179 1825 2787 2348 (Adank et al. 2004) Note: Shaded cells represent languages where F1 is higher for the rounded vowel.

As shown in Table 3, two studies (Raphael et al. 1978 and Pols et al. 1973) found that F1 was higher with /y/, while one study (Adank et al. 2004) found the opposite. The stimuli differ, from /hVt/ (Pols et al.) to /əpVp/ (Raphael et al. 1978) to /sVs/ (Adank et al.) context, and the speakers differ from 50 males (Pols et al.) to 20 males (Adank et al.) to 1 male (Raphael ey al.). The studies also differ in dialect, although two studies whose F1 values differs (Raphael et al. 1978 and Adank et al. 2004) have speakers of the same dialect – Southern Standard.

Interestingly, all three studies are consistent in their findings that F2 and F3 are lower with /y/ than with /i/.

34 There is always a possibility that different stimuli (i.e. different consonantal contexts) contributed to the different relationship between /i/ F1 and /y/ F1 in these two studies, and that

F2 and F3 are more resilient to various contexts, probably because the differences in F2 and

F3 are larger. We can assume that /s/ preceding the vowel can lower the vowel’s F1 because

/s/ is a fricative and, thus, has a more constricted articulation. (Although Adank et al. 2004 measured formants in the middle of the steady state of a vowel in order to avoid the influence of the surrounding consonants, and the vowels were on average around 80-200ms in duration).

However, previous studies on coarticulation (section 2.4) found that a vowel’s F1 is hardly affected by differences in the place, manner and voicing of the surrounding consonants, at least in English (e g. Hillenbrand et al. 2001), or that F1 is affected by the place of articulation of the surrounding consonants in Danish, English and German (Steinlen 1995).

Moreover, there is a tendency towards centralization for vowels in contexts compared to vowels in isolation (e.g. Lindblom 1963), so that F1 of lower vowels gets lower and F1 of higher vowels higher (e.g. Flemming 2007, Hillenbrand et al. 2001).

This short digression on three Dutch studies teaches us that F2 and F3 remain stable and are less influenced by different stimuli, or by different acoustic measurement techniques employed; we should also be aware of the possibility of finding slightly different results between two or more independent studies.

In sum, F2 and F3 are lower with /y/ than with /i/ all the time, while F1 can be lower or higher. Articulatorily, /y/ was found to be produced with more back and lowered tongue body in comparison with /y/, and the lips are “moderately closed”.

2.2.2 Mid Front Rounded/Unrounded Pairs

Table 4 summarizes the results for mid front rounded/unrounded pairs from several languages.

35 Table 4. Mid front rounded/unrounded pair(s) Language and Source Speaker(s) and Stimuli F1 (Hz) F2 (Hz) F3 (Hz) unround round unround round unround round French /e, ø/ 365 375 1912 1459 1 (Gendrot and Adda-Decker /ɛ, œ/ 10 male, real words - various 438 400 1695 1444 2004) German, North /e, ø/ 4 male, nonsense syllables – 393 393 2010 1388 2651 2045 2 (Strange et al. 2004) /ɛ, œ/ unspecified 573 559 1738 1353 2454 2277 Dutch /e, ø/ 50 male, real words - /hVt/ 407 443 2017 1497 2553 2260 3 (Pols et al. 1973) /ɛ, œ/ 583 438 1725 1498 2471 2354 Swedish 24 male, isolation/sustained 4 345 380 2250 1730 2850 2290 (Fant et al. 1969) Korean 10 male, real words /hVda/ 5 490 459 1968 1817 2644 2468 (Yang 1992) Estonian 1 male, isolation 6 356 376 1810 1546 2532 2044 (Eek and Meister 1994) Hungarian 4 males, real words – various contexts 7 380 400 2150 1530 (Tarnóczy 1964) Finnish 1 male, real words (unspecified) 8 450 460 1900 1500 (IIvonen and Huhe 2005) Mongolian 1 male, real words (unspecified) 9 570 570 1900 1550 (IIvonen and Huhe 2005) Note: Shaded cells represent languages where F1 is higher for the rounded vowel

36 Table 4 shows 9 languages and their mid rounded/unrounded vowel pairs. The languages are the same as in Table 3, except that Iaai is missing, since it does not have mid front rounded vowels. Of the 9 languages, only French and German have two pairs – a mid high and a mid low pair.

The results are similar to the results for the high front pair. F2 and F3 values are consistently lower for the rounded vowel. F2 values range from about 100-600Hz, and F3 values range from around 200-600Hz. F1 can either be higher (6 cases) or lower (3 cases) for the rounded vowel compared to its unrounded counterpart, or the values can show no difference (2 cases). F1 values range from around 0-40Hz.

With French and German, F2 values show that the low mid unrounded /ɛ/ is more back than the high mid unrounded /e/, while their respective rounded counterparts /œ/ and /ø/ do not show that difference.

Table 5 presents the three studies done on Dutch. Adank et al. (2004) do not have the low mid pair.

37 Table 5. Three studies on Dutch Language Speakers and Stimuli F1 (Hz) F2 (Hz) F3 (Hz) unround round unround round unround round

Dutch /e, ø/ 50 male, real words - /hVt/ 407 443 2017 1497 2553 2260 (Pols et al., 1973) /ɛ, œ/ 583 438 1725 1498 2471 2354

Dutch, Southern Standard /e, ø/ 1 male, nonce words - /əpVp/ 341 375 1956 1530 2669 2229 (Raphael et al. 1978) /ɛ, œ/ 538 382 1508 1400 2377 2238

Dutch, Northern Standard /e, ø/ 20 male, real words - /sVs/ 400 375 1995 1563 2583 2241 (Adank et al, 2004)

Dutch, Southern Standard /e, ø/ 20 male, real words - /sVs/ 384 374 1993 1539 2616 2377 (Adank et al, 2004)

Note: Shaded cells represent languages where F1 is higher for the rounded vowel.

38 As above, with high vowels, in two studies (Pols et al. 1973 and Raphael et al. 1978) F1 is higher for the rounded counterpart, while in one study (Adank et al. 2004) F1 is lower. Such a difference does not occur with F2 and F3.

Thus, with both high and mid vowels, Adank et al. (2004) found lower F1 with rounded vowels. Can different contexts produce this variation? And, if so, which of the three contexts is more neutral? /hVt/ or /hVd/ is often referred to as “null context’ (e.g. Recasens

1999; Stevens and House 1963), presumably because it is assumed that the preceding consonant has more effect on the vowel (carry-over coarticulation), and /h/, as a glottal fricative, has no oral place of articulation. However, we shall see in section 2.4 on coarticulation that the directionality of coarticulation varies from language to language. Still,

F2 should primarily be affected and not F1, as mentioned earlier.

Raphael et al. (1978) found that, for Dutch, the mid low pair is qualitatively different from the high and mid high pairs. /œ/ F1 is much lower (around 100Hz and 200Hz, depending on the study) than /ɛ/ F1, and that difference is greater than between the high and mid high pairs, so it seems that, apart from the lip constriction, there is a difference in tongue height between /ɛ/ and /œ/, with /œ/ being lower. EMG (Electromyograph) data from the same study also indicate that /œ/ might be half-closed and /ɛ/ half-open. However, muscle activity cannot for certain tell whether it is only the tongue height that makes the difference in F1, or only lip constriction, or both, since the muscle activity with this pair is different, more complicated, and somewhat contradictory, than with the mid pair and the high pair.

In sum, with front vowels, F2 and F3 are consistently lower with the rounded member of the pairs, while F1 of the rounded member of the pair can be lower or higher. Generally, mid pair F1 values have a larger range (0-40Hz) than high pair F1 values, mid pair F2 values

39 have a larger range (100-600Hz) than high pair F2 values, while the opposite holds with F3 - the high pair has a larger range than mid pairs F3 values (200-600Hz).

2.2.3 High Back Rounded/Unrounded Pair

Table 6 summarizes results for high back rounded/unrounded pair from several languages.

40 Table 6. High back rounded/unrounded pair Language and Source Speaker(s) and Stimuli F1 F2 F3 /ɯ/ /u/ /ɯ/ /u/ /ɯ/ /u/ Korean /ɯ, u/ 10 male, real words - /hVda/ 1 405 369 1488 981 2497 2565 (Yang 1996) Paicî 5 male, real words -various 2 333 318 1380 787 2257 2320 (Gordon and Maddieson 2004) Thai 2 male, isolation 3 410 365 1365 758 2548 2568 (Abramson 1962) Vietnamese 1 male, real words, /t_/ 4 446 411 1289 923 (Nguyen and Srihari 2004) Khmer, Battambang 1 male, real words -various 5 496 452 1633 862 (Wayland 1998) Note: Shaded cells represent cases where rounded vowels have higher F3 than the corresponding unrounded vowels.

41 Information about high back unrounded vowels comes from 5 Asian languages that belong to 4 language families: Tai-Kadai (Thai), Austro-Asiatic (Khmer and Vietnamese), Korean

(Korean), and Austronesian (Paicî).

The results show that F1 and F2 are always lower for the rounded /u/, while F3 is always higher for the rounded /u/, the difference not being large.

Based on the presence of lip constriction with rounded vowels, we expect lower F1 for

/u/ compared to /ɯ/. This expectation is borne out. Consistently lower F1 with /u/ suggests a narrower constriction either at the lip aperture or at the tongue area, or both. Recall that /u/ is pronounced with more lip rounding than /y/, so that rounding the lips for /u/ and keeping the same tongue shape as for /ɯ/ will cause a more prominent F1 decrease. Since there have been no articulatory studies on back vowel pairs, we still do not know whether the same relationship holds with the back pair with respect to the tongue – namely, whether /u/ has a lower tongue body than /ɯ/. Thus, either /u/ is not articulated with the lower tongue body, which will raise

F1, or, even if it is, the acoustic result is not strong enough to override the acoustic result of lip rounding. Therefore, the back pair differs from front pairs with regards to F1.

We expected lower F2 for the rounded vowel, and the data confirm that. Consistently lower F2 with /u/ suggests a longer tube in front of the tongue constriction and/or a smaller constriction at the lips in comparison to /ɯ/. Unfortunately, of these 5 languages, only Korean has also front pairs, so we cannot compare ranges for other languages. For Korean, the F2 difference between /i/ and /y/ as well as between /e/ and /ø/ is 100Hz, while the F2 difference between /ɯ/ and /u/ is 500Hz. Thus, /ɯ/ and /u/ differ more in F2 than members of any front pair. This difference can be caused by the presence/absence of lip rounding or fronting/backing of the tongue, or both. This is probably the reason why a number of authors assume that high back vowels also differ in tongue position, namely, that there is a back /u/ and a more central

42 /ɨ/. After all, /ə/ is a central vowel and its F2 is around 1500Hz, which is close to /ɯ/ F2. The only way to determine the exact place of articulation for /ɯ/ is to do an articulatory study.

Such a study was done on Korean (Yang 1999), with the conclusion that both /ɯ/ and /u/ have a constriction 8cm from the glottis (although they differ in tongue shape). At least for Korean, then, the 500Hz difference in F2 seems to be made predominantly by the lips as the active articulator, combining protrusion and rounding. However, looking at F3 values tells a different story.

We expect narrowing of the constriction area at the lips to lower F3. We do not find that with the high back vowel pair in the three studies that present F3 results. F3 is higher with

/u/ by about 20Hz to 70Hz. The difference between the two vowels is much smaller than with the high front pair, where it ranges from 300-1000Hz. This might indicate that the lip aperture

(constriction at the lips) remains the same for both /ɯ/ and /u/, or, if anything, /u/ has a slightly larger lip aperture. In Korean, at least, we know that the lips are protruded 1cm for /u/ in comparison to /ɯ/ (Yang 1992); thus /u/ is articulated with a longer cavity in front of the constriction, which should lower all formants. Higher F3 with the rounded member is most likely the result of the tongue constriction being located near the mid F3 node.

The F1 difference between the two members of the pair range 15-40Hz, for F2 300-

800Hz and for F3 20-70Hz.

In sum, F1 and F2 are lower with the rounded /u/ than with the unrounded /ɯ/, while

F3 is slightly higher. Based on the only articulatory study on Korean, we can also conclude that the tongue constrictions for /ɯ/ and /u/ are located at the same place in the oral cavity,

8cm from the glottis.

2.2.4 Mid Back Rounded/Unrounded Pairs

Table 7 summarizes results for mid back rounded/unrounded pair(s) from several languages.

43 Table 7. Mid back rounded/unrounded pair(s) Language and Source Speakers and Stimuli F1 F2 F3

Paicî /ɤ o/ 422 383 1513 781 2256 2375 1 5 male, real words - various (Gordon and Maddieson, 2004) /ʌ ɔ/ 573 604 1500 971 2387 2303 Iaai /ɤ o/ 2 male, real words - various 2 400 470 1250 950 (Maddieson and Anderson 1995) Thai /ɤ o/ 2 male, isolation 3 515 485 1285 875 2500 2608 (Abramson, 1962) Vietnamese /ɤ, o/ 1 male, real words - /t_/ 4 645 772 1330 1224 (Nguyen and Srihari 2004) Khmer, Battambang /ɤ o/ 1 male, real words - various 5 665 574 1615 1059 (Wayland 1998) Note: Shaded cells represent cases where rounded vowels have higher F1 and F3 than the corresponding unrounded vowels.

44 Information about mid back unrounded vowels comes from the same 5 Asian languages. 4 languages have the high mid pair, and only Paicî has both the high and the low mid pair.

As expected, the rounded member of the mid pair has lower F2 than its unrounded counterpart. Contrary to expectations, F1 and F3 can be lower or higher for the rounded vowel, but they are not both higher in the same language.

F1 and F3 should be lower for the rounder counterpart, if the two members are the pair in every respect and differ only in lip constriction, or what I call a “true pair”. Thus, the fact that F1 in a language such as Vietnamese can also be higher with the rounded vowel indicates that the rounded vowel is produced with the lower tongue body than the unrounded vowel in some languages, and that the influence on the wider tongue constriction predominates acoustically. Also, the fact that F3 in a language such as Thai can be higher with the rounded vowel indicates that the tongue constriction for the rounded vowel is located near the middle

F3 node, which is, for male speakers, at about 7-8cm from the glottis; thus, the resulting F3 in these languages is a combination of F3 lowering at the lips and F3 raising at the node, and the node constriction predominates acoustically. English vowel /u/ was also found to have tongue constriction 7-8cm from the glottis. During the production of the English vowel /u/, tongue

constriction Ac is located 7-8cm from the glottis l. This explains why in Thai, for example, F3 is higher with rounded vowels – the constriction at the F3 node raises F3.

The study of Iaii also has an articulatory component – video images of the lips. The results show that the unrounded /ɤ/ and rounded /o/ have a similar lip aperture (in mm2). Thus, as I mentioned above, the lip aperture can be similar for the rounded and the unrounded vowel, and thus not contributing to formant lowering at that particular antinode. Also, the authors suggest that, judging /ɤ/ from video images, it is most likely back.

45 F1 difference ranges from 30-130Hz, F2 difference 100-700Hz and F3 difference 20-

100Hz.

2.2.5 Summary

Table 8 summarizes the results of the studies reviewed above.

Table 8. Summary for all studies for all rounded (+r) / unrounded (-r) vowel pairs. Vowel F1 F2 F3 Pairs high front +r < -r, +r > -r (0-20Hz) +r < -r (100-450Hz) +r < -r (300-1000Hz)

high back +r < -r (15-40Hz) +r < -r (300-800Hz) +r > -r (20-70Hz)

mid front +r < -r, +r > -r (0-40Hz) +r < -r (100-600Hz) +r < -r (200-600Hz)

mid back +r < -r, +r > -r (30-130Hz) +r < -r (100-700Hz) +r < -r, +r > -r (20-100Hz)

Table 8 shows that all rounded (+r) / unrounded (-r) vowel pairs consistently have F2 lower for the rounded member than the unrounded member. The greatest difference in F2 is between the members of the high back pair /ɯ u/, 300-800Hz, and the smallest difference is between the members of the high front pair /i y/. The reason for such difference between /ɯ/ and /u/ can be threefold: (i) /ɯ/ is articulated more front than /u/; (ii) the lip aperture for /u/ is much smaller, i.e. /u/ is very rounded and protruded; (iii) the articulatory difference is not as big as with the other pairs, but it is more prominent acoustically (e.g. Stevens 1998). On the other hand, one of the reasons for the smaller difference between /i/ and /y/ can be the fact that /y/ is not as rounded as /u/.

F1 is the most variable of all three acoustic properties - F1 can be both lower and higher for the rounded vowel, except for the high back pair, where it is always lower.

Therefore, all pairs but the high back can have the tongue lower for the rounded member,

46 depending on the language. The greatest difference in F1 is between the members of the mid back pair, 30-130Hz, and the smallest difference is between the members of the high front pair.

F3 can be either lower (front vowels), or higher and lower (mid back) or higher (high back) for the rounded member of the pair. Only /u/ has higher F3 compared to /ɯ/, which is most likely the consequence of the tongue constriction being located at the F3 middle node.

The greatest difference in F3 is between the members of the high front pair, 300-1000Hz, and the smallest between the members of the high back pair.

Thus, the high back pair differs from other pairs: its F2 difference is the largest; its F3 difference is the smallest, with only /ɯ/ having higher F3 values than /u/; only /ɯ/ has F1 values lower than /u/.

2.2.6 Back or Central?

For some of the languages in Tables 6 and 7, the investigators either claim that back and mid rounded vowels do not have real unrounded counterparts, like /ɯ/ or /ɤ/, but that, in fact, we are dealing with unrounded central vowels, like /ɨ/ or /ə/, or they say they are not sure whether the vowel in question is back or central. These conclusions are based on acoustic data.

The following examples will illustrate the issues. For Iaai, Gordon and Maddieson

(2004) claim that /o/ has a unrounded counterpart /ɤ/, because formant analysis indicates so; but the authors also mention a previous study by Ozanne-Rivierre (1976), which refers rather to a central unrounded vowel /ə/. Thus, Gordon and Maddieson argue for the backness on the basis of F2, which lies between /e/ and /o/ F2, and ranges from 1100Hz to 1500Hz. On the other hand, for Paicî, Maddieson and Anderson (1995) claim that all three back unrounded vowels are, in fact, central, since their F2 values range from 1220Hz to 1800Hz; however, the

47 authors continue to use the back vowel symbols. For Thai, Abramson (1962) only refers to central unrounded vowels. For Vietnamese, Nguyen and Srihari refer to back unrounded vowels, but another study (Winn et al. 2008) mentions the problem, and, in order to avoid discussion, symbolizes the vowels using orthographic symbols. In sum, without reliable articulatory studies, opinions will continue to be divided on the nature of these vowels.

What influences the authors of these studies to opt for a central vowel instead of a back vowel? Schwa is a central vowel and its F2 values are around 1500Hz (F1 - 500, F3 - 2500)

(Stevens 1998); F2 values for back unrounded vowels range from around 1300-1600Hz. Thus, as some authors explicitly indicate, acoustically, these vowels are midway between /i/ and /u/.

The following Table compares F2 values of these four high vowels, based on the studies reviewed in the previous sections. F2 values are collapsed for all languages mentioned.

Table 9. F2 of the high vowels High Vowels /i/ /y/ /ɯ/ /u/ F2 (Hz) 2300-1900 2200-1700 1600-1300 1000-750

The values for the back pair do not overlap for different languages; the lowest /ɯ/ F2 value is

1300Hz, and the highest /u/ F2 value is 1000Hz. However, the values for the front pair overlap

(not for the same language), so that both /i/ and /y/ can cover a common range from 2200Hz to

1900Hz. Thus, there is a greater difference between the members of the back pairs than the front pair.

Now let’s look at the mid pairs.

Table 10. F2 of the mid vowels Mid Vowels front unrounded front rounded back unrounded back rounded F2 (Hz) 2250-1800 1800-1300 1600-1200 1200-800

48 With mid vowels, F2 values do not overlap, like for high front vowels, nor are they far apart like for high back vowels. F2 values are much more symmetrically arranged. F2 values of the front rounded and back unrounded vowels overlap.

In sum, the high back pair members differ in F2 more than any other pair – their F2 values are about 300Hz apart, while for other pairs F2 values either overlap or meet. This might prompt researchers to treat /ɯ/ as a central vowel, rather than back. In the next section, I will look at the properties of the high central unrounded vowel cross-linguistically to set the stage for looking at Turkish.

2.2.7 Comparing High Back and High Central Unrounded Vowels: /ɯ/ and /ɨ/

According to the UPSID database, 14.19% (or 64 languages) of languages surveyed have the high central unrounded vowel /ɨ/. Only one of these languages also has /ɯ/ - Nimboran

(Witotan). But there is also a question: Are these 64 vowels really articulatorily central or back? What do /ɨ/ and /ɯ/ symbolize? One of these languages is Thai (UPSID), and as we saw above, Thai linguists do not agree on this matter. It is thus crucial to do articulatory studies on such languages, since acoustic data can be misinterpreted.

There have been a number of acoustic studies on Korean, and many claim that Korean has the central vowel /ɨ/ (e.g. Ahn and Iverson 2004, Kim 1968, Lee 1999). Yang (1992) did an MRI study which showed that that Korean does not have a central vowel, but a back vowel

/ɯ/, based on the constriction location of the vowel. The tongue shapes for /ɯ/ and /u/ differ, however. The same was found for Turkish (Kiliç and Öğüt 2004). In fact, /ɯ/ has a similar vocal tract shape to /i/, with a smaller pharyngeal cavity. Compared to /u/, the pharyngeal cavity is larger than the oral cavity, while for /u/, the two cavities are similar in size. Also, the tongue tip is close to the lower teeth, unlike for /u/, where the tip is still low, but pulled

49 backwards. Thus, although from acoustics, we can infer with more certainty some things about articulation, a lowered formant value of one vowel with respect to another can occur for several reasons. Moreover, very frequently, two or more articulatory movements combine into one acoustic outcome.

Parker (2000) did a survey of languages that contain high or mid front, central and back vowels with the same rounding. He found 2 languages, Nimboran and Bora (Witotan), with both the high central unrounded and back unrounded vowels /ɨ ɯ/, 1 language, Moro

(Niger-Congo), with the same combination of mid vowels /ə ɤ/, and 1 language, Axluxlay

(Panoan), with the same combination of low vowels /a ɑ/. Parker (2001) also did an acoustic study on Bora vowels, uttered in isolation, with 14 speakers (6 female, 8 male). Bora has three high unrounded vowels /i ɨ ɯ/. Table 11 represents average formant frequencies for male speakers’ high vowels.

Table 11. Bora high vowels F1 (Hz) F2 (Hz) F3 (Hz) /i/ 324 2257 (2525-2050) 3221 /ɨ/ 396 1781 (1925-1675) 2891 /ɯ/ 385 1488 (1675-1200) 2601

Values in brackets represent approximate mean highest and lowest values for the 8 male speakers. Table 11 shows that F2 values of /ɯ/ and /ɨ/ are distinct, with /ɨ/ having 300Hz higher F2 mean values than /ɯ/. The two vowels are very close in F1, and they differ more in

F3, with /ɨ/ having F3 values around 200Hz higher than /ɯ/.

The F2 values for /ɯ/ in Bora are similar to F2 values of /ɯ/ in the 5 languages mentioned above. In none of these 5 languages do F2 values overlap with Bora /ɨ/ F2 values.

Yet, since only Bora speakers need to maintain the difference between high central and back vowels, and Bora does not have /u/, we might expect /ɯ/ F2 values to be lower. However, this

50 is not the case even in such conditions. Therefore, it seems that /ɯ/ F2 values are what they are, and /ɯ/ is not articulatorily a central vowel.

In sum, although there is a larger difference in F2 values between /ɯ/ and /u/ than between other rounded/unrounded pair members, still F2 values for /ɨ/ and /ɯ/ clearly differ.

An articulatory study will contribute even more to entangling the confusion that has been created about the articulatory properties of back unrounded vowels.

The next section focuses on the seemingly peculiar behaviour of the back unrounded vowel /ɯ/.

2.3 High Back Unrounded Vowel /ɯ/

There is an indication that Turkish /ɯ/ phonetically behaves differently from other Turkish vowels, and thus, its relationship with its rounded counterpart /u/ may not be the same as the relationships that holds between the members of the other two pairs.

Phonologically, the nature of /ɯ/ is straightforward - in vowel harmony, /ɯ/ behaves like a back vowel. Recall that, due to the treatment of /ɯ/ as a phonetically central vowel instead of a back vowel, some authors argue that vowel harmony provides evidence that back and central vowels pattern together (e.g. Parker 2000). Like with other languages, on phonetic grounds, the idea that /ɯ/ is central comes from acoustic and not articulatory data. With regards to its distribution in words, /ɯ/ combines only with /a/, due to the frontness and roundness nature of the vowel harmony.

Phonetically, however, the nature of /ɯ/ does not seem so straightforward. There are three reasons for this. One reason has already been mentioned above – its F2 values being midway between /i/ and /u/, /ɯ/ has been regarded either as a central vowel /ɨ/ or a back vowel

/ɯ/. Secondly, /ɯ/ has been found by at least one study on Turkish (Kiliç et al. 2006) to be the

51 significantly shortest Turkish vowel. And, thirdly, /ɯ/ behaves peculiarly in Turkish loanwords, as discussed in Chapter 1. Thus, in these three aspects, /ɯ/ stands out from the other 7 Turkish vowels.

2.3.1 The Place of Articulation of /ɯ/: Back or Central

With respect to its place of articulation, Turkish /ɯ/ has been claimed to be either a back vowel (e.g. Demircan 1979, Demirezen 1986, Kornfilt 1997 - as cited in Kiliç and Öğüt 2004;

Zimmer and Orgun, 1999), or a central vowel (Esling 1994, Ergenç 1989, Selen 1979, as cited in Kiliç and Öğüt 2004). These claims have been made mostly based on acoustic data.

Acoustic data places /ɯ/ as a central vowel based on its F2 values. /ɯ/ F2 values are between

/i/ F2 and /u/ F2 values. It is not clear, however, whether these studies assume that /ɯ/ is articulatorily a central vowel as well. The only MRI articulatory study done on /ɯ/ characterizes /ɯ/ as a back vowel (Kiliç and Öğüt 2004).

According to Anderson (1975), when referring to “central” vowels in Thai, Khmer and

Vietnamese, the authors in fact refer to the mid or intermediate F2 values these vowels have, which are between high /i/ and low /u/, and the term “central” does not imply that the tongue position is central between /i/ and /u/, such as for IPA /ɨ/. To make the matter more confusing, in the phonetic literature, it is common to represent F1 on a inverted y-axis and F2 on an inverted x-axis, so that the obtained quadrilateral mirrors the oral cavity, thus implying that there is one-to-one correspondence between F1 and tongue height and between F2 and tongue frontness. Not only does such representation give the wrong picture of back unrounded vowels being central, but it also completely disregards the effect lip rounding can have on F1 and F2, and completely ignores F3 as an acoustic property of vowels that plays an important role in vowel identification.

52 The only MRI articulatory study on Turkish vowels concluded that /ɯ/ is a back vowel

(Kiliç and Öğüt 2004). The stimuli used were isolated, sustained Turkish vowels. The study was done with 5 male speakers. There was no statistical significance between the constriction location for /u/ and /ɯ/, meaning that the two vowels /u/ and /ɯ/ have the same place of articulation. Other articulatory properties measured (constriction degree, oral cavity area and pharyngeal cavity area) were found to differ significantly between /ɯ/ and /u/. Looking at individual results, the difference in constriction degree shows that for one speaker /u/ was less constricted, for three speakers, /u/ was more constricted, and for one speaker there was no difference. Thus, there was no consistency with respect to constriction degree. However, the results for the oral cavity area and pharyngeal cavity area show consistency, with the oral cavity area being larger and the pharyngeal cavity area being smaller for /u/. This implies that, although the constriction locations did not differ, the tongue still assumes different shapes during the production of these two vowels. Based on the MRI study done Kiliç and Öğüt

(2004), during the production of /u/ and /ɯ/, the oral cavity and pharyngeal cavity lengths are the same, since the constriction location is the same. However, the whole body mass of the tongue is moved back for /u/ compared to /ɯ/, which results in a larger cavity in front of the constriction and a smaller cavity behind the constriction for /u/. Also, /u/ is produced with the tongue tip facing up, while with /ɯ/, the tongue tip rests on the lower teeth.

The acoustic and auditory data from the same study (Kiliç and Öğüt 2004) show the

following results. First, F3-F2 (Bark) values and F1-f0 (Bark) values significantly differed between /u/ and /ɯ/, but F3-F2 (Bark) values did not differ between /ɯ/ and /e/. (It is argued that the Bark auditory scale is better than the acoustic Hertz scale to represent the way human auditory system analyzes speech sounds; see, for example, Stevens (1998); Zwicker (1961,

1975)). Thus, acoustically, /ɯ/ is close to the mid front unrounded /e/. Second, auditorily, /ɯ/

53 was back, but could also occupy the auditory space of the central /ɨ/ and the mid back /ɤ/.

Thus, auditorily, /ɯ/ could be confused in frontness with the high central unrounded vowel /ɨ/ and in height with the mid back unrounded vowel /ɤ/.

Another perception study done on 11 vowels /i y ɯ u e ø ɚ o æ ʌ ɑ/ and 4 languages

(English, German, Thai and Turkish) found that /ɯ/ is perceived similarly by the speakers of these 4 languages – generally, very close to /ø/ and /ɚ/, and closer to front or mid than back vowels, and in-between mid-high and high (Terbeek 1977). It is interesting that the unrounded

/ɯ/ is perceived as rounded even by Turkish listeners.

2.3.2 Duration of /ɯ/: Is it Shorter than Other Turkish Vowels?

The second controversial issue with the Turkish vowel /ɯ/ involves its duration. Two studies measured the duration of Turkish vowels, and one found that /ɯ/ is the shortest Turkish vowel.

Turkish words are generally stressed on the final syllable. In both studies, native Turkish words were used. In the first study (Arısoy at al. 2004), with six female speakers, stimuli were polysyllabic words (mostly disyllabic), and the duration of the vowels in initial syllables

(unstressed) and final syllables (stressed) was measured. The target vowel occurs word- initially (e.g. akar), word-finally (e.g. /rakɯ/) or between two consonants (e.g. /kokot/). Some vowels were preceded or followed by different consonants, all voiceless obstruents, and other vowels were word-final or word-initial. Results show that /i/ or /y/ were the shortest vowels in initial and final syllables, respectively, and /ɯ/ was the third or fourth shortest vowel in the same positions. In fact, all four high vowels were shorter than non-high vowels, with /ɯ/ in the final syllable approaching mid and low vowels in duration. Also, the vowels in initial unstressed syllables were approximately two or three times shorter than the same vowels in the final stressed syllables.

54 In the second study, on the contrary, /ɯ/ was found to be the shortest vowel (Kiliç et al. 2006). There were 13 speakers (male and female) and disyllabic real words were used as stimuli. The target vowel was located in the first, unstressed, syllable, either preceded by a consonant or not. As the stimuli list is not presented in the article, it is impossible to say if the stimuli were controlled for the type of consonant. The results again show that high vowels were shorter than low vowels, but /ɯ/ was the shortest vowel, and its duration significantly differed from the duration of other vowels. The duration of /ɯ/ ranges from 22ms to 56mm, with the average 43ms.

These stimuli were presented to children with normal and impaired hearing (average

12.4 years). The stimuli varied based on the duration of the vowel – from approximately 30-

32ms to approximately 487-510ms, depending on the vowel. The normal-hearing children had no problem recognizing /i/ at all durations, but for other vowels, the percentage of correct answers differed. /œ/ had the lowest percentage of correct answers, with answers getting better as the duration increased. /u/ and /ɯ/ were next in terms of recognition. Interestingly, for /ɯ/, the percentage of correct answers decreased as the vowel duration increased.

With hearing-impaired children, the percentage of correctly recognized vowels was much lower. With /ɯ/, again, the percentage of correct answers decreased as the vowel duration increased, with the shortest /ɯ/ being correctly indentified 47% of the time, and longest /ɯ/ being correctly identified 0% of the time. /ɯ/ was confused with a number of vowels, both rounded and unrounded. Also, /y, u, e, o/, when shortest (30-60ms), were most frequently confused with /ɯ/, but such confusion does not occur with longer durations. The study concluded that hearing-impaired children rely more on vowel duration than on spectral properties to identify vowels: they have heard /ɯ/ as the shortest vowel before, and assume that a vowel is /ɯ/ if it is the shortest.

55 Turning to other languages, /ɯ/ was also found to be inherently shorter than other

Korean high vowels, 144ms, compared to /i/ and /u/, 160ms and 165ms, respectively.

However, /ɯ/ is not the shortest vowel, since the low back unrounded /ʌ/ is of the same duration (Chung et al. 1999). Also, Korean /ɯ/ (or /ɨ/) is characterized phonologically as the least marked vowel, based on phonological processes of vowel harmony and vowel coalescence, as well as /ɯ/ vowel deletion in certain contexts (Lee 1999). In Khmer, /ɯ/ was also not found to be the shortest vowel (Woźnica 2009).

Thus, although /ɯ/ might not be the shortest vowel in a language’s vowel inventory, its duration can still play a role in phonological/phonetic processes or vowel perception.

2.3.3 /ɯ/ in Loanwords

The third type of behaviour that singles out /ɯ/ from the other Turkish vowels is its patterning in loanwords, as briefly described in Chapter 1. Here I give a more detailed presentation.

Table 12 illustrates the major patterns of adaptation of Turkish vowels in 6 languages. In all these languages, Turkish words were adapted under the same social circumstances – prolonged occupation.

Table 12. Major patterns of adaptation of Turkish vowels into 6 languages13. Language /y/ /œ/ /ɯ/ Vowel Inventory Albanian [y] [ə] /i y u ə ɛ ɔ a/ Bulgarian [u] [ɔ] [ɤ] /i u ɤ ɛ ɔ a/ Greek [u] [o] [i] /i u e o a/ Hungarian [i] /i y u e ø ɛ o a ɒ/14 Romanian [u] [o] [ɨ] / [ə] /i ɨ u e ə o a/ Serbian [u] [o] all vowels /i u e o a/

13 Sources for languages: Albanian, Boretzky 1975; Bulgarian, Rollet 1996; Greek, Rollet 1996; Hungarian, Rollet 1996; Macedonian, Friedman 1986, 2003; Romanian, Rollet 1996 and Wendt 1960; Serbian, Škaljić 1966. 14 Hungarian also contrasts long and short vowels. 56 Table 12 illustrates the major patterns of adaptation of the Turkish vowels in 6 languages. For example, in Bulgarian /ɯ/ is, by default, adapted as [ɤ], but, when preceded by a postalveolar consonant, it is adapted as [i].

The column “vowel inventory” shows the inventory of the borrowing language. For three languages some vowels are bolded, to make more obvious that these languages have a central or a back unrounded vowel. This is important to explain patterns of adaptation for the vowel /ɯ/.

The vowel /y/ has the most straightforward pattern of adaptation, as it is always adapted as the back rounded [u]. Thus, the features high/low and round/unrounded are preserved at the expense of the feature front/back consistently in all languages that do not have

/y/. Only Hungarian and Albanian have /y/ in their vowel inventories, as represented by shaded cells.

The vowel /œ/ is somewhat less consistently adapted. It is primarily adapted as a mid back rounded vowel [o] or [ɔ], depending on which of these two a language has. Thus, just like with /y/, the features high/low and rounded/unrounded are preserved at the expense of the feature front/back. In case of Albanian, /œ/ is adapted as the high front rounded [y]; thus, the features rounded/unrounded and front/back are preserved at the expense of the feature high/low. Only Hungarian has a mid front rounded vowel.

There are two general patterns of adaptation of the vowel /ɯ/. In languages that have a central or back unrounded vowel, like /ɨ/ (Romanian), /ə/ (Albanian, Romanian) or /ɤ/

(Bulgarian), /ɯ/ is adapted as these vowels. This can be explained in two ways, as illustrated in Table 13.

57 Table 13. Vowel features and the first pattern of of adaptation of the vowel /ɯ/ /ɯ/ [back, high, unrounded] /ɤ/ [back, mid, unrounded] /ɨ/ [central, high, unrounded] /ə/ [central, mid, unrounded] Bulgarian Romanian Albanian, Romanian

First, since in Turkish phonology, /ɯ/ patterns as a back vowel, then the features unrounded and back can be preserved at the expense of the feature high, as in Bulgarian; alternatively the features high and unrounded can be preserved at the expense of the feature back, as in

Romanian, or the feature unrounded can be preserved, as in Albanian and Romanian.

This adaptation pattern can also be explained with reference to phonetics

(acoustics/perception). The vowels /ɯ ɤ ɨ ə/ have similar F2 values, 1200-1600Hz, as previously discussed. Thus, /ɯ/ can be misperceived as the central vowels /ɨ ə/. In addition, acoustically, it is the closest vowel to /ɤ/.

The second pattern of adaption of /ɯ/ is found in languages that do not have a central or back unrounded vowel. In this case, /ɯ/ is adapted as [i] (Greek, Hungarian) or as all vowels (Serbian). Thus, in Greek and Hungarian, the features high/low and rounded/unrounded are preserved at the expense of the features front/back, just like with the vowels /y/ and /œ/ discussed previously. That is a straightforward pattern of adaptation.

On the other hand, in Serbian, the vowel /ɯ/ does not have a straightforward pattern of adaptation, as it is adapted as all 5 vowels /i ɛ a o u/, as presented in section 1.1.

Vowels are usually described along three dimensions: front/back, high/low and rounded/unrounded. Of the three vowel properties/dimensions, in languages with categorical adaptation patterns and without a central or back unrounded vowel, vowel rounding is preserved (Bulgarian, Greek, Romanian, Serbian, Albanian, Hungarian), while vowel frontness is rarely preserved. It seems that vowel rounding, whether as a phonological feature or as a

58 phonetic property, at least in Turkish, is stronger than other vowel properties, especially vowel frontness.

Also, recall that /ɯ/ is deleted next to /r/ in Serbian, while in Albanian, Greek and

Romanian, /ɯ/ is not deleted in the same environment.

With respect to deletion, Serbian has a svarabhakti phonetic vowel in the same context, next to a syllabic /r/ and that the vowel is acoustically similar to schwa. Thus, Serbian borrowers delete /ɯ/ and do not treat it as a phonological vowel (Gudurić and Petrović 2005)

(1).

(1) /prst/  [pərəst] ‘finger’

(1) shows that Serbian phonology and orthography do not recognize a vowel preceding and following syllabic [r], but phonetically it is still present.

This still does not explain why /ɯ/ is adapted as all 5 Serbian vowels, especially in the light of the Greek adaptation, where, offered the choice of the same 5 vowels, /ɯ/ follows a straightforward adaptation pattern and is adapted, by default, as [i].

Turkish loanwords into Serbian and neighbouring languages were not influenced by

Turkish orthography, Turkish was written in Arabic script and Serbian in Cyrillic. Most of the borrowers were illiterate, and the borrowed words are not scientific words intended for the educated scientific community, but ordinary, everyday words that people used in everyday life

(spoon, pillow, eggplant, etc.). Thus, it appears that we can study the way sounds were heard or perceived by listeners15.

15 With some other loanwords, such as recent English loanwords in the majority of borrowing languages, the choice of a vowel is very frequently influenced by the way that vowel is orthographically represented in English; this can obscure the way that vowel is heard or perceived by listeners (e.g. Kaneko 2006; Vendelin and Peperkamp 2004).

59 In sum, research indicates that /ɯ/ behaves like no other Turkish vowel: it may or may not be shorter than other vowels, it may be articulatorily back or central, it does not always have a straightforward adaptation pattern in loanwords and it can also be deleted in loanwords.

/ɯ/ certainly requires closer attention.

2.4 Coarticulation

Since vowels are much more frequently used in different contexts, and not in isolation, phonetic description of vowels needs to include an examination of vowels in words. While the articulation of vowels in isolation is an ideal, “target” articulation, the articulation of vowels in context (words) shows the effect that preceding and/or following sounds can have on vowels, which can change the articulation and acoustic properties of ideal, pure vowels. Some issues pertaining to coarticulation are discussed in this section.

2.4.1 Defining Coarticulation

We saw above that some of the studies on rounded/unrounded vowel pairs used stimuli where vowels were produced in isolation, i.e. not surrounded by consonants or other vowels, while other studies used stimuli where vowels were placed in real or invented words, i.e. were flanked by different consonants or vowels. In case of the second type of stimuli, the researchers were careful to measure vowel formant values in the middle of the vowel in order to minimize the influence the surrounding sounds can have on that vowel.

Sounds are rarely produced in isolation. In speech, they are generally surrounded by other sounds and there is no clear-cut delineation between sounds. There is a period of time when the articulation of the preceding sound has not been finished, but the articulation of the following sound has already begun. Such events are called coarticulation.

60 Coarticulation can be defined as the accommodation of articulators from one sound to another, where articulators “overlap in time and interact with one another” (Farnetani and

Recasens 2010:316; Rosner and Pickering 1994). Thus, in speech, instead of having one invariable instance of a sound all the time, we get many different realizations whose properties vary based on the environment. Still, among a multitude of such different realization, listeners in the communication process can recognize and classify a particular sound. Thus, there are

“invariant, discrete units underlying” all this variability – target articulations (Kühnert and

Nolan 1999: 7).

Various theories of coarticulation have been proposed. Each model/theory “succeeds only partially in accounting for speakers’ behaviour” (Farnetani and Recasens 1997: 63). It rather seems that speakers of different languages apply different models of coarticulation. The following sections briefly touch upon several issues that pertain to coarticulation and are relevant for the present study: directionality, universality and domain of coarticulation, timing,

C-to-V coarticulation with English vowels, perception of coarticulated vowels, ad C-to-V coarticulation with reduced vowels, such as schwa.

2.4.2 Directionality of Coarticulation

One of the questions that theories of coarticulation try to answer pertains to the direction of coarticulation, which is, in turn, tightly connected to questions about the origins of coarticulation. Sounds can influence preceding and following sounds; thus, the influence can go in both directions, and sounds can have “reciprocal influences” on each other (Farnetani and Recasens 2010). For instance, in an English word like /əmæs/ ‘amass’, the velum, which is lowered during the production of /m/, might not be completely raised when the articulation of

/æ/ has begun, so that /æ/ ends up partially nasalized. Thus, the articulation of the preceding

61 sound carries over to the next sound. Also, in the same word, the velum might have been lowered in the anticipation of /m/ before the articulation of /ə/ has been finished, so that /ə/ is partially nasalized. Thus, the articulation of the following sound is anticipated. The first type of interference is called carry-over coarticulation, and the second anticipatory coarticulation. It is generally assumed that carry-over coarticulation is mechanical or physical in nature – an incomplete accommodation of speech organs, while anticipatory coarticulation can be psychological/cognitive in nature, since the speaker plans ahead the next sound(s), as well as mechanical (e.g. Bell-Berti 1975, Fowler and Saltzman 1993).

This study will examine whether Turkish vowels exhibit a carry-over or an anticipatory

C-to-V coarticulation or both, and whether one of these kinds of coarticulation is more prominent than the other. The study will also look at each vowel separately in order to determine whether the direction of coarticulation depends on the vowel, with some vowels being more influenced by the preceding and others by the following consonant.

2.4.3 Universality of Coarticulation

If some types of coarticulation are mechanical in nature, and occur due to vocal tract constraints (Solé 2007), we would assume that all languages will exhibit similar patterns of coarticulation. This does not appear to be the case (i.e. Keating 1985, Kingston and Diehl

1994, Solé 2007). Generally speaking, some phonetic details are preferred because of “the economy of effort” (Keating 1990), but are not the only option. Language speakers can choose to follow this “default” pattern or not. For example, it is assumed that vowels are universally longer before voiced sounds. Keating found that there are languages where this is not the case

(English vs. Czech and Polish). Thus, “physical factors clearly influence vowel duration, but they do not control it” (120).

62 With respect to coarticulation, Solé (2007) concluded that some phonetic details are mechanical in nature, and some not. For instance, with regards to nasalization there are two types of languages; one is Spanish-like, where coarticulatory nasalization occurs more or less on the same portion of a vowel, no matter the rate of speech and vowel duration, and the second is like American English, where the duration of nasalization is strictly proportional to speech rate and vowel duration.

C-to-V coarticulation differs across languages, for example, between English and

French (Oh 2008), and between Danish, English and German (Steinlen 2005). Steinlen (2005) found that Danish vowels generally were less prone to coarticulation than English and German vowels. Also, patterns of coarticulation differed among the three languages. For instance, while alveolar consonants significantly affected all German and most English back vowels by raising their F2, in Danish they significantly affected only /u/’s F2. However, although there was no significant difference, the change in F2 goes in the same direction; namely, the languages did not differ, for example, in that Danish vowels had their F2 lowered, opposite to

German vowels. Thus, the coarticulation difference is rather the difference in the magnitude of the effect consonants have on vowels. Steinlen compared the “null” /hVt/ context to the /CVC/ symmetrical contexts, where both Cs (consonants) are of same the place of articulation.

Though languages have different coarticulation patterns, coarticulation is learnable, and although second-language learners start by referring to their native language coarticulation patterns, they can learn patterns of adaptation of the second language (e.g. Oh 2008).

This study will examine how much Turkish vowels are affected by adjacent consonants and whether some vowels are affected more than others.

63 2.4.4 Domain of Coarticulation

Another issue related to the direction of coarticulation and interlanguage variation concerns its domain, or whether it is local or long-distance. In particular, it has been found that vowels can influence vowels across consonants. This is not local coarticulation. However, languages differ in the presence or absence of such coarticulation, with American English and Swedish showing long-distance coarticulation, unlike Russian (Öhman 1966, 1967). One of the proposed explanations is that languages with larger sound inventories exhibit less coarticulation than languages with smaller inventories (e.g. Manuel 1987, Solé 1992). This is, however, not always the case (e.g. Solé and Ohala 1991). In addition, lip rounding/protrusion with /u/ can begin four to six segments prior to the vowel /u/ in some languages (Kühnert and

Nolan 1999). This indicates that anticipatory coarticulation is very much cognitive in nature and can be long-distance in some languages (French, Benguerel and Cowan 1974), but not in others (Russian, Kozhevnikov and Chistovich 1965). For Turkish, anticipatory coarticulation

was found with all consonants preceding a rounded vowel, CnV (Boyce 1988, 1989).

The present study focuses on immediate C-to-V coarticulation and does not investigate coarticulation patterns that extend beyond adjacent vowels. However, in a future study, it will be interesting to investigate how far away the consonantal influence extends in Turkish, with mono-syllabic words across word-boundaries, as well as within the same word of polysyllabic words.

2.4.5 Unit of Coarticulation

Speech can be described as a serial sequence of discrete units. These have been variously claimed to be syllables, phonemes, articulatory gestures, and muscle contractions (e.g. Kent and Minifie 1977). The theories of coarticulation from the 1960’s to today differ with respect

64 to the level, or the size, of overlapping units, and, as research has progressed, the units found to be relevant have been argued to be smaller and smaller. Today, researchers view assimilation as a process where phonological features interact, and coarticulation as a process where articulatory gestures overlap (e.g. Browman and Goldstein 1986, 1989). Articulatory gestures are movements of articulators in the production of a sound. For instance, /i/ is produced with one oral gesture, raising of the front part of the tongue body, while /u/ is produced with two gestures, lip rounding/protrusion and raising of the front part of the tongue body.

In general, there is more coarticulation if the two articulators share an articulator (e.g.

Fowler and Saltzman 1993). For example, /i/ and /k/ share the tongue as the articulator, with

/i/ raising the front part of the tongue, and /k/ the back part. These two conflicting gestures cause maximal gestural interference, in comparison to /i/ and /b/, which do not share a common articulator, and, thus, cause “minimal gestural interference”.

In this study, ultrasound imaging is used in order to examine how tongue height and frontness in vowels, as tongue raising/lowering and tongue fronting/backing gestures, are affected by the neighbouring consonants with different places of coarticulation.

2.4.6 Time and Coarticulation

Research shows that each of the speech organs moves at a specific speed, and that it takes different amounts of time for, for example, the tongue to assume a different shape than for the lips to assume a different shape (Stevens 1998). For most unreduced vowels, i.e. full vowels, it takes about 100ms to change the tongue shape from one configuration to another. For reduced vowels, this time is much shorter, and a reduced vowel does not reach its target articulator position. The lips take 50-100ms to change from a rounded to an unrounded configuration, but

65 can take as long as 300ms. Generally, the average movement of the articulators takes around

200-300ms, while the average duration of a sound is 70-90ms in natural speech, so that “It is clear that the articulatory movements to produce a given phone must be interleaved with the movements that are required to produce adjacent phones.” (p. 48).

There is more coarticulation in fast speech, but slow and deliberate speech is not free of coarticulation (e.g. Whalen et al. 2004). For instance, it was found that, in Swedish,

(Lindblom 1994), vowels undergo less target undershoot (phonetic vowel reduction, where vowels do not reach their ideal targets) in clear speech, but undershoot is still present. Thus, listeners “expect coarticulation” and there is no “theoretical need for hyperarticulated targets”

(exaggerated speech) (p. 157).

The Turkish /ɯ/ might be the shortest Turkish vowel and its duration was found to be

43ms on average (Kiliç et al. 2006). If that is the case, then we can expect /ɯ/ to be more prone to coarticulation than other Turkish vowels, as there is no sufficient time during the production of /ɯ/ for articulatory gestures to realize their target, and there is more possibility for the neighbouring consonant gestures to impose.

2.4.7 English Vowels and Coarticulation

Several acoustic studies have been done on the coarticulation of English vowels, of which I will mention three, Stevens and House (1963), Hillenbrand et al. (2001) and Gay (1974).

Stevens and House (1963) and Hillenbrand et al. (2001) did acoustic studies of English vowels and generally obtained similar results. Both studies examined vowels produced in isolation as well as vowels in context. They treated formant values of the vowels in isolation as target values, and compared them to the production of the vowels in different contexts. The manner of the consonant articulation and its voicing did not have much effect on the vowels,

66 but the place of articulation had an effect, almost exclusively on F2 values. I present here the most robust findings. High back rounded vowels /u/ and /ʊ/ were mostly affected by postdental consonants (alveolar and postalveolar), and their F2 values were increased by 350Hz and

200Hz, respectively (Stevens and House), or by 500Hz for men and 600Hz for women, and

210Hz for men and 280Hz for women, respectively (Hillenbrand et al.). Front vowels /ɪ ɛ æ/ lowered their F2 next to postdental and labial consonants by around 100-200Hz (Stevens and

House), or next to labials by around 85-100Hz (Hillenbrand et al.). Also, back vowels raised their F2 next to velars, by around 100Hz for men and 120Hz for women (Hillenbrand et al.).

The two studies differed in that Stevens and House only looked at male speakers’ production, in symmetrical contexts, where vowels are preceded and followed by the same consonant; thus, from their study we cannot conclude anything about the direction of coarticulation. Hillenbrand et al. used both asymmetrical and symmetrical contexts, and their results show that the vowels were influenced by the preceding consonants much more than by the following consonants. Thus, anticipatory coarticulation, where speech planning processes are mostly at work, is more robust than carry-over coarticulation, which is, largely, a consequence of mechanical properties of the vocal tract, as discussed in section 2.4.2.

In the Hillenbrand et al. study, vowels were on average 200ms in duration. Both studies measured formants in the middle of the vowel – steady state. Thus, even though the vowels are longer than 90ms (Stevens, 1998, referring to natural speech), since it takes approximately

200-300ms for articulators to change from one configuration to another, the effect of surrounding consonants on vowels is present.

Gay (1974) did an articulatory and an acoustic study on three male speakers of English with three vowels /i u a/ and stops with three places of articulation /p t k/. The results show that all three vowels exhibit “articulatory undershoot”, and that /i/ and /u/ remain “highly

67 stable” with respect to their target articulation with all three consonants, while the articulation of /a/ shows intraspeaker variation and is more prone to influence of the context. However, this is not reflected acoustically, since the acoustic variability for all three vowels is the same.

Thus, the articulation of some vowels needs to be kept stable by the speaker more than the articulation of other vowels, since in the first case, variability in articulation can more readily result in larger acoustic variability. Two theories that have been proposed to account for why some vowels are more common cross-linguistically than others, quantal theory (Stevens 1998) and dispersion theory (Lindblom 1990), with both arguing that these three “corner” vowels are stable.

In section 2.4.3 the universality of coarticulation was discussed and it was concluded that some aspects of coarticulation are universal while others are not. This study will examine

Turkish C-to-V coarticulation. Will the major trends in English C-to-V coarticulation be similar for Turkish? If not, how do the two languages differ?

2.4.8 Vowel Perception and Coarticulation

Vowel duration influences perception, but more so for some languages than others. For example, it has been found that duration has a greater influence for German than for English

(Hillenbrand at al. 2000; Strange and Bohn 1998). It is argued that one reason for this is a greater difference in duration between high and low vowels in German than in English

(Strange and Bohn 1998). Also, vowels used in connected speech in experiments (e.g.

Hillenbrand et al. 1995) are overall shorter than vowels used in citation form (e.g. Crystal and

House 1988; van Saten 1992). It is not clear, however, whether duration plays an important role, since some vowel pairs were better classified in discriminant analysis when duration was added to formants in some studies on English (e.g. Hillenbrand et al. 1995, 2000), but not in

68 others (Zahorian and Jagharghi 1993). In all these studies, citation form one-syllable words were used. A question remains how vowels would be discriminated in normal speech. Also,

Zahorian and Jagharghi found that vowels are better classified when adjacent to some consonants than to others. Vowels were classified the worst when preceded by /t/, or when followed by a velar stop, for example. Unfortunately, no information was given on the vowel duration itself.

Also, from section 2.4.3 recall that some phonetic properties are argued to be universal, while others are considered default. More specifically, for example, labial consonants either lower F2 of front unrounded vowels or do not have effect on them, but they never raise F2 of front unrounded vowels. However, the extent to which labial consonants influence F2 is language-specific. We can expect Turkish to generally exhibit more or less coarticulation than

English, or to exhibit more or less coarticulation on some vowels than others, but we do not expect, for example, Turkish /u/ F2 values to lower in the presence of the postalveolar, opposite to English.

2.4.9 Reduced Vowels

Vowel coarticulation is also discussed in relation to the so-called undershoot hypothesis and/or reduction hypothesis, and the contextual assimilation hypothesis. According to the undershoot hypothesis, while vowels in isolation are produced with articulators reaching their planned target, vowels in context are produced with articulators falling short of that target (Lindblom

1963). Such vowels are not full, but reduced vowels. Reduced vowels tend to shift their formant values towards the centre of the acoustic space, and can become similar to the neutral vowel /ə/ - centralization hypothesis (e.g. Kondo 1994; Stevens and House 1963). However, according to the contextual assimilation hypothesis, vowels are influenced by surrounding

69 sounds and shift towards the articulation of these surrounding sounds (e.g. Flemming 2007, van Bergem 1994).

Vowel reduction does not occur in all languages, but largely in those languages where stress is strongly correlated with duration (Lindblom 1963), and even these languages differ in the magnitude of vowel reduction (Nord 1986). For example, in Polish and Swedish, formant frequencies do not change depending on whether the vowel is stressed or not. Lindblom (1963) compared F1 and F2 for Swedish vowels in stressed vs. unstressed syllables, and F1 and F2 of the same vowels in stressed syllables with different durations, and obtained the same results.

In English, on the other hand, vowels are prone to reduction in unstressed syllables (Nord

1986).

This study will examine whether Turkish vowels in context exhibit centralization or contextualization, or both.

2.4.10 Schwa

Schwa is often claimed to be a special vowel: it exhibits shorter duration than other vowels, it is more prone to coarticulation, and it is variously adapted in loanword adaptations in different languages and even in the same language. One of the reasons cited for schwa being prone to the influence of the surrounding consonants (and vowels) is that it is usually short, and as such, articulators do not have sufficient time to reach their target. Schwa is generally shorter than 100ms, which is much shorter than the time it takes to change the articulators from one position to another.

In short English sentences spoken at a normal speech rate, schwa was found to be around 50ms long (Stevens 1998). In the sentence /pæs ə dɪp/ “Pass a dip”, schwa is surrounded by alveolar consonants and front vowels, all of them articulated with the front part

70 of the tongue, which is reflected as high F2; schwa has an F2 around 1500Hz (male speaker).

In another sentence /ɹʌb ə bʊk/ “Rub a book”, schwa is surrounded by labial consonants, produced with the closure at the lips with the tongue in neutral position, and back vowels; all these articulations are reflected as low F2; schwa has an F2 around 900Hz. Even if the articulators start their adjustments for the schwa in the middle of the preceding consonant and end in the middle of the following consonant, it still takes 130 to 150ms to accomplish the target position for schwa (Stevens 1998).

English schwa duration varies across studies from 34ms (Kondo 1994) to 64ms

(Flemming and Johnson 2007), compared to other vowels which go up to 150ms in fluent speech (van Santeen 1992). Moreover, in some situations in rapid speech, the two surrounding consonants can overlap, and the schwa between them can be just one glottal pulse.

Schwa is often deleted in languages (Dutch, English, French, Hindi) (Flemming 2007).

Schwa is deleted because of extreme gestural overlap in languages such as English and

German (e.g. Beckman 1996; Davidson 2006). Other vowels are also subject to deletion in

German, but they are deleted much less frequently than schwa (Kohler and Rogers 2001).

Beckman (1996) points to a larger phenomenon that encompasses schwa deletion and vowel devoicing in languages such as Japanese, Korean and Montréal French. Vowel devoicing occurs between devoiced consonants as a consequence of an almost complete gestural overlap between consonants. In such a situation, it is too short to even realize the glottal gesture for the vowel. Devoicing has also been noticed for English schwa (Davidson 2006). Because schwa is very short and, in English, it occurs where it does not contrast with other vowels, it is not so important to maintain the contrast. Thus, both schwa deletion and devoicing can occur as a consequence of gestural overlap between two consonants.

71 According to Kondo (1994), based on F2, schwa shows contextual variability throughout the vowel, while a similar study done on Swedish /ø/ (Öhman 1966) shows vowel variability only at the edges of the vowel. The conclusion is that schwa is unspecified or targetless.

In second language learning and loanwords, people often have problems dealing with schwa. For instance, in Cantonese, English schwa is adapted as [a:] in open syllables, as [ɐ] or

[ø] in closed syllables and stressed [ɝ] is adapted as [œ:] (Yip 2006). Yip excluded words with some other choice, which comprise 15%. Interestingly, even speakers of a language that has a schwa have such variable adaptation patterns. For example, English schwa is the vowel most variably adapted in Mandarin Chinese - in 29 different ways - /a/ (29%) and then /ə/ (15%) being the most frequent adaptations (Lin 2008, 2009), although Mandarin has schwa in its vowel inventory. Lin (2008/2009) suggests that /ə/ is unspecified and there are no restrictions for it to be adapted as any vowel. Neither of these two studies looks at the role preceding and following consonants can have of /ə/ adaptation.

Based on the results of some previous studies, the Turkish /ɯ/ behaves, in some respects, like /ə/: it can be very short, it is adapted as all Serbian vowels, and can be acoustically central. The study will examine the Turkish /ɯ/ with respect to its duration and place of articulation.

2.5 Research Questions and Predictions

The goal of the first part of the study, articulation and acoustics of Turkish vowels in isolation, is to determine phonetic characteristics of Turkish rounded/unrounded vowel pairs without the influence of the surrounding consonants. The research questions are the following.

72 1. Do rounded/unrounded pairs of vowels have the same place of articulation? Do they differ only in lip rounding, i.e., are they true rounded/unrounded pairs, or is there a difference also in the tongue shape and/or position, and if so, what is the difference?

2. Is the articulatory relationship the same between rounded and unrounded vowels in all three vowel pairs, or do they differ, and if so, in which way? Specifically, is there a difference between front and back pairs, and between high and mid front pairs?

3. How are these three pairs of rounded/unrounded vowels distinguished acoustically, using formants (F1, F2 F3)?

4. Particular attention will be paid to the high back unrounded vowel /ɯ/: Is it back or central?

5. How is the articulatory difference between the members of the three pairs of rounded/unrounded vowels realized acoustically?

6. How are the vowels discriminated among themselves in terms of F1, F2 and F3?

The goal of the second part of the study, on the articulation and acoustics of Turkish vowels in context, is to determine whether Turkish rounded/unrounded vowel pairs are affected by preceding and following consonants with four different places of articulation, and if so, how. The research questions are the following.

1. Do preceding and following consonants at each of the four different places of articulation influence the articulation and acoustic of Turkish vowels? If yes, how?

2. Does the preceding or following consonant have more influence, or do both have equal influence on the vowel?

3. How do phonetic properties of the vowels differ based on different places of articulation of the consonants?

4. How are the different vowels affected by a consonant with the same place of articulation?

73 5. Do vowels that belong to the same vowel pair get affected in different ways? Do the three different vowel pairs get affected in the same way?

6. Which articulatory (tongue height, tongue frontness) and acoustic dimension (F1, F2, F3) is affected the most?

7. With respect to /ɯ/: Is /ɯ/ the shortest vowel? Is /ɯ/ more liable to be affected by different consonants than other vowels?

8. How are the vowels in different context discriminated among themselves with F1, F2 and

F3?

Based on everything said above on the theory behind vowel production and the results of the studies already done, the following predictions can be made.

1. With respect to rounded/unrounded pair members, all three Turkish rounded/unrounded vowel pairs are true pairs:

(i) Articulatorily, the tongue height and location during the production of the rounded

and unrounded pair members /i y/, /ɯ u/ and /e œ/ are the same. The vowels differ in

that the rounded members, /y/, /u/ and /œ/, are produced with an additional constriction

at the lips, while their counterparts, /i/, /ɯ/ and /e/, do not have a lip constriction.

(ii) Acoustically, F1, F2 and F3 of the rounded pair members, /y/, /u/ and /œ/, will be

lower than F1, F2 and F3 of their unrounded counterparts /i/, /ɯ/ and /e/.

2. With respect to rounded/unrounded pair member, all or some of the three Turkish rounded/unrounded vowel pairs are not true pairs:

(i) Articulatorily, one of the pair members can be produced with a higher or lower

tongue body, and/or more front or more back articulation than the other pair member;

specifically, rounded vowels /y œ u/ will have lower and more back tongue body than

their unrounded counterparts /i e ɯ/.

74 (ii) Acoustically, we cannot predict the outcome in such cases, unless we know what is

actually happening articulatorily. Based on the literature review, the following specific

predictions can be made.

With high front vowels, /y/ will have lower F2 than /i/; the difference ranging from 100Hz to

450Hz. /y/ will also have lower F3 than /i/, ranging from 300Hz to 1000Hz. With respect to

F1, we can expect either lower F1 or higher F1 with /y/ than with /i/, the difference ranging form 0-20Hz.

With mid front vowels, /œ/ will have lower F2 than /e/; the difference ranging from

100-600Hz. /œ/ will also have lower F3 than /e/, ranging from 200- 600Hz. With respect to

F1, we can expect either lower F1 or higher F1 with /œ/ than with /e/, the difference ranging from 0-40Hz. The mid pair /e œ/ can be qualitatively different than the high pairs, i.e. greater difference between /e/ and /œ/ than between /i/ and /y/ or /ɯ/ and /u/.

With high back vowels, /u/ will have lower F1 for /u/ than for /ɯ/, ranging from 15-

40Hz. /u/ will have lower F2 than /ɯ/, the difference ranging from 300-800Hz. We can expect higher F3 with /u/ than with /ɯ/, the difference ranging from 20-70Hz. The predictions for the high back pair /ɯ u/ are less strong than the predictions for the other two pairs, since there are fewer studies on this pair, particularly articulatorily studies.

3. With respect to rounded/unrounded pairs:

(i) Articulatorily, the tongue will be higher in the production of /i y/ and /ɯ u/ in

comparison to /e œ/. The tongue will be more front with /i y/ and /e œ/ than with /ɯ u/.

No predictions can be made as to whether the tongue is of the same or different height

with /i y/ or /ɯ u/, or whether the tongue is of the same frontness with /i y/ or /e œ/.

(ii) Acoustically, F1 of /i y/ and /ɯ u/ will be lower than F1 of /e œ/. F2 of /i y/ and /e

œ/ will be higher than F1 of /ɯ u/. No predictions can be made as to whether the

75 tongue is of the same or different height with /i y/ or /ɯ u/, or whether the tongue is of

the same frontness with /i y/ or /e œ/.

4. With respect to the vowel /ɯ/:

(i) duration: /ɯ/ is/is not the shortest vowel in the Turkish sound system

(ii) place of articulation: /ɯ/ is a back/central vowel

5. With respect to C-to-V coarticulation:

(i) Patterns of coarticulation in Turkish can differ somewhat from the patterns of

coarticulation in other languages. That can be true especially when Turkish is

compared to a language with a smaller vowel inventory – Turkish can exhibit less

coarticulation. For instance, Serbian has a smaller vowel inventory compared to

Turkish – 5 vs. 8 vowels, so that Serbian allows more coarticulation than Turkish,

especially with high and mid vowels. Moreover, at least with labial vowel to consonant

coarticulation, it was found that Turkish employs the so-called “look-ahead model” –

anticipatory coarticulation that extends to all consonants preceding the vowel, CnV

(Boyce 1988, 1989). That model was put forward based on Russian data (Kozhevnikov

and Chistovich 1965). It does not, however, take into account consonant to vowel

coarticulation.

(ii) If the pattern of coarticulation differs between the borrowing and the source

language, then borrowers can have problems perceiving a vowel they do not have in

their language, in connected speech, since they need time to discern “invariant, discrete

units underlying this variability” (Farnetani and Recasens 2010: 7). That is why

Serbian borrowers would treat Turkish /ɯ/ as a central vowel, more variable than other

vowels – its coarticulatory acoustic space probably stretches all the way to the central

76 vowel acoustic space. Thus, borrowing, in this case, is probably not being done by bilinguals, as suggested by, for example, Paradis and LaCharité (1997).

(iii) Although vowels can influence vowels across consonants, in the case of Turkish

/ɯ/, this influence is very limited, since only /ɯ/ and /a/ can occur in the same word.

Still, it might explain why /ɯ/ is adapted as /a/ sometimes.

(iv) Preceding as well as following consonants will have more influence on a vowel with respect to the front/back dimension, as reflected acoustically mostly in F2.

Although it was found that for English that anticipatory coarticulation is more prominent, Japanese and Catalan contradict that (Kiritani et al. 1977, Recasens 1986).

Coarticulation noticed during articulation does not have to be reflected acoustically: some vowels may show more coarticulation during articulation than others, but, acoustically, the difference might not be significant.

(v) Generally, vowels in context will have their acoustic space smaller than vowels in isolation: F1 and F2 will show more centralized values.

(vi) Some vowels may be more prone to the consonantal influence than others (e.g.

Gay 1974, Recasens 1985, Stevens and House 1963), “presumably since the tongue body becomes highly constrained when fronted and raised simultaneously (Recasens

1999, p. 81). It was found that low vowels are more prone to coarticulation influence

(Gay 1974, Recasens 1999).

(vii) If the Turkish vowel /ɯ/ is exceedingly short compared to other vowels, then we can expect it to be more prone to coarticulation, like schwa. Shorter vowels can lead to problems with perception, more so when preceded by some consonants than others.

Turkish does not have reduced vowels, but /ɯ/ shows some patterns of behaviour similar to reduced vowels. For example, it is deleted in loanwords.

77 (viii) Adjacent labial consonants will significantly lower F2 of some or all front

vowels. Adjacent alveolar and postalveolar consonants will significantly raise F2 of

some or all back vowels and lower F2 or front vowels. Adjacent velar consonants will

raise F2 of front vowels, and can lower or raise F2 of back vowels.

2.6 Summary

This chapter has been crucial for the understanding of the study. The chapter contains both theoretical and empirical foundations as well as the major issues that the study focuses on: the theory behind the articulation and acoustics of vowels and previous studies done on vowels.

Thus, all that has been said in Chapter 2 helps us to formulate the research questions and the hypotheses given above.

The following five chapters deal with the acoustic and articulatory experiments, starting with Chapter 3, where the experiment methodology is described in detail.

78 CHAPTER 3

EXPERIMENTAL METHODOLOGY

The present study investigates Turkish vowels in two ways. First, their articulatory properties are examined, i.e. the ways in which they are articulated in the oral cavity. Second, their acoustic properties are examined, i.e. the ways their articulation is reflected in the speech sound wave exiting the oral cavity. Thus, two different experimental phonetic methodologies were employed: ultrasound video imaging to study articulation, and audio recording of sound waves to study acoustics.

In this chapter, I describe in detail the methodology used in the four experiments carried out for this work: ultrasound imaging technology (3.1), on overview of previous studies using ultrasound in linguistics (3.2), measurements used in the present study (3.3), equipment and procedures (3.4), participants (3.5), stimuli (3.6), measurement analysis (3.7), and statistical tests used (3.8).

3.1 Recording Articulation Using Ultrasound Imaging

Ultrasound is any sound wave with a very high frequency, above the threshold for human hearing, 20,000Hz. Ultrasound produced by ultrasound imaging machines used to record tongue movements ranges from 2 to 7Mz. When emitted from the ultrasound machine transducer probe, ultrasound travels until it reaches the density difference between two tissues, when it bounces back. The distance from the probe to the object from which the ultrasound reflected is measured as the time it takes the wave to return to its source. In articulatory studies using ultrasound, a transducer probe is located under the chin and the ultrasound beam is directed vertically. Since the greatest density difference which the emitted ultrasound first reaches is between the tongue (muscle, soft tissue) and the air above the tongue, an image of

79 the upper surface of the tongue is obtained; the image of the tongue appears as a white line

(Figure 1).

Ultrasound has been used for over three decades by researchers to study speech sounds

(Stone 2005). In comparison with other articulatory methodologies used to record tongue movement, such as MRI, x-ray and EMA (electromagnetic articulometer), ultrasound has its advantages and disadvantages. The information on the ultrasound technique is taken from

Bressmann (2008), Gick (2002) and Stone (2005).

The following are some of the main benefits of ultrasound. The researcher can do data collection via ultrasound recording relatively easily. The ultrasound technique is a real-time imaging technique, i.e. the researcher can watch on a screen what is being recorded, and can adjust the parameters if necessary. The participants find ultrasound recording to be relatively comfortable in comparison to MRI and EMA; it is also non-invasive and is considered biologically safe in comparison to x-ray. Moreover, both sagittal (side) scans and coronal

(front) scans can be obtained.

The two major drawbacks to ultrasound are low frame rate, and the impossibility to always visualize the palate and the extreme front and back of the tongue. The standard frame rate for ultrasound machines is 30 frames per second, which is particularly inconvenient when a researcher is studying speech events that are very short. There are, however, ultrasound machines that record 90 or 100 frames per second (e.g. Stone 2010, Vaissière et al. 2010).

This is better than what some other imaging techniques can do, like MRI, with 9 or 11 frames per second (e.g. Byrd et al. 2009, Lee et al. 2006), but still much lower than some other tracking techniques, like EMA, whose sampling rate ranges from 200-400Hz (e.g. Hoole and

Nguyen 1999). The other major drawback to ultrasound is that the palate and the parts of the tongue located on the extreme left and right edges of the image are not visible. From a sagittal

80 scan, the very front and the very back parts of the tongue, in the majority of cases, cannot be obtained, because bones such as the mandible and the hyoid refract the ultrasound; also when the tongue tip is raised, the air pouch created underneath reflects the ultrasound beam, and does not allow it to reach the tongue above. The bones and the air pouch appear as dark shadows on the image. Somewhat less than 1 cm of the tongue tip is not visible, but since the anterior portion of the blade is visible, tongue tip movements can be deduced (Stone 2005).

A midsagittal ultrasound image of the tongue is illustrated in Figure 1.

tongue surface

back of the tongue front of the tongue

hyoid bone mandible shadow shadow Figure 1. Midsagittal image of the articulation of the vowel /a/

A midsagittal image involves the “vertical plane through the midline of the body; divides the body into right and left halves” (Online Medical Dictionary). The white curved line running from the left through the right side of the image (“tongue surface”) is the image of the tongue.

The front part of the oral cavity is on the right hand side of the image, and the back on the left.

Two shadows or dark spots are visible, one in the right bottom corner made by the jaw bone -

“the mandible shadow”, and the other on the opposite side made by the hyoid bone.

81 3.2 A Short Overview of Previous Ultrasound Studies on Vowels

A number of articulatory studies have been done on vowels using ultrasound. As discussed in section 3.1, an ultrasound image has its limitations – the back part of the tongue, important for describing low, pharyngeal vowels is missing, the tip of the tongue, which may be important in determining the shape of the tongue, is not visible, and the lips cannot be recorded. However, whatever information is available is, in most cases, adequate in describing the majority of vowels, unlike some consonant articulations.

There have been two kinds of ultrasound studies on vowels: qualitative, aiming at describing vowel articulation, and quantitative, aiming at measuring some aspects/parameters of vowel articulation. Just like with acoustic studies, researchers conducting ultrasound studies on vowels measure parameters that best quantify the answers to their particular research questions. However, contrary to acoustics, where measuring formants to determine vowel qualities is a widely accepted standard approach, in ultrasound studies various measurements have been suggested for determining vowel qualities from ultrasound images, but none has as yet been standardized, as ultrasound research is still relatively new.

Studies done at the University of Maryland by Maureen Stone and colleagues were among the first studies to look at vowels in more detail. In a qualitative study on English vowels, they classified the overall tongue shapes as belonging to three categories: front raising, back rising and complete groove (Stone and Lundberg 1996). The high front vowel /i/ and the mid high front vowel /e/ are characterized by the raising of the front portion of the tongue, more so for /i/. The tongue is grooved at the back. However, the mid low front vowel /ɛ/ has an overall different tongue shape, with a groove in the middle running all the way from the front to the back of the tongue. Back vowels are characterized by the raising of the back portion of the tongue, more for the low vowel /ɑ/, and less for the other vowels, which can

82 perhaps be better described as “no anterior raising”. Posterior grooving is present in all cases, and is more pronounced with high vowels. Similar results were obtained for /i u ɑ/ in a study by Bressmann et al. (2005).

Quantitative methodologies can be roughly divided into three groups, based on the type of measurements used. First, some studies measure real distances in millimeters (mm), between, for instance, a reference point and the highest point of the tongue. These studies focus on one specific part of the tongue, and try to answer specific questions, such as: Which of the two vowels is more retracted, and how much? The goal of such studies is, for instance, to determine properties such as vowel height (English, Whalen et al. 2010), constriction degree

(German, Pouplier et al. 2004), and vowel root retraction (Hungarian, Benus and Gafos 2007;

St’át’imcets, Hudu 2008).

Second, there are studies that use coefficients based on a real reference in a measurement unit, for a more general comparison of tongue shapes (e.g. Bressmann et al.

2005, where Anteriority, Concavity and Asymmetry Indices are used).

Third, some studies statistically compare the whole tongue shape in order to determine similarities and differences in vowel production (e.g. Hungarian, Benus and Gafos 2007;

English, Davidson 2006; English Zharkova and Hewlett 2009; English, Morrish et al. 1985).

These three types of studies are presented with a few examples for each.

3.2.1 Overall Tongue Contour/Shape

Some studies that use different ways to quantify the overall tongue contour/overall shape are presented in this section. For instance, Morrish et al. (1985) and Davidson (2006) use polynomial functions from mathematics to study tongue contours. Each tongue contour represents a curve of some sort. These curves can be mathematically described using

83 polynomial functions. Since curve shapes differ, not all curves are best represented with the same mathematical function. Thus, vowels, based on the tongue shapes assumed during their production, can be quantified using different polynomial functions. Figure 2 illustrates this.

front of the tongue

Figure 2. Smoothing splines for the Turkish /e/

Figure 2, done in MATLAB, illustrates the curving fitting process. First, the x and y coordinates are imported into MATLAB, and this gives a certain limited number of dots in the figure that characterize the tongue shape in two dimensions: the x-axis (i.e. vertical distance from the transducer, “0” on the x-axis in the figure) represents tongue height and the y-axis

(i.e. horizontal distance from the transducer reference point to the tongue) represents tongue frontness. MATLAB offers a number of polynomial functions which mathematically calculate other (unlimited number of) dots/points between those that have already been imported, and connects them into a curved line. When presented graphically, the curves obtained this way look like the two curved lines in Figure 4. The original x and y coordinates are visible as black dots. For this figure, two curve fittings were tested, the solid line represents the 8th polynomial, and the dotted line represents the smoothing spline polynomial. Spline is defined as “a piecewise polynomial function that can have a locally very simple form, yet at the same time be globally flexible and smooth” (Mathworld Wolfram). From pieces of the x- and y-axes, a whole curved line is obtained/constructed using a polynomial function (Bartels et al. 1987). It 84 is obvious that the smoothing spline better fits/approximates the dots than the 8th polynomial for this vowel tongue shape, especially in the left half of the image. However, the smoothing spline curve is not always a better fit, and there are examples of tongue shapes where other polynomials are a better fit.

Next, the curves thus generated can be compared. For instance, Davidson (2006) introduced a statistical method used in other sciences – Smoothing Spline (SS) ANOVA. She compared vowels by reference to the similarities and differences in the whole tongue shape using the smoothing-spline ANOVA statistical tool, a tool which “characterize[s] the whole tongue surface” (e.g. Davidson 2006:407) and “compare[s] tongue curve shapes” (408).

Smoothing spline is a “piecewise polynomial function” (409) which connects the successions of dots (line) in the best possible way (the best fit), at the same time smoothing the possible

“noisy” or ragged appearance of a line. The best fit, i.e. the smoothing, is mathematically calculated according to a polynomial function formula.

Then the statistical method SS ANOVA is applied to compare the shapes of two or more smoothed curves in order to determine whether they significantly differ, just like any other ANOVA. In addition, curves can be divided into parts, and parts of interest can be compared, which enables the user to pinpoint more precisely where the curves differ from each another.

Techniques of this kind are very useful for the study of articulation. By comparing various shapes the tongue assumes during vowel production, we can determine where two vowels differ and how. However, it is difficult to relate articulation results obtained in this way with acoustic analysis with formants in a study like the present one, which focuses on combining articulation and acoustics.

85 Another way to quantify overall tongue shape is introduced by Benos and Gafos

(2007). Their goal was to determine the similarities and differences between tongue contours, and they did this by overlaying two tongue contours and calculating the area between them: a larger area means that two contours differ more and the production of two vowels differs more, while a smaller area means that two contours differ less.

Zharkova and Hewlett (2009) compared the tongue contours by dividing each tongue contour into the same number of dots, and applying a mathematical method called mean nearest neighbouring distance: Each dot on the tongue contour is compared to each dot on the other tongue contours, and the average is calculated for all distances. In this way, it can de determined where exactly the two tongue contours differ significantly, and where they are similar.

In sum, measuring the overall tongue contour/tongue shape can be done in various ways. This type of measurement allows us to compare tongue shapes among different vowels, and to infer how similar or different vowels are based on the whole tongue shape they assume during articulation.

3.2.2 Using Coefficients

The second group of studies uses coefficients based on a real reference in a measurement unit for a more general comparison of tongue shapes. An example of the second group of studies is the study done by Bressmann et al (2005). An inclusive measurement that enables a connection with acoustics is the Anteriority Index, which measures the position of the tongue body mass for one vowel compared to another. Since this measurement is used in the present study, it will be described in detail in section 3.7. The same study also used the other two measurements, the Concavity Index and the Asymmetry Index. The Concavity Index measures the degree to

86 which the whole tongue is concave and convex along the midline. The Asymmetry Index determines whether the left and the right sides of the tongue are the same height with respect to the midline groove, or whether one side is higher or lower than the other. For both of these measures, apart from the midsagittal tongue image, images of the left and the right sides of the tongue are made, or a parasagittal image. The Asymmetry Index is of interest as the study compared the normal tongue shape with the tongue shape of a person with tongue cancer before and after a tongue surgery.

3.2.3 Measuring Real Distances in mm

Finally, the third group of studies measures real distances in mm, for instance, between a reference point and the highest point of the tongue. Thus, apart from referring to the shape of the whole tongue or to a number of points on the tongue surface, we can also describe vowels by referring to one particular point on the tongue surface. For instance, Whalen et al. (2010) measured the highest point of the tongue and the narrowest constriction between the palate and the tongue. The location of the palate was determined on separate recordings where the participant swallowed water (e.g. Epstein and Stone 2005; Mielke et al. 2005). Similarly,

Pouplier (2004) measured constriction degree for tense and lax German vowels. Hudu (2008) was interested in tongue root retraction and measured the height of the tongue (in mm) from the transducer x axis to the back of the tongue in St’át’imcets (Salish language family).

The studies discussed so far have, for the most part, focused on the sagittal plane.

Besides recording and measuring the tongue in the sagittal plane, it can be useful to describe tongue shapes in the coronal plane (“relating to, or having the direction of the coronal suture or of the plane dividing the body into front and back portions”, Online Medical Dictionary) as well (Stone et al. 1988). Stone et al. quantitatively measure the height of the tongue during the

87 production of English vowels, i.e. vertical displacement from the transducers, at six places, anterior left, mid and right and posterior tongue left, mid and right. For instance, they found that in terms of anteriority the tongue is slightly convex for /i/ (6.12mm displacement), with the right side of the tongue being higher than the left side (asymmetrical), while in terms of posteriority the tongue is concave (3.10mm displacement).

Some of these measurements work better in some situations, depending on what the goal of research is. In the present study, specific measurements are used for two reasons. First, one of the goals of the study is to connect articulation and acoustics, and since it is widely accepted that formants refer to tongue height and frontness, it makes sense to measure tongue height and frontness. It would also make sense to measure constriction degree and location, if it were not for the limitations of the ultrasound images to reflect the palate. The palate can be reconstructed from images of swallowing, but that does not work all the time or with all speakers. Thus, a larger pool of speakers is needed and, preferably, a pre-screening. Second, some measurements, although well-conceived, such as smoothing-spline analysis, do not directly connect articulation and acoustics, and not all readers can immediately connect such results with what they know about vowel articulation.

3.3 Articulatory and Acoustic Measurements Used in the Study

Having given the background on ultrasound studies, I now describe the ultrasound study of

Turkish vowels. With respect to acoustics, F1, F2 and F3 were measured. Vowel duration was also measured16.

16 It is important to note that lip shape is also important when studying rounded vowels. There are several reasons why lip shape is not addressed in this study. First, the set up allowed only simultaneous video recording of the profile (Figures 1 and 7), and not the front of the face, which would give only partial information about lip shape, such as lip protrusion, but not the measurement that would be more important – lip aperture (e.g. Linker 1982; Maddieson and Anderson 1995). In a separate study, it would be useful to record lip shape using a video recorder in order to compare lip aperture for the pairs of rounded/unrounded vowels. We expect the lip aperture to be smaller for rounded vowels because the lips are rounded, but 88 With respect to vowel articulation, the following measurements were used: Tongue

Height, Tongue Frontness (Tongue Height Location) and the Anteriority Index (AI).

Constriction Location and Constriction Degree, for which a clear image of the palate is needed, could be done only for one speaker, P1 (female). The results are included, more for illustrative purposes than for analysis.

Following the vowel theory that describes vowels along the high/low and front/back dimensions (section 2.1.2), vowels were compared with respect to the highest point of the tongue: (i) how high the tongue is and (ii) how front or back that highest point of the tongue is.

Figure 3. IPA vowel chart (Taken from IPA 2005).

The IPA chart in Figure 3 uses the terms “close” and “open” to refer to high vowels/narrow constriction and low vowels/wide constriction, respectively. Thus, the IPA chart is a combination of both the High/Low, Front/Back and the Palatal/Dorsal/Pharyngeal/Labial articulatory models. High vowels /i y u ɯ/ are expected to have the tongue higher than mid there is evidence that the lip aperture can be very similar between a pair of the rounded/unrounded vowels (section 2.1.2.1). A study of lip shape in Turkish vowels would make a study on Turkish rounded/unrounded vowels more complete. Other directions for further research are given in the final chapter.

89 vowels /e œ/ and low /a/, and the mid vowels are expected to have the tongue higher than low vowel /a/; front vowels /i y e œ/ have the highest point of the tongue more front than back vowels /u ɯ o/. This was straightforward to measure, and was done for all three Turkish speakers whose articulation was recorded. However, one of the disadvantages of the ultrasound recording is that the very anterior and the very posterior part of the oral/pharyngeal cavity are not visible on the image, as discussed in section 3.1. As we will see in the results (Chapter 4), this did not impede the measuring of the non-pharyngeal vowels, because the highest point of the tongue does not reach that front, but the measuring of the height for pharyngeal vowels /o a/ gave results which cannot be interpreted in the same way.

Following the vowel theory that describes vowels along the four places of articulation, as labial, palatal, velar and pharyngeal, vowels were compared with respect to the constriction location and degree: (i) at which location in the oral cavity is the constriction between the tongue and the palate the narrowest and (ii) how narrow the constriction is.

Thus, vowels /i y u ɯ/ have a constriction more narrow than vowels /e œ/ and /a/, while vowels /e œ/ have a more narrow constriction than the vowel /a/; vowels /i y e œ/ have the narrowest tongue constriction in the palatal region, the vowels /u ɯ o/ have the narrowest tongue constriction in the dorsal region, and the vowel /a/ has its narrowest constriction in the pharyngeal region. The vowels /y œ u o/ also have another constriction at the lips. The relevant limitation of the ultrasound technique, mentioned in section 3.1, is that ultrasound images cannot record the palate, and the palate is needed in order to measure the distance between the tongue and the palate, i.e. constriction degree. There is a way around this - the reconstruction of the palate from the images where the participants swallow and thus make contact between the tongue and the palate (e.g. Epstein and Stone 2005; Mielke et al. 2005). In the present study, this did not work for all participants – for two speakers, the palate was either

90 blurred and not visible during swallowing, or it was only partially visible. Thus, the results presented here are from one female participant.

3.4 Equipment and Procedure

The four experiments were carried out and all data was collected at the University of Toronto.

The acoustic data were recorded in the soundproof booth of the Phonetic Laboratory of the

Department of Linguistics, using a digital audio recorder Fostex FR-2 and an ATR condenser microphone. Quantization was 16-bit with a sampling rate of 44.1 kHz.

The ultrasound articulation data were recorded in the Voice and Resonance Laboratory of the Speech-Language Pathology Department, using a General Electric Logiq Alpha 100 MP ultrasound machine (General Electric Medical Systems, PO Box 414, Milwaukee, WI 53201,

USA). The transducer was a 6.5 MHz endocavity transducer model E72 with a micro convex curved array scanner with a 114 degrees view. The image focus depth was 10 cm, and the frame rate 30 frames/sec.

During the ultrasound recording, the participants were seated in an upright position in a comfortable chair. In order to prevent possible head movements and the movement of the transducer probe during speech production, the Comfortable Head Anchor for Sonographic

Examinations (CHASE, by Johnson, Bloorview Macmillan Children’s Centre, Toronto,

Ontario), developed at the University of Toronto, was used (Bressmann 2008). Thus, the transducer and the head are immobilized, while the jaw (along with the tongue) moves in accordance to speech sounds. Therefore, the point where the transducer contacts the chin can be used as the stable reference point (Bressmann, 2008; Stone 2005; Stone and Davis 1995).

91 The participants read the stimuli off the computer screen placed in front of them. The stimuli were presented one by one using power point slides. The slides were changed by the author from another computer. Figure 4 shows a speaker during the recording.

microphone

CHASE

stimuli

Figure 4. Recording using ultrasound at the Speech-Language Pathology Department, University of Toronto

3.5 Participants

For the articulation recording, the participants were 3 Turkish native speakers, 2 female (P1 and P2) and 1 male (P3), with ages ranging from 19 to 23 (average 21). They were students at the University of Toronto, and they had lived in Canada prior to the recording for 5 months to

5 years (average 2 years). In Turkey, they lived in Istanbul (north-west) (P1 and P3) and Izmir

(south-west) (P2).

The recordings for this work were made in 2009. At that time, it was common to have

1 to 5 participants/speakers in ultrasound studies. Today the technique for recording and analysing ultrasound images has advanced, and it is common to have a larger number of participants in experiments of this kind.

92 For the acoustic recording, in addition to the 3 speakers mentioned above, there were 3 more speakers. The participants were 6 Turkish native speakers, 3 female (P1, P2 and P4) and

3 male (P3, P5 and P6), with ages ranging from 19 to 38 (average age 28.5). They were students at the University of Toronto, and they had lived in Canada prior to the recording for 5 months to 12 years (average 5 years). In Turkey they lived in Istanbul (P1 and P3), Izmir (P2),

Samsun (north) (P4), Cide (north) (P5) and Mardin (south-east) (P6).

3.6 Stimuli

The stimuli were of two kinds. First, the 8 Turkish vowels /i y ɯ u e œ o a/ were uttered sustained, in isolation (Experiments 1 and 2). Second, the 8 Turkish vowels were uttered in context, preceded and followed by consonants with different places of articulation embedded in nonce words (Experiments 3 and 4).

For Experiment 1, articulation of 8 vowels in isolation (duration ranged from 700ms to

1s), each vowel was repeated 3 times in a row. Thus, the number of tokens was 3 speakers x 8 vowels x 6 repetitions = 144 tokens altogether.

For Experiment 2, acoustics of 8 vowels in isolation, the number of tokens varied per speaker, 3, 6 or 9. The number of tokens was 264 altogether.

For Experiments 3 and 4, articulation and acoustics of vowels in consonantal contexts, the stimuli were vowels embedded in nonce words. The following Table 1 presents the stimuli.

Table 1. Stimuli for vowels in consonantal contexts Preceding labelled in Tables Following labelled in Tables as as where Labial /bVC/ L_ /CVb/ _L C = /b, d, dʒ, g/ Alveolar /dVC/ A_ /CVd/ _A V = /i y ɯ u e œ o Postalveolar /dʒVC/ PA_ /CVdʒ/ _PA a/ Velar /gVC/ V_ /CVg/ _V

93 Note: symmetrical environments were not used, e.g. /bVb/

These words were embedded into a carrier sentence: /ʃahika ______akɯl etti/ “Shahika said

____”. The participants were instructed to read sentences at a normal reading speed.

For Experiment 3, only the articulation of the vowel /ɯ/ in consonantal contexts was analyzed. There were 3 repetitions for each context. Thus, the number of tokens was 3 speakers x 4 contexts x 3 repetitions = 36 tokens altogether.

For Experiment 4, acoustics of 8 vowels in consonantal contexts, there were 3 repetitions for each context. Thus, 6 speakers x 8 vowels x 3 repetitions x 4 context = 576 tokens altogether.

3.7 Analysis

The analysis of the acoustic data was performed using PRAAT software (Boersma and

Weenink 2010). Formants F1, F2 and F3 (Hz) were measured. For both vowels in isolation and in context, formants and intensity were measured in the middle of the vowels, using the formant analysis algorithm, with a 23.3ms Gaussian window.

The initial analysis of the raw ultrasound data was done using Ultra-CATS software

(Ultrasonographic Contour Analyzer for Tongue Surfaces, Gu et al. 2004, University of

Toronto). The most central frame, i.e. the one at the midpoint of the vowel, was determined using the wave form that accompanies ultrasound recording in the Ultra-CATS program; this central frame was analyzed.

As a reference point for measurement, the point where the transducer touches the chin was chosen. Taking this point as a reference, for each selected frame, Ultra-CATS creates a grid in the form of the polar coordinate system. Tongue contours were traced manually. The grid yields two polar coordinate system measurements, angles and distances. Thus, from Ultra-

94 CATS, I obtained the distances (mm) from the transducer reference point to the tongue contour, at different angles. The maximum and minimum possible angles Ultra-CATS allows are -85 to 85. However, the tongue contour measurements cover the -45 to 45 range at the most. This is illustrated in Figure 5.

95 (i)

front

back

(ii)

Figure 5. Tongue contour in the Ultra-CATS without the grid (i) and with the grid (ii)

Figure 5 shows an image of tongue contour obtained by ultrasound and processed in Ultra-

CATS. The tongue contour is the curved white line. The first figure (i) shows that the very back part of the tongue is not visible and the very front part of the tongue is also obscured

96 (dark shadows). The second figure (ii) shows the same image with the Ultra-CATS grid imposed on it. Ultra-CATS uses the grid to calculate the measurements.

The measurements obtained (distances and angles) using the grid were transferred to

Excel. Some measurements were done directly in Excel (Anteriority Index, Constriction

Degree and Location) and for the other measurements (Tongue Height and Tongue Frontness), the data were transferred and analyzed in MATLAB 7.7.

3.7.1 Tongue Height and Tongue Frontness

Tongue Height and Tongue Frontness were calculated in the following way. The Polar coordinate system measurements were converted into the Cartesian coordinate system, so instead of angles and distances, tongue contours were represented as distances on the x and y axes. These data were further processed in MATLAB, where a best fitted mathematical curve was applied to each tongue contour separately. In this way, the tongue contour, which was previously defined by Ultra-CATS with a limited number of points (8 or 12), was now defined by an indefinite number of points, and measurements could have been taken anywhere on the tongue contour.

The highest point of the tongue was measured on the y-axis and the location of the highest point of the tongue on the x-axis, from the transducer point of reference. MATLAB automatically provides these two measurements, as illustrated in Figure 6.

97 Tongue Frontness (mm)

highest point of the tongue

Tongue Height (mm)

transducer reference point

Figure 6. Measuring Tongue Height and Tongue Frontness

Figure 6 shows the vowel tongue contour of the vowel /y/. MATLAB supplies precise x- and y-axis measurements, like those showed in the box.

3.7.2 Anteriority Index (AI)

The Anteriority Index (AI) measures the “relative position of the main mass of intrinsic tongue tissue in the oral cavity” (Bressmann et al. 2005: 577). A similar idea was originally proposed for palatography as Centre of Gravity (COG) (Mizutani et al. 1988), and has been used for palatography since 1991 (e.g. Gibbon and Nicolaidis 1999). A similar COG formula as used by Hardcastle et al. (1991) is given below:

98 (0.5R8  1.5R7  2.5R6  3.5R5  4.5R4  5.5R3  6.5R2  7.5R1) COG  total number of contacts where R is the row of electrodes and the number preceding R is the coefficient, which weights each row and increases with anteriority. This method is described in more detail below.

The COG formula was modified for ultrasound contours by Bressmann et al. (2004), where rows were replaced by angles. The AI formula I used is adapted from Bressmann et al. for this study and is given below:

(yA  2yB  3yC  4yD  5yE  6yF  7yG) AI  yA  yB  yC  yD  yE  yF  yG

where yA to yG represent the distance, in the Polar coordinate system, from the transducer reference point to the tongue contour under different angles (A, B, C, D, E, F, G), as given by the Ultra-CATS. Figure 7 below illustrates this.

line 27 tongue contour

line 7

line 3 line 2 line 1

x-axis reference point

Figure 7. Anteriority Index illustrated

99 The grid, consisting of 36 lines, is overlaid on the ultrasound image. The starting point for each of these lines is the transducer reference point. The leftmost and the rightmost lines are at approximately 5 degree angles with respect to the horizontal x-axis. For example, the first line on the right, line 1 in Figure 10, is at a 5 degree angle with respect to the horizontal x-axis; the second rightmost line, line 2, is at a 10 degree angle, etc. Based on the tongue shape, some lines intersect the tongue contour, and others do not. For instance, in Figure 7, lines 7 to 27 intersect the tongue. Symbol “y” in the formula above stands for the length (mm) of a line that intersects the tongue, from the reference point to the tongue contour. For the formula, seven most representative lines were chosen for each speaker, lines that intersect with the tongue with all 8 vowels. Thus, for each person separately, the lowest and the highest angles were determined for all vowels, in Excel; the middle seven angles were used in the formula. The angles vary -10 to 20 for speaker 1 and 3, and 0 to 25 for speaker 2.

The higher the AI index is, the more front the tongue body is, and vice versa.

3.7.3 Constriction Location and Constriction Degree

Constriction Location identifies where the tongue and the palate come closest to each other;

Constriction Degree is the distance between the tongue and the palate at the constriction location point. The measurement is again done relative to a reference point – the transducer.

For Constriction Location and Constriction Degree, the palate was taken into consideration. In order to perform these measurements, the location of the palate is needed.

The palate was successfully reconstructed from swallowing images for P1 (female). Figure 8 illustrates how Constriction Location and Constriction Degree were measured.

100 Constriction Location (mm)

80

70

60

50 palate 40 i4 30 Constriction Degree (mm) 20 10

0 -30 -20 -10 0 10 20 30 40 50

transducer reference point

Figure 8. Measuring Constriction Degree and Constriction Location

Figure 8 represents two contours – the tongue is the lower contour and the palate the higher.

Based on the Cartesian coordinate system for the tongue contour and the palate contour, the

Constriction Location measurement was obtained as the location on the x-axis which represents the shortest distance (mm) between the tongue and the palate, and the Constriction

Degree measurement was obtained as the actual shortest distance between the tongue and the palate. This was done in Excel with measurement points supplied by the Ultra-CATS grid.

Each grid measurement point of the tongue contour and each measurement point of the palate contour were compared, until the two points closest to each other were found.

101 3.8 Statistical Analysis

For the articulatory data, a detailed statistical analysis was not done due to a small sample size

- 3 speakers; only paired samples t-tests were used sparingly in order to compare among certain pairs of individual vowels, as well as among the three rounded/unrounded pairs. A more detailed statistical analysis was done for the acoustic data.

The following statistic tests were performed.

First, repeated measures analysis of variance (ANOVA) was used in order to compare:

(i) (Experiment 2) all vowels in isolation. Within-subject factors were Rounding (2 levels:

Rounded and Unrounded) and Vowels (3 levels: /i ɯ e/ for unrounded vowels; /y u œ/ for rounded vowels); between-subject factor was Gender (2 levels: male and female).

(ii) (Experiment 4) a vowel in isolation with the same vowel in four different consonant contexts. Within-subject factors were Context (5 levels: L, A, PA, V and a vowel in isolation) and Consonantal Position (2 levels: preceding and following). Between-subject factor was

Gender (2 levels: male and female). Also, in order to compare only the consonantal contexts themselves, ANOVA with within-subject factor Context (4 levels: L, A, PA and V) was used.

If a significant difference was reported, a post-hoc test was used to analyze differences within the factor. A post-hoc test used is the Pairwise Comparison, with Bonferroni adjustment, with p = 0.05.

Also, paired samples t-tests were used, at p = 0.05, in order to compare:

(i) (Experiment 1 and 2) rounded vowels with their unrounded counterparts

(ii) (Experiments 3) a vowel in each consonantal context with the same vowel is isolation

(iii) (Experiment 4) the effect of Consonantal Position on each consonantal context separately, i.e. differences between a vowel preceded and followed by the same consonant (e.g. L_ vs. _L).

102 The level of significance is always set at p < 0.05; in case the p-value is smaller, p <

0.01, it is noted in the text.

All ANOVA statistic tests were done applying Bonferroni correction/adjustment, which controls for the number of levels in a factor, which can differ between tests. Although applying Bonferroni adjustment is a textbook example of how to do tests, Bonferroni adjustment, or adjustments of any kind, have also been criticized as “unnecessary” or

“deleterious” (see, for example Feise 2002, Garamszegi 2006, Perneger 1998). Namely, when we compare more than two items, a statistical test compares them two by two, and we run the risk of getting too many statistical significances – the test becomes too liberal. In order to counteract that possibility, we are instructed to apply adjustments, which “adjust” for a number of items compared, and we end up getting less statistical significances. As a result, adjustments can return very conservative results – almost nothing is significant.

In this study, I applied Bonferroni adjustment, and all my results, summaries, discussions and conclusions are derived from the statistical significance based on the adjustment, but the preceding discussion should be kept in mind.

Finally, I used discriminant analysis in order to determine whether the acoustics measurements F1, F2, F3 and intensity can distinguish between Turkish vowels in isolation and /ɯ/ in the four different contexts, and if any of the contexts can be confused among themselves and vowels in isolation (Experiment 4).

The goal of the statistical procedure called discriminant analysis is to determine how much the acoustic measurements like F1, F2 and F3 contribute to the classification of the 8

Turkish vowels. Discriminant analysis answers questions of the following type: Is the information obtained from F1 and F2 sufficient enough to classify all vowels correctly? Does the classification improve when we add the information from F3? Are some vowels better

103 classified than others? If a vowel is not classified very well, with which vowels is it confused the most? For instance, Hillenbrand et al. (1995) used discriminant analysis for American

English vowels and Strange et al. (2005) used it to compare North German and American

English vowels; Weenink (2006), after testing several vowel identification procedures, concludes that “Discriminant analysis has proven to be an invaluable technique because it can function as a reference system in vowel segment classification. It constitutes the baseline against which other classifiers can be compared” (p. 204). In addition, there is evidence that the discrimination by the listeners and the discrimination done by the statistical discriminant analysis procedure are very similar (Hillenbrand et al. 1995). The results were obtained based on individual tokens.

All statistical tests were done in SPSS 17.0.

3.9. Summary

The goal of Chapter 3 was to describe the set up for the four experiments, including the equipment, the participants. the stimuli, the procedure and the measurements. Special attention was paid to describe the ultrasound techniques for recording speech sounds, and the way articulatory measurements were performed. In the next four chapters, the results of the two acoustic (Chapters 5 and 7) and two articulatory experiments (Chapters 4 and 6) are presented.

104 CHAPTER 4 EXPERIMENT 1: ARTICULATION OF SUSTAINED VOWELS IN ISOLATION

Chapters 4 and 5 present the results of Experiments 1 and 2, respectively, which investigate phonetic properties of the 8 Turkish vowels in isolation. Chapter 4 deals with articulatory properties and Chapter 5 with acoustic properties of the vowels.

Recall from Chapter 2 that the goal of Experiment 1 was to describe the articulation of the 8 Turkish vowels in isolation. This experiment was designed to answer the following three questions: (i) whether the members of the three rounded/unrounded vowel pairs differ in tongue height and/or tongue frontness, as vowels are usually described in terms of height and frontness; (ii) whether /ɯ/ is a central or a back vowel, based on whether there is a difference in tongue frontness between /ɯ/ and /u/; (iii) and how the three vowel pairs differ among themselves.

Chapter 4 is organized in the following way. Section 4.1 describes vowels qualitatively with reference to tongue shape. Sections 4.2 to 4.4 describe vowels using three quantitative measurements, Tongue Height, Tongue Frontness and Anteriority Index, respectively. In section 4.6, additionally, Constriction Location and Degree measurements are presented for the one speaker for whom the palate was clearly visible in swallowing images.

The three speakers (P1 and P2, female; P3, male) were recorded using ultrasound.

There were 8 sustained vowels x 6 repetitions x 3 speakers = 144 tokens. The vowels were sustained on average 700ms to 1s. The image of the tongue that belongs to the frame in the middle of the vowel production (i.e. durational mid point) was used. The statistical paired samples t-test was used to compare individual differences between rounded vs. unrounded vowels of the same pair (e.g. /y/ vs. /i/) and between the three vowel pairs (e.g. /i y/ vs. /e œ/).

105 4.1 Tongue Shape

Section 4.1 qualitatively describes shapes the tongue assumes during the production of the 8

Turkish vowels.

The following figures represent tongue shapes for the 8 vowels for P1, P2 (both female) and P3 (male). The x-axis and y-axis limits are the same on all figures for the same speaker for purposes of comparison, but vowels differ with respect to how much space the tongue occupies with respect to the axes (see Chapter 3). Also, axes limits differ with different speakers. Figures 1-4 illustate the vowels /i y/, /ɯ u/, /e œ/ and /a o/, respectively, and Figure

5 illustrates the three vowel pairs together per speaker. The unrounded vowels are represented with a solid line and the rounded vowels are represenred wth a dashed line.

106 Figure 1 shows average tongue shapes for the high front rounded/unrounded pair /i y/, from

P1-P3.

P1

i y

P2 i y

back front

P3 i y

Figure 1. Tongue shapes during the production of /i/ (solid line) and /y/ (dashed line) for P1- P3 (units on the axes represent 5mm; “0” is the transducer reference point)

107 Figure 1 shows that the vowels /i/ and /y/ had very similar tongue shapes within a speaker, as well as between speakers. The speakers were similar in that the tongue was overall slightly more front for /i/, higher for /i/ in the front region, and higher for /y/ in the back region. P1 and P2 differed from P3. P1 and P2 had a domed tongue shape for both vowels. P3 differed from the other two speakers in having a less curved, more flat tongue shape for both vowels; also, for P3, there was a greater difference between the two vowels, as the tongue was more raised for /i/ than for /y/ at the front, while it was the opposite at the back.

108 Figure 2 shows average tongue shapes for the high back rounded/unrounded pair /ɯ u/, from

P1-P3.

P1

ɯ

u

P2

ɯ back u front

P3

ɯ

u

Figure 2. Tongue shapes during the production of /ɯ/ (solid line) and /u/ (dashed line) for P1- P3 (units on the axes represent 5mm; “0” is the transducer reference point)

109 Figure 2 shows that the vowels /ɯ/ and /u/ also had similar tongue shapes within a speaker.

The tongue was again overall more front for the unrounded /ɯ/, higher for /ɯ/ in the front region, and higher for /u/ in the back region. Tongue shape was also domed for the three speakers. However, the tongue shape differed more among the three speakers than was the case with /i y/. P1 and P3 had a clear domed shape all the way through, while P2 had a domed/humped shape at the back and then the tongue straightened up at the front.

110 Figure 3 shows average tongue shapes for the mid rounded/unrounded pair /e œ/, from P1-P3.

P1

e œ

P2

e back front

œ

P3

e

œ

Figure 3. Tongue shapes during the production of /e/ (solid line) and /œ/ (dashed line) (units on the axes represent 5mm; “0” is the transducer reference point)

111 Figure 3 shows again that vowels /e/ and /œ/ had similarities and differences. The tongue was still overall more front for the unrounded /e/, higher for the unrounded /e/ in the front region, and higher for the rounded /œ/ in the back region, like with the other two pairs. Differently from the high vowels, mid vowels’ tongue shape is much less curved. Also, /e/ and /œ/ differed more in tongue shape between themselves than either /i/ and /y/ or /ɯ/ and /u/. /e/ was much more front than /œ/, especially for P2 and P3, and /e/ is more curved than /œ/, particularly for P1 and P2.

In sum, the unrounded vowels were more front and higher at the front than the rounded vowels. Vowels /ɯ u/ were articulated further back than vowels /i y/, as expected. The tongue was more bunched, and, therefore, higher for /ɯ u/, while the tongue was lower and more spread for /i y/. The mid pair was slightly lower than the high front pair, as expected, the the tongue was less bunched and more spread. Also, /e/ and /œ/ differed overall more between themselves than the members of the other two pairs. Thus, judging by overall tongue shape,

/ɯ/ is a back and not a central vowel, very similar in shape to /u/, and not considerably more back then /u/.

112 Figure 4 shows average tongue shapes for the low unrounded vowel /a/ and the mid back rounded vowel /o/, from P1 to P3.

P1

a o

P2

back front

a o

P3

a o

Figure 4. Tongue shapes during the production of /a/ (solid line) and /o/ (dashed line) (units on the axes represent 5mm; “0” is the transducer reference point)

113 The /a/ and /o/ tongue curves are given here as a reference, but these two vowels are not considered a rounded/unrounded vowel pair phonetically; though both are back, /a/ is low and

/o/ is mid. Figure 4 shows that their tongue shapes, at least for the part of the tongue visible on ultrasound images, were, surprisingly, quite similar.

114 Figure 5 shows average tongue shapes for all three rounded/unrounded pairs per speakers.

P1 ɯ-u

i-y

e-œ

P2 ɯ-u

i-y

back front e-œ

P3 ɯ-u

i y e œ

Figure 5. Tongue shapes for the three vowel pairs (unrounded-solid line, rounded-dashed line)

115 Figure 5 shows that P1 and P2 had the three vowel pairs clearly separated from one another, while with P3 tongue shapes for the vowels are closer to each other and overlap; particularly, the mid pair seems to be in between the two high pairs in the horizontal dimension. The mid vowel pair is less front than the high front pair with all three speakers. Although /ɯ/ is more front than /u/ with all three speakers, so are the the other two unrounded vowels from their rounded counterparts.

4.2 Tongue Height

Section 4.2 presents results of the Tongue Height measurement for the 8 Turkish vowels.

Recall that the initial analysis of the raw ultrasound data was done using Ultra-CATS software (Ultrasonographic Contour Analyzer for Tongue Surfaces, Gu et al. 2004, University of Toronto). As a reference point for measurement, the point where the transducer touches the chin was chosen. Taking this point as a reference, for each selected frame, Ultra-CATS creates a grid in the form of the polar coordinate system. Tongue contours were traced manually. The grid yields two polar coordinate system measurements, angles and distances. Tongue Height and Tongue Frontness were calculated in the following way. The Polar coordinate system measurements were converted into the Cartesian coordinate system, so instead of angles and distances, tongue contours were represented as distances on the x and y axes. The highest point of the tongue was measured on the y-axis and the location of the highest point of the tongue on the x-axis, from the transducer point of reference. MATLAB automatically provides these two measurements. (For more information about the Tongue Height and the Tongue

Frontness measurement, please refer to Chapter 3.)

Figure 6 shows the results of the Tongue Height measurement averaged for the three speakers.

116 *

Figure 6. Mean Tongue Height (mm) averaged for the three speakers for all vowels

Figure 6 shows that the tongue reached its highest point during the production of the high back vowels /ɯ u/ and its lowest point during the production of the mid front vowels /e œ/. A paired samples t-test (α=.05) showed that the three vowel pairs (/i y/, /ɯ u/, /e œ/ significantly differed from each other in tongue height: t(35)=-7.516 (/iy-ɯu/ pairs), 10.479

(/iy-eœ/ pairs), 36,465 (/ɯu-eœ/ pairs) (all p<.01).

For vowels within pairs, paired samples t-test showed that /i/ was significantly higher than /y/, t(17)=2.987 (p<.01).

Vowels /o/ and /a/, which do not constitute a pair, were similar in height to the high front vowel pair, and /a/ was lower than /o/. As already mentioned, this result was largely a consequence of the ultrasound imaging limitations, as the constriction in the pharyngeal cavity could not be visualized.

117 Figure 7 presents Tongue Height for each speaker separately.

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Figure 7. Mean Tongue Height values (mm) for the three speakers separately for all eight vowels

Figure 7 shows that, generally, P3 (male) had the highest values and P2 (female) the lowest values of the three speakers.

For all three speakers, the tongue was raised most for /ɯ u/ and least for /e œ/. The interspeaker variation was explored using paired samples t-tests (α=.05). As expected, the mid vowel pair /e œ/ differed significantly in height from the two high vowel pairs /i y/ and /ɯ u/ for all three speakers; from the high front vowel pair: t(11)=10.187 (P1), 16.530 (P2) (both p<.01), 2.446 (p<.05) (P3); from the high back vowel pair: t(11)=23.259 (P1), 15.305 (P2),

118 12.002 (p<.05) (P3) (all p<.01). Additionally, the high back vowel pair /ɯ u/ was significantly higher than the high front vowel pair for P1 and P3: t(11)=-15.558 (p<.01) (P1) and -8.579 (p<.05) (P3).

With respect to differences among pair members themselves, /i/ was consistently always higher than /y/, but that difference was significant only for P3: t(5)=7.534 (p<.01).

Also, /e/ and /œ/ significantly differed with P1 and P2: t(5)=3.441 (p<.05) (P1) and 8.100

(p<.01) (P2), although the difference was in the opposite direction.

4.3 Tongue Frontness

Section 4.3 presents results of the Tongue Frontness measurement for the 8 Turkish vowels.

Figure 8 shows the result of the Tongue Frontness measurement averaged for the three speakers.

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Figure 8. Mean Tongue Frontness (mm) averaged for the three speakers for all vowels

119 Figure 8 shows that, according to the Tongue Frontness measurement, the tongue was most front during the production of the high front vowels /i y/ and least front during the production of the high back vowels /ɯ u/. Paired samples t-test (α=.05) showed that all vowel pairs differed among each other, t(35)=24.358 (/iy-ɯu/ pairs), 2.105 (/iy-eœ/ pairs), -4.578 (/ɯu- eœ/) pairs (all p<.01).

The tongue was always more front for unrounded vowels. Paired samples t-test showed that all unrounded vowels were significantly more front than their rounded counterparts: t(35)=4.849 (/i/ and /y/), -3.128 (/ɯ/ and u/) and 6.997 (/e/ and /œ/) (all p<.01).

/a/ and /o/ were the least front vowels; /o/ was more front than /a/.

Figure 9 presents Tongue Height for each speaker separately.

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* *

*

Figure 9. Mean Tongue Frontness (mm) for the three speakers separately for all eight vowels 120 Figure 9 shows that, generally, P1 (female) had the lowest values of the three speakers, while

P2 (female) and P3 (male) had similar values.

With all three speakers, the tongue was in the most front position for the front vowel pair /i y/ and in the least front position for the back vowel pair /ɯ u/. Paired samples t-test showed that the tongue was significantly more front for the high front vowel pair than the mid and the back vowel pair for all three speakers; high front vs. high back vowel pair, t(11)=15.481 (P1), 12.755 (P2), 16.269 (P3) (all p<.01); high front vs. mid front vowel pair, t(11)=10.272 (P1), 7.383 (P2), 11.103 (P3) (all p<.01). Additionally, the high back vowel pair was significantly more back than the mid vowel pair with only two speakers, P1 and P2: t(11)=12.839 (P1), -2.301 (P2) (both p<.01).

With respect to vowels within each vowel pair, the unrounded vowel was always more front than its rounded counterpart, except for P1’s high front vowels. Paired samples t-test showed that unrounded /e/ was significantly more front than its rounded counterpart /œ/ for all speakers, P1-P3: t(5)=2.702 (p<.05), 8.363 (P1), 10.536 (P3) (both p<.01). Additionally, /i/ was significantly more front than /y/ for speakers P2 and P3: t(5)=4.651 (P2), 4.612 (P3)

(both p<.01). Also, /ɯ/ was significantly more front than /u/ only for P1, t(5)=6.902

(p<.01).

/a/ and /o/ were consistently more back than other vowels, and /a/ was consistently more back than /o/.

4.4 Anteriority Index

Section 4.4 presents results of the Anteriority Index measurement for the 8 Turkish vowels.

121 Recall that the Anteriority Index (AI) measures the “relative position of the main mass of intrinsic tongue tissue in the oral cavity” (Bressmann et al. 2005: 577). The COG formula was modified for ultrasound contours by Bressmann et al. (2004), where rows were replaced by angles. The AI formula I used is adapted from Bressmann et al. for this study and is given below:

(yA  2yB  3yC  4yD  5yE  6yF  7yG) AI  yA  yB  yC  yD  yE  yF  yG

where yA to yG represent the distance, in the Polar coordinate system, from the transducer reference point to the tongue contour under different angles (A, B, C, D, E, F, G), as given by the Ultra-CATS. (For more information about AI measurement, pleas refer to Chapter 3.)

Figure 10 shows the result of the Anteriority Index (AI) measurement averaged for the three speakers.

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Figure 10. Mean Anteriority Index averaged the three speakers for all vowels

Figure 10 shows that, according to the Anteriority Index measurement, the tongue body was the most front during the production of the high front vowels and the least front during the

122 production of the high back vowels, as expected. Paired samples t-test (α=.05) showed that all three pairs of vowels significantly differed from each other: t(35)=12.004 (/iy-ɯu/ pairs),

18.239 (/iy-eœ/ pairs) and

-4.406 (/ɯu/-/eœ/) (all p<.01).

Unrounded vowels were always more front. Paired samples t-test showed that this difference was significant for all three vowel pairs: t(35)=3.611 (/i-y), 4.915 (/ɯ-u/) and

9.017 (/e-œ/) (all p<.01).

/o/ and /a/ were the least front vowels; /o/ was less front than /a/.

Figure 11 presents AI for each speaker separately.

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Figure 11. Mean AI values for the three speakers separately for all eight vowels

123 For all speakers, /i y/ was the most front pair, and /ɯ u/ the least front.

Paired samples t-test showed that the tongue was significantly more front for the high front vowel pair than both the mid vowel pair and the back vowel pair for all three speakers; high front vs. high back vowel pair: t(11)=9.366 (P1), -8.579 (P2), 6.344 (P3) (all p<.01); high front vs. mid front vowel pair: t(11)=8.339 (P1) (p<.01), 2.446 (P2) (p<,05), 12.731

(P3) (p<.01). Interestingly, the high back vowel pair was significantly more back than the mid front pair with only two speakers, P1 and P2: t(11)=-4.883 (P1) , 12.002 (P2) (both p<.01).

With respect to vowels within each vowel pair, the unrounded vowel was always more front than its rounded counterpart. Paired samples t-test showed that unrounded /e/ was significantly more front than its rounded counterpart /œ/ for two speakers, P1 and P3: t(5)=9.718 (P1), 12.649 (P3) (both p<.01). Also, /i/ was significantly more front than /y/ for speakers P2 and P3: t(5)=7.534 (P2), 6.504 (P3) (both p<.01). Finally, /ɯ/ was significantly more front than /u/ only for P1: t(5)=8.598 (p<.01).

/o/ was less front than /ɯ u/. The least front vowel was either /a/ (P1 and P3) or /o/

(P2).

4.5 Summary and Discussion of the Articulatory Data

Recall that this experiment was designed to answer the following three questions: (i) whether the members of the three rounded/unrounded vowel pairs differ in tongue height and/or tongue frontness, as vowels are usually described in terms of height and frontness; (ii) whether /ɯ/ is a central or a back vowel, based on whether there is a difference in tongue frontness between

/ɯ/ and /u/; and (iii) how the three vowel pairs differ among themselves.

According to the overall tongue shape and the three articulatory measurements used, the three vowel pairs were distinct from each other in height and frontness, as expected. With

124 respect to individual pair members, overall tongue shape shows that unrounded vowels were more front than their rounded counterparts, which is statistically confirmed. Tongue shapes also showed that unrounded vowels were higher than their rounded counterparts in the front region, but lower in the back region. The height difference was statistically confirmed only with the /i y/ pair.

Interspeaker variation in the articulation of vowels is evident. For P3, the two high pairs were not distinguished by height, and the high back pair was not distinguished in frontness from the mid pair. Although /i/ was always higher than /y/ in the front region, this difference was not significant for P1 and P2. Although /e/ was generally higher than /œ/ in the front region, this difference was confirmed only for P2; for P1 the difference in the opposite direction was confirmed statistically and in the tongue shape images (Figure 3). With regards to frontness, generally, unrounded vowels were more front than their rounded counterparts, but that difference was not confirmed for P1 /ɯ u/ and for P2 and P3 /i y/. In fact, it is evident that

/e/ and /œ/ differed in frontness more than /ɯ/ and /u/.

The two measures for frontness, Tongue Frontness and AI give very similar results.

125 Figure 12 represents the Tongue Height/Tongue Frontness articulatory vowel space based on mean values for the three speakers together.

64 ɯ u 62

o i 60

a 58 y 56 Tongue Height (mm) Height Tongue œ 54 e 52 25 20 15 10 5 0 -5 -10 Tongue Frontnesss (mm)

transducer front - back reference point

Figure 12. Tongue Height and Tongue Frontness averaged for the three speakers together

In Figure 12, and in the subsequent figures in this chapter, the front-back dimension is reversed to make it more compatible with the acoustic data presented in the subsequent chapters.

High back vowels appear to be higher than high front vowels on ultrasound images.

The horizontal line that runs through /i/ and /u/ on Figure 12 and similar figures that follow signifies an imaginary horizon. This better represents the actual height of the vowels: /i/ and

/u/ are the same in height and /a/ is not actually much lower than /o/.

Figure 12 shows that, of the three rounded/unrounded pairs, the tongue was the least front for the back /ɯ u/ pair, most front for the high front /i y/ pair, and lowest for the mid /e

126 œ/ pair. /i/ and /y/ differed the most in height, while /e/ and œ/ differed the most in frontness.

Again, recall that the ultrasound did not capture the very back part of the tongue in the pharyngeal cavity, so that the measurements for /a/ and /o/ should be taken with caution.

Individual differences among speakers were noticed and statistically confirmed. This variation is discussed next.

P1 (female) employed both tongue height and frontness to distinguish among the three vowel pairs. With respect to individual pair members, P1 employed both strategies to distinguish between mid vowels /e/ and /œ/, only tongue frontness to distinguish between back vowels /ɯ/ and /u/, and neither of the two strategies to distinguish between /i/ and /y/.

Articulatory vowel space for P1 with all tokens is represented in Figure 13.

u ɯ 64 o 61

y 58 a 55

i 52 œ e 49 Tongue Height (mm) Height Tongue 46

43 20 15 10 5 0 -5 -10 Tongue Frontness (mm)

transducer

front - back reference point

Figure 13. Tongue Height and Tongue Frontness with all tokens, for Participant 1 (female)

For Participant 1, the three vowel pairs are well separated from each other in the articulatory vowel space. Of the individual pair members, back vowels /ɯ/ and /u/ are well separated from

127 one another, as are mid vowels /e/ and /œ/, while high front vowels /i/ and /y/ overlap considerably in the articulatory vowel space.

P2 (female) distinguished between high and mid vowels using both tongue height and frontness, while she distinguished between the two high vowel pairs using only tongue frontness. With respect to the individual pair members, tongue height and frontness separated

/e/ from /œ/, only tongue frontness separated /i/ from /y/, while neither of the two dimensions

(height or frontness) distinguished between /ɯ/ and /u/. Only with P2, tongue frontness and AI yielded different results with /e/ and /œ/, as AI failed to indicate the difference in frontness between these two mid vowels. Articulatory vowel space for with all tokens P2 is represented in Figure 14.

ɯ 59 i y 56 u 53 o 50

47 e 44 a 41

Tongue Height (mm) Height Tongue œ 38

35 30 25 20 15 10 5 0 -5 -10 Tongue Frontness (mm)

front - back transducer

reference point

Figure 14. Tongue Height and Tongue Frontness with all tokens for Participant 2 (female)

For Participant 2, the three vowel pairs are well separated from each other. Individual vowel pair members show more overlap than with P1: while mid /e/ and /œ/ are well separated, there was an overlap between /ɯ/ and /u/, and between /i/ and /y/ in both height and frontness. All

128 four high vowels are produced with very similar tongue height; mid vowels differ considerably in frontness, with /œ/ being almost as back as /u/. This was not the case with P1, where both mid vowels are articulated slightly less front than /i y/, but still in the front position.

P3 (male) distinguished between the two high pairs using tongue frontness, and between the two front pairs using both tongue height and tongue frontness strategies, while he distinguished between /ɯu/ and /eœ/ pairs employing only tongue height. With regards to individual pair members, P3 distinguished between /i/ and /y/ using both tongue height and tongue frontness, between /e/ and /œ/ using only tongue frontness, while, just like P2, neither of the two dimensions (height or frontness) distinguished between /ɯ/ and /u/. Articulatory vowel space with all tokens for P3 is represented in Figure 15.

80

u 77 ɯ o 74 i 71 y 68 a 65 e œ 62 Tongue Height (mm) Height Tongue 59

56 30 25 20 15 10 5 0 -5 -10 Tongue Frontness (mm)

transducer front - back reference point

Figure 15. Tongue Height and Tongue Frontness with all tokens for Participant 3 (male)

For Participant 3, the vowels were mostly well separated, except for an overlap in both height and frontness between /ɯ/ and /u/. Again, /e/ and /œ/ are far apart horizontally in the articulatory space, with /œ/ being as back as the back vowels.

129 For all three speakers, mid vowels /e/ and /œ/ were always well separated in the articulatory vowel space in both dimensions, so much so that the tongue can be almost in the position for back vowels during the production of the rounded /œ/. The other two vowel pairs can overlap, the back pair being most prone to overlap.

Mid vowels /e/ and /œ/ require tongue frontness to differentiate between them with all three speakers, while for two speakers, tongue height is required as well. High front vowels /i/ and /y/ and high back vowels /ɯ/ and /u/ are separated either with tongue frontness only, or they are not separated at all. Looking at the speakers, P1 employs the two strategies the most to distinguish between rounded and unrounded vowel pairs, while P1 employs the two strategies the least. Thus, in the articulatory vowel space, the three speakers differentiate between unrounded vowels and their rounded counterparts by different tongue positions in horizontal and vertical dimensions, but the speakers differ in their combination and presence or absence of a strategy.

Figure 16 represents the Tongue Height/Anteriority Index articulatory space based on mean values for the three speakers together.

64 ɯ u 62 o i 60

58 y a 56 Tongue Height (mm) Height Tongue 54 e œ 52 4.4 4.3 4.2 4.1 4 3.9 3.8 Anteriority Index

Figure 16. Tongue Height and Anteriority Index averaged for all speakers together

130 Whether the Tongue Frontness or Anteriority Index measurement was used, the result is almost identical. The only difference was with /o/ and /a/, where with the Tongue Frontness measure, /a/ was more back than /o/, while, with the AI, /a/ was more front than /o/. Recall that the vowels /o/ and /a/ could not be captured completely during ultrasound recording.

Tables 1-4 summarize the main findings with respect to the articulation data.

Table 1. Summary of the main results, averaged for the three speakers /iy/ vs. /ɯu/ /iy/ vs. /eœ/ /ɯu/ vs. /eœ/ Tongue Height /ɯ u/ = /i y/ /i y/ > /e œ/ /ɯ u/ > /e œ/ Tongue Frontness /i y/ > /ɯ u/ /i y/ > /e œ/ /e œ/ > /ɯ u/

Table 2. Summary of the main results for individual pair members /e/ vs. /œ/ /i/ vs. /y/ /ɯ/ vs. /u/ Tongue Height /i/ > /y/ Tongue Frontness /e/ > /œ/ /i/ > /y/ /ɯ/ > /u/

Table 1 shows results averaged across the three speakers which indicates that the /e œ/ pair the lowest, while the /i y/ pair is the most front and the /ɯ u/ pair the most back of the three vowel pairs. Table 2 shows that all unrounded vowels are significantly more front than their rounded counterparts, while only /i/ is significantly higher than /y/.

Table 3. Summary of the main results for vowel pairs, per speaker (shading represent significant difference) /iy/ = /ɯu/ /iy/ > /eœ/ /ɯu/ < /eœ/ P1 P2 P3 P1 P2 P3 P1 P2 P3 Tongue Height Tongue Frontness

131 Table 4. Summary of the main results for individual pair members, per speaker /e/ vs. /œ/ /i/ vs. /y/ /ɯ/ vs. /u/ P1 P2 P3 P1 P2 P3 P1 P2 P3 Tongue /e//œ/ /i/>/y/ Height Tongue /e/>/œ/ /e/>/œ/ /e/>/œ/ /i/>/y/ /i/>/y/ /ɯ/>/u/ Frontness

Tables 3 and 4 show that, individually, speakers agree more on the difference between vowel pairs than on the difference between individual pair members in the direction of difference.

The differences in height and frontness between /i y/ and /e œ/ are most consistent.

With individual pair members, speakers vary with respect to the presence/absence of difference and its direction. With respect to direction, tongue frontness is more consistent than tongue height. Generally, /e/ and /œ/ show the most difference, and /ɯ/ and /u/ the least.

4.6 Constriction Location and Constriction Degree

Recall that according to the Palatal/Dorsal/Pharyngeal/Labial Model (e.g. Wood 1982), vowels are best described with constriction location and constriction degree, where constriction location involves one or more of palatal, dorsal, pharyngeal and labial places of articulation.

For example, /u/ is dorsal and labial with narrow constriction, i.e. /u/ has two constrictions, at the lips and at the dorsum/soft palate, and the tongue constriction is narrow, while /a/ is pharyngeal with wide constriction, i.e. with /a/ the tongue is backed towards the pharyngeal wall and the constriction is wide. This is illustrated in Figure 17 (repeated from Chapter 2).

132 i u

a

.

Figure 17. Labial, palatal, velar and pharyngeal places of articulation for vowels.

In order to measure Constriction Location (CL) and Constriction Degree (CD) it is necessary for the palate to be visible. The palate could be completely reconstructed from swallowing images only for P2 (female). For the male speaker (P3), the palate was almost completely invisible, and for P1 (female) only a partial palate was recoverable.

I include here the data only for P2. Due to the very low number of tokens recovered from only one speaker, the results are presented only for illustrative purposes, and are not to be taken as conclusive.

Figure 18 present results for Constriction Degree; Tongue Height for P2 is also given for comparison.

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Figure 18. Mean Constriction Degree (mm) (left) and Tongue Height (mm) (right) for P2

(female)

Figure 18 shows that /i y/ had the smallest constriction degree, and /e œ/ the largest, meaning that the space between the tongue and the palate was the smallest with /i y/ and the largest with /e œ/. Paired samples t-test (α=.05) showed that these differences were significant, t(11)=-7.949 ((iy-ɯu/ pairs),

-6.859, (/iy-eœ/ pairs) and -7.012 (/ɯu/-/eœ/ pairs) (all p<.01).

134 The constriction was always more narrow for the unrounded vowel, meaning that there was less space between the tongue and the palate with the unrounded vowel, but only the difference between /e/ and /œ/ was significant: t(5)=-3.871 (p<.05).

/a/ had a similar constriction degree to /œ/, and smaller than /o/.

When we compare the results obtained with the Constriction Degree measurement and the Tongue Height measurement, we can see that there are similarities and differences. Both measurements agree that /e œ/ are mid vowels, while /i y/ and /ɯ u/ are high vowels.

However, according to Constriction Degree, the two high pairs significantly differ, with /i y/ having a more narrow constriction, while, according to Tongue Height, the two high pairs do not differ significantly.

With respect to individual pair members, the two measurements agree that unrounded vowels had narrower constriction than their rounded counterparts, or the tongue is higher during the production of unrounded vowels. Also, the two measurements agree that only /e/ and /œ/ significantly differ; according to Constriction Degree, /e/ has narrower constriction, while according to Tongue Height, /e/ is higher than /œ/.

Figure 19 present results for Constriction Location; Tongue Frontness for P2 is also given for comparison.

135 * *

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Figure 19. Mean Constriction Location (mm) (left) and Tongue Frontness (mm) (right) for P2 (female)

Figure 19 shows that /i y/ had the most front and /ɯ u/ the least front constriction location, meaning that the constriction was the most narrow at the front with /i y/ and at the back with

/ɯ u/. These differences were significant: t(11)=14.084 (/iy-ɯu/ pairs), 6.346 (/iy-eœ/ pairs), -

8.779 (/ɯu/-/eœ/ pairs) (all p<.01).

For all unrounded vowels the constriction was located significantly more front than for their rounded counterparts: t(5)=2.725 (/i/ vs. /y/), -3.327 (/ɯ/ vs. /u/), 3.783 (/e/ vs. /œ/) (all p<.05).

136 Constriction Location for /a/ was located more back than for the two high back vowels and /o/.

When we compare the results obtained with the Constriction Degree measurement and the Tongue Height measurement, we see that there are similarities and differences. Both measurements agree that the three vowel pairs significantly differ from each other. Both measurements also agree that /e/ and /œ/ significantly differ as well as /i/ and /y/. Additionally, according to Constriction Location /ɯ/ and /u/ significantly differ.

Tongue Frontness and Height, on the one hand, and Constriction Location and Degree, on the other hand, agree, but also differ in comparing the three vowel pairs. The reason they differ is that they measure two different things. Constriction Location and Degree are looking for the point on the tongue which is closest to the palate. Tongue Height and Frontness are looking for the highest point of the tongue, no matter whether that point is the closest to the palate or not, and determine its horizontal and vertical coordinates. Interestingly, the

Anteriority Index, although not measuring one point on the tongue, but a more general tongue shape, gives very similar results to the Tongue Frontness measurement.

4.7 Conclusion

This chapter presented the results of the Experiment 1, with the goal of describing the tongue during the articulation of the eight Turkish vowels in isolation. Three questions were addressed in this chapter. The first question was whether the members of the three rounded/unrounded vowel pairs differ in tongue height and/or tongue frontness. The data show that unrounded vowels were generally more front and higher than their rounded counterparts. However, this difference was not always statistically significant, and interspeaker variation was present. In frontness: all speakers /e/ > /œ/, P2 and P3 /i/ > /y/, P1 /ɯ/ > /u/. Thus, for all three

137 speakers there is a difference in mid front vowels, for two speakers a difference in high front vowels and for one speaker a difference in back vowels. In height: P1 and P2 /e/ > /œ/, P3 /i/

> /y/. Thus, for two speakers there is a difference in mid front vowels and for one speaker a difference in back vowels. This variation likely reflects variation across the larger population.

However, there is an overall tendency for unrounded vowels to be more front and higher than rounded vowels. This also does not imply that the three rounded/unrounded vowel pairs are not true pairs, or that the way in which true pairs were defined previously (i.e. they do not differ in tongue shape/position) should be revised. Overall, tongue shapes were similar between the members of the pairs, there was a definite pattern in the way unrounded vowels differed from their rounded counterparts, vowel pairs differed in how similar their members were, and not all speakers showed significant difference. These similarities between pair members in shape and in patterns in which they differ will be discussed in Chapter 8. There is much more consistency in the way the three vowel pairs differed among each other, the second question. The third question was whether /ɯ/ is a central or a back vowel. The data definitely show that /ɯ/ is articulatorily a back vowel.

Further investigation would benefit from a larger number speakers and tokens, which would give more conclusive results.

In the next chapter, the acoustic properties of the vowels in isolation are presented.

138 CHAPTER 5

EXPERIMENT 2: ACOUSTICS OF SUSTAINED VOWELS IN ISOLATION

Chapters 4 and 5 present the results of Experiments 1 and 2, respectively, which investigate phonetic properties of the 8 Turkish vowels in isolation. Chapter 4 dealt with articulatory properties and this chapter deals with acoustic properties of the vowels.

The goal of Experiment 2 was to describe the acoustic properties of the 8 Turkish vowels in isolation. This experiment was designed to answer the following three questions: (i) how/to what extent the members of the three rounded/unrounded vowel pairs differ in F1, F2 and F3; (ii) whether formant values of /ɯ/ differ considerably from those of /u/, so that, looking just at the acoustics, /ɯ/ can be judged a central vowel (iii) and how the three vowel pairs differ among themselves.

Chapter 5 is organized in the following way. Sections 5.1-5.3 present F1, F2 and F3 results, respectively, and section 5.4 summarizes the acoustic results. In section 5.6, articulatory results from Chapter 4 and acoustic results are discussed together.

Six speakers were recorded using an audio recorder, 3 male and 3 female. There were 8 sustained vowels x 3 repetitions x 6 speakers = 144 tokens. The vowels were sustained on average 700ms to 1s. The middle of the vowel is taken for analysis. Please refer to Chapter 3 for more detail. Repeated measures ANOVA was used as the main statistical test with two within-subject factors, Rounding (2 levels: Rounded and Unrounded) and Vowels (3 levels: /i

ɯ e/ for unrounded vowels; /y u oe/ for rounded vowels). The between-subject factor was

Gender (2 levels: male and female). A Bonferroni post-hoc test was used to compare vowel pairs, the three rounded vowels among themselves and the three unrounded vowels among themselves. Additionally, a paired samples t-test was used to compare individual differences between vowels of the same pair (e.g. /y/ vs. /i/).

139 In the bar graphs in this chapter, an asterisk denotes that there is a significant difference between members of a pair. The tests also provide results for significant difference between the three vowel pairs, but this is not indicated on the bar graphs.

5.1. F1

Figure 1 shows results of the F1 measurement averaged for the six speakers.

*

Figure 1. Mean F1 (Hz) averaged for the six speakers for all vowels (asterisk denotes significant difference between unrounded and rounded vowels)

With respect to F1, there were significant effects of Vowel (F(1.384,22.148=248.786, p<.01),

Rounding (F(1,16)=24.585, p<.01) and Gender (F(1,16)=24.946, p<.01), with females having higher values than males. Results by gender are presented later.

All vowel pairs significantly differed in F1 from each other, based on a post-hoc test

(with Bonferroni adjustment), /e œ/>/ɯ u/>/i y/ (all p<.01).

140 Unrounded vowels generally had higher F1 than their rounded counterparts, except /i/.

However, only /e/ had significantly higher F1 than /œ/, based on a paired samples t-test, t(17)=5.432 p<.01; in fact, /i/ F1 was lower than /y/ F1, although not significantly.

Three interactions were significant. The Vowel*Gender interaction was significant

(F(2,32)=16.337, p<.01), because there was a larger difference between males’ and females’

F1 values for /e œ/ (around 130Hz) than for the other two vowel pairs (around 60 and 30 Hz).

Also, the Rounding*Gender interaction was significant (F(1,16)=7.508, p<.05), as females exhibited a greater difference between rounded and unrounded vowels (around 70Hz) than males (around 20Hz). Mean F1 for males and females are illustrated in Figure 2.

141

Figure 2. Mean F1 values for all vowels for males (above) and females (below)

Figure 2 shows that, while the members of the two high pairs differed similarly in F1 values for both males and females, when it comes to the mid pair, /e/ F1 was much higher than /œ/ F1 for females. Otherwise, except for the females having higher values than males, the F1 values for the two genders were very similar.

The significant Rounding*Vowel interaction (F(2,32)=43.365, p<.01) is explored below in more detail.

Additional ANOVAs were run with unrounded and rounded vowels separately. With unrounded vowels, there was a significant effect of Vowel (F(3,32)=460.143, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all unrounded vowels differed significantly from each other, /e/ > /ɯ/ > /i/ (p<.01). Thus, as expected, F1 was the highest with the mid vowel and the lowest with the high vowels. Interestingly, the two high vowels also differed in F1. A significant Vowel*Gender interaction (F(2,32)=50.639, p<.01) occurred since there was a greater difference between males’ and females’ F1 values for /e/

(around 200Hz) than for the other two unrounded vowels (around 40Hz).

142 With rounded vowels, there was also a significant effect of Vowel

(F(1.474,22.583)=33.239, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that

/y/ and /u/ had lower F1 than /œ/ (p<.01), /œ/ > /y,u/.

5.2 F2

Figure 3 shows the results of the F2 measurement averaged for the six speakers.

*

* *

Figure 3. Mean F2 averaged for the six speakers for all vowels (asterisk denotes significant difference between unrounded and rounded vowels)

With respect to F2, there were significant effects of Vowel (F(1.476,23.614)=322.625, p<.01), Rounding (F(1,16)=1701.477, p<.01) and Gender (F(1,16)=150.609, p<.01), with females having higher F2 than males.

All vowel pairs significantly differed in F2 from each other, based on a post-hoc test

(with Bonferroni adjustment), /i y/ > /e œ/ > /ɯ u/ (all p<.01).

143 Generally, unrounded vowels had significantly higher F2 than their rounded counterparts. Based on a paired samples t-test, these differences were significant: t(17)=12.257 (/i-y/), 18.695 (/ɯ-u/), 10.338 (/e-œ/) (all p<.01).

Two interactions were significant. For the Rounding*Gender interaction

(F(1,16)=79.986, p<.01), there was a greater difference between females’ unrounded and rounded vowels (around 800Hz), than between males’ unrounded and rounded vowels (around

500Hz). Mean F2 for males and females are illustrated in Figure 4.

144

Figure 4. Mean F2 values for all vowels for males (above) and females (below)

Figure 4 shows that, except for the females having higher values than males, F2 values for the two genders were very similar.

The Rounding*Vowel interaction (F(2,32) = 14.775, p<.01) is further explored in more detail below.

Additional ANOVAs were run with unrounded and rounded vowels separately. With unrounded vowels, there was a significant effect of Vowel (F(1.407,22.515)=169.986, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all unrounded vowels significantly differed from each other, /i/ > /e/ > /ɯ/ (all p<.01).

With rounded vowels, there was a significant effect of Vowel

(F(1.281,20.493)=277.418, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all rounded vowels significantly differed from each other, /y/ > /œ/ > /u/ (all p<0.1).

5.3 F3

Figure 5 shows results of the F3 measurement averaged for the six speakers.

145 *

Figure 5. Mean F3 (Hz) averaged for the six speakers for all vowels (asterisk denotes significant difference between unrounded and rounded vowels)

With respect to F3, there were significant effects of Vowel (F(2,32)=55.767, p<.01),

Rounding (F(1,16)=130.638, p<.01) and Gender (F(1,16)=48.298, p<.01, as females had higher F3 values than males.

All vowel pairs significantly differed in F3 from each other, based on a post-hoc test

(with Bonferroni adjustment), /i y/ > /ɯ u/ > /e œ/ (all p<.01).

Unrounded vowels generally had higher F3 than rounded vowels, as expected.

However, paired samples t-test showed that only /i/ had F3 values significantly higher than /y/

(p<0.1). Also, /ɯ/ F3 was higher than /u/ F3, although not significantly.

Three interactions were significant. The Vowel*Gender interaction was significant

(F(2,32)=20.474, p<.01), as /ɯ u/ F3 values differed less between males and females (around

200Hz) than /i y/ values (around 400Hz) or /e œ/ values (around 500Hz). Also, the

Rounding*Gender interaction was significant (F(1,16)=32.872, p<.01), as there was a greater

146 difference between females’ unrounded and rounded vowels (around 500Hz), than between males’ (around 200Hz). Mean F3 for males and females are illustrated in Figure 6.

Figure 6. Mean F3 values for all vowels for males (above) and females (below)

Figure 6 shows that males and females differed in F3 values for the high back and the mid pair: while with females F3 values for the two pairs are similar, for males the back pair had higher F3 values.

147 The Rounding*Vowel interaction was also significant (F(2,32)=50.774, p<.01), which was explored further in more detail.

Additional ANOVAs were run with unrounded and rounded vowels separately. With unrounded vowels, there was a significant effect of Vowel (F(2,32)=61.858, p<.01). A post- hoc test (with Bonferroni adjustment) revealed that /i/ had significantly higher F3 values than the other two unrounded vowels (p<.01). The Vowel*Gender interaction was significant

(F(2,32)=7.833, p<.01), as males’ and females’ /ɯ/ differed less (around 200Hz) than male and female /i/ (600Hz) or /e/ (800Hz).

With rounded vowels, there was a significant effect of Vowel

(F(1.389,22.222)=31.315, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that

/u/ had significantly higher F3 values that the other two rounded vowels (p<.01). There was a significant Gender*Vowel interaction (F(2,32)=7.885, p<.01), as male and female /u/ differed less (around 100Hz) than male and female /y/ (300Hz) or /œ/ (400Hz).

5.4 Summary and Discussion of the Acoustic Data

Recall that this experiment was designed to answer the following three questions: (i) whether the members of the three rounded/unrounded vowel pairs differ in F1, F2 and F3; (ii) whether formant values of /ɯ/ differ considerably from those of /u/, so that, looking just at the acoustics, /ɯ/ can be judged a central vowel (iii) and how the three vowel pairs differ among themselves.

All three vowel pairs were distinct from each other on F1, F2 and F3 measurements, but the situation is not so straightforward with individual unrounded/rounded pair members.

148 Vowel Pairs Rounded vs. Unrounded Vowels

F1 /e œ/ > /ɯ u/ > /i y/ /e/ > /œ/

F2 /i y/ > /e œ/ > /ɯ u/ /i/ > /y/. /e/ > /œ/, /ɯ/ > /u/

F3 /i y/ > /ɯ u/ > /e œ/ /i/ > /y/

With respect to vowel pairs, the three vowel pairs differed from each other in all three formants. With respect to individual pair members, all three unrounded vowels had higher F2 than their rounded counterparts, only /e/ had higher F1 than /œ/, and only /i/ had higher F3 than /y/.

The following scatter plot represents the F1/F2 acoustic space with mean values for all speakers together.

2500 2300 2100 1900 1700 1500 1300 1100 900 700 200 y i ɯ u 300

400 œ

F1 (Hz)F1 o 500 e 600

a 700

800 F2 (Hz)

Figure 7. F1/F2 acoustic space averaged for all speakers

149 Figure 7 shows that, of the three rounded/unrounded pairs, F1 was the lowest and F2 the highest for the high front pair /i y/, F2 was the lowest for the back pair, and F1 was the highest for the mid pair. While the rounded/unrounded members of the two high vowel pairs did not differ much in F1, the members of the mid pair did differ considerably, with /e/ having higher

F1. On the other hand, the rounded/unrounded members of the two high vowel pairs differed considerably in F2, while the members of the mid pair differed less.

Gender differences were noticed and statistically confirmed. Both male and female speakers use F1 and F2 to distinguish between the three pairs. There are gender similarities and differences with respect to individual pair members. Males and females distinguish between /e/ and /œ/ with both F1 and F2, and both use only F2 to distinguish between /i/ and

/y/. However, while male speakers use only F2 to distinguish between /ɯ/ and /u/, female speakers use both F1 and F2.

Figure 8 illustrates the F1/F2 acoustic vowel space with mean values for males (above) and females (below).

2300 2100 1900 1700 1500 1300 1100 900 700 200 y u i 300 ɯ

400 œ F1 (Hz)F1 e o 500

600 a 700 F2 (Hz)

150 2700 2500 2300 2100 1900 1700 1500 1300 1100 900 700 y 300 i ɯ u 400

o œ 500 F1 (Hz) 600

e 700 a

800 F2 (Hz)

Figure 8. F1/F2 acoustic space with mean values for the male (above) and female (below) speakers

Figure 8 shows that the F1/F2 acoustic vowel space for male and female speakers looks very much like the acoustic vowel space for all speakers together (Figure 4). Male and female speakers differ in that the differences in F1 and F2 between rounded/unrounded members of all three pair were greater for females than for males. For example, mean /ɯ/ and /u/ differ

600Hz in F2 for males, but 800Hz for females.

Figure 9 shows the acoustic vowel space for the male (above) and female (below) speakers with all tokens. Note that ovals in these figures are used for illustrative purposes and are not automatically calculated (e.g. based on 95%S.E.).

151 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 200 i y u 250 ɯ 300 350 400 œ e 450

F1 (Hz)F1 500 550 o 600 a 650 F2 (Hz) 700

2900 2700 2500 2300 2100 1900 1700 1500 1300 1100 900 700 500 200 y u i 300 ɯ 400 œ 500

F1 (Hz) F1 o 600

700 e a 800

F2 (Hz) 900

Figure 9. F1/F2 acoustic space with all tokens for the male (above) and female (below) speakers

For males and females not all vowel pairs are well separated from each other. For males, the /i y/ pair is separated from the other two pairs, but the other two pairs overlap, while for females, the /e œ/ pair is well separated from the other two pairs, but the other two pairs overlap. For males, that overlap is concentrated on the vowels /e œ ɯ/, where /œ/ overlaps with both in its

F1 and F2 values. For females, /ɯ/ and /y/ overlap, as their F2 values are quite close together.

For females, /œ/ F2 values are even lower than /ɯ/ F2 values. /i/ and /u/ do not overlap for 152 males or females. Of the individual pair members, for females they are all well separated, while for males /e/ and /œ/overlap.

Thus, in answer to the first question, how the three vowel pairs differ among themselves, the results show that they differ in all three formants among each other.

The second question was whether the members of the three rounded/unrounded vowel pairs differ in F1, F2 and F3. The results show that all three unrounded vowels had higher F2 than their rounded counterparts, but not all unrounded vowels differed in F1 and F3 from rounded vowels: /e/ differed from /œ/ in F1, and /i/ differed from /y/ in F3. Finally, to answer the third question, the results show that while F1 and F3 values of /ɯ/ and /u/ did not differ significantly, F2 values did. /ɯ/ F2 values can reach 1300Hz for males and 1700Hz for females, with female values being close too /y/ F2 values. While for males /y/ and /ɯ/ did not overlap in the F1/F2 acoustic vowel space, for females they did overlap considerably. On the other hand, /ɯ/ and /u/ F2 values were not close and their vowel spaces did not overlap.

5.5 Articulation and Acoustics

This section discusses the results of Experiment 1, articulation, and Experiment 2, acoustics, together. Tables 1-4 summarize the main findings of Experiments 1 and 2.

Table 1. Summary of the main results of the Tongue Frontness and F2 measurements for vowel pairs

/i y/ vs. /ɯ u/ /i y/ vs. /e œ/ /ɯ u/ vs. /e œ/

Tongue Frontness /i y/ > /ɯ u/ /i y/ > /e œ/ /e œ/ > /ɯ u/

F2 /i y/ > /ɯ u/ /i y/ > /e œ/ /e œ/ > /ɯ u/

Table 1 shows that, based on the articulatory Tongue Frontness measurement, the /i y/ pair was articulated with the tongue in the more front position, and the /ɯ u/ pair with the tongue

153 in the more back position, which is to be expected from the front and back vowels, respectively. Additionally, the mid front pair /e œ/ was articulated less front than the high front pair /i y/. Acoustic measurement F2 reflects tongue fronting, in that the more front the tongue is, the higher F2 is obtained. In the case of the Turkish vowel pairs, F2 closely reflects tongue frontness: the /i y/ pair has the highest F2, and the /ɯ u/ pair the lowest, while the /e œ/ pair has F2 values in between.

Table 2. Summary of the main results of the Tongue Height and F1 measurement for vowel pairs

/i y/ vs. /ɯ u/ /i y/ vs. /e œ/ /ɯ u/ vs. /e œ/

Tongue Height /ɯ u/ > /i y/ /i y/ > /e œ/ /ɯ u/ > /e œ/

F1 /ɯ u/ > /i y/ /e œ/ > /i y/ /e œ/ > /ɯ u/

Table 2 shows that, based on the articulatory Tongue Height measurement, the two high vowel pairs were articulated with the tongue in the highest position, while the mid pair /e œ/ was articulated with the tongue in the lowest position. This is to be expected from the high and mid vowels. However, the two high vowel pairs differed in tongue height as well, with the tongue being higher with /ɯ u/. This is also evident in the overall tongue shapes for P1 and P3.

Acoustic measurement F1 reflects tongue height, in that the higher the tongue is, the lower F1 is obtained by such a vocal tract configuration. In the case of the Turkish vowel pairs, F1 reflects tongue height with the mid pair and the high front pair, and with the mid pair and the back pair. With the two high pairs, based on the Tongue Height measurement, we would expect /i y/ > /ɯ u/ in F1, and this is not the case. Break down by speaker shows the same tendency, Figure 10.

154

Figure 10. F1 per speaker

Figure 10 shows the speaker breakdown, where it is evident that /ɯ u/ > /i y/ for 5 out of 6 speakers, although the difference was significant only for one speaker. This can happen for several reasons. First, articulation data came from three speakers, one of which does not show the higher tongue for the back vowel pair; we do not know what the data would look like with the other three speakers whose articulation was not recorded. Second, the reason might lie in the measurement itself. Recall that the Constriction Degree measurement for P2 showed that the constriction was narrower for /i y/ than for /ɯ u/, which agrees with the higher F1 for /i y/.

Table 3. Summary of the main results of the Tongue Frontness and F2 measurements for rounded vs. unrounded vowels /e/ vs. /œ/ /i/ vs. /y/ /ɯ/ vs. /u/ Tongue Frontness /e/ > /œ/ /i/ > /y/ /ɯ/ > /u/ F2 /e/ > /œ/ /i/ > /y/ /ɯ/ > /u/

Table 3 shows that, based on the articulatory Tongue Frontness measurement, all unrounded vowels were articulated more front than their rounded counterparts. This is reflected in F2, as all unrounded vowels had higher F2 than their rounded counterparts. Constriction at the lips

155 for rounded vowels and its absence for unrounded vowels is another factor contributing to the difference in F2.

Table 4. Summary of the main results of the Tongue Height and F1 for rounded vs. unrounded vowels /e/ vs. /œ/ /i/ vs. /y/ /ɯ/ vs. /u/ Tongue Height /i/ > /y/ F1 /e/ > /œ/

Table 4 shows that, based on the articulatory Tongue Height measurement, only /i/ was articulated higher than /y/. Looking at the overall tongue shape, we could see the pattern that runs through all vowel pairs, where unrounded vowels were articulated higher than rounded vowels in the front region. Although F1 reflects tongue height, /i/ was not significantly lower in F1 than /y/. However, looking at the speakers separately, 5 out of 6 speakers had F1 values

/i/ < /y/, although not significantly. Thus, what shows as significant articulatorily may not show as significant acoustically, in statistical tests. In other words, the significance of articulation results is not directly transferable to significance in acoustic results.

Also, F1 values for /e/ were generally higher than for /œ/, as 5 speakers (including P2) out of 6 speakers had F1 values higher for /e/. The Tongue Height measurement per speaker did not show that /e/ was consistently higher than /œ/. With F1, constriction at the lips is another factor that contributes to lowering all three formants. If we rightly presume that /œ/ has a lip constriction, this would explain why /œ/ has lower F1. Thus, the interplay of two factors, tongue height and presence/absence of lip rounding, yields the results we see in Table

4. Moreover, the Constriction Degree measurement for P2 showed that /e/ had a significantly narrower constriction than /œ/, which would contribute to its having higher F1.

156 Table 5. Summary of the main results of the F3 measurement for vowel pairs /iy/ vs. /ɯu/ /iy/ vs. /eœ/ /ɯu/ vs. /eœ/ Tongue Height /ɯ u/ > /i y/ /i y/ > /e œ/ /ɯ u/ > /e œ/ Tongue Frontness /i y/ > /ɯ u/ /i y/ > /e œ/ /e œ/ > /ɯ u/ F3 /i y > /ɯ u/ /i y > /e œ/ /ɯ u/ > /e œ/ The results of F3 match the Tongue Frontness Results with the two high pairs and the two mid pairs, while they match the results of Tongue Height with the back/mid pair. F3 is the most complex formant with two inner nodes and antinodes (see below), and, thus, the interpretation of articulation by looking at F3 is also complex and not so straightforward.

N A N A N A

Figure 11. Nodes and antinodes (N – node; A – antinode)

As the constriction at the node raises F3, while the constriction at the antinode lowers F3, we can presume that the high front pair is the closest of the three pairs to an inner node N3, the mid pair is the closest the inner antinode A2, and the back pair is inbetween A2 and N2. That would explain their relative differences in F3.

Table 6. Summary of the main results of the F3 for rounded vs. unrounded vowels /e/ vs. /œ/ /i/ vs. /y/ /ɯ/ vs. /u/ F3 /i/ > /y/

157 With respect to unrounded/rounded vowel pairs, F3 is said to be lower with rounded vowels.

In this study, F3 is lower with all rounded vowels compared to their unrounded counterparts, while the difference is significant only with /i/ vs. /y/.

In sum, with respect to vowel pairs, all three pairs differed from each other articulatorily and acoustically, in tongue frontness and height, F1, F2 and F3. With respect to individual vowel pair members, we saw in section 4 that all unrounded vowels were articulated with a more front tongue than their rounded counterparts, while all unrounded vowels were also articulated higher, although only /i/ and /y/ significantly so. Overall tongue shapes show that the tongue remains in a similar position with rounded and unrounded vowels of the same pair. Thus, articulatorily, although rounded and unrounded vowels differ with reference to the tongue, that difference is patterned and predictable. Only the /e œ/ pair differs more than the other two pairs in overall tongue shape. Also, Constriction Degree measurement showed that

/e/ and /œ/ were the only pair that differs, with /œ/ having a smaller constriction. With respect to acoustic data, all rounded vowels differed from unrounded vowels in that they had lower

F2, due to tongue frontness and lip rounding. Lip rounding did not seem to consistently affect

F1 and F3.

Recall that in previous studies (section 2.2.2), the /e œ/ pair was found to be qualitatively different from the other two pairs. As far as articulatory measurements are concerned, all pairs behaved similarly. The scatter plots showed that /e œ/ is the only pair whose articulation tokens do not overlap, as /œ/ is articulated further back, and with some speakers almost as back as the back vowels. This is also reflected acoustically, as /œ/ F2 can be as low as /ɯ/, and even lower. Moreover, acoustic vowel space showed that /œ/ has lower

F1 than /e/ for male and female speakers, which can reflect the difference in height as well.

158 Finally, with respect to /ɯ/, the data show that, articulatorily, /ɯ/ and /u/ behave like the other two rounded/unrounded pairs, and even more like a pair than /e/ and /œ/.

Acoustically, /ɯ/ F2 was problematic for a number of studies, which identified /ɯ/ as a central vowel. In the present study, /ɯ/ F2 was around 1500Hz, which falls in the middle of the /ɯ/

F2 range from other studies, 1600-1300Hz. Moreover, /y/ (around 1750Hz) and /ɯ/ F2 difference is statistically significant (p < .01).

5.6 Conclusion

The results of Experiment 2 were presented in this chapter. These are the main findings.

Tongue Frontness and F2 are consistent in differentiating between the three vowel pairs. With

Tongue Height and F1, the mid vowel pair is consistently differentiated from the other two pairs, while there is a mismatch in Tongue Height and F1 values for the two high pairs, in fact, our expectations of what can be inferred from F1 about articulation does not match the articulation results. The main reason for this might be that there was a low number of speakers for articulation (3), and there is no doubt, that with a larger pool of speakers, the results would be more reliable. Also, the way Tongue Height was measured might contribute as well. Recall from Chapter 4 that if we were to run an imaginary horizontal line through /i/ and /u/ to signify an imaginary horizon, there would not be so much difference in height between the two vowel pairs. Finally, the fact the results of the Constriction

Degree measures match the results of F1 for the two high vowels, might indicate that future studies should pay more attention to Constriction Degree and less to Vowel Height.

Unrounded vowels consistently have higher F2 than rounded vowels, while F1 and F3 are less consistent when it comes to reflecting rounding. Moreover, a lesson learned is that

159 what is significant with articulation is not necessarily reflected as significant in acoustics, and vice versa, i.e. there is no one-to-one relationship between articulation and acoustics.

/e/ and /œ/ differ more than the other two vowel pairs less articulatorily and more acoustically, with /œ/ having higher F1 with males and females. Since we would expect /œ/ to have lower F1 because of lip rounding, higher F1 for /œ/ can indicate that Turkish has /e/ and

/ø/ vowels instead.

Finally, although /ɯ/ is undoubtedly articulatorily a back vowel, its F2 is as high as F2 of /y/, for example.

Experiments 1 and 2 focused on the 8 Turkish vowels in isolation. Next, Experiment 3 and 4 focus on the same 8 Turkish vowels in different consonantal contexts. Experiment 3

(Chapter 6) deals with the articulation of the vowel /ɯ/ in context. /ɯ/ was given more attention since there is evidence that it behaves differently from the other 7 vowels (Chapter

7).

160 CHAPTER 6

EXPERIMENT 3: C-TO-V COARTICULATION WITH VOWEL /ɯ/ - ARTICULATION

Chapters 6 and 7 extend the study of the phonetic properties of the Turkish vowels to different consonantal contexts. Chapter 6 focuses on the articulation (ultrasound) of the vowel /ɯ/ in context, while Chapter 7 focuses on the acoustics of the eight vowels in context.

Recall from Chapter 2 that the goal of Experiment 3 was to answer the following questions: (i) Do preceding and following consonants of the four different places of articulation influence the articulation of the Turkish vowel /ɯ/, and if so, how? (ii) Does the preceding or following consonant have more influence? (iii) Which articulatory dimension

(tongue height or tongue frontness) is affected the most?

Chapter 6 is organized the following way. Section 6.1 describes the vowel /ɯ/ in different consonantal contexts qualitatively with reference to tongue shape. Sections 6.2 to 6.4 describe vowel /ɯ/ in consonantal contexts, using the same three quantitative measurements used in Chapter 4 (articulation of vowels in isolation): Tongue Frontness (section 6.2), Tongue

Height (section 6.3) and the Anteriority Index (section 6.4). Section 6.5 summarizes the main findings.

The data from the same three speakers (P1 and P2, female; P3, male) from Chapter 4 was used. The speakers were recorded using ultrasound. There were 12 nonce words x 1 vowel x 3 tokens x 3 speakers = 108 tokens. The stimuli consisted of the vowel /ɯ/ preceded and followed by four obstruents, three stops and one affricate, with four different places of articulation. The speakers were instructed to pronounce the words at a normal speaking speed, so that the vowels were not sustained. The analysis was done on the frame in the middle of the vowel production. The stimuli were monosyllabic CVC nonce words. These words were embedded into a carrier sentence: /ʃahika ______akɯl etti/ “Shahika said ____”.

161 Table 1. Stimuli for vowels in consonantal contexts Context Preceding labeled as Following labeled as Labial bɯd, bɯdʒ, bɯg L_ dɯb, dʒɯb, gɯb _L Alveolar dɯb, dɯdʒ, dɯg A_ bɯd, dʒɯd, gɯd _A PostAlveolar dʒɯb, dʒɯd, dʒɯg PA_ bɯdʒ, dɯdʒ, gɯdʒ _PA Velar gɯb, gɯd, gɯdʒ V_ bɯg, dɯg, dʒɯg _V

The statistical test used in this experiment is the paired samples t-test, in order to compare /ɯ/ in isolation with /ɯ/ in each of the four consonantal contexts. For instance, /ɯ/ in isolation was compared with /ɯ/ preceded by a postalveolar (PA_).

162 6.1 Tongue Shape

Figures 1 illustrates averaged tongue shapes for /ɯ/ in isolation and preceded by the four

consonants for P1 (female). Tongue shapes are taken from the midpoint of the vowel.

ɯ back front

PA_ A_

V_ L_

Figure 1. Comparing tongue shapes for /ɯ/ in isolation and in the four preceding contexts for P1: /ɯ/ full black line; L_ dashed line (LɯA, LɯPA, LɯV); A_ dotted line (AɯL, AɯPA, AɯV); PA_ dashed dotted line (PAɯL, PAɯA, PAɯV); V_ solid grey line (VɯL, VɯA, VɯPA)

Figure 1 shows that some contexts raised and others lowered the tongue compared to /ɯ/ in

isolation. The tongue shape for /ɯ/ in isolation (solid black line) was more domed and

concentrated, between

-15 and 25 on the x-axis, than it was in other contexts. All consonants kept the same domed

tongue shape except PA and A, which raised the front part of the tongue. PA changed the

tongue shape the most and fronted the tongue. V conserved the /ɯ/ tongue shape the most. L

and V shifted the tongue back.

163

Figure 2 illustrates tongue shapes /ɯ/ in isolation and followed by four consonants for P1

(female). Tongue shapes are taken from the midpoint of the vowel.

front

ɯ

_V _PA _A _L

Figure 2. Comparing tongue shapes for /ɯ/ in isolation and in the four following contexts for P1: /ɯ/ full black line; L_ dashed line (LɯA, LɯPA, LɯV); A_ dotted line (AɯL, AɯPA, AɯV); PA_ dashed dotted line (PAɯL, PAɯA, PAɯV); V_ solid grey line (VɯL, VɯA, VɯPA)

With following consonants, the tongue shape did not change a lot. In all contexts the tongue was lowered compared to /ɯ/ in isolation.

164 6.2 Tongue Height

Figure 3 represents Tongue Height during the articulation of /ɯ/, when /ɯ/ was preceded and followed by consonants with 4 different places of articulation. The results are given for all 3 speakers combined.

*** * * * /ɯ/ in isolation

Figure 3. Mean Tongue Height (mm) for the three speakers for vowel /ɯ/ preceded (white) and followed (black) by different consonants; the asterisk represents significant difference between a consonantal context and /ɯ/ in isolation

Compared to /ɯ/ in isolation, all four following consonants (black columns) lowered tongue height, _V the most. On the other hand, three preceding consonants (white columns) lowered tongue height, PA_ the most, and V_ raised the tongue.

Corresponding initial and final consonants had different influences on /ɯ/ tongue height. _L and _V influenced tongue height more than a preceding L_ and V_. On the other hand, a preceding A_ and PA_ had more influence than a following _A and _PA.

Overall, the visual impression is that following consonants had less influence on tongue height than preceding consonants, as following consonants lowered the tongue in a uniform manner. A paired samples t-test showed that all following consonants lowered tongue height:

165 _L t(26)=4.432 (p<.01), _A t(26)=2.703 (p<.05), _PA t(26)=2.231 (p=.05), _V t(26)=7.318 (p<01). On the other hand, preceding consonants differed in the direction and amount of influence. A paired samples t-test showed that preceding A_ and PA_ significantly lowered tongue height: A_ t(26)=11.3287, PA_ t(26)=17.445 (both p<.01).

The following figure represents Tongue Height by speaker and context.

P3

P1

P2

Figure 4. Tongue Height (mm) for /ɯ/ preceded and followed by different consonants, by speaker (P1-solid line, P2-dashed line, P3-dotted line)

Generally, following consonants had less influence on the tongue height of /ɯ/ than preceding consonants, most notably for P1 and P2; the lines on the left (preceding consonantal contexts) are more jagged than the lines on the right (preceding consonant contexts).

With respect to preceding consonants, the speakers showed similarities and differences.

With all three speakers, A_ and PA_ lowered the tongue, with PA_ having a stronger influence.

The three speakers differed in how the tongue height was affected by the preceding L_ and V_: with P2 and P3, L_ lowered the tongue, while with P1, L_ raised the tongue; with P1 and P2,

V_ raised the tongue, while with P3, V_ lowered the tongue. P3 (male), whose tongue was

166 quite high during the articulation of /ɯ/ in isolation, had all consonants, in fact, lowering the tongue.

With respect to the following consonants, with all three speakers, all consonants lowered the tongue. This lowering was most prominent with P3, whose /ɯ/ in isolation was generally much higher.

In order to explore, in more detail, how /ɯ/ in isolation differed from /ɯ/ in each context separately for each speaker, paired samples t-tests were used. Only with P3, /ɯ/ preceded and followed by all four consonants lowered tongue height, while with P1 and P2 only /ɯ/ preceded by A_, PA_ and V_ differed from /ɯ/ in isolation. Paired samples t-tests showed these results. P1: A_ t(8)=6.152, PA_ t(8)=16.268, V_ t(8)=-3.874 (all p<.01). P2:

A_ t(8)=9.301, PA_ t(8)=9.299, V_ t(8)=-8.737 (all p<.01). P3: L_ t(8)=3.503, A_ t(8)=8.292, PA_ t(8)=9.230, V_ t(8)=7.678 ; _L t(8)=5.408, _A t(8)=6.699, _PA t(8)=7.839, _V t(8)=13.968 (all p<.01).

In sum, /ɯ/ followed by a consonant was articulated with the tongue in a lower position than /ɯ/ in isolation; this difference was uniform across consonantal contexts, as the sustained vowel in isolation was hyperarticulated. Thus, apart from a general influence an adjacent sound can have on the vowel, none of the following consonants influenced the tongue in any specific way. On the other hand, /ɯ/ preceded by a consonant was articulated with lower (L_, A_, PA_) or higher (V_) tongue height than /ɯ/ in isolation, indicating that preceding consonants with different places of articulation had a specific influence on the tongue position during the articulation of /ɯ/.

The three speakers shared some similarities, and also differed. With P3, the tongue was significantly lowered in all contexts. With P1 and P2, the tongue was significantly lowered when /ɯ/ was preceded by A_ and PA_, and the tongue was significantly raised when /ɯ/ was

167 preceded by V_. With P1 and P2, L_ did not significantly change tongue height. Also, all three speakers showed the same relative pattern of difference between tongue height when /ɯ/ was preceded by the three consonants: PA_ < A_ < V_.

6.3 Tongue Frontness

Figure 5 represents Tongue Frontness during the articulation of /ɯ/, when /ɯ/ was preceded and followed by consonants with 4 different places of articulation. The results are given for all

3 speakers combined.

***** *

/ɯ/ in isolation

Figure 5. Mean Tongue Frontness (mm) for the three speakers for vowel /ɯ/ preceded (white) and followed (black) by different consonants; the asterisk represents significant difference between a consonantal context and /ɯ/ in isolation

Compared to /ɯ/ in isolation, different consonants had different influence on /ɯ/ tongue frontness. The tongue was most front when PA_ preceded /ɯ/, and least front when L_ preceded /ɯ/.

168 The visual impression is that the corresponding initial and final consonants had different influences on /ɯ/ tongue fronting. Preceding consonants (white columns) had more prominent influence (as with tongue height), from considerable tongue fronting (PA_) to considerable tongue backing (L_). A paired samples t-test showed that L_ and A_ backed the tongue, while PA_ and V_ fronted the tongue: L_ t(26)=7.837, A_ t(26)=3.727, PA_ t(26)=-

17.954, V_ t(26)=-3.226 (all p<.01). Following consonants (black columns) had a less prominent influence on /ɯ/ tongue fronting, although that influence was more prominent than with Tongue Height. A paired samples t-test showed that _L and _A fronted the tongue: _L t(26)=-2.301, _A t(26)=-2.394 (p<.05).

The following figure represents Tongue Frontness by speaker.

P1

P2 P3

Figure 6. Tongue Frontness (mm) for /ɯ/ preceded and followed by different consonants, by speaker (P1-solid line, P2-dashed line, P3-dotted line)

Just as with tongue height, generally, for all three speakers, different preceding consonants have more influence on /ɯ/ tongue frontness (the line is more jagged) than the consonants following /ɯ/.

169 There are similarities and differences in how various initial consonants affected /ɯ/ tongue frontness with the three speakers. PA_ consistently shifted the tongue forward, while L_ consistently shifted the tongue back. A_ and V_ showed interspeaker variation, in that they shifted the tongue back or front, depending on the speaker.

In order to explore, in more detail, how /ɯ/ in isolation differed from /ɯ/ in each context separately for each speaker, paired samples t-tests were used. With all three speakers,

L_ shifted the tongue back: t(8)=10.797 (P1), t(8)=6.306 (P2), t(8)=2.638 (P3) (all p<.01), while PA_ shifted the tongue forward: t(8)=-14.783 (P1), t(8)=-12.129 (P2), t(8)=19.171

(P3) (all p<.01). With P1 and P2, A_ also backed the tongue: t(8)=8.915 (p<.01) (P1), t(8)=2.343 (p<.05) (P2). With P2 and P3, V_ fronted the tongue t(8)=-3.218 (p<.05) (P2), t(8)=-13.918 (p<.01) (P3), while with P1, V_ backed the tongue t(8)=3.468 (p<.01).

With following consonants, _L fronted the tongue with P2 and P3: t(8)=-2.486 (P2), t(8)=

-3.152 (P3) (both p<.05). With P1, _PA backed the tongue t(8)=4.971 (p<.01; with P3, _A fronted the tongue t(8)=-2.641 (p<.05).

Recall that with Tongue Height, /ɯ/ followed by a consonant was articulated with the tongue in a more front position than /ɯ/ in isolation, this difference was uniform across consonantal contexts, as the sustained vowel in isolation was hyperarticulated. With Tongue

Frontness, however, following consonants show more specific influence than with Tongue

Height. Still, it is evident again that four different consonants preceding /ɯ/ influenced its articulation more prominently: the tongue was considerably more front with PA_, less with V_, or the tongue was more back (L_, A_) compared to /ɯ/ in isolation.

Similarities among the three speakers, as well as interspeaker variation, were noticed.

The speakers were most consistent with L_, which shifted the tongue back, and PA_, which

170 shifted the tongue front. Speakers were less consistent with A_ and V_. Moreover, the three speakers showed very similar relative patterns of difference between tongue frontness when

/ɯ/ was preceded by the three consonants: PA_ < V_ < L_, A_.

6.4 Anteriority Index

Figure 7 represents the Anteriority Index during the articulation of /ɯ/, when /ɯ/ was preceded and followed by consonants with 4 different places of articulation. The results are given for all 3 speakers combined.

****

/ɯ/ in isolation

Figure 7. Mean Anteriority Index for the three speakers for vowel /ɯ/ preceded (white) and followed (black) by different consonants; the asterisk represents significant difference between a consonantal context and /ɯ/ in isolation

Compared to /ɯ/ in isolation, three following consonants _A, _PA, _V fronted the tongue, while

_L backed the tongue. Paired samples t-tests showed no significant difference between tongue frontness of /ɯ/ in isolation and tongue frontness of /ɯ/ followed by any consonant. With respect to the preceding consonants, L_ and A_ backed the tongue, while PA_ and V_ fronted

171 the tongue. Paired samples t-tests showed that /ɯ/ in isolation significantly differed from /ɯ/ preceded by consonants with four different places of articulation: L_ t(26)=9.157 (p<.01), A_ t(26)=2.407 (p<.05), PA_ t(26)=-9.145 (p<.01), V_ t(26)=-3.177 (p<.01).

Figure 8 represents Anteriority Index by speaker.

P1

P3 P2

Figure 8. Anteriority Index for /ɯ/ preceded and followed by different consonants, by speaker (P1-solid line, P2-dashed line, P3-dotted line)

Generally, for all three speakers, different preceding consonants showed more influence (the line is more jagged) than following consonants (the line is more flat). With respect to preceding consonants, the speakers were similar in that PA_ always fronted the tongue, and L_ always backed the tongue. A_ and V_ fronted or backed the tongue, depending on the speaker.

Overall, the shift is of a much smaller magnitude with different following consonants compared to the preceding consonants.

There is interspeaker variation. In order to explore, in more detail, how /ɯ/ in isolation differed from /ɯ/ in each context separately for each speaker, paired samples t-tests were used.

With all three speakers, L_ backed the tongue: t(8)=21.113 (P1), t(8)=6.829 (P2), t(8)=4.519 172 (P3) (all p<.01), and PA_ always fronted the tongue: t(8)=-8.016 (P1), t(8)=-18.421 (P2), t(8)=-7.545 (P3) (all p<.01). With P2 also, _L fronted the tongue t(8)=-2.331 (p<.05) and

_PA backed the tongue t(8)=3.585 (p<.01). Additionally, with P3, V_ fronted the tongue t(8)=-8.723 (p<.01), and with P1, A_ also fronted the tongue t(8)=-8.061 (p<.01).

In sum, /ɯ/ followed by a consonant was articulated with the tongue in a more front

(_L, A_, V_) or more back position (PA_) than /ɯ/ in isolation; this difference was not significant across consonantal contexts. Thus, following consonants had little influence of tongue fronting. On the other hand, preceding consonants had significant influence on tongue fronting, with L_ and A_ backing the tongue, and PA_ and V_ fronting it.

There was interspeaker variation. PA_ fronted the tongue with all three speakers, and L_ backed the tongue with all three speakers. V_ fronted the tongue with P3, A_ fronted the tongue with P1. Of the following consonants, only _L fronted and _PA backed the tongue for

P2.

Given that /ɯ/ is a back, velar vowel, and an alveolar consonant is a “front” consonant, the question is why a preceding alveolar backs the tongue. Figure 9 compares /ɯ/ in isolation with /ɯ/ in the preceding alveolar context broken down into A_L, A_A, A_PA and A_V, for P1.

173 back front ɯ

A_A A_V A_PA A_L

Figure 9. Comparing /ɯ/ in isolation with /ɯ/ in the detailed alveolar context (/ɯ/ full black line; A_L dashed line; A_A dotted line; A_PA dashed dotted line; A_V solid grey line)

In all four detailed contexts, although the whole tongue body was moved backwards under the

influence of the preceding alveolar, the front part of the tongue, the blade and the tip were

moved up. To raise the tongue tip, the tongue dorsum has to be moved back/lowered. Because

of the way ultrasound images conveyed visual information about the tongue (chapter 3),

measurement (in mm) we obtained was for the tongue body as the highest point, and, thus, the

tongue was moved back in comparison to the tongue during the articulation of /ɯ/ in isolation.

However, if we were to have the image of the palate, most likely, the narrowest constriction

would be located at the front, with the blade and the tip of the tongue.

174 6.5 Summary of the Articulation Data

Figure 10 represents Tongue Height/Tongue Frontness articulatory space mean for the three

speakers. V ɯ 64 front L back 63 A PA 62

L 61

V 60

PA A 59

Tongue Height (mm) Height Tongue 58

57

56 18 16 14 12 10 8 6 4 2 0 Tongue Frontness (mm)

Figure 10. Tongue Frontness/Tongue Height articulatory space averaged for the three speakers together for /ɯ/ in preceding (white squares) and following (black squares) contexts, with reference to /ɯ/ in isolation (black circle); also, /ɯ/ followed by all four consonants is circled.

Generally, the articulatory space occupied by /ɯ/ preceded by different consonants was larger

than the articulatory space occupied by /ɯ/ followed by different consonants.

All consonants lowered the tongue. The effect of the preceding consonants with the

four different places of articulation is more prominent. The most prominent influence was

exerted by a postalveolar consonant, which considerably fronted and lowered the tongue. An

alveolar and a velar also fronted the tongue, while a labial backed the tongue.

On the other hand, following consonants had less influence on the articulation of /ɯ/;

the articulatory space for /ɯ/ in four different consonantal contexts was smaller, it was shifted

lower and mostly back, and was more focused.

175

Figures 11-13 represent scatter plots for each participant mean.

66 V

L 64 back front ɯ

PA 62 A A 60 L V 58 PA Tongue Height(mm) 56

7 5 3 54 15 13 11 9 Tongue7 Frontness5 (mm)3 1 -1 -3 -5 Tongue Frotness (mm)

Figure 11. Preceding (white squares) and following (black squares) articulatory space for P1 (female) relative to /ɯ/ in isolation (black circle); also, /ɯ/ followed by all four consonants is circled.

With P1 (female), initial consonants had a greater influence than final consonants, as the

articulatory space was larger. Different preceding consonants had different influence on /ɯ/: a

postalveolar lowered and fronted the tongue, an alveolar lowered and backed the tongue, a

labial and a velar raised and backed the tongue.

176 Figure 12 represents scatter plots for P2.

60

V 58 front back 56 PA L ɯ A 54 L 52 Tongue Height (mm) V A 50 PA

48 22 20 18 16 14 12 10 8 6 4 2 0 Tongue Frontness (mm)

Figure 12. Preceding (white squares) and following (black squares) articulatory space for P2 (female) relative to /ɯ/ in isolation (black circle); also, /ɯ/ followed by all four consonants is circled.

With P2 (female), again, preceding consonants had a greater influence than following

consonants: a postalveolar lowered and fronted the tongue, an alveolar lowered and backed the

tongue, a labial backed the tongue, and a velar raised and fronted the tongue.

177 Figure 13 represents scatter plots for P3.

76

ɯ 74 back front 72 L V 70 L A 68 PA A Tongue Height (mm) Height Tongue PA V 66

64 20 18 16 14 12 10 8 6 4 2 0 Tongue Frontness (mm)

Figure 13. Preceding (white squares) and following (black squares) articulatory space for P3 (male) relative to /ɯ/ in isolation (black circle); also, /ɯ/ followed by all four consonants is circled.

Different from the other two speakers, for P3 all consonants lowered tongue height relative to

/ɯ/ in isolation. Like with the other two speakers, with P3, initial consonants had a greater

influence than final consonants. With respect to the front/back dimension, an alveolar, a

postalveolar and a velar fronted the tongue, while a labial backed the tongue.

In sum, the Tongue Height/Tongue frontness articulatory space for /ɯ/ preceded by

different consonants was similar with the three speakers. The size of the articulatory spaces

differed among the three speakers, with P3 having the smallest size and P2 the largest. P3 also

had the highest tongue position, and his contextual articulatory space was lower compared to

/ɯ/ in isolation. On the other hand, the articulatory space for /ɯ/ followed by different

consonants was much smaller. For example, for P1, the articulatory spaces are illustrated in a

13/-3 (x-axis) with 64/56 (y-axis) limits. However, the acoustic space for /ɯ/ under the

178 influence of following consonants was much smaller, and could fit into a smaller axes limit,

7/1 (x-axis) with 62/58 (y-axis). The situation was similar with the other two speakers.

A preceding postalveolar consonant had the most stable place in the articulatory space across speakers with respect to both dimensions: it consistently lowered and fronted the tongue relative to the other three consonants, and relative to /ɯ/ in isolation.

With a preceding labial consonant the tongue was always more back and with the preceding velar the tongue was always raised compared to /ɯ/ preceded by a postalveolar.

With a preceding alveolar consonant, the tongue was always more back and high compared to

/ɯ/ preceded by a postalveolar. Since for P3 all consonantal contexts lowered the tongue considerably, it is impossible to make comparisons only with reference to /ɯ/ in isolation.

Figure 14 represents the Tongue Height/Anteriority Index articulatory space mean for the three speakers.

ɯ L 64 63 L PA 62 A 61 V V 60 A 59 PA

Tongue Height (mm) Height Tongue 58

57

56 4.25 4.2 4.15 4.1 AI 4.05 4 3.95 3.9

Figure 14. Tongue Height/Anteriority Index articulatory space for the three speakers together for /ɯ/ in initial (white squares) and final (black squares) contexts, with reference to /ɯ/ in isolation (black circle)

179 The articulatory space with both Tongue Frontness and the Anteriority Index measurements on the x-axis look quite similar. Initial consonants had a stronger effect than final consonants.

With initial consonants, a postalveolar fronted and lowered the tongue, a velar raised the tongue, a labial backed the tongue and an alveolar backed and lowered the tongue.

Tables 2-3 summarize the main results.

Table 2. Summary of the main results, averaged by the three speakers Preceding C Following C Tongue Height A_ PA_  all  Tongue Frontness L_ A_  PA_ V_  _L _A 

Table 2 shows that, generally, following consonants had more consonant specific influence than preceding. However, as we saw above, this is partly the consequence of P3 having all consonants lowering and fronting the tongue, and partly because of the uniform influence all following consonants exert on the tongue in comparisons to /ɯ/ in isolation.

Table 3. Summary of the main results, by speaker Preceding C Following C P1 P2 P3 P1 P2 P3 Tongue Height A_ PA_  A_ PA_  all  all  V_  V_  Tongue Frontness PA_  PA_ V_  PA_ V_ _L  _L _A  L_ A_ V_  L_ A_   _PA  L_ 

Table 3 shows that only for P3 all following consonants showed significant difference in both dimensions, because P3’s /ɯ/ in isolation is articulated considerably more high and front than

/ɯ/ in any consonantal context. Otherwise, following consonants did not exert significant influence. Preceding consonants had influence more on tongue frontness than on tongue height.

180 6.6 Conclusion

Recall that the goal of this experiment was designed to answer the following questions: (i) Do preceding and following consonants of the four different places of articulation influence the articulation of the Turkish vowel /ɯ/, and if so, how? (ii) Does the preceding or following consonant have more influence? (iii) Which articulatory dimension (tongue height or tongue frontness) is affected the most?

Preceding and following consonants influenced the articulation of vowel /ɯ/, with preceding consonants having more influence than following consonants. Preceding consonants with four different places of articulation did not have the same influence. A preceding postalveolar lowered and fronted the tongue the most, consistently for all speakers, but its influence on tongue height was not so pronounced. And, generally, tongue frontness was affected more than tongue height. The speakers showed more similarities in tongue height, where the pattern of tongue lowering was consistently PA_ < A_ < V_. A labial consonant, preceding or following, showed the least consistency across speakers.

The following chapter investigates acoustic properties of all 8 Turkish vowels in consonantal contexts.

181 CHAPTER 7

EXPERIMENT 4: C-TO-V COARTICULATION – ACOUSTICS

Chapters 6 and 7 present the results of Experiments 3 and 4, respectively, which investigate phonetic properties of the eight Turkish vowels in context. The previous chapter, Chapter 6, dealt with the articulation of the vowel /ɯ/ in four different consonantal contexts. This chapter presents the results of Experiment 4, whose general goal was to examine the acoustic properties of the eight Turkish vowels in four different consonantal contexts.

The specific goals of Experiment 4 were to answer the following questions: (i) Do preceding and following consonants with four different places of articulation influence the acoustics (F1, F2, F3) of the Turkish vowels, and if so, how? (ii) Does the preceding or following consonant with the same place of articulation have more influence? (iii) How are different vowels affected by a consonant with the same place of articulation? (iv) Do vowels that belong to the same vowel pair get affected in the same way or in different ways? (v) Do the three different vowel pairs get affected in the same way? (vi) Which acoustic dimension

(F1, F2, F3) is affected the most? (vii) Is /ɯ/ the shortest vowel, and is /ɯ/ more liable to the influence of different consonants than other vowels?

Chapter 7 is organized in the following way. Sections 7.1 to 7.8 present results of F1,

F2 and F3 for the eight Turkish vowels: /ɯ/ (section 7.1), /u/ (section 7.2), /i/ (section 7.3), /y/

(section 7.4), /e/ (section 7.5), /œ/ (section 7.6), /o/ (section 7.7) and /a/ (section 7.8). These sections answer questions i), ii), iv), v) and vi) above. In addition, section 7.1 also presents the results of discriminant analysis, with the aim of determining how well F1, F2 and F3 separate

/ɯ/ in different consonantal contexts from the eight Turkish vowels in isolation, answering question viii) above. Sections 7.9 and 7.10 summarize the main results with reference to preceding and following consonants, and with reference to the four different places of

182 articulation; they answer question iii) above. Section 7.11 presents the results of the vowel duration measurement, and answers question vii) above. In section 7.12, preliminary results with real Turkish words are given. Section 7.13 concludes the chapter.

The data in Chapters 7 are from 6 speakers (3 male and 3 female). The stimuli were the same as for Experiment 3, consisting of nonce monosyllabic CVC words, with the eight vowels preceded and followed by four obstruents, three stops and one affricate, with four different places of articulation. These words were embedded into a carrier sentence: /ʃahika

______akɯl etti/ “Shahika said ____”. There were, for each vowel, 12 nonce words x 1 vowel x 3 tokens x 6 speakers = 216 tokens. The participants were instructed to read sentences at a normal reading speed. The analysis was done on the frame in the middle of the vowel production. Table 1 illustrates the stimuli for the vowel /ɯ/; the stimuli are the same for the other seven vowels, only the vowel changes.

Table 1. Example of stimuli with the vowel /ɯ/ Context Preceding labeled as Following labeled as Labial bɯd, bɯdʒ, bɯg L_ dɯb, dʒɯb, gɯb _L Alveolar dɯb, dɯdʒ, dɯg A_ bɯd, dʒɯd, gɯd _A PostAlveolar dʒɯb, dʒɯd, dʒɯg PA_ bɯdʒ, dɯdʒ, gɯdʒ _PA Velar gɯb, gɯd, gɯdʒ V_ bɯg, dɯg, dʒɯg _V

With respect to statistics, as the main test repeated-measures ANOVA was used, with one within-subject factor, Context (5 levels: a vowel in isolation, and the same vowel in four consonantal contexts) and one between-subject factor, Gender (2 levels: male and female), supplemented with a Bonferroni post-hoc test. Additionally, discriminant analysis was employed in order to determine how distinguishable a vowel in different consonantal contexts is from the eight Turkish vowels in isolation.

183 7.1 C-to-V Coarticulation with Vowel /ɯ/

7.1.1 F1

Figure 1 shows F1 of /ɯ/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers, and for males and females separately. For example, L encompasses the following words: /bɯd, bɯdʒ, bɯg, dɯb, dʒɯb, gɯb/. The horizontal line represents F1 of /ɯ/ in isolation. Asterisk signifies a significant difference between /ɯ/ in isolation and /ɯ/ in a consonantal context. A significant difference among /ɯ/ in the four contexts was obtained and reported here, but not illustrated on the figures. This explanation also applies to such figures illustrating F2 and F3 in this section.

* ***

/ɯ/ in isolation

184

Figure 1. F1 of /ɯ/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F1, there was a significant effect of Context (F(2.784,144.770)=36.006, p<.01) and Gender (F(1,52)=18.813, p<.01), as females had higher F1 than males. A post- hoc test (with Bonferroni adjustment) showed that all four consonants raised F1 of /ɯ/ in isolation (p<.01). In addition, an adjacent PA raised F1 the least compared to the other three consonants (p<.01): L, A, V>PA.

The significant Position*Context interaction (F(2.906,151.099)=7.110, p<.01) is explored in more detail below. Figure 2 shows /ɯ/ preceded and followed by the consonants with four different places of articulation.

185 * * * * * * *

/ɯ/ in isolation

Figure 2. F1 of /ɯ/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(3.375,175.497)=17.579, p<.01). A post-hoc test (with Bonferroni adjustment) showed that all four preceding consonants raised F1 of /ɯ/ in isolation (p<.01). In addition, V_ raised F1 less than L_ and A_

(both p<.05): L_, A_,>V_.

With following consonants, there was a significant effect of Context

(F(3.017,156.884)=25.957, p<.01). A post-hoc test (with Bonferroni adjustment) showed that

_L, _A and _V raised /ɯ/ F1 (p<.01). Additionally, _PA raised F1 less than the other three consonants (all p<.01): _L, _A, _V>_PA.

186 7.1.2 F2

The following figure shows F2 of /ɯ/ adjacent to the consonants with four different places of articulation, L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers, and for males and females separately.

*

/ɯ/ in isolation

Figure 3. F2 of /ɯ/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), averaged for females (white) and males (black) (below)

187 With respect to F2, there was a significant effect of Context (F (2.429,126.288)=27.705, p<.01) and Gender (F, 1, 52)=59.531, p<.01), as females had higher F2 than males. A post- hoc test (with Bonferroni adjustment) showed that PA raised F2 of /ɯ/ in isolation (p<.01). In addition, PA raised F2 the most compared to the other three contexts (p<.01) and L lowered

F2 the most compared to the other three contexts (p<.05): PA>A, V >L.

The significant Position*Context interaction (F(3.494,181.664)=30.363, p<.01) is explored in more detail below. Figure 4 shows /ɯ/ preceded and followed by the consonants with four different places of articulation.

* * * * *

/ɯ/ in isolation

Figure 4. F2 of /ɯ/ preceded (white) and followed (black) by consonants with the four places of articulation, and averaged for the six speakers

With preceding consonants, there was a significant effect of Context (F (3.323,

172.797)=61.452, p<.01). A post-hoc test (with Bonferroni adjustment) showed that A_

(p<.05) and PA_ (p<.01) raised F2 of /ɯ/ in isolation, while L_ (p<.01) lowered it.

188 Additionally, /ɯ/ in all consonantal contexts differed from each other (p<.01):

PA_>A_>V_>L_.

With following consonants, there was a significant effect of Context

(F(2.601,135.248)=5.808, p<.01). A post-hoc test (with Bonferroni adjustment) showed that

_PA (p<.01) and _V (p<.05) raised F2. In addition, F2 of /ɯ/ in _PA context was higher than

F2 of /ɯ/ in _L and _A contexts (p<.05): _PA>_L, _A.

7.1.3 F3

The following figure shows F3 of /ɯ/ adjacent to the consonants with four different places of articulation, L (labial), A (alveolar), PA (postalveolar) and V (velar) for all speakers, and for males and females separately.

/ɯ/ in isolation

189

Figure 5. F3 of /ɯ/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F3, there were significant effects of Context (F(1.855,96.469)=6.636, p<.01) and Gender (F,1,52)=130.813, p<.01), with females having higher F3 values. A post-hoc test showed that none of the consonants significantly changed F3 of /ɯ/ in isolation. Additionally,

F3 of /ɯ/ in A context was significantly higher than F3 of /ɯ/ in the other three consonantal contexts (p<.01), and F3 of /ɯ/ in PA context was higher than F3 of /ɯ/ in V context: A>L,

PA, V and PA>V.

The significant Position*Context interaction (F(3.082,160.270)=6.557, p<.01) is explored in more detail below. Figure 6 shows /ɯ/ preceded and followed by the consonants with four different places of articulation.

190 * /ɯ/ in isolation

Figure 6. F3 of /ɯ/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

With preceding consonants, there was a significant effect of Context (F(2.504,

130.185)=10.043,p<.01). A post-hoc test (with Bonferroni adjustment) showed that V_ lowered F3 of /ɯ/ in isolation (p<.01). Additionally, F3 of /ɯ/ in V_ context was lower than

F3 of /ɯ/ in the three other contexts (p<.01), while F3 of /ɯ/ in A_ context was higher than

F3 of /ɯ/ in the other three contexts (p<.01): A>L, PA>V.

With following consonants, there was a significant effect of Context (F(2.591,

134.712)=3.112, p<.01). A post-hoc test (with Bonferroni adjustment) showed that none of the consonants raised or lowered F3 of /ɯ/ in isolation. In addition, F3 of /ɯ/ in _A context was higher than F3 of /ɯ/ in the other three contexts, _L (p<.01), _PA and _V (both p<.05):

_A>_L, _PA _V.

191 7.1.4 Summary of the Acoustic Data

Table 2 summarizes the main results of Experiment 4 with the vowel /ɯ/.

Table 2. Summary of the main results with the vowel /ɯ/

F Comparing Preceding C Following C

/ɯ/ in isolation &

/ɯ/ in four consonantal all_  _L _A _V 

F1 contexts

/ɯ/ in four consonantal L_ A_>V_ _L _A _V>_PA contexts

/ɯ/ in isolation &

/ɯ/ in four consonantal A_ PA  L  _PA _V 

F2 contexts

/ɯ/ in four consonantal PA_>A_>V_>L_ _PA>_L _A contexts

/ɯ/ in isolation &

/ɯ/ in four consonantal V_ 

F3 contexts

/ɯ/ in four consonantal A_>L_ PA_>V_ _A>_L _PA _V contexts

Table 2 shows that adjacent consonants had more influence on F1 and F2 of /ɯ/ in isolation than on F3, as only V_ influenced /ɯ/ F3. Also, preceding consonants had more influence than following consonants with all three formants, judging by how many consonants influenced

192 formant change of /ɯ/ in isolation (e.g. all preceding consonants vs. three following consonants raised F1) and how much four consonantal contexts differed among each other

(e.g. with F2, all four preceding consonantal contexts differed among each other vs. only following _PA differed from _L and _A).

Figure 7 illustrates the F1/F2 acoustic vowel space with the vowel /ɯ/ in isolation and in the four preceding and following consonantal contexts, for male and female speakers separately.

193 1700 1600 1500 1400 1300 1200 300

ɯ 350

400 F1 (Hz)F1

450

500 F2 (Hz)

2100 2000 1900 1800 1700 1600 1500 1400 1300 350

ɯ

400 F1 (Hz)F1

450 F2 (Hz)

Figure 7. F1/F2 acoustic vowel space representing vowel /ɯ/ (black circle) preceded (white squares) and followed (black squares) by consonants with the four places of articulation, averaged for 3 males (above) and 3 females (below): L = , A = , PA = , V = 

Figure 7 shows that the acoustic space was larger for /ɯ/ in the four preceding than in the four following consonantal contexts, for both males and females. In the F2 dimension, the acoustic space for /ɯ/ with preceding consonants spanned around 400Hz/700Hz (males/females), while

194 for the following consonants it was around 150Hz/200Hz (males/females). In the F1 dimension, there was no difference with females, as /ɯ/ with preceding and following consonants spanned around 40Hz, while for males, this range was larger in the following context than in the preceding context, around 30Hz vs. 70Hz.

All consonants lowered F1. Some consonants raised F2, some lowered it. For both males and females, only L_ and _L lowered F2, while all other consonants raised F2, PA_ the most.

Although both A_ and _A and PA_ and _PA caused /ɯ/ F2 to increase, the increase was more prominent with A_ and PA_, i.e. when /ɯ/ was preceded by these consonants. In the same manner, while both L_ and _L decreased F2, the decrease was more prominent with L_. On the other hand, V_ and _V did not differ much in how they affected male F2, and they influenced female F2 in the direction opposite from the other consonants, namely, _V raised F2 more than

V_.

195 Figure 8 illustrates the F1/F2 acoustic vowel space with all eight Turkish vowels in isolation and with vowel /ɯ/ in four different consonantal contexts.

2300 2100 1900 1700 1500 1300 1100 900 700 250 i y 300 u ɯ 350

400 œ o 450

F1 (Hz) 500 e 550

600 a 650

700 F2 (Hz)

2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 250 300 i y 350 ɯ u 400 450 œ o 500

F1 (Hz) 550 600 650 700 e a 750 800 F2 (Hz)

Figure 8. F1/F2 acoustic vowel space representing eight Turkish vowels in isolation (black circles), and /ɯ/ preceded (white) and followed (black) by consonants with four different places of articulation, averaged for 3 males (above) and 3 females (below): L = , A = ,

PA = , V = 

196

Figure 8 shows that with males, /ɯ/ in PA_ context was higher than /y/ F2 and close to /e/ F2, while /ɯ/ in L_ was close to /a/ F2. With males, PA_ F2 also reached /y/ and /e/ F2. With respect to F1, /ɯ/ in A_ context for males, and /ɯ/ in _A, L_ and _L contexts for females reached /œ/ and /o/ F1.

Recall that three specific goals of Experiment 4 were to answer the following questions: (i) Do preceding and following consonants with four places of articulation influence the acoustics (F1, F2, F3) of a Turkish vowels, and if so, how? (ii) Does the preceding or following consonant with the same place of articulation have more influence on the vowel?

(iii) Which acoustic dimension (F1, F2, F3) is affected the most?

The results show that the four consonantal places of articulation differed in how they influence /ɯ/ formants. F1 was raised by all four consonants. F2 was raised by A and PA, lowered by L, while V had the least influence on /ɯ/ F2. F1 and F2 had more influence on /ɯ/ than F3. Preceding consonants influenced vowel /ɯ/ more than following consonants.

197 7.1.5 Discriminant Analysis

The goal of the discriminant analysis is to determine how F1, F2 and F3 together identify and set apart /ɯ/ produced in different consonantal contexts from the 8 Turkish vowels produced in isolation.

Table 3 shows the results for all speakers together.

Table 3. Confusion matrix for /ɯ/ in contexts, and all 8 vowels in isolation with F1, F2, F3 as factors

L A PA V /ɯ/ /i/ /y/ /u/ /e/ /œ/ /o/ /a/ L 51.2 11.1 11.7 13.3 0.6 0.6 7.8 0.6 3.3 A 27.7 23.9 28.9 15.0 0.6 0.6 0.6 2.2 1.1 PA 8.7 10.4 54.6 13.1 5.5 4.4 2.2 0.5 0.5 V 26.2 15.3 30.1 18.0 0.5 1.6 3.8 1.6 1.1 1.1 0.5

/ɯ/ 24.2 24.2 24.2 27.3 /i/ 3.0 75.8 21.2 /y/ 39.4 60.6 /u/ 9.1 3.0 78.8 9.1 /e/ 3.0 87.9 9.1

/œ/ 18.2 3.0 6.1 36.4 12.1 24.2 /o/ 20.0 70.0 10.0 /a/ 100.0

Table 3 shows how well F1, F2 and F3 separate the vowel /ɯ/ in different consonant contexts from the 8 vowels in isolation. For example, /ɯ/ adjacent to a labial (L) can be confused with

/ɯ/ (0.6% of the tokens), /y/ (0.6%), /u/ (7.8%), /œ/ (0.6%) and /o/ (3.3%) in isolation; on the other hand, F1, F2 and F3 separate quite well /ɯ/ adjacent to a labial (L) and /i e a/ in isolation.

198 Several things are worth noting. First, /ɯ/ adjacent to a labial (51.2%) or postalveolar

(54.6%) was classified better than /ɯ/ adjacent to an alveolar (23.9%) or velar (18%); thus,

/ɯ/ in some contexts is less confusable than /ɯ/ in other contexts. Second, /ɯ/ in all four contexts was also confusable with some Turkish vowels in isolation, from 13.2%

(postalveolar) to 4.5% (alveolar). In all four contexts, /ɯ/ was confused with /y/ and /œ/; it was confused with /u/ the least. Third, /ɯ/ in alveolar, postalveolar and velar contexts can also be confused with /a/, although the percentage is low.

/ɯ/ adjacent to a labial was classified correctly 51.2%; with respect to other vowels, it is confused mostly with Turkish /u/ and /o/, and to a lesser extent /y/ and /œ/ - all rounded vowels. /ɯ/ adjacent to an alveolar was classified correctly only 23.9%; it is less confused with other Turkish vowels than /ɯ/ adjacent to a labial - it can be confused with Turkish /œ,

/a/, /i/, /y/ and /e/. /ɯ/ adjacent to a postalveolar was classified correctly 54.6%; it is mostly confused with /i/ and /y/, and to a lesser extent as /e/, /œ/ and /a/. /ɯ/ adjacent to a velar was classified correctly only 18%; it is mostly confused with /y/, and never with /u/.

When F1, F2 and F3 measured at three points of the vowel, beginning, mid and end, were used in discriminant analysis, better classification results were obtained for all speakers.

Here is an example with P1. For P1, with only F1, F2 and F3 mid values, /ɯ/ in context comparing to other vowels was classified correctly 62%; when F1, F2 and F3 beginning and end values were added, the classification was better, 80.8%. Mostly the improvement was that

/ɯ/ in context was not confused with other vowels, while it was still confused with /ɯ/ in other consonantal contexts. The situation is similar with the other two speakers.

Thus, it seems that using more measures than only mid F1, F2 and F3 helps the identification of vowels up to a certain point (e.g. Hillenbrand et al. 1995, Strange et al. 1983,

Strange and Bohn 1998). In the present study, adding spectral information from the beginning

199 and the end of the vowel helped the separation of /ɯ/ in different consonantal contexts from the 8 Turkish vowels produced in isolation, but did not much help the separation of /ɯ/ in different consonantal contexts among each other. For arguments against the need for

“dynamic” spectral information of such type for monophthongs, even in coarticulation, see, e.g. Harrington and Cassidy (1994). Also, there is a limit on the amount of information that can improve classification; for instance, Hillenbrand et al. (1995) found that the information from two points, beginning and end, of vowels better separated the vowels in the discriminant analysis test, but the information for the three points (beginning, mid and end) did not improve classification further.

7.1.6 Summary

This section discusses the results of Experiment 3, articulation, and Experiment 4, acoustics with respect to vowel /ɯ/.

Table 4. Summary of the articulation and acoustic results

Measurement Preceding C Following C

Tongue Height all  (V_ ) all 

F1 all  all 

Tongue Frontness L_ A_  PA_ V_  _L _A _V  PA 

F2 A_ PA_ V_  L  _A _PA _V  L 

Table 4 summarizes the main findings of the articulation and acoustic results. As we saw in

Chapter 4, there is not necessarily a direct correspondence between articulation and acoustics when it comes to statistical significance. In other words, if, for example, a consonant significantly raises the tongue during the production of a vowel, that does not mean that the

200 same consonant will significantly lower F1 of the same vowel. It is more appropriate to compare general tendencies of the consonants to influence a vowel. That is the reason why

Table 4 does not focus only on significant results.

Table 4 overall shows that the two dimensions differ. While consonants had a more general influence on Tongue Height and F1, consonants had a more specific influence on

Tongue Frontness and F2.

All consonants lowered Tongue Height (V_ raised the tongue, not significantly) and all consonants raised F1 compared to /ɯ/ in isolation. The articulatory space was larger for preceding contexts compared to following contexts. This difference was not reflected in the acoustic space. Moreover, while a certain consistency is present with the way preceding consonants influenced tongue height (PA_ lowered it the most and V_ the least), this consistency was not mirrored acoustically. Thus, consonants with four different places of articulation influenced the articulation of the vowel /ɯ/ in the tongue height dimension, but these differences were attenuated or levelled acoustically in the F1 dimension.

With Tongue Frontness and F2 the situation is different. Consonant specific influence was felt more than with Tongue Height and F1. The strongest and most consistent correspondence between articulation and acoustics is evident with PA_ and L_. PA_ fronted the tongue the most and only L_ backed the tongue. Thus, we expect F2 to be raised the most with

PA_ and to be lowered with L_. These expectations are borne out. The discrepancy which appears with preceding alveolar, where alveolar backed the tongue but its F2 values raised was addressed in chapter 6. A preceding velar had the least consistent influence of the four consonants, as it significantly fronted the tongue for P2 and P3, and backed the tongue for P1.

Acoustically, V_ fronted the tongue with male and female speakers, and this was not statistically significant.

201 With tongue frontness and F2, preceding contexts occupied a larger articulatory and acoustic space compared to following contexts. For example, the articulatory space in the front/back dimension was approximately 14mm with the preceding context, and 5mm with the following context – the preceding context space being 3 times larger; the acoustic space in the

F2 dimension was approximately 350Hz for males and 500Hz for females, and finally 100Hz for both males and females. This leads to the conclusion that following consonants affect /ɯ/ less in consonant specific ways, and more in a general way: any following consonant would affect a hyperarticulated vowel.

Thus, consonants had a more general influence on the vowel /ɯ/ in the Tongue Height and F1 dimensions, while a consonant-specific influence was felt more in the Tongue

Frontness and F2 dimensions. Due to the large F2 scope for the preceding contexts, /ɯ/ in different contexts was confusable with other vowels in isolation, as shown by discriminant analysis: /ɯ/ in L context could also be identified as /u/, while /ɯ/ in PA context could also be identified with front unrounded vowels.

7. 2 C-to-V Coarticulation with Vowel /u/

7.2.1 F1

Figure 9 shows F1 of /u/ adjacent to the consonants with four different places of articulation, L

(labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately. For example, L encompasses the following words: /bud, budʒ, bug, dub, dʒub, gub/. The horizontal line represents F1 of /u/ in isolation. Asterisk signifies a significant difference between /u/ in isolation and /u/ in a consonantal context. A significant difference among /u/ in the four contexts was obtained and reported here, but not illustrated in the figures.

202 * * *

/u/ in isolation

Figure 9. F1 of /u/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

203 With respect to F1, there was a significant effect of Context (F(3.196,166.171)=6.149, p<.01). A post-hoc test (with Bonferroni adjustment) showed that L, A (both p<.01) and V

(p<.05) raised F1 of /u/ in isolation. /u/s in the four consonantal contexts did not differ from each other.

The significant Position*Context interaction (F(2.145,111.538)=3.681, p<.05) is explored in more detail below. Figure 10 shows /u/ preceded and followed by the consonants with four different places of articulation.

* * * * /u/ in isolation

Figure 10. F1 of /u/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(2.159,112.252)=3.066, p<.05). A post-hoc test (with Bonferroni adjustment) showed that L_ raised F1 (p<.01). /u/s in the four consonantal contexts did not differ from each other.

204 With following consonants, there was a significant effect of Context

(F(3.201,166.437)=7.104, p<.01). A post-hoc test (with Bonferroni adjustment) showed that

_L (p<.01), _A and _V (both p<.05) raised F1. /u/s in the four consonantal contexts did not differ from each other.

7.2.2 F2

The following figure shows F2 of /u/ adjacent to the consonants with four different places of articulation, L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

* ***

/u/ in isolation

205

Figure 11. F2 of /u/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F2, there was a significant effect of Context (F(3.150,163.826)=107.820, p<.01) and Gender (F(1,52)=17.068, p<.01), as females had higher F2 than males. A post- hoc test (with Bonferroni adjustment) revealed that all consonants raised F2 of /u/ in isolation

(p<.01). In addition, PA raised F2 the most compared to the other three contexts (p<.01), and

A raised F2 more than L and V (p<.01): PA>A>L, V.

The significant Position*Context Position interaction (F(3.102,161.305)=16.153, p<.01) is explored below in more detail. Figure 12 shows /u/ preceded and followed by the consonants with four different places of articulation.

206 *** * ** * *

/u/ in isolation

Figure 12. F2 of /u/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(3.357,174.583)=118.000, p<.01). A post-hoc test (with Bonferroni adjustment) showed that all preceding consonants raised F2 (p<.01). Additionally, PA_ raised F2 the most compared to the other three contexts

(p<.01), and A_ raised F2 more than L_ and V (p<.01): PA_>A_>L_, V_.

With following consonants, there a significant effect of Context

(F(3.258,169.425)=33.641. A post-hoc test (with Bonferroni adjustment) showed that all following consonants raised F2. /u/ in the four consonantal contexts did not differ among each other.

207 7.2.3 F3

The following figure shows F3 of /u/ adjacent to the consonants with four different places of articulation, L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

* /u/ in isolation

Figure 13. F3 of /u/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

208 With respect to F3, there were significant effects of Context (F(2.312,120.232)=11.486, p<.01) and Gender (F(1,52)=228.475, p<.01), with females having higher F3. A post-hoc test (with Bonferroni adjustment) revealed that PA lowered F3 of /u/ in isolation (p<.01).

Additionally, PA lowered F3 more than L (p<.05) and A (p<.01), and V lowered F3 more than A (p<.01): PA

There were no significant interactions.

7.2.4 Summary

Table 5 summarizes the main results of Experiment 4 with the vowel /u/.

Table 5. Summary of the main results with the vowel /u/ F Comparing Preceding C Following C /u/ in isolation & L_  _L _A _V  F1 /u/ in four consonantal contexts /u/ in four consonantal contexts

/u/ in isolation & all_  all_  F2 /u/ in four consonantal contexts /u/ in four consonantal contexts PA_>A_>V_ L_

/u/ in isolation & PA  F3 /u/ in four consonantal contexts /u/ in four consonantal contexts PA

Table 5 shows that adjacent consonants had more influence on F1 and F2 of /u/ in isolation than on F3, as only PA influenced /u/ F3 and the influence of the preceding and following consonants did not differ. All consonants influenced F2, while only some consonants influenced F1. The fact that /u/ F1 did not differ among the four consonantal contexts shows that there was no consonant specific influence on F1. On the other hand, there was a consonant

209 specific influence on /u/ F2 with preceding consonants, which indicates that preceding consonants had more influence on F2 than following.

Figure 14 illustrates the F1/F2 acoustic vowel space with all eight Turkish vowels in isolation and with vowel /u/ in four different consonantal contexts.

2300 2100 1900 1700 1500 1300 1100 900 700 250 i y 300 u ɯ 350

400 œ o 450

F1 (HZ) 500 e 550

600 a 650

700 F2 (HZ)

2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 250 300 y i 350 ɯ u 400 450 œ o 500 550 F1 (Hz) 600 650 700 e a 750 800 F2 (Hz)

Figure 14. F1/F2 acoustic vowel space representing eight Turkish vowels in isolation (black circles), and /u/ preceded (white) and followed (black) by consonants with four different places of articulation, averaged for 3 males (above) and 3 females (below): L = , A = , PA =

, V = 

210 Figure 14 shows that the acoustic space was larger for /u/ in the four preceding than in the four following consonantal contexts, for both males and females. In the F2 dimension, the acoustic space for /u/ with preceding consonants spanned around 400Hz/500Hz

(males/females), while with following consonants the range was around 100Hz (males and females). In the F1 dimension, there was no difference, and /u/ with preceding and following consonants spanned around 40Hz (both males and females). Thus, the major difference between the preceding and following contexts was in F2.

All consonants raised F1 and F2.

PA_ raised F2 the most for both male and females. L_ raised F2 the least for males, while L_ and V_ raised F2 the least for females. Although all following consonants also raised

F2, they did not show consonant specific influence, and F2 of /u/ in the following contexts were rather grouped together.

Thus, in the F1/F2 acoustic space, /u/ in the PA_ context had values close to /ɯ/ and

/œ/ F2, and, for females, close to /œ/ F1.

Recall that three specific goals of Experiment 4 were to answer the following questions: (i) Do preceding and following consonants with four places of articulation influence the acoustics (F1, F2, F3) of a Turkish vowels, and if so, how? (ii) Does the preceding or following consonant with the same place of articulation have more influence on the vowel?

(iii) Which acoustic dimension (F1, F2, F3) is affected the most?

The results show the four consonants differed in how they influence /u/ formants. F1 was raised by all four consonants, but there was no difference between the F1 of /u/ in the four contexts. F2 was raised by all four consonants, PA the most, L the least. Preceding consonants had more influence on F2. F3 was influenced the least of the three formats.

211 7.2.5 Comparing the Vowel /ɯ/ and the Vowel /u/

The vowel /ɯ/ and the vowel /u/ had several things in common. First, all consonants, both preceding and following, raised F1. Second, preceding consonants had more influence on F2 than following consonants, as the range of F2 values was twice as large with preceding consonants. Third, PA_ raised F2 the most for both /ɯ/ and /u/, while L_ raised F2 the least for

/u/ and lowered F2 for /ɯ/.

The vowels differed in the following ways. First, the range of F2 values was larger for

/ɯ/ than for /u/. Second, while all consonants raised /u/ F2, some consonants raised and some lowered /ɯ/ F2. This is understandable if we take into account that /u/ is a vowel with extreme

(low) F2 values. Third, consonants affected /ɯ/ F3 more than /u/ F3, as preceding and following consonants did not differ in their influence on /u/ F3.

Thus, /u/ preceded by PA_ reached /ɯ/ and /œ/ F2 values, while /ɯ/ preceded by PA_ reached /y/ and /e/ F2 values.

212 7.3 C-to-V Coarticulation with Vowel /i/

7.3.1 F1

Figure 15 shows F1 of /i/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately. For example, L encompasses the following words: /bid, bidʒ, big, dib, dʒib, gib/. The horizontal line represents F1 of /i/ in isolation. Asterisk signifies a significant difference between /i/ in isolation and /i/ in a consonantal context. A significant difference among /i/ in the four contexts was obtained and reported here, but is not illustrated in the figures.

* * **

/i/ in isolation

213

Figure 15. F1 of /i/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F1, there were significant effects of Context (F (3.299,171.536)=31.953, p<.05) and Gender (F,1,52)=45.798, p<.0), with females having higher F1 values than males. A post-hoc test (with Bonferroni adjustment) revealed that all consonants raised F1 of

/i/ in isolation (all p<.01). /i/ in the four consonantal contexts did not differ among each other.

The significant Position*Context interaction (F(3.005,156.256)=11.033, p<.01) is explored next in more detail. Figure 16 shows /i/ preceded and followed by the consonants with four different places of articulation.

214 ** * * * * **

/i/ in isolation

Figure 16 F1 of /i/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following separately. With preceding consonants, there was a significant effect of Context (F(4,208)=19.837, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all preceding consonants raised F1 (p<.01). /i/ in the four consonantal contexts did not differ among each other.

With following consonants, there was a significant effect of Context

(F(4,208)=27.054, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all following consonants raised F1 (p<.01). In addition, _L and _V raised F1 more than _PA

(p<.01): _L, _V>_PA.

215 7.3.2 F2

The following figure shows F2 of /i/ adjacent to the consonants with four different places of articulation, L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

**** /i/ in isolation

Figure 17. F2 of /i/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

216

With respect to F2, there were significant effects of Context (F(2.898,150.716)=41.622, p<.01) and Gender (F,1,52)=492.985,p<.01), with females having higher F2. A post-hoc test

(with Bonferroni adjustment) revealed that all consonants lowered F2 of /i/ in isolation (all p<.01). /i/ in the four consonantal contexts did not differ among each other.

The significant Position*Context interaction (F(2.005,104.279)=9.697, p<.01) is explored in more detail below. Figure 18 shows /i/ preceded and followed by the consonants with four different places of articulation.

********/i/ in isolation

Figure 18. F2 of /i/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following contexts separately. With preceding consonants, there was a significant effect of Context (F(3.168,164.37)=24.747, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all preceding consonants lowered F2 (all p<.01). Additionally, PA_ lowered F2 more than A_ (p<.01): PA_

217 With following consonants, there was a significant effect of Context

(F(4,208)=30.733, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all following consonants lowered F2 (all p<.01). Also, _A lowered F2 more than _PA, and _L lowered F2 more than _PA (p<.05) and _V (p<.01): _A<_PA and _L<_PA, _V.

7.3.3 F3

Figure 19 shows F3 of /i/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

** **

218

Figure 19. F3 of /i/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F3, there were significant effects of Context (F(3.094,160.900)=77.174, p<.01) and Gender (F(1,52)=475.827, p<.01), with females having higher F3. A post-hoc test (with Bonferroni adjustment) showed that all consonants lowered F3 of /i/ in isolation (all p<.01). /i/ in the four consonantal contexts did not differ among each other.

The significant Position*Context interaction (F(2.712,140.021)=20.715, p<.01) is explored in more detail below. Figure 20 shows /i/ preceded and followed by the consonants with four different places of articulation.

219 ** ** ** * * /i/ in isolation

Figure 20. F3 of /i/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(4,208)=58.184, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all preceding consonants lowered F3

(all p<.01). In addition, V_ lowered F3 the least compared to the other three contexts (all p<.01), and PA_ lowered F3 more than A_ (p<.05): V_

With following consonants, there was a significant effect of Context

(F(4,208)=53.610, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all following consonants lowered F3 (all p<.01). Additionally, _L (p<.05) and _V (p<.01) lowered F3 more than _A and _PA: _L _V<_A, _PA.

220 7.3.4 Summary

Table 6 summarizes the main results of Experiment 4 with the vowel /i/.

Table 6. Summary of the main results with the vowel /i/ F Comparing Preceding C Following C /i/ in isolation & all_  _all  F1 /i/ in four consonantal contexts /i/ in four consonantal contexts _L _V>_PA

/i/ in isolation & all_  _all  /i/ in four consonantal contexts F2 _A<_PA /i/ in four consonantal contexts PA_

Table 6 shows that adjacent consonants influenced all three formants more or less equally, as all consonants either lowered or raised formants of /i/ in isolation and /i/ in different contexts differed among each other. In fact, /i/ in the four preceding as well as in the four following contexts differed among each other the most in F3. Specific consonantal influence was the least prominent with F1.

Figures 21b. and 21d. illustrate the F1/F2 acoustic vowel space with vowel /i/ in four different consonantal contexts, and with the eight Turkish vowels in isolation as a reference.

Figures 21a.and 21c. represent a zoomed acoustic space, with the vowel /i/ in isolation and in the four consonantal contexts. Namely, as we will see further on, with some vowels, consonants hardly change vowel formants, so that a zoomed in figure is needed to be able to

221 notice the changes better. This will be done with other vowels where the acoustic space is also

dense, and, thus, less discernible in the usual-size scatter plot /y œ o a/.

a. 1970 1960 1950 1940 1930 1920 1910 1900 1890 1880 310

315

320

325

F1 (HZ) 330

335

340

345

350 F2 (HZ) b. 2300 2100 1900 1700 1500 1300 1100 900 700 250 i y 300 u ɯ 350

400 œ o 450 F1 (HZ) F1 500 e 550

600 a 650

700 F2 (HZ)

222

c. 2550 2530 2510 2490 2470 2450 2430 2410 2390 2370 320

330

340

350

360

F1 (HZ) 370

380

390

400

410

F2 (Hz) 420

d. 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 250

300 i y u 350 wɯ 400

o 450 oeœ F1 (HZ) 500

550

600

650

700 e 750 F2 (Hz)

Figure 21. F1/F2 acoustic vowel space representing eight Turkish vowels in isolation (black circles), and /i/ preceded (white) and followed (black) by consonants with four different places of articulation, averaged for 3 males (a, b) and 3 females (c, d): L = , A = , PA = , V

= 

223 Figure 21 shows that there was not much difference in the acoustic space between /i/ preceded by consonants and /i/ followed by consonants. In the F2 dimension, the acoustic space for /i/ with preceding consonants spanned around 70Hz/120Hz (males/females), while with following consonants the range was around 60Hz/170Hz (males/females). In the F1 dimension, the acoustic space for /i/ with preceding consonants spanned around 20Hz/30Hz (males/females), while with following consonants the range was around 30Hz/50Hz (males/females). Thus, there was not much difference between preceding and following contexts for both males and females.

All consonants raised F1 and lowered F2.

For both males and females, PA_ lowered F2 the most and L_ lowered F2 the least, while the situation was opposite with the following consonants. For both males and females,

PA_ raised F1 the least, while and V_ and L_ raised F1 the most; the situation was the same with the following consonants. However, none of the consonants distinguished itself particularly in the magnitude of change in F2.

Thus, in the F1/F2 acoustic space, /i/ in none of the contexts came close to F2 of any vowel in isolation; it approached F1 of /ɯ/ (males and females) and /œ/ (females).

Recall that three specific goals of Experiment 4 were to answer the following questions: (i) Do preceding and following consonants with four places of articulation influence the acoustics (F1, F2, F3) of a Turkish vowels, and if so, how? (ii) Does the preceding or following consonant with the same place of articulation have more influence on the vowel?

(iii) Which acoustic dimension (F1, F2, F3) is affected the most?

The results show that the four consonants differed in how they influence /i/ formants.

F1 was raised by all four consonants, with _L and _V raising F1 the most. F2 was lowered by

224 all four consonants, PA_ the most, L_ the least. Generally, preceding and following consonants had similar influence on all three formants. F3 was influenced the most of the three formats.

7. 4 C-to-V Coarticulation with /y/

7.4.1 F1

Figure 22 shows F1 of /y/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately. For example, L encompasses the following words: /byd, bydʒ, byg, dyb, dʒyb, gyb/. The horizontal line represents F1 of /y/ in isolation. Asterisk signifies a significant difference between /y/ in isolation and /y/ in a consonantal context. A significant difference among /y/ in the four contexts was obtained and reported here, but not illustrated on the figures.

*** * /y/ in isolation

225

Figure 22. F1 of /y/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F1, there was a significant effect of Context (F(4,208)=8.604, p<. 01). A post-hoc test (with Bonferroni adjustment) showed that all consonants raised F1 of /y/ in isolation (all p<.01). /y/ in the four consonantal contexts did not differ among each other.

The significant Position*Context interaction (F(2.848,148.072)=11.568, p<.01) is explored below in more detail. Figure 23 shows /y/ preceded and followed by the consonants with four different places of articulation.

226 *** * * *

/y/ in isolation

Figure 23. F1 of /y/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(3.225,167.720)=8.378, p<.01). A post-hoc (with Bonferroni adjustment) test revealed L_, A_ and PA_ raised F1 (all p<.01). /y/ in the four consonantal contexts did not differ among each other.

With following consonants, there was a significant effect of Context

(F(4,208)=11.777, p<.01). A post-hoc test (with Bonferroni adjustment) showed that _L

(p<.05), _A and _V (both p<.01) raised F1. In addition, _PA raised F1 less than _A and _V

(both p<.01): _A, _V>_PA.

227 7.4.2 F2

Figure 24 shows F2 of /y/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

* /y/ in isolation

Figure 24. F2 of /y/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

228 With respect to F2, there were significant effects of Context (F(3.442,179.007)=7.546, p<.01) and Gender (F,1,52)=146.937, p<.05), with females having higher F2. A post-hoc test (with Bonferroni adjustment) revealed that L_ lowered F2 of /y/ in isolation. In addition,

L_ lowered F2 of /y/ more than the three other contexts (all p<.01): L

The significant Position*Context interaction (F(2.797,145.428)=8.027, p<.01) is explored in more detail below. Figure 25 shows /y/ preceded and followed by the consonants with four different places of articulation.

* /y/ in isolation

Figure 25. F2 of /y/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(3.093,160.811)=4.822, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that none of the consonants significantly raised or lowered F2 of /y/ in isolation. Additionally, F2 of /y/ in L_ context was lower than F2 of /y/ in V_ context (p<.05): L_

229 With following consonants, there was a significant effect of Context

(F(4,208)=11.498, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that _L lowered F2. Additionally, F2 of /y/ in _L and _V contexts was lower than F2 of /y/ in _A and

_PA contexts (all p<.01): _L, _V<_A, _PA.

7.4.3 F3

Figure 26 shows F3 of /y/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

* /y/ in isolation

230

Figure 26. F2 of /y/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F3, there were significant effects of Context (F(3.000,155.989)=11.522, p<.01) and Gender (F(1,52)=140.567, p<.01), with females having higher F3. A post-hoc test (with Bonferroni adjustment) showed that A raised F3 of /y/ in isolation. In addition, A was higher than F3 of /y/ in the other three contexts (p<.01): A>L, PA, V.

Position*Context interaction was not significant (F(3.196,166.171)=1.653, p=.176).

231 7.4.4 Summary

Table 7 summarizes the main results of Experiment 4 with the vowel /y/.

Table 7. Summary of the main results with the vowel /y/ F Comparing Preceding C Following C /y/ in isolation & L_ A_ PA_  _L _A _V  F1 /y/ in four consonantal contexts /y/ in four consonantal contexts _A _V>_PA

/y/ in isolation & L_  F2 /y/ in four consonantal contexts /y/ in four consonantal contexts L_

/y/ in isolation & A  F3 /y/ in four consonantal contexts /y/ in four consonantal contexts A>L PA V

Table 7 shows that adjacent consonants had more influence on F1 /y/ in isolation than on F2 and F3. Namely, only A influenced /y/ F3 and the influence of the preceding and following consonants did not differ. Although preceding and following consonants differed in their influence on F2, only L_ lowered F2.

Figure 27 illustrates the F1/F2 acoustic vowel space with vowel /y/ in four different consonantal contexts (a, c), and with all eight Turkish vowels in isolation (b, d). A zoomed acoustic space is given in a. and c. in order to better appreciate /y/ in the four consonantal contexts.

232

a. 1760 1740 1720 1700 1680 1660 1640 1620 1600 1580 1560 280

290 y 300

310

320 F1 (HZ) F1 330

340

350

360

370 F2 (Hz) b. 2300 2100 1900 1700 1500 1300 1100 900 700 250 i y 300 u wɯ 350

400 oeœ o 450 F1 (HZ) F1 500 e 550

600 a 650

700 F2 (Hz)

233

c. 1970 1950 1930 1910 1890 1870 1850 1830 1810 1790 1770 310

320

y 330 F1 (HZ) F1

340

350

360 F2 (Hz) d. 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 250 y u i 350 wɯ

o 450 oeœ

F1 (HZ) F1 550

650

e a 750

850 F2 (Hz)

Figure 27. F1/F2 acoustic vowel space representing eight Turkish vowels in isolation (black

circles), and /y/ preceded (white) and followed (black) by consonants with four different places

of articulation, averaged for 3 males (above) and 3 females (below): L = , A = , PA =

, V = 

234 Figure 27 shows that the acoustic space was more or less the same size with /y/ in the four preceding and following consonantal contexts, for both males and females. In the F2 dimension, the acoustic space for /y/ with preceding consonants spanned around 130Hz/80Hz

(males/females), while with following consonants the range was around 180Hz/180Hz

(males/females). In the F1 dimension, there was no difference, and /y/ with preceding and following consonants spanned around 30Hz (both males and females). Thus, there was no major difference between the preceding and following contexts in the F2 and F1 dimensions.

For both males and females, some consonants lowered and some raised F2. For males, all consonants raised F1, while for females some consonants raised and some lowered F1.

For both males and females, L_ and _L raised F2 the most. The other consonants did not have a consistent influence. For both males and females, V_ either lowered F1 (females) or raised F1 (males), while PA_ raised F1 the most.

In the F1/F2 acoustic space, in none of the contexts did /y/ reach the F1 or F2 of any vowel in isolation.

Recall that three specific goals of Experiment 4 were to answer the following questions: (i) Do preceding and following consonants with four places of articulation influence the acoustics (F1, F2, F3) of Turkish vowels, and if so, how? (ii) Does the preceding or following consonant with the same place of articulation have more influence on the vowel?

(iii) Which acoustic dimension (F1, F2, F3) is affected the most?

The results show the four consonants differed in how they influenced /y/ formants. L was most consistent in raising F2, PA_ and V_ were most consistent in raising F1 the most and the least, receptively. Since the ranges of F1 and F2 values dd not differ much with preceding and following consonants, preceding and following consonants had similar influence on F1 and

F2 of /y/ in isolation. F3 was influenced the least of the three formats.

235 7.4.5 Comparing the Vowel /i/ and the Vowel /y/

The vowel /i/ and the vowel /y/ had several things in common. First, preceding and following consonants had similar influence on F2, in the sense that the range of F2 values was more or less the same in both cases, with females in both cases having a larger F2 range. Second, the

F1 and F2 ranges were not large and they were clustered together, so that we cannot say that one particular consonant influenced F2 considerably more compared to the other consonants.

The vowel /i/ and the vowel /y/ also differed. First, while all consonants raised /i/ F1, some raised and some lowered /y/ F1; this is particularly evident in the male/female scatter plots. Second, while all consonants lowered /i/ F2, some consonants raised and some lowered

/y/ F2. This is understandable if we take into account that /i/ is a vowel with extreme (low) F2 values. Third, while F1/F2 acoustic space of /y/ in context clustered around /y/ in isolation,

F1/F2 acoustic space of /i/ in context was somewhat separated from /i/ in isolation. Fourth, while /y/ in some consonantal contexts reached, only with males, /ɯ/ F1, /i/ reached F1 of /ɯ/ and /œ/. Finally, consonants affected /i/ F2 more than /y/ F3, as preceding and following consonants did not differ in their influence on /y/ F3.

7.4.6 Comparing the /i y/ Pair and the /ɯ u/ Pair

The two high pairs showed a number of differences, rather than similarities. First, while consonants raised F1 of /i ɯ u/, some consonants lowered F1 of /y/ for females. This is unusual, as high vowels have extreme low F1 values, even more, as the front pair /i y/ in isolation had lower F1 values than the back pair /ɯ u/. Preceding and following consonants did not differ very much in how they affect F1 range, and their influence was not very consistent.

The most consistent influence had _PA, which raised F1 the least with /i ɯ u/, and even lowered /y/ F1.

236 Second, the F2 range for the high back pair /ɯ u/ was considerably larger with preceding consonants then with following consonants, while the F2 range of the high front pair was similar in both cases. This indicates that the high back vowels were more affected by specific preceding constantans. Third, of these preceding consonants, PA_ caused F2 to raise considerably, and L caused F2 to raise the least (with /u/) or not to raise at all (with /ɯ/). With the high front pair, none of the consonants had such a strong influence on F2, as all consonants changed F2 as little so that they clustered together; PA_ lowered /i/ F2 the most, but with /y/, it is L_ that caused F2 to raise the most.

/i/ and /u/, as the vowels with extreme F2 values, did not change their F2 values by raising or lowering F2, respectively. Still, they differed in their F2 ranges, with /i/ having a smaller range and /u/ larger. On the other hand, /ɯ/ and /y/, not having such extreme F2 values, changed F2 by both raising and lowering it. However, although both /y/ and /ɯ/ belonged to the “inner vowels” with reference to F2, they behave in different ways. As a consequence, of high vowels, it was only the back pair that can have F2 values close to F2 values of some other vowels, such as /y e ɯ œ/. In other words, the high back pair /ɯ u/ was much more prone to coarticulation in the F2 dimension than the high front pair /i y/. Neither pair was prone to coarticulation in the same magnitude in the F1 dimension.

Of the four high vowels, consonants influenced the F3 of the rounded vowels /y u/ less than the F3 of the unrounded vowels /i ɯ/. There was no difference in how preceding and following consonants affected the rounded vowels.

7.5 C-to-V Coarticulation with Vowel /e/

7.5.1 F1

The following figure shows F1 of /e/ adjacent to the consonants with four different places of articulation, L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for

237 males and females separately. For example, L encompasses the following words: /bed, bedʒ, beg, deb, dʒeb, geb/. The horizontal line represents F1 of /e/ in isolation. An asterisk signifies a significant difference between /e/ in isolation and /e/ in a consonantal context. A significant difference among /ɯ/ in the four contexts was obtained and reported here, but not illustrated on the figures.

**** /e/ in isolation

.

238 Figure 28. F1 of /e/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F1, there were significant effects of Context (F(2.939,152.845)=67.565, p<.01) and Gender (F (1,52)=75.104, p<.01), with females having higher F1 than males. A post-hoc test (with Bonferroni adjustment) revealed that all consonants lowered F1 of /e/ in isolation (all p<.01). Additionally, PA and V lowered F1 more than L and A (all p<.01): PA,

V

The significant Position*Context interaction (F(2.672,138.957=6.949, p<.01) was explored in more detail below. Figure 29 shows /e/ preceded and followed by the consonants with four different places of articulation.

** * * * * ** /e/ in isolation

Figure 29. F1 of /e/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

239 Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(3.234,168.171)=42.840, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all preceding consonants lowered F1 (all p<.01). Additionally, PA_ and V_ lowered F1 more than L_ and A_ (all p<.01): PA_, V_

With following consonants, there was a significant effect of Context

(F(3.295,171.315)=31.185, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all following consonants lowered F1 (all p<.01). Additionally, _PA lowered F1 more than

_L (p<.05) and _A (p<.01): _PA<_L, _A.

7.5.2 F2

Figure 30 shows F2 of /e/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

* /e/ in isolation

240

Figure 30. F2 of /e/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F2, there were significant effects of Context (F(2.578,134.036)=17.610, p<.01) and Gender (F(1,52)=178.972, p<.01), with females having higher F2. A post-hoc test (with Bonferroni adjustment) revealed that V raised F2 of /e/ in isolation. In addition, V raised F2 of /e/ more than the other three contexts (all p<01), and F2 of /e/ in PA context was higher than F2 of /e/ in L context (p<.01): V>L, A, PA and PA>L.

The significant Position*Context interaction (F(2.900,150.795)=14.969, p<.01) is explored in more detail below. Figure 31 shows /e/ preceded and followed by the consonants with four different places of articulation.

241 * * * /e/ in isolation

Figure 31. F2 of /e/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(4,208)=14.506, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that V_ raised F2 of /e/ in isolation. In addition, V_ was higher that F2 of /e/ in the other three contexts (all p<.01): V_>L_ A_ PA_.

With the following consonants, there was a significant effect of Context

(F(3.362,174.806)=18.414, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that _PA and _V raised F2 in isolation. Additionally, _PA and _V raised F2 of /e/ more than _L and _A contexts (all p<.01): _PA, _V>_L, _A.

242 7.5.3 F3

Figure 32 shows F3 of /e/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

**** /e/ in isolation

Figure 32. F3 of /e/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

243 With respect to F3, there were significant effects of Context (F(2.749,142.967)=32.133, p<.01) and Gender (F(1,52)=601.285, p<.01), with females having higher F3. A post-hoc test (with Bonferroni adjustment) showed that all consonants raised F3 of /e/ in isolation (all p<.01). /e/ in the four consonantal contexts did not differ among each other.

The significant Position*Context interaction (F(2.672,138.943)=4.130, p<.05) is explored below in more detail. Figure 33 shows /e/ preceded and followed by the consonants with four different places of articulation.

** ** ** ** /e/ in isolation

Figure 33. F3 of /e/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(4,208)=21.430, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that preceding all consonants raised F3 (all p<.01). /e/ in the four consonantal contexts did not differ among each other.

244 With following consonants, there was a significant effect of Context

(F(3.416,177.653)=21.976, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all following consonants raised F3 (all p<.01). /e/ in the four consonantal contexts did not differ from each other.

7.5.4 Summary

Table 8 summarizes the main results of Experiment 4 with the vowel /e/.

Table 8. Summary of the main results with the vowel /e/ F Comparing Preceding C Following C /e/ in isolation & all_  _all  F1 /e/ in four consonantal contexts /e/ in four consonantal contexts PA_ V_

/e/ in isolation & V_  _PA _V  F2 /e/ in four consonantal contexts /e/ in four consonantal contexts V_>L_ A_ PA_ _PA _V>_L _A

/e/ in isolation & all_  _all  F3 /e/ in four consonantal contexts /e/ in four consonantal contexts

Table 8 shows that adjacent consonants had more influence on F1 and F2 of /e/ in isolation than on F3, as the influence of the preceding and following consonants did not differ. The fact that /e/ F3 did not differ among the four consonantal contexts shows that there was no consonant specific influence on F3. On the other hand, all consonants influenced F1 and F3, while only some consonants influenced F2. Preceding and following consonants had similar influence on all three formants.

245 Figure 34 illustrates the F1/F2 acoustic vowel space with all eight Turkish vowels in isolation and with the vowel /e/ in four different consonantal contexts.

2300 2100 1900 1700 1500 1300 1100 900 700 250 i y 300 u wɯ 350

400 oeœ o 450

F1 (Hz) F1 500 e 550

600 a 650

700 F2 (Hz)

2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 250 300 y i 350 u wɯ 400

o 450 oeœ 500 550 F1 (Hz) F1 600 650 700 e a 750 800 F2 (Hz)

Figure 34. F1/F2 acoustic vowel space representing eight Turkish vowels in isolation (black circles), and /e/ preceded (white) and followed (black) by consonants with four different places of articulation, averaged for 3 males (above) and 3 females (below): L = , A = , PA =

, V = 

246 Figure 34 shows that the acoustic space was similar with /e/ in the preceding and following consonantal contexts, for both males and females. In the F2 dimension, the acoustic space for

/e/ with preceding and following consonants spanned around 100Hz/200Hz (males/females). In the F1 dimension, the acoustic space for /e/ with preceding consonants spanned around

70Hz/50Hz (males/females) and with preceding consonants around 40Hz (males and females).

Thus, in the F2 dimension, there was no difference in the magnitude, while in F1 dimension, there was minimal difference.

All consonants lowered F1. With males, all consonants raised F2, while with females, some consonants raised and some lowered F2.

V raised F2 the most for both male and females and L_ raised F2 the least. Although all following consonants also raised F2, they did not show consonant specific influence, and the

F2s of /e/ in the following contexts were rather grouped together.

Thus, in the F1/F2 acoustic space, only with males, /e/ F1 reached F1 of /œ/ and /o/ in isolation.

Recall that three specific goals of Experiment 4 were to answer the following questions: (i) Do preceding and following consonants with four places of articulation influence the acoustics (F1, F2, F3) of Turkish vowels, and if so, how? (ii) Does the preceding or following consonant with the same place of articulation have more influence on the vowel?

(iii) Which acoustic dimension (F1, F2, F3) is affected the most?

The results show the four consonants differed in how they influence /e/ formants. F1 was lowered by all four consonants, while F2 can be raised or lowered, V the most, L the least. Preceding and following consonants did not differ much in the magnitude on influence on any formant of /e/. F3 was influenced the least of the three formats.

247 7.6 C-to-V Coarticulation with Vowel /œ/

7.6.1 F1

Figure 35 shows F1 of /œ/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately. For example, L encompasses the following words: /bœd, bœdʒ, bœg, dœb, dʒœb, gœb/. The horizontal line represents F1 of /œ/ in isolation. Asterisk signifies a significant difference between /œ/ in isolation and /œ/ in a consonantal context. A significant difference among /œ/ in the four contexts was obtained and reported here, but not illustrated on the figures.

* * /œ/ in isolation

248

Figure 35. F1 of /œ/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F1, there were significant effects of Context (F(2.026,105.341)=8.707, p <

.01) and Gender (F(1,52)=26.580, p<.01), as females had higher F1. A post-hoc test (with

Bonferroni adjustment) revealed that L and A raised F1 of /œ/ in isolation (both p<.01). In addition, F1 of /œ/ in L and A contexts was higher than F1 of /œ/ in PA context (p<.01, p<.05) and V context (both p<.01): L, A>PA, V.

Position*Context interaction was not significant (F(1.978,102.862)=.792, p=.454).

7.6.2 F2

The following figure shows F2 of /œ/ adjacent to the consonants with four different places of articulation, L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

249 * /œ/ in isolation

Figure 36. F2 of /œ/ adjacent to consonants with four places of articulation averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F2, there were significant effects of Context (F(3.190,165.865)=3.227, p<.05) and Gender (F(1,52)=21.725, p<.01), as females had higher F2 than males. A post-

250 hoc test (with Bonferroni adjustment) shows that V raised F2 of /œ/ in isolation (p<.05). /œ/ in the four consonantal contexts did not differ among each other.

The significant Position*Context interaction (F(2.081,108.197)=5.390, p<.01) is explored below in more detail. Figure 35 shows /œ/ preceded and followed by the consonants with four different places of articulation.

* *

/œ/ in isolation

Figure 37. F2 of /œ/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(2.668,138.714)=6.283, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that V_ raised F2 of /œ/ in isolation. Additionally, F2 of /œ/ in V_ context was higher than F2 of /œ/ in L_ and A_ contexts

(all p<.01): V_>L_, A_.

With following consonants, there was no significant effect of Context

(F(2.990,155.488)=2.559, p=.057). A post-hoc test (with Bonferroni adjustment) revealed

251 that _A raised F2 (p<.01). /œ/ in the four consonantal contexts did not differ among each other.

7.6.3 F3

Figure 38 shows F3 of /œ/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

*

/œ/ in isolation

252

Figure 38. F3 of /œ/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F3, there were significant effects of Context (F(2.358,122.635)=7.778, p<.01) and Gender (F(1,52)=182.764, p<.01), with females having higher F3. A post-hoc test (with Bonferroni adjustment) revealed that A raised F3 of /œ/ in isolation (p<.01).

Additionally, A was higher than F3 of /œ/ in the other three contexts, L (p<.05), PA and V

(both p<.01): A>L, PA, V

The significant Position*Context interaction (F(2.727,141.830)=3.047, p<.05) is explored below in more detail. Figure 39 shows /œ/ preceded and followed by the consonants of four different places of articulation.

253 *

/œ/ in isolation

Figure 39. F3 of /œ/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(4,208)=10.622, p<.01). A post-hoc test (with Bonferroni adjustment) revealed A_ raised F3 (p<.01). In addition, F3 of

/œ/ in A_ context was higher than F3 of /œ/ in the other three contexts (p<.01): A_>L_, PA_

V_.

With following consonants, there was no significant effect of Context

(F(4,208)=2.249, p=.065).

7.6.4 Summary

Table 9 summarizes the main results of Experiment 4 with the vowel /œ/.

254 Table 9. Summary of the main results for the vowel /œ/ F Comparing Preceding C Following C /œ/ in isolation & L A  F1 /œ/ in four consonantal contexts /œ/ in four consonantal contexts L A > PA V

/œ/ in isolation & V_  _A  F2 /œ/ in four consonantal contexts /œ/ in four consonantal contexts V_>L_ A_

/œ/ in isolation & A_  F3 /œ/ in four consonantal contexts /œ/ in four consonantal contexts A_>L_ PA_ V_

Table 9 shows that adjacent consonants had more influence on F2 of /œ/ in isolation than on

F1 and F3, as there was no difference in how preceding and following consonants affected F1, and as following consonants did not significantly change F3. With all three formants, only some consonants caused the formant to change. A significant change involved the raising of the three formants. All formants also involved consonant specific influence. For F2 and F3 this influence was restricted to the preceding consonants, which implies that preceding consonants were more strongly influenced F2 and F3.

Figure 40 illustrates the F1/F2 acoustic vowel space with vowel /œ/ in four different consonantal contexts (a, c), and with all eight Turkish vowels in isolation (b, d). A zoomed acoustic space is given in a. and c. in order to better appreciate /œ/ in four consonantal contexts.

255 a. 1480 1460 1440 1420 1400 1380 1360 440

450 F1 (HZ) F1 460

470 F2 (HZ)

b. 2300 2100 1900 1700 1500 1300 1100 900 700 250 i y 300 u ɯ 350

400 œ o 450

500 F1 (HZ) F1 e 550

600 a 650

700 F2 (HZ)

256 1620 1600 1580 1560 1540 1520 c. 460

œ 470

480

490 F1 (Hz) F1

500

510

520 F2 (Hz)

d. 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 250 300 i y u 350 ɯ 400

450 œ o 500

F1 (Hz) 550 600 650 700 e a 750 800 F2 (Hz)

Figure 40. F1/F2 acoustic vowel space representing eight Turkish vowels in isolation (black

circles), and /i/ preceded (white) and followed (black) by consonants with four different places

of articulation, averaged for 3 males (above) and 3 females (below): L = , A = , PA =

, V = 

257 Figure 40 shows that the acoustic space was similar with /œ/ in preceding and following consonantal contexts. In the F2 dimension, the acoustic space for /œ/ with preceding consonants spanned around 150Hz/70Hz (males/females), while with following consonants the range was around 70Hz/50Hz (males/females). In the F1 dimension, the acoustic space for /œ/ with preceding and following consonants spanned around 20Hz (males and females). Thus, the major difference appears to be in F2 between preceding and following contexts, and more so for males.

All consonants raised F1 for both males and females, while all consonants raised F2 for males, but raised and lowered F2 for females.

There was not much consistency in how different consonants affected male and female

F1 and F2. For example, while V_ raised F1 the least and L_ the most for males, this was not the case with females, with whom preceding and following consonants did not exert consistent influence.

Thus, in the F1/F2 acoustic space, /œ/ did not reach F1 or F2 of any vowel in isolation.

Recall that three specific goals of Experiment 4 were to answer the following questions: (i) Do preceding and following consonants with four places of articulation influence the acoustics (F1, F2, F3) of Turkish vowels, and if so, how? (ii) Does the preceding or following consonant with the same place of articulation have more influence on the vowel?

(iii) Which acoustic dimension (F1, F2, F3) is affected the most?

The results show the four consonants differed in how they influence /œ/ formants, but there was hardly any consistency between preceding and following contexts, and males and females. Additionally the range of F1 and F2 values was quite narrow in the acoustic space, so we can conclude that consonant-specific influence on /œ/ was less prominent compared to some of the other vowels. Preceding consonants had more influence on F2 and F3. F2 is the

258 formant most influenced by consonants, while F1 was influenced equally by preceding and following consonants, and F3 was not significantly influenced by following consonants.

7.6.5 Comparing the Vowel /e/ and the Vowel /œ/

The vowel /e/ and the vowel /œ/ were similar in that with males, consonants only raised F2, while with females, consonants raised and lower F2.

Otherwise, they were the most diverse of the three pairs. First, while consonants lowered /e/ F1, consonants raised /œ/ F1. Second, the value range of F1 was twice as large with /e/ as with /œ/, and with /œ/ there was no difference between the preceding and following contexts. Third, F2 range was smaller with /œ/ than with /e/. This makes /œ/ adjacent to all consonants cluster together, and none of the consonants changed /œ/ formant values enough to reach formant values of another vowel in isolation. On the other hand, /e/ F1 values in some consonantal contexts approached /œ/ and /o/ F1 values. Finally, both preceding and following consonants affected /e/ F3, while only preceding affected /œ/ F3.

7.6.6 Comparing the /e œ/ Pair and the /i y/ Pair

The two front pairs /e œ/ and /i y/ had in common (with other vowels as well) the fact that the

F1 range was rather small. However, the two front pairs /e œ/ and /i y/ differed in a number of ways. First, and differently from the back pair, /e œ/ and /i y/ had in common a smaller F2 range, indicating that they were less affected by consonants. However, while the F2 range was rather restricted with the high front pair /i y/ and the rounded mid vowel /œ/, the unrounded mid vowel /e/ had a slightly larger F2 range. Second, while all consonants lowered /i/ F2, some consonants lowered and some raised /y e œ/ F2. This is understandable as /i/ was the

259 only front vowel with extreme F2 values. Third, while V_ raised F2 of /e œ/ the most, this was not the case with /i y/.

Next, while consonants generally raised /i y œ/ F1, consonants lowered /e/ F1. Fourth, while preceding and following consonants had different specific influence on /i y e/ F1, preceding and following consonants did not differ in how they affected/ œ/ F1. Fifth, while

PA_ raised F1 the least or lowered it with the /i y œ/, PA_ raised /e/ F1 the most.

Consonants affected /i e œ/ F3 the most, and /y/ F3 the least. With /y œ/ an alveolar consonant raised F3 the most, while with /i e/ the F3 influence was more uniform.

Finally, F1 of /i y e/ in some contexts reached F1 of some vowels in isolation, while that of /œ/ did not. In reference to this, one more thing front vowels had in common is that, in context, they never approached F2 of any other vowel, which is different from what happened with high back vowels.

7.7 C-to-V Coarticulation with Vowel /o/

7.7.1 F1

Figure 41 shows F1 of /o/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately. For example, L encompasses the following words: /bod, bodʒ, bog, dob, dʒob, gob/. The horizontal line represents F1 of /o/ in isolation. Asterisk signifies a significant difference between /o/ in isolation and /o/ in a consonantal context. A significant difference among /o/s in the four contexts was obtained and reported here, but not illustrated on the figures.

260 ****

/o/ in isolation

Figure 41. F1 of /o/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F1, there were significant effects of Context (F(1.947,101.236)=21.247, p<.01) and Gender (F(1,52)=23.510, p<.01), with females having higher F1 than males. A

261 post-hoc test (with Bonferroni adjustment) showed that all consonants raised F1 of /o/ in isolation (p<.01). /o/ in the four consonantal contexts did not differ among each other.

The significant Position*Context interaction (F(2.385,124.002)=5.200, p<.01) is explored below in more detail. Figure 42 shows /o/ preceded and followed by the consonants with four different places of articulation.

** ** ** **

/o/ in isolation

Figure 42. F1 of /o/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(3.030,157.579)=16.355, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all preceding consonants raised F1 (p<.01). /o/ in the four consonantal contexts did not differ among each other.

With following consonants, there was a significant effect of Context

(F(2.808,146.008)=15.232, p<.01). A post-hoc test (with Bonferroni adjustment) revealed

262 that all following consonants raised F1 (p<.01). Additionally, _L raised F1 more than _A

(p<.01): _L>_A.

7.7.2 F2

Figure 43 shows F2 of /o/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

* * * *

/o/ in isolation

263

Figure 43. F2 of /o/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F2, there were significant effects of Context (F(3.043,158.253)=127.844, p<.01) and Gender (F(1,52)=40.348, p<.01), with females having higher F2 than males. A post-hoc test (with Bonferroni adjustment) revealed that all consonants raised F2 of /o/ in isolation (all p<.01). Additionally, PA raised F2 the most compared to the other three contexts

(all p<.01), and A raised F2 more than L and V (both p<.01): PA>A>L, V.

The significant Position*Context interaction (F(2.075,107.898)=13.025, p<.01) is explored in more detail below. Figure 44 shows /o/ preceded and followed by the consonants with four different places of articulation.

264 ** * * * ***

/o/ in isolation

Figure 44. F2 of /o/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(2.981,155.006)=130.742, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all preceding consonants raised F2 (all p<.01). Additionally, PA_ raised F2 the most compared to the other three contexts (all p<.01), A_ raised F2 more than L_ and V_ (both p<.01), and V_ raised F2 more than L_ (p<.05): PA_>A_>V_>L_.

With following consonants, there was a significant effect of Context

(F(2.596,134.990)=43.344, p<.01). A post-hoc test (with Bonferroni adjustment) revealed that all following consonants raised F2 of /o/ (all p<.01). /o/ in the four consonantal contexts did not differ among each other.

265 7.7.3 F3

Figure 45 shows F3 of /o/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

** /o/ in isolation

Figure 45. F3 of /o/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

266 With respect to F3, there were significant effects of Context (F(2.608,135.611)=20.501, p<.01) and Gender (F(1,52)=276.549, p<.01), with females having higher F3 than males. A post-hoc test (with Bonferroni adjustment) revealed that PA and V contexts lowered F3 of /o/ in isolation (p<.01). In addition, F3 of /o/ in L and A contexts was higher than F3 of /o/ in PA and V contexts (p<.01), and F3 of /o/ in A context was higher than F3 of /o/ in L context

(p<.01): L A>PA, V and A>L.

Position*Context interaction was not significant (F(2.259,117.489)=1.321, p=.272).

7.7.4 Summary

Table 10 summarizes the main results of Experiment 4 with the vowel /o/.

Table 10. Summary of the main results with the vowel /o/ F Comparing Preceding C Following C /o/ in isolation & /o/ in four consonantal all_  all_  F1 contexts /o/ in four consonantal _L>_A contexts /o/ in isolation & /o/ in four consonantal all_  all_  F2 contexts /o/ in four consonantal PA_>A_>V_>L_ contexts /o/ in isolation & /o/ in four consonantal PA V  F3 contexts /o/ in four consonantal PA V

267 Table 10 shows that adjacent consonants had more influence on F1 and F2 of /o/ in isolation than on F3, as only PA and V influenced /o/ F3 and the influence of the preceding and following consonants did not differ. All consonants influenced F1 and F2. While /o/ F1 differed among the four following consonantal contexts, /o/ F2 differed among the four preceding contexts. Thus, following consonants specific influence was felt more with F1, and preceding consonants specific influence with F2.

Figure 46 illustrates the F1/F2 acoustic vowel space with vowel /o/ in four different consonantal contexts (a, c), and with all eight Turkish vowels in isolation (b, d). A zoomed acoustic space is given in a. and c. in order to better appreciate /o/ in four consonantal contexts.

268 a. 1160 1140 1120 1100 1080 1060 1040 1020 1000 980 960 940 450

460 F1 (HZ) F1

470

480 F2 (HZ)

b. 2300 2100 1900 1700 1500 1300 1100 900 700 250 i y 300 u ɯ 350

400 œ o 450

F1 (HZ) 500 e 550

600 a 650

700 F2 (HZ)

269 c. 1280 1260 1240 1220 1200 1180 1160 1140 1120 1100 1080 1060 1040 1020 1000 500

510

520 F1 (Hz) F1

530

540 F2 (Hz)

d. 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 250 300 i y u 350 ɯ 400 450 œ o 500

F1 (Hz) F1 550 600 650 700 e a 750 800 F2 (Hz)

Figure 46. F1/F2 acoustic vowel space representing eight Turkish vowels in isolation (black

circles), and /o/ preceded (white) and followed (black) by consonants with four different places

of articulation, averaged for 3 males (above) and 3 females (below): L = , A = , PA =

, V = 

270 Figure 46 shows that the acoustic space was larger for /o/ with preceding than with following consonants, for both males and females. In the F2 dimension, the acoustic space for /o/ with preceding consonants spanned around 200Hz/250Hz (males/females), while with following consonants the range was around 80Hz/50Hz (males/females). In the F1 dimension, there was no difference, and /o/ with preceding and following consonants spanned around 20Hz (both males and females). Thus, the major difference between the preceding and following contexts was in F2.

All consonants raised F1 and F2.

PA_ raised F2 the most for both male and females, while L_ raised F2 the least. With males _PA and _L showed the same influence, but not with females. F1 was not influenced in such a consistent way.

Thus, in the F1/F2 acoustic space, /o/ in the PA_ context had F2 values close to /a/ in isolation.

Recall that three specific goals of Experiment 4 were to answer the following questions: (i) Do preceding and following consonants with four places of articulation influence the acoustics (F1, F2, F3) of Turkish vowels, and if so, how? (ii) Does the preceding or following consonant with the same place of articulation have more influence on the vowel?

(iii) Which acoustic dimension (F1, F2, F3) is affected the most?

The results show the four consonants differed in how they influence /o/ formants. Both

F1 and F2 are raised by all four consonants, but there was more difference in the F2 of /o/ in the four contexts. Preceding consonants influenced F2 more, and following F1 more. F2 is raised the most by PA_ and the least by L_. F3 was influenced the least of the three formants.

271 7.8 C-to-V Coarticulation with vowel /a/

7.8.1 F1

Figure 47 shows F1 of /a/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately. For example, L encompasses the following words: /bad, badʒ, bag, dab, dʒab, gab/. The horizontal line represents F1 of /a/ in isolation. Asterisk signifies a significant difference between /a/ in isolation and /a/ in a consonantal context. A significant difference among /a/ in the four contexts was obtained and reported here, but not illustrated on the figures.

****/a/ in isolation

272

Figure 47. F1 of /a/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F1, there were significant effects of Context (F(3.341,173.740)=15.391, p<.01) and Gender (F(1,52)=54.186, p<.01), with females having higher F1 than males. A post-hoc test (with Bonferroni adjustment) showed that all consonants lowered F1 of /a/ in isolation (p<.01). In addition, PA lowered F1 the most compared to the other three consonants

(p<.01): PA

The significant Position*Context interaction (F(2.810,146.132)=14.961, p<.01) is explored below in more detail. Figure 48 shows /a/ preceded and followed by the consonants with four different places of articulation.

273 *** * * /a/ in isolation

Figure 48. F1 of /a/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(3.122,162.322)=22.052, p<.01). A post-hoc test (with Bonferroni adjustment) showed that PA_ and V_ lowered F1 of

/a/ in isolation (p<.01). Additionally, PA_ lowered F1 the most compared to the other three contexts (p<.01), and V_ lowered F1 compared to L_ and A_ (p<.05): PA_

With following consonants, there was a significant general effect of Context

(F(3.699,192.341)=8.628, p<.01). A post-hoc test (with Bonferroni adjustment) showed that

_L, _A and _PA lowered F1 of /a/ in isolation (p<.01). /a/ in the four consonantal contexts did not differ among each other.

274 7.8.2 F2

Figure 49 shows F2 of /a/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

****

/a/ in isolation

Figure 49. F2 of /a/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

275

With respect to F2, there were significant effects of Context (F(2.362,122.831)=140.946, p<.01) and Gender (F(1,52)=17.819, p<.01), with females having higher F2 than males. A post-hoc test (with Bonferroni adjustment) revealed that all consonants raised F2 compared to

/a/ in isolation (p<.01). In addition, PA raised F2 the most compared to the other three contexts (p<.01), and L the least compared to the other three contexts (p<01): PA>A, V>L.

The significant Position*Context interaction (F(2.530,131.547)=4.365, p<.01) is explored below in more detail. Figure 48 shows /a/ preceded and followed by the consonants with four different places of articulation.

* * ** ** * *

/a/ in isolation

Figure 50. F2 of /a/ preceded (white) and followed (black) by consonants with the four places of articulation, averaged for the six speakers

Additional ANOVAs were run with preceding and following consonants separately. With preceding consonants, there was a significant effect of Context (F(2.758,143.424)=70.895, p<.01). A post-hoc test (with Bonferroni adjustment) showed that all preceding consonants

276 raised F2 compared to /a/ in isolation (p<.01). Additionally, PA_ raised F2 the most compared to the other three contexts (p<.01), and L_ the least compared to the other three contexts

(p<01): PA_>A_, V_>L_.

With following consonants, there was a significant effect of Context

(F(2.811,146.177)=76.636, p<.01). A post-hoc test (with Bonferroni adjustment) showed that all following consonants raised F2 compared to /a/ in isolation (p<.01). In addition, _PA raised F2 the most compared to the other three contexts (p<.01), and _A raised F2 more than

_L (p<01): _PA>_L, _A, _V and _A>_L.

7.8.3 F3

Figure 51 shows F3 of /a/ adjacent to the consonants with four different places of articulation,

L (labial), A (alveolar), PA (postalveolar) and V (velar), for all speakers and for males and females separately.

/a/ in isolation

277

Figure 51. F3 of /a/ adjacent to consonants with four places of articulation, averaged for the six speakers (above), and averaged for females (white) and males (black) (below)

With respect to F3, there were significant effects of Context (F(2.258,117.431)=9.184, p<.01) and Gender (F(1,52)=159.979, p<.01), with females having higher F3. A post-hoc test (with Bonferroni adjustment) revealed that none of the consonants significantly raised or lowered F3 of /a/ in isolation. In addition, F3 of /a/ in PA context was lower than F3 of /a/ in

L and A contexts (p<.01): PA

There was no significant Position*Context interaction (F(2.509,130.462)=1.209, p=.307.

278 7.8.4 Summary

Table 11 summarizes the main results of Experiment 4 with the vowel /a/.

Table 11. Summary of the main results with the vowel /a/ F Comparing Preceding C Following C /a/ in isolation & PA_ V_  _L _A _PA  F1 /a/ in four consonantal contexts /a/ in four consonantal contexts PA_

/a/ in isolation & all_  _all  /a/ in four consonantal contexts F2 _PA>_L _A _V /a/ in four consonantal contexts PA_>A_ V_>L_ A_>_L /a/ in isolation &

F3 /a/ in four consonantal contexts /a/ in four consonantal contexts PA

Table 11 shows that adjacent consonants had more influence on F1 and F2 of /a/ in isolation than on F3, as none of the consonants changed /a/ F3, and the influence of the preceding and following consonants did not differ. Also, consonants influenced F2 the most, as all consonants influenced F2 and there was a consonant specific influence of both the preceding and the following consonants.

Figure 52 illustrates the F1/F2 acoustic vowel space with vowel /a/ in four different consonantal contexts (a, c), and with all eight Turkish vowels in isolation (b, d). A zoomed acoustic space is given in a. and c. in order to better appreciate /a/ in the four consonantal contexts.

279

a. 1450 1430 1410 1390 1370 1350 1330 1310 580

590

600

610

620 F1 (Hz)

630

640

650 F2 (Hz) b. 2300 2100 1900 1700 1500 1300 1100 900 700 250 i y 300 u ɯ 350 400 œ o 450 500 F1 (Hz) F1 e 550 600 a 650 700 F2 (Hz)

280

c. 1640 1620 1600 1580 1560 1540 1520 1500 1480 1460 1440 1420 1400 1380 1360 1340 640 650 660 670 680 690 700 F1 (Hz) F1 710 720 730 740 750 760 F2 (Hz)

d. 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 250 300 i y 350 ɯ u 400 450 œ o 500

F1 (Hz) 550 600 650 700 e a 750 800 F2 (Hz)

Figure 52. F1/F2 acoustic vowel space representing eight Turkish vowels in isolation (black

circles), and /a/ preceded (white) and followed (black) by consonants with four different places

of articulation, averaged for 3 males (above) and 3 females (below): L = , A = , PA =

, V = 

281 Figure 52 shows that the acoustic space was similar for /a/ in the four preceding and following consonantal contexts, for both males and females. Only F1 with females differed. In the F2 dimension, the acoustic space for /a/ with preceding consonants spanned around 120Hz/200Hz

(males/females), while with following consonants the range was around 100Hz/200Hz (males and females). In the F1 dimension, the acoustic space for /a/ with preceding consonants spanned around 40Hz/80Hz (males/females), while with following consonants the range was around 40Hz/50Hz (males and females).

All consonants lowered F1 and raised F2.

PA_ and V_ raised F2 the most for both males and females, while L raised F2 the least.

Also, PA_ and V_ lowered F1 the most for both males and females.

Thus, in the F1/F2 acoustic space, /a/ in the PA_, V_ and _PA contexts had F2 values close to /ɯ/ and /œ/.

Recall that three specific goals of Experiment 4 were to answer the following questions: (i) Do preceding and following consonants with four places of articulation influence the acoustics (F1, F2, F3) of Turkish vowels, and if so, how? (ii) Does the preceding or following consonant with the same place of articulation have more influence on the vowel?

(iii) Which acoustic dimension (F1, F2, F3) is affected the most?

The results show the four consonants differed in how they influence /a/ formants. PA_ raised F2 the most, and L_ the least, while PA_ also lowered F1 the most. F1 and F2 differed in that consistent consonants specific influence was felt more with F2. Preceding and following consonants did not differ much in their influence on consonants. F3 was influenced the least of the three formats.

282 7.9 Vowels in Isolation and in Context: Contextualization and Centralization

There is evidence that vowels in context have reduced F1/F2 vowel space compared to vowels in isolation – centralization (e.g. Lindblom 1963). There is also evidence that vowels in context shift their F1 and, primarily, F2 values to values of the surrounding sounds – contextualization (e.g. Flemming 2007; van Bergem 1994). This section summarizes the results of the F1/F2 acoustic space with reference to centralization and contextualization.

283 Figure 53 illustrates the way each vowels’ acoustic space changes when vowels are put into context.

2300 2100 1900 1700 1500 1300 1100 900 700 200 i y 250 u ɯ 300 350 400 œ o e 450 F1 (Hz) F1 500 550 a 600 650 700 F2 (HZ)

2700 2500 2300 2100 1900 1700 1500 1300 1100 900 700 200 i 250 y u 300 ɯ 350 o 400 œ 450 500

F1 (Hz) F1 e 550 600 a 650 700 750 F2 (Hz)

Figure 53. Comparing the F1/F2 acoustic space of vowels in isolation (black circles) to the

F1/F2 acoustic space of vowels in context (white circles), separately for males (above) and females (below)

The acoustic space of vowels in context was overall smaller than the acoustic space of vowels in isolation.

284 F1 of all vowels in contexts showed centralization. By centralization, we assume that

F1 is moving towards the F1 of the central and mid portion of the F1/F2 acoustic vowel space.

F2 of all vowels in context showed centralization, except /e/ and /y/ for males, and /e/ and /a/ for females. Male speakers’ /e/ F2 and /y/ F2, in fact, moved away from the centre of the acoustic space. Female speakers’ /e/ F2 did not change either way, while /a/ F2 moved away from the centre as well.

In sum, the centralization hypothesis is confirmed by the data, as, in the F1/F2 acoustic vowel space, F1 and F2 values of vowels in isolation generally shift towards the centre.

285 7.10 Same Consonantal Context with Different Vowels

Recall that one of the specific goals of Experiment 4 was to answer the question of how different vowels are affected by consonantal context. Figures 54-57 show how each vowel’s acoustic space changes under the influence of the four consonantal places, from Labial to

Velar, respectively. The influence illustrated refers to a general tendency, and is not, necessarily, statistically significant. Figure 54 illustrates the way the eight vowels in isolation changed when adjacent to a labial consonant.

2500 2300 2100 1900 1700 1500 1300 1100 900 700 200 i 250 y u 300 ɯ 350 400 o 450 œ 500

F1 (Hz) F1 e 550 600 a 650

F2 (Hz) 700

Figure 54. F1/F2 acoustic space of vowels in isolation (black circles) compared to F1/F2 acoustic space of vowels in Labial context (white circles) for both males and females

An adjacent labial consonant raised F2 of back vowels /u o a/ and front /œ/, and lowered F2 of back /ɯ/ and front /i y e/. An adjacent labial raised F1 of all high vowels and mid /œ o/, and lowered F1 of the mid /e/ and the low /a/. Next, Figure 55 illustrates the way the eight vowels in isolation changed when adjacent to an alveolar consonant.

286 2500 2300 2100 1900 1700 1500 1300 1100 900 700 200

250 i y u 300

ɯ 350

400 o œ 450 F1 (Hz) F1 e 500

550

600 a 650

F2 (Hz) 700

Figure 55. F1/F2 acoustic space of vowels in isolation (black circles) compared to F1/F2 acoustic space of vowels in Alveolar context (white circles)

An adjacent alveolar raised F2 of all back vowels, and front /y e œ/ (although the raise of /y/ and /e/ F2 was not so prominent), and lowered F2 of front /i/. An adjacent alveolar raised F1 of all high vowels and the front /œ/, and raised F1 of the mid /e/ and the low /a/.

287 Next, Figure 56 illustrates the way the eight vowels in isolation changed when adjacent to a postalveolar consonant.

2500 2300 2100 1900 1700 1500 1300 1100 900 700 200 250 i y u 300 ɯ 350 400 o œ 450

F1 (Hz) F1 e 500

550

a 600 650

700 F2 (Hz)

Figure 56. F1/F2 acoustic space of vowels in isolation (black circles) compared to F1/F2 acoustic space of vowels in Postalveolar context (white circles)

An adjacent postalveolar raised F2 of all back vowels and front /y e œ/, and lowered F2 of front /i/. An adjacent postalveolar raised F1 of all high vowels and the mid /œ o/, and lowered

F1 of the mid /e/ and the low /a/. Finally, Figure 57 illustrates the way the eight vowels in isolation changed when adjacent to a velar consonant.

288 2500 2300 2100 1900 1700 1500 1300 1100 900 700 200 250 i y u 300

ɯ 350 400 œ o 450 F1 (Hz) F1 500 e 550 600 a 650 700 F2 (Hz)

Figure 57. F1/F2 acoustic space of vowels in isolation (black circles) compared to F1/F2 acoustic space of vowels in Velar context (white circles)

An adjacent velar raised F2 of all back vowels and front /y e œ/, and lowered F2 of /i/. An adjacent velar raised F1 of all high vowels and the mid /œ o/, and lowered F1 of the mid /e/ and the low /a/.

Table 12 summarizes the main findings.

Table 12. Summary of the changes in F1 and F2 values in coarticulation contexts Labial Alveolar Postalveolar Velar         back u o a ɯ ɯ u o a ɯ u o a ɯ u o a F2 front œ i y e y e œ i y e œ i e œ i y

high i y ɯ u i y ɯ u i y ɯ u i y ɯ u F1 mid œ o e œ o e œ o e œ o e low a a a a

289 With respect to F1, consonants with four places of articulation had the same influence on F1, as F1 increased with all high vowels /i y ɯ u/ and the mid rounded vowels /œ o/, while F1 decreased with the mid unrounded vowel /e/ and the low vowel /a/.

With respect to F2, consonants with four places of articulation differed in the way they affected different vowels. An adjacent alveolar and postalveolar had the same influence on the vowels, while an adjacent labial and velar differed. The four back vowels differed in how different consonants affected their F2. F2 increased with all four back vowels /ɯ u o a/ under the influence of three consonants, alveolar, postalveolar and a velar. Under the influence of a labial, however, F2 also increased with the three back vowels /u o a/, but F2 decreased with the back /ɯ/.

The four front vowels /i y e œ/ also differed in the way different consonants affected their F2. All four consonants uniformly affected /i/ and /œ/ F2, but in the opposite ways, as /i/

F2 deceased and /œ/ F2 increased. The front vowels /y/ and /e/ were affected in a most diverse way by the four consonants. A labial decreased F2 of both /y/ and /e/, an alveolar and postalveolar increased F2 of both /y/ and /e/ F2, while a velar decreased /y/ F2 and increased

/e/ F2.

Recall from section 7.9 that the data showed that the vowels in consonantal contexts had a general tendency towards centralization. However, section 7.10 shows that the specific influence of the surrounding consonants is also evident, but not for both F1 and F2. In fact, the influence of different consonants on F1 is rather uniform in direction (if not in extent). Thus, assimilation has less influence on F1. On the other hand, the direction of F2 shift depends on the place of articulation of the surrounding consonant. Thus, centralization has less and contextualization more influence on F2. Thus, if we take centralization and assimilation to be

290 two competing forces exerted on vowels, centralization wins with F1, and assimilation with

F2.

7.11 Duration

One of the specific goals of Experiment 4 was to answer the question of whether /ɯ/ is a short vowel, and, as such, more prone to coarticulation. This question is addressed in this section.

Duration for all vowels in context is shown in Figure 58. The duration was averaged across all vowel contexts.

Figure 58. Duration for the eight vowels, averaged across all four contexts and averaged for the six speakers

Duration values for all tokens were analyzed in a repeated measures analysis of variance, with within-subject factor of Vowels (8 levels) and a between-subject factor of Gender (2 levels: male and female).

291 There was a significant effect of Vowels (F(6.501,1391.296)=512.315, p<.01) and

Gender (F,1,214)=83.919, p<.01), with males having shorter /ɯ/, /œ/, /o/ and /a/.

The shortest vowel was /ɯ/, with an average of 65ms, and it differed significantly from all vowels (p<.01). Of the high vowels, /y/ and /u/ did not differ in duration (p=1.000), and of the non-high vowels, /œ/, /o/ and /a/ did not differ in duration (all p=1.000).

With regards to individual speakers, /ɯ/ was either the shortest vowel (P1, P3, P5, P6) or the third shortest vowel (P2, P4). For P2 the shortest vowel is /y/ and with P4, /i/. The longest vowel varies between /œ/ (P3, P5, P6), /o/ (P2) and /a/ (P4, P1).

Recall that one of the goals of Experiment 4 was to answer the question of whether the vowel /ɯ/ is the shortest Turkish vowel, and, as such, more prone to the influence of different consonants compared to the other seven vowels. The results show that /ɯ/ is indeed the shortest of the eight vowels, and significantly so. Two previous studies measured the duration of Turkish vowels (Arısoy at al. 2004 and Kiliç et al. 2006) and Kiliç et al. found that /ɯ/ is the shortest Turkish vowel. (Please refer to section 2.3.2 for more details). Their stimuli were disyllabic real words and the target vowel was located in the first, unstressed, syllable, either preceded by a consonant or not. The results showed that the duration of /ɯ/ ranged from 22ms to 56mm, with the average 43ms. In the present study, monosyllabic words were used, so that the vowel was always stressed. That is likely the reason why, in the present study, the duration of the vowel /ɯ/ was 65ms average, or longer than the previous studies where it was unstressed.

Research shows that speech organs move at a specific speed, and it takes different amount of time for, for example, the tongue to assume a different shape than for the lips

(Stevens 1998). (More about this in sections 2.4.6 and 2.4.9.) For most vowels, it takes about

100ms to change the tongue shape from one configuration to another; the lips take 50-100ms

292 to change from a rounded to an unrounded configuration, but can take as long as 300ms. Thus, generally speaking, high vowels should be more prone to coarticulation, based on duration alone (there may be other factors involved that make some vowels less and some more prone to coarticulation). During the production of /ɯ/, averaging 65ms in duration in a stressed position, the tongue and the lips do not have enough time to completely change from one configuration to another.

/ɯ/ is a back vowel, with the tongue dorsum raised. Thus, when /ɯ/ is adjacent to a velar consonant, which has a similar configuration, the speech organs would need to adapt less than when /ɯ/ is adjacent to a postalveolar or an alveolar consonant, where the tongue is in the more front position. This is shown by the results reported in section 7.1. In fact, /ɯ/ was the vowel most prone to coarticulation in the F2 dimension, with its F2 range spanning from PA_ to L_ 400Hz for males and 600Hz for females. This issue will be tackled in Chapter 8, when we discuss the adaptation of the Turkish vowel /ɯ/ in loanwords from several languages.

7.12 Preliminary Results with Real Words

Together with nonce words, real Turkish words with the vowel /ɯ/ were also recorded. A complete analysis of those data remains to be done in the future. Here, two conclusions based on preliminary results will be mentioned.

First, the F1/F2 acoustic space was very similar with nonce and real words.

Postalveolar consonants raised /ɯ/ F2 by around 350Hz, alveolars raised F2 by 100Hz, while labials lowered F2. Generally, F1 of /ɯ/ in context was lower than F1 of /ɯ/ in isolation. Also,

F2 occupied a range of around 400Hz.

Second, /ɯ/ as an unstressed vowel can be up to two times shorter than /ɯ/ in a stressed syllable. The shortest /ɯ/ was 10ms long in the word /kɯnap/. Generally, /ɯ/ was the

293 shortest in between /k/ and /l/, and between /k/ and /n/. In some cases, there was no vowel present at all.

A study with real words opens many possibilities, as we saw above.

7.13 Conclusion

Chapter 7 presented the results of Experiment 4, whose general goal was to examine the acoustic properties of the eight Turkish vowels in four different consonantal contexts.

The specific goals of Experiment 4 (as outlined at the beginning of the Chapter) were to answer the following questions: (i) Do preceding and following consonants with four different places of articulation influence the acoustics (F1, F2, F3) of the Turkish vowels, and if so, how? (ii) Does the preceding or following consonant with the same place of articulation have more influence? (iii) How are different vowels affected by a consonant with the same place of articulation? (iv) Do vowels that belong to the same vowel pair get affected in the same way or in different ways? (v) Do the three different vowel pairs get affected in the same way? (vi) Which acoustic dimension (F1, F2, F3) is affected the most? (vii) Is /ɯ/ the shortest vowel, and is /ɯ/ more liable to the influence of different consonants than other vowels?

The eight Turkish vowels differed in the way they were affected by consonants with four different places of articulation. The vowels differed in their susceptibility to coarticulation. The vowel /ɯ/ was most prone to coarticulation, followed by the vowel /u/. The least susceptible to coarticulation were the vowels /i/, /y/ and /œ/. The other three vowels, /e/

/o/ and /a/ are in between. The vowel /ɯ/ was also the shortest vowel of the eight, which contributed to its susceptibility to coarticulation. However, the high front vowels /i y/ were also shorter compared to the mid and low vowels, but were much less susceptible to coarticulation. Thus, duration in the sense of not having enough time to complete a transition

294 for one articulatory configuration to another, is not the only factor that renders a vowel prone to the influence of surrounding consonants. Some vowel configurations seem to be more stable than others, at least acoustically. This study looked only at the acoustics of the seven vowels, but it would be interesting in the future to look at the articulation for these seven vowels, in order to see whether, for example, /i y/ are less prone to coarticulation in that domain as well.

In consonantal contexts, vowels tended to centralize their F1 more and to contextualize

F2 values. Thus, the influence consonants had on F1 was more general, while a consonant specific influence was felt more in the F2 dimension. A postalveolar consonant raised F2 the most for all four back vowels, while a labial consonant caused the lowest F2 values.

The three vowel pairs differed in the way they were affected by consonants. The /ɯ u/ pair was the most prone to coarticulation, with a postalveolar raising F2 the most, and a labial either lowering F2 (/ɯ/) or raising it the least (/u/). The /i y/ pair was the least susceptible to coarticulation. The vowels /e/ and /œ/ differed the most compared to the members of the other two pairs: the F1 change went in the opposite direction.

With the vowels prone to coarticulation, consonants affected F2 more than F1, while

F3 was affected the least. For these vowels, preceding consonants had more influence than following consonants, especially with regards to F2.

Chapter 8 discusses the main findings and the relevance of the study to some larger issues in vowel production and sound production in general.

295 CHAPTER 8

DISCUSSION AND CONCLUSION

8.1 Reviewing the Goals and the Contributions

The goal of this study was to examine phonetic properties of the three Turkish rounded/unrounded vowel pairs /i y/, /e œ/ and /ɯ u/. The Turkish vowel system is interesting from the phonetic and phonological perspective for at least two reasons. First, although it is an eight-vowel system, it has three vowel pairs which differ in rounding, so, in that sense, it can be said to be crowded. Second, one of these pairs is a back rounded/unrounded vowel pair /ɯ u/, which is not very frequent cross-linguistically; according to the UPSID database

(Maddieson and Precoda 1992), 41 out of 451 languages surveyed, or 9.09%, have the vowel

/ɯ/, and only 30 languages, or 6.65%, have both vowels /ɯ/ and /u/.

With respect to the rounded/unrounded vowel pairs, some acoustic studies have been done on front pairs, particularly the high front rounded/unrounded vowel pair /i y/, mostly in

French, German, Dutch and Chinese (see Chapter 2 for details). There are few articulatory studies with front rounded/unrounded vowel pairs and coarticulation studies with rounded/unrounded vowel pairs. Back pairs have not been studied extensively. There is one study that deals with the articulation of the Turkish vowels in isolation using the MRI technique (Kiliç and Ögüt 2004). No studies have investigated phonetic properties of the high back rounded/unrounded vowel pair in different consonantal contexts. Moreover, the vowel

/ɯ/ is particularly interesting from the loanword perspective; different from other Turkish vowels, it has been adapted variously and variably by a number of borrowing languages, which in itself is an interesting topic for an extensive future study (chapter 1).

The present study analyzed phonetic properties of Turkish vowels in isolation and in different consonantal contexts. Studying the acoustics and articulation of Turkish vowels in

296 isolation served a double purpose. First, the work describes the vowels in as much relevant phonetic detail as possible; recall, for example, that there is disagreement in the literature about whether the vowel /ɯ/ is back or central (section 2.2.6). Second, the work serves as a basis from which the coarticulation effects on the vowels can be judged. Studying phonetic properties of Turkish vowels in context contributed to a better understanding of how rounded and unrounded vowels differed in their susceptibly to the influence of adjacent consonants. In the present study, the acoustics of all eight Turkish vowels in context and the articulation of the vowel /ɯ/ in context were investigated in particular detail. It would be informative to analyze the articulation of all the vowels in the four different consonantal contexts in a future study.

In order to realize of the goal of the study, four experiments were conducted.

Experiments 1 and 2 investigated, respectively, the articulation and the acoustics of the eight

Turkish vowels in isolation; Experiment 3 examined the articulation of the vowel /ɯ/ in different consonantal contexts, and Experiment 4 examined the acoustics of the eight Turkish vowels in consonantal contexts. Moreover, overall tongue shapes were visually compared, and the duration of the vowels was measured as it could contribute to the susceptibility of the consonantal influence. For Experiments 1 and 3, tongue height and tongue frontness were measured, and for Experiments 2 and 4, formants F1, F2 and F3 were measured.

The following three sections each review one of the three general issues outlined in

Chapter 2: phonetic properties of Turkish vowels in isolation (section 8.2), phonetic properties of Turkish vowels in different consonantal contexts (section 8.3), phonetic properties of the

Turkish vowel /ɯ/ with reference to loanwords (section 8.4).

297 8.2 Vowels in Isolation

With respect to vowels in isolation, several specific questions were posed in section 2.6.

Do rounded/unrounded vowel pairs have the same place of articulation and differ only in lip rounding; in other words, are they true rounded/unrounded pairs, or is there a difference also in tongue shape and/or position? The study showed that all three unrounded vowels had a similar tongue shape as their rounded counterparts. Generally, they differed in tongue frontness, as unrounded vowels were articulated significantly more front than their rounded counterparts. The members of the /e œ/ vowel pair differed the most between each other. The reason for that can be that the rounded lip configuration induces the change of the tongue shape/location. Still, as we shall see below, articulatory differences may or may not be reflected in acoustic properties; it is mostly by reference to acoustic properties that listeners identify vowels.

The second question refers to the acoustic properties of the three vowel pairs: How are these three pairs distinguished acoustically? The most consistent finding was that all three unrounded vowels had higher F2 than their rounded counterparts, which can be a consequence of tongue fronting or the difference in lip constriction, or a combination of both.

The third question addresses the vowel /ɯ/. Is it a back or a central vowel? The results showed that /ɯ/ is articulatorily a back vowel, although its F2 is almost as high as /y/ F2.

These questions and other questions put forward in section 2.5, as well as the relationship between acoustics and articulation, are expanded upon below.

With respect to the two articulatory measures or dimensions, tongue frontness and tongue height, unrounded vowels in isolation were mostly differentiated from their unrounded counterparts by tongue frontness. Namely, all unrounded vowels were articulated significantly more front than their rounded counterparts, e.g. /i/ was articulated more front than /y/. On the

298 other hand, tongue height significantly differentiated only /i/ from /y/. These were general tendencies, as interspeaker variation was present. The most consistent finding was that /e/ was significantly more front than /œ/ for all three speakers. This is also evident in the articulatory vowel space for some speakers, where the vowel /œ/ was as back as the two high back vowels

/ɯ u/, while the vowel /e/ was articulated more front. Apart from this, the vowel /ɯ/ was very close to the vowel /u/ in the articulatory vowel space for two speakers, where their tokens overlap, while for one speaker /ɯ/ was significantly more front than /u/. However, overall tongue shapes showed that the members of the vowel pairs had similar tongue shapes. A larger number of speakers would yield more conclusive results.

With respect to the three acoustic measures, F2 differentiated the vowels in isolation the most. Namely, all unrounded vowels had significantly higher F2 than their rounded counterparts, e.g. /i/ had higher F2 than /y/. This can indicate that the tongue was in the more front position or that the lip constriction area was larger during the articulation of unrounded vowels compared to their rounded counterparts, or both.

Tables 1-3 compare formants of the three rounded/unrounded vowel pairs, high front, mid front and high back, respectively, produced in isolation, in different languages, including the results for Turkish from the present study.

299 Table 1. Formants of the high front vowel pair. Languages Speaker(s) and F1 (Hz) F2 (Hz) F3 (Hz) Stimuli unround round unround round unround round Danish 10 male, /hVt/ 250 250 2400 1800 (Steinlen 2005) Dutch 50 male, real 294 305 2208 1730 2766 2208 (Pols et al. 1973) words - /hVt/ North German 10 male, /hVt/ 250 250 2100 1600 (Steinlen 2005) Estonian 1 male, (Eek and Meister isolation/sustained 254 254 1881 1780 2980 2156 1994) Swedish 24 male, 255 260 2190 2060 3150 2675 (Fant et al. 1969) isolation/sustained Turkish 3 male, 3 female, 300 325 2400 1700 3300 2500 (current study) isolation

Table 1 compares formant values of the high front rounded/unrounded vowel pair /i y/ in six languages. With respect to F2, /i/ has higher values than /y/. For the present study, these values are approximately 2400Hz vs. 1700Hz. The difference is similar for Danish, Dutch and

German, while for Swedish and Estonian, /i/ and /y/ F2 values differ less, by approximately

200Hz. None of the other five studies presents statistical results comparing /i/ vs. /y/ F2 values.

300 Table 2. Formants of the mid front vowel pair(s). Language and Speaker(s) and F1 (Hz) F2 (Hz) F3 (Hz) Source Stimuli unround round unround round unround round

Dutch /e, 50 male, real words 407 443 2017 1497 2553 2260 (Pols et al. ø/ - /hVt/ 1973) /ɛ, 583 438 1725 1498 2471 2354 œ/

Swedish 24 male, 345 380 2250 1730 2850 2290 (Fant et al. 1969) isolation/sustained Korean 10 male, real words 490 459 1968 1817 2644 2468 (Yang 1992) /hVda/ Estonian 1 male, isolation (Eek and Meister 356 376 1810 1546 2532 2044 1994) Danish /e, 10 males, /hVt/ 310 340 2200 1600 (Steinlen ø/ 2005) /ɛ, 400 400 2000 1600 œ/ German, /e, 340 340 2200 1400 North ø/ 10 males, /hVt/ (Steinlen /ɛ, 550 550 1800 1400 2005) œ/ Turkish 3 male, 3 female, 600 450 1900 1500 2600 2500 (current study) isolation

301 Table 2 compares formant values of the mid front rounded/unrounded vowel pair(s) in seven languages. With respect to F2, the unrounded vowel always had higher F2 values than its rounded counterpart. For the present study, these values were 1900 vs. 1500Hz. The difference is similar for Danish, Korean and Swedish, while for Estonian, Dutch and German the difference was smaller.

Danish, Dutch and German have two pairs of mid front rounded/unrounded vowels, high mid /e ø/ and low mid /ɛ œ/. Danish high mid front /e ø/ and low mid front /ɛ œ/ vowels have F2 values around 2200Hz/1600Hz and 2000Hz/1600Hz, respectively; German high mid front /e ø/ and low mid front /ɛ œ/ vowels have F2 values around 2200Hz/1600Hz and

2000Hz/1400Hz, respectively; and Dutch high mid front /e ø/ and low mid front /ɛ œ/ vowels have F2 values around 2000Hz/1500Hz and 1730Hz/1500Hz, respectively. Thus, F2 values of the unrounded high mid and low mid vowels differ in these three languages. However, it is interesting that F2 values of the rounded high mid and low mid vowels do not differ. F2 values of the Turkish unrounded mid vowel in the current study are inbetween F2 values of /e/ and /ɛ/ in the other three languages, likely due to Turkish having only one mid front pair and not having to maintain the contrast. F2 values of the Turkish rounded mid vowel are similar to F2 values of both /ø/ and /œ/ in the other three languages.

With respect to F1, for languages that have two pairs of mid front vowels, the mid low vowel pair had higher F1, which is to be expected. Turkish has only one pair of mid front vowels. F1 values of /ɛ/ and /œ/ differed significantly, approximately 150Hz. However, as the articulatory study showed that there was no difference in height between these two vowels, the

F1 difference can be attributed to the difference in the size of the lip aperture. Thus, the

Turkish mid front pair /ɛ œ/ did not differ in height, but in frontness.

302 Table 3. Formants of the high back vowels. Speaker(s) and Language and Source F1 F2 F3 Stimuli /ɯ/ /u/ /ɯ/ /u/ /ɯ/ /u/ Korean /ɯ, u/ 10 male, real words - 1 405 369 1488 981 2497 2565 (Yang 1996) /hVda/ Thai 2 male, isolation 2 410 365 1365 758 2548 2568 (Abramson 1962) Turkish 3 males, 3 females, 3 370 350 1500 800 2800 2700 (current study) isolation

Table 3 compares formant values of the high back rounded/unrounded vowel pair /ɯ u/ in

Korean, Thai and Turkish. With respect to F2, the unrounded vowel always had higher F2 values than its rounded counterpart. For the present Turkish study, these values were 1500Hz vs. 800Hz; the difference is similar for the other two languages. With respect to F1, /ɯ/ always has lower values than /u/.

In the present study, F1 was significantly higher only with /e/ in comparison to /œ/, and

F3 was significantly higher only with /i/ in comparison to /y/. The members of the /e œ/ vowel pair were more differentiated than the members of the other two vowel pairs, as /e/ had significantly higher F1 and F2 than /œ/. This is also evident in the acoustic vowel space, where the mid front vowel /œ/ had F1 and F2 very close to the high back vowel /ɯ/. Also, articulatorily, the tongue is as back during the production of the front vowel /œ/ as during the production of the back vowel /ɯ/. At least one acoustic study found that the mid front pair is qualitatively different from the high front pair (Raphael et al. 1978, for Dutch) (section 2.2.2).

According to the High/Low, Front/Back Model of articulation and acoustics (section

2.1.2: e.g. Bell 1867, Stevens 1998), the particular position of speech organs during the production of vowels enhances particular speech sound wave frequencies. Thus, tongue height is acoustically mostly inversely reflected in F1, with high vowels having lower F1 than mid

303 vowels, and mid vowels having lower F1 than low vowels. Tongue frontness is acoustically mostly reflected in F2, with front vowels having higher F2 than central vowels, and central vowels having higher F2 than back vowels. Moreover, lip rounding and/or protrusion generally lowers F1, F2 and F3.

In the case of Turkish vowels in isolation, tongue frontness and F2 correspond to each other with all three rounded/unrounded vowel pairs: /e/, /i/ and /ɯ/ were significantly more front and had significantly higher F2 than /œ/, /y/ and /u/, respectively. Thus, what is significant articulatorily is also significant acoustically. With respect to tongue height and F1, there is a considerable variation. /i/ was articulated higher than /y/ (significant only for P3) and

/i/ F1 was lower than /y/ F1 (not significant); this shows that what is significant articulatorily does not have to be significant acoustically, and vice versa; however, the correspondence is there – the lower the vowel, the higher its F1. Lip shape could also contribute to lower F1 with

/y/ than with /i/. Thus, these two competing forces, higher tongue position for /i/ and lip rounding for /y/, both contributed to the F1 difference in values, which went slightly, but not significantly, in favour of /i/ F1 having lower tongue height than /y/. With the other two vowel pairs, lip rounding seemed to be the major influence, as their members did not differ in tongue height and F1 was lower with rounded vowels compared to their unrounded counterparts.

Also, lip rounding/protrusion had more influence on lowering /œ/ F2 than /u/ F2.

Although rounded vowels differ from their unrounded counterparts in being articulated with rounded and/or protruded lips, it is, in fact, the size of the lip aperture that needs to be smaller with rounded vowels in comparison to their unrounded counterparts in order to cause a drop in formant frequencies. As mentioned previously (section 2.1.2.1), in the Austronesian language Iaai, the back rounded vowel /ɔ/ and the back unrounded vowel /ɤ/ have the same lip aperture and lip constriction, as lip height and width differ between these two vowels in such a

304 way that they “balance each other out” and do not lower formant frequencies (Maddieson and

Anderson 1995: 175). In the present study, lip shape was not recorded and measured for the

Turkish vowels. A future study on lip shape during the production of Turkish vowels, similar to studies done by, for example, Lisker (1989) and Maddieson and Anderson (1995), would contribute considerably to the phonetics of Turkish vowels and a better understanding of formant frequencies in this study.

From the present study, we can tentatively suggest that Turkish /i/ and /y/ differ in lip shape, but do not differ much in lip aperture, while /e/ and /œ/, and /ɯ/ and /u/ differ in lip aperture.

F3 should also lower with rounded vowels compared to their unrounded counterparts.

This is confirmed with all three vowel pairs, significantly only with the /i y/ pair. The other theory on acoustics and articulation (described in detail in section 2.1.2.3),

Palatal/Dorsal/Pharyngeal/Labial Model (e.g. Chiba and Kajiyama 1941, Fant 1960, Stevens

1998, Wood 1982), has a different approach in explaining change in formant frequencies.

Formant frequencies change based on the location of the constriction during the articulation of vowels. A constriction at the point of minimum volume velocity and maximum pressure increases frequency (node), while a constriction at the point of maximum volume velocity and minimum pressure decreases frequency (antinodes). While the frequencies associated with F1 and F2 can change at two and four places in the oral cavity, respectively, the frequencies associated with F3 can change at six places, three nodes and three antinodes (Figure 1).

305

N A N A N A

Figure 1. Nodes and antinodes (N – node; A – antinode)

Thus, it can be said that F3 is more “susceptible” to change than the other three formants, and the difference in F3 between rounded vowels and their unrounded counterparts is more difficult to explain as there are more opportunities for F3 to fluctuate in the middle of the oral cavity.

Another specific question addressed in the study was how the three rounded vowels differed among each other and how the three unrounded vowels differ among each other. The mid vowel /e/ had significantly higher F1 than the high vowel /ɯ/, which is to be expected as mid vowels are articulated lower than high vowels. Interestingly, the high back vowel /ɯ/ had significantly higher F1 than the high front vowel /i/; as this difference was not caused by tongue height (/ɯ/ was articulated higher than /i/), the other contributing factor can be the lip shape. Without data on lip shape, we can only speculate that during the articulation of /i/ the lip aperture was smaller, perhaps as the lips were more spread than during the articulation of

/ɯ/. With respect to F2, the high front vowels /i/ and /y/ had higher F2 than the mid front vowels /e/ and /œ/, as expected, as they were more front than /e/ and /œ/. Recall that in the

Turkish vowel inventory given in Chapter 2, following Zimmer and Orgun (1999), Turkish has

306 low vowel /a/, and that mid front /e œ/ are not a ‘true pair’, /e/ being mid high, and /œ/ mid low.

Based on both the articulatory and acoustic data, the present study is in agreement with the Kiliç and Öğüt (2004) study (Table 4).

Table 4. Turkish vowels Vowels Front Central Back High i y ɯ u Mid e œ o

Low ɑ

Table 4 shows that Turkish has the low back vowel /ɑ/. The results of the present study show that mid front vowels constitute a pair when it comes to height, but that, in comparison to languages which have two sets of mid front pairs, F1 values of the Turkish pair was neither high nor low.

Previous questions related to the difference between rounded vs. unrounded vowels.

This study also asked the question whether and how vowel pairs differed among each other, e.g. the high front pair /i y/ vs. the high back pair /ɯ u/. The three vowel pairs differed among each other in all measurements, tongue height and frontness, F1, F2 and F3. The high back pair had the highest tongue position, while the high front pair had the most front tongue position; the mid pair had the highest F1 and the high front pair the highest F2. Judging by the overall tongue shapes and the articulatory vowel space, the mid /e œ/ pair differed from the two high pairs, as its members /e/ and /œ/ differed between each other more than /i/ and /y/ differed between each other or /ɯ/ sand /u/, particularly for P2 and P3.

The study has done a lot to answer the questions posed at the beginning about the phonetic properties of Turkish vowels in isolation: how unrounded vowels differ from their rounded counterparts, how vowel pairs differ from each other, what is the phonetic nature of 307 the vowel /ɯ/. Still, due to time and space considerations, the study is not exhaustive and directions for further study come to mind, some of them opened by the results of the present study. For example, with rounded and unrounded vowels, the tongue and the lips are active articulators; thus, an investigation of the difference in lip aperture and lip shape would further the understanding of the phonetics of rounded/unreduced pairs. Also, other articulatory measures could be explored with reference to the tongue, such as constriction degree and constriction location, or quantification of tongue shape.

8.3 Vowels in Context

With respect to vowels in context several specific questions were put forward in section 2.5.

Do preceding and following consonants with four different places of articulation influence the acoustics of the Turkish vowels, and if so, how? Do preceding or following consonants have more influence? Which acoustic dimension is affected the most? Which vowel is affected the most? (As only the articulation of the vowel /ɯ/ was studied in context, this will be discussed later in more detail.) Recall that the stimuli were monosyllabic words, so the vowel was always stressed. Of the eight Turkish vowels, judging by the change in formant values, the vowel /ɯ/ was the most susceptible to consonantal influence, followed by the vowel /u/; the other vowels were much less influenced by surrounding consonants. Thus, the three rounded/unrounded vowel pairs differed in that the high back pair /ɯ u/ was considerably more prone to coarticulation than the two front vowel pairs. Of the two front pairs, the high back pair was more conservative when it comes to coarticulation. Preceding consonants influenced vowels more than following, particularly with respect to F2. Thus, F2 values for /ɯ/ in preceding consonantal context ranged from around

400Hz(males)/600Hz(females), while, in the following context, it ranged approximately

308 150Hz(males)/200Hz(females). Naturally, this difference was not present with vowels like /i/ or /y/, which were minimally susceptible to consonantal influence.

Vowels with extreme formant values were not influenced by consonants in such a way as to make these values more extreme. For example, the vowel /u/, which already had extremely low F1 and F2 values, under consonantal influence only raised F1 and F2 values and did not lower them. This is what differentiates the two members of the high back pair /ɯ u/, as /ɯ/ F2 values decreased under consonantal influence (labial consonant), while /u/ F2 values did not. Thus, while all consonants raised /u/ F2, some raised and some lowered /ɯ/ F2.

Of the consonants with four different places of articulation, a postalveolar consonant had the strongest influence on /ɯ/ and /u/ F2, raising it. This is expected, as back vowels are articulated with the back part of the tongue raised towards the velar region, while the postalveolar consonant is articulated with a more front tongue. Therefore, the tongue needs to change its shape from front raising to back raising. The alveolar consonant also raised F2, but not as much. All consonants also raised F2 values of the back vowels /o/ and /a/ in a similar manner, but to a considerably smaller degree (Table 5).

F1 (Hz) F2 (Hz) Vowel L_ A_ PA_ V_ L_ A_ PA_ V_ i + + + - - - - - y + + + e - - - - + œ + + + ɯ + + + + - + + u + + + + + o + + + + + + + + a - - + + + + Table 5. Summary of the consonantal influence on Turkish vowels.

309 Table 5 summarizes the significant influence preceding consonants with different places of articulation had on the eight Turkish vowels. Some of the main observations are the following.

A preceding labial, alveolar and postalveolar raised F1 of the majority of vowels, while a velar more evenly raised and lowered F1 of the vowels. Also, /ɯ/ and /o/ were affected by all four consonants, while /a/ was the least affected. With respect to F2, a preceding labial raised F2 values of /u o a/, an alveolar and a postalveolar raised F2 of all back vowels, and a velar raised

F2 of /e œ u o a/. Also, /i/ and /u o a/ were affected by all four consonants, while /y/ was not affected by any. Although this illustrates which vowels were affected by which consonants, it ignores the magnitude of influence. For example, a postalveolar raised /u/ F2 around 400Hz for females, while a labial consonant raised /u/ F2 by about 100Hz.

Hardly any studies have used stimuli with a postalveolar consonant and no studies have been done on the coarticulation effects consonants have on the high back unrounded vowel

/ɯ/. Here, the results of the present study are compared to the results of three more comprehensive studies on coarticulation, Hillenbrand et al. 2001 and Stevens and House 1963 on American English, and Steinlen 2005 on Danish, German and British English. English does not have rounded/unrounded vowel pairs, and Danish, English and German do not have the back rounded/unrounded vowel pair. As with these three studies, the results of the present study confirm that the high back vowel(s) are more prone to coarticulation in the F2 dimension, particularly next to an alveolar consonant, than either high front vowels or non- high back vowels. The studies also agree that preceding consonants have more influence on the vowels than following consonants.

However, the studies on different languages also show different results. For instance, by comparing three languages in the same study, Steinlen (2005) showed that German was more susceptible to coarticulation than Danish, including the F1 dimension. For Danish, none

310 of the preceding consonants affected F1 compared to the neutral vowel context, while for

German, a preceding alveolar and velar significantly lowered F1 of some vowels (both front and back, high and low, rounded and unrounded). Although the present study on Turkish shows that, compared to vowels in isolation, F1 of most vowels was either lowered or raised in a number of consonantal contexts, the significance of these results cannot directly be compared to the results for Danish and German, as the stimuli differ in a manner that does not allow such direct comparison. Namely, Steinlen (2005) used nonce words of the /hVt/ type as the neutral context for target vowels, while the present study used sustained vowels in isolation as the neutral context. The significant difference in F1 between the vowels in isolation and the vowels in context in the present study is, for the most part, accounted for by hyperarticulation affects and it cannot be directly attributed to the influence of particular consonants. For example, all four consonants significantly raised /i/ F1; however, the increase in F1 in the PA,

A, L and V contexts did not differ among each other. That tells us that specific consonants themselves did not have their own idiosyncratic influence of /i/ F1; rather, the presence of any consonant, no matter what its place of articulation, raised F1. The same reasoning can be applied to F2.

For Danish, German and English, a preceding labial consonant lowered values of some front vowels, while alveolar and velar consonants raised F2 values for some back vowels. In all these cases, F2 of the vowel /i/ was never affected by consonants, and F2 of the vowels with extremely low or high values was not affected by consonants. For the present study, it can be said that a labial consonant only lowered F2 of the front vowel /y/.

The languages also differ, in that, for example, Danish was less prone to consonantal influence than German. It is difficult to compare languages precisely across different studies; however, some conclusions can be drawn. For Danish, only /u/ F2 was raised significantly

311 when next to an alveolar consonant, by approximately 100Hz, while for German /u ʊ ɔ a/ F2 were raised significantly in the same context by 100, 70, 90 and 80Hz, respectively, and some front vowels’ F2s were significantly lowered in the same context. In American English, the most prominent influence was the one alveolars environment had on the back vowels /u ʊ/, around 250Hz (Hillenbrand et al. 2001); the alveolar context had a slightly stronger influence on the same vowels in British English. In the present study, F2 of all four back vowels was raised the most in the postalveolar context, the difference ranging from approximately 600Hz with /ɯ u/ to approximately 200Hz with /o a/. The influence of the alveolar was less prominent.

Recall from sections 2.4.6 and 2.4.9 that the changes in vowel formants due to coarticulation are frequently discussed in relation to the undershoot hypothesis and/or reduction hypothesis and the contextual assimilation hypothesis. According to the undershoot hypothesis, while vowels in isolation are produced with articulators reaching their planned target, vowels in context are produced with articulators falling short of that target (Lindblom

1963). The shift of the formant values towards the centre of the acoustic space is also labeled centralization (e.g. Kondo 1994; Stevens and House 1963). According to the contextual assimilation hypothesis, vowels are influenced by surrounding sounds and shift towards the articulation of these surrounding sounds (e.g. Flemming 2007, van Bergem 1994). The present study shows that both contextualization and centralization forces are at work, centralization more for F1 and contextualization more for F2.

The present study on the coarticulation of Turkish vowels is the first study to have analyzed coarticulation with the high back vowel /ɯ/ and compared members of the rounded/unrounded vowel pairs with respect to the influence of the adjacent consonants on format values. It is also one of the rare studies that looks into the influence of the postalveolar

312 consonants on vowels. A future study on the articulatory effects of coarticulation on all the vowels could deepen our understanding of the relationship between acoustics and articulation in this domain.

8.4 The Vowel /ɯ/

Recall that the vowel /ɯ/ is particularly interesting from the loanword perspective, as it has been adapted variously and variably by a number of borrowing languages. The question that immediately comes to mind is: Is /ɯ/ more prone to the influence of different consonants than other vowels? If so, is this because /ɯ/ is the shortest vowel? Recall that it takes a certain amount of time for articulators such as the tongue and lips to reach their target position/shape, approximately 100ms (e.g. Stevens 1998) (section 2.4.6). The present study shows that, acoustically, the vowel /ɯ/ is more susceptible to coarticulation than the other Turkish vowels, particularly in the F2 dimension. F2 values can vary up to 600Hz with preceding consonants, with a postalveolar raising F2 the most and a labial lowering F2 values. In fact, /ɯ/ F2 values in the postalveolar and alveolar contexts can reach F2 values of /y/ and /e/ in isolation.

With respect to articulation, preceding consonants had more influence than following consonants for all three speakers, and a preceding postalveolar had the most influence, fronting the tongue.

Moreover, the vowel /ɯ/ was the shortest of the eight vowels, and in a stressed syllable, its duration was, on average, 65ms, significantly different from the other vowels. The next shortest vowel was /i/ (70ms), followed by /y/ and /u/ (74ms). (As expected, high vowels were shorter than non-high vowels.) This confirms the previous finding by Kiliç et al. (2006), where /ɯ/ in real Turkish disyllabic words was found to be significantly shorter than other vowels; the duration was on average 43ms, as the stimuli contained unstressed /ɯ/. The

313 present study, however, does not confirm the study by Arɩsoy et al. (2004), where /ɯ/ was not found to be the shortest vowel, and, in the final, stressed syllable, even approached non-high vowels in duration. In the present study, stimuli are uniform, CVC monosyllabic words, while

Arɩsoy et al. (2004) used real words where the target vowel was located in different syllables, such as, for example, open CV syllable or closed CVC syllable. It is possible that the difference between the Arɩsoy et al. (2004) study on the one hand, and the Kiliç et al. (2006) and present study, on the other hand, was caused by different stimuli structure, particularly related to the open/closed syllables and the position of the vowel in a word.

Vowel coarticulation can occur when a vowel does not have a duration that is long enough, approximately 100ms, to enable speech organs (tongue, lips) to assume their target position (Stevens 1998). As the Turkish vowel /ɯ/, the shortest of the eight Turkish vowels, has, at a normal speech rate, on average, the duration of 65ms in a stressed syllable and 43ms in an unstressed syllable, the speech organs do not have time enough to make a complete transition from the preceding consonant to the vowel /ɯ/. This situation makes the vowel /ɯ/ retain some of the speech organ configuration of the preceding consonant. This makes /ɯ/ similar to the vowel schwa, whose duration ranges from 34ms (Kondo 1994) to 64ms

(Flemming and Johnson 2007), and which is very malleable, particularly in the F2 dimension

(e.g. Kondo 1994). Schwa is also prone to deletion (Flemming 2007) and is variously and variably adapted in loanwords (e.g. Lin 2008, 2009; Yip 2006).

The various and variable loanword adaptation of the Turkish /ɯ/ was what prompted the phonetic research of this dissertation. Recall from Chapter 1 that Serbian lacked Turkish vowels /y ɯ œ/, and while the front rounded vowels /y/ and /œ/ were adapted in a fairly consistent way, as /u/ and /u/ or /o/, respectively, the vowel /ɯ/ was adapted as all five Serbian vowels and was also deleted next to /r/. Therefore it was assumed that the adaptation of /ɯ/ as

314 all five vowels might be caused by the influence of the adjacent consonants, i.e. the phonetic properties of /ɯ/ change based on the phonetic properties of the preceding and/or following consonants. One of the goals of the experiments was to determine the phonetic properties of

/ɯ/ and how they change in context.

In the present study, the results show that, in isolation, /ɯ/ F2 range, was around

1600Hz average for all speakers, and that, in consonantal contexts, the values range from

1250Hz to 1650Hz (400Hz) for males and from 1350Hz to 2000Hz for females (650Hz).

Previous studies on the vowel /ɯ/ in five languages showed that its F2 values range from

1300-1600Hz for males. Thus, Turkish /ɯ/ F2 values are lower than in other languages (except

Khmer), and approach /y/ F2 values.

Turkish /ɯ/ F1 values, were around 350Hz, ranging from 250-450Hz for males, and

370-450Hz for females. Previous studies found that /ɯ/ F1 values range from 300-500Hz.

Thus Turkish /ɯ/ F1 values are similar to other languages. F1 values of /ɯ/ in context approach F1 of mid vowels /œ/ (around 450Hz) and /o/ (around 480Hz) in isolation.

Moreover, F1 values of /ɯ/ in context approach F1 values of /e/ (around 400Hz) in context.

In the Turkish speakers’ F1/F2 acoustic space of vowels in isolation, /ɯ/ and /y/, and

/ɯ/ and /œ/ overlap, mostly in the F2 dimension. Moreover, /e/ in context and /ɯ/ in context also overlap. For females, F1/F2 of /e/ in context reaches 450Hz/2000Hz, while /ɯ/ in context reaches 500Hz/2000Hz. For males, F1/F2 of /e/ in contexts reaches 400Hz/1650Hz, while /ɯ/ in context reaches 450Hz/1650Hz. Discriminant analysis shows that, when all three formants are taken into account, /ɯ/ is the most confusable vowel, confused with /u i y o e/, in that order.

Adjacent consonants change /ɯ/ F2 values in the following way: a postalveolar raises

/ɯ/ F2 values to 1900Hz average, an alveolar raises F2 to 1700Hz, a velar raises F2 to

315 1600Hz, and a labial lowers F2 values to 1300Hz (average for male and female). In sum, /ɯ/ values range from 1200Hz to 2000Hz (males and females together). Thus, /ɯ/ formant values come close to /e/ and /a/ in isolation. Besides /ɯ/, only /u/ has such a wide range of F2 values of all Turkish vowels.

Recall that, in Chapter 1, some Turkish words adapted in Serbian are given as illustration of the variable adaptation of the vowel /ɯ/. After having done the phonetic analysis of the vowel /ɯ/ in different consonantal contexts, let’s go back to these words and try to see whether our knowledge of the contextual influence can explain this variable adaption. The following words, repeated from Chapter 1, show the variable adaptation of the vowel /ɯ/ (1).

Turkish Serbian

1 a. /bahʃɯʃ/ [bakʃiʃ] ‘tip’

b. /barɯm/ [barem] ‘at least’ * [barim]

c. /bɯrek/ [burek] ‘pie’ * [burik]

d. /tɕadɯr/ [tɕador] ‘tent’ * [tɕadir]

e. /satɯr/ [satara] ‘meat cleaver’ * [satira]

The vowel /ɯ/ following a post-alveolar /ʃ/ and alveolar /t d r/ consonant was adapted as

Serbian /i e/ (1a-1b). As the results of the current phonetic study show, F2 values of /ɯ/ following an alveolar and a postalveolar consonant were raised so that they reached the F2 values of the Turkish front vowels /y e/, and come close to the F2 values of the Turkish /i/. In

1c, /ɯ/ was adapted as /u/ next to a labial consonant /b/. However, the last two examples of adaptation (1d and 1e) are more difficult to explain by referring to the acoustic study, as the segmental environment (adjacent consonants and the other vowel in the word) seems to be identical or very similar to 1c, yet /ɯ/ was adapted as /o/ and /a/, respectively. Thus a larger

316 study on loanwords is necessary, covering a number of the adapted words, and treating them statistically, to single out exceptions, which are present in almost every adaptation situation.

In regular speech, vowels are always found in context, instead of having one variable instance of sound all the time. The listener’s task is to find, among a multitude of such different realization, “invariant, discrete units underlying” that variability (Kühnert and Nolan

1999:7). Serbian does not have the vowels /y œ ɯ/. Therefore, Serbian speakers had the task to deduce the vowels’ “pure” phonetic properties from all variable realizations of these vowels.

/y/ and /œ/ F2 values vary around 200Hz in contexts compared to their F2 values in isolation.

Moreover, /y/ and /œ/ are both rounded vowels, which is an extra visual cue for the borrowers.

Namely, studies have found that visual cues play an important role in sound perception (e.g.

Johnson and Mackenzie 2006; Johnson and DiCanio 2007; Winters 2000). On the other hand,

/ɯ/ lacks strong visual cues, shows variability in acoustic cues, and is the shortest Turkish vowels.

The fact that in Greek and Hungarian the Turkish /ɯ/ was adapted as /i/ shows that languages can choose between various repair strategies. Serbian borrowers opted for a phonetic approach, while Hungarian and Greek borrowers opted for a more phonological approach. Also, Hungarian has a different phonological vowel system from Serbian; Greek, although it has the same phonological vowel system, might differ in the vowels’ phonetic properties from Serbian, or the nature of the language contact was such that Greek had more bilingual Greek/Turkish speakers who had access to Turkish phonology (e.g. La Charité and

Paradis 2005, Paradis and La Charité 1997).

Languages/dialects with the same vowel inventory have been known to exhibit different patterns of adaptation of the same source language, just as two or more source

317 languages with the same phonological sound inventory can have their sounds adapted in different ways in the same borrowing language.

As an example of the first case of adaptation, English interdental fricatives /θ ð/ are adapted as /s z/ in French French, and as /t d/ is Quebec French, which otherwise have the same consonant inventory (e.g. Brannen 2002). The difference between the two dialects of

French is that European French has a dental coronal fricative /s/,̪ while Quebec French has an alveolar coronal fricative /s/. Thus, a non-contrastive phonetic detail plays a role in this adaptation (Kang 2010). In a similar fashion, it may be that Greek and Serbian vowel inventories differ in a non-contrastive feature.

As an example of the second case of adaptation, French /y/ is adapted as Serbian /i/, and French /ø œ/ as Serbian /e/. Thus, the “same” Turkish and French vowels have a different pattern of adaptation in the same language. There is a difference in the time of adaptation,

French loanwords being more recent; still, none of the adaptations are on-line adaptations, and

French loanwords are well established as well. The orthography does not play a role either

(section 2.3.3). Therefore, Turkish and French “same” vowels can differ phonetically enough to cause various perceptions. With French words, the feature rounded/unrounded is sacrificed, which does not happen with Turkish. Perhaps French vowels are not as rounded phonetically as Turkish vowels. In fact, two studies, one on French (Perkell 1996) and the other on Turkish

(Boyce 1989), show that French and Turkish differ in their rounding coarticulation patterns. In

Turkish, rounding is propagated across consonants between two rounded vowels, i.e. lip constriction is present all the time. In French, lip constriction is not present on consonants in the same situation. It looks as if rounding is much more prominent in Turkish, which is not surprising, as Turkish has a phonological process vowel harmony, where vowels in a word have to agree in rounding.

318 Greek, Hungarian and Serbian do not have central vowels. Borrowing languages that have a central unrounded vowel adapted Turkish /ɯ/ as that vowel, which indicates once again that perception plays an important role in adaptation. Namely, /ɯ/ F2 values are close to the central vowel F2 values, and /ɯ/ can be perceived as a central vowel. Also, /ɯ/ can be perceived as mid /ə/ or “near-back” /ɤ/ (e.g. Sabev 2013; Ternes and Vladimirova-Buhtz 1999, for Bulgarian) since their F2 values are similar as well. The study on Bora vowels /i ɨ ɯ/ found that /ɨ/ F2 values are around 1800Hz and /ɯ/ F2 values are around 1500Hz, which clearly differentiated between the high central unrounded and the high back unrounded vowel (Parker

2001) (section 2.2.6). In Turkish, where such a contrast does not have to be maintained, still average /ɯ/ F2 values do not approach the values of a central unrounded vowel. However, even in Bulgarian, /ɯ/ preceded by a postalveolar was adapted as /i/, although by default it is adapted as a central vowel.

In order to carry out a more comprehensive study on loanwords, it would be desirable to do perception tests and compare the results with the patterns of adaptation we see here. One reason for doing such a study is that these adaptations are not recent and many of the words are well-incorporated into the borrowing language. Another reason is that, in perception experiments, listeners do not always substitute foreign vowels with the same native vowels with which that language substitutes the same foreign vowel in loanword adaptations. For example, German vowels are not replaced by the same Japanese vowels with which they are substituted in loanword adaption; instead of /ju/ and /e/, listeners substitute both high and mid front vowels with /u/ (Dohlus 2010). Such a perception study on Turkish would be interesting as it would tell us how much perception (phonetics) and how much phonology might have played a role in the adaptation of the Turkish vowels /y œ ɯ/.

319 Turkish has a back (not central) vowel /ɯ/, which is the shortest Turkish vowel and the vowel most prone to coarticulation. Its F1 and F2 values in different consonantal contexts can reach F1 and F2 values of other vowels. These factors can contribute to the variable phonetic adaptation of the vowel /ɯ/ in loanwords in languages that do not have that vowel. The fact that languages that borrowed Turkish words differ in their adaptations of the vowel /ɯ/ shows that a borrowing language can choose between different adaption strategies, as some studies mentioned above show.

This dissertation grew out of questions which emerged from patterns of loanword adaptation of the vowel /ɯ/. The dissertation answered some questions pertaining to loanwords. However, the adaptation of Turkish vowels should be the sole topic of a future study. An exhaustive phonetic study on Greek and Serbian vowels would help answer the question of whether different /ɯ/ adaptations are caused by different phonological make-up of these two vowel system or by phonetic features that differentiated these two vowel systems.

This phonetic study should include perception tests as well. Sociolinguistic and historical issues surrounding language contact between Turkish and Greek and Turkish and Serbian would also contribute to a better understanding of the issues. The data used in this study on which conclusions on patterns of loanword adaptations are based did not incorporate statistical data. It would be helpful to quantify the adaptation patterns (e.g. how many Turkish words containing the vowel /ɯ/ were borrowed in which language, in how many of these words /ɯ/ is adapted as /i/ or /u/, which consonants surround /ɯ/ in these words). As no studies have been conducted on the adaptation of the back unrounded vowel, which is particularly prone to coarticulation and has no strong visual phonetic cues, a comprehensive study of this kind would fill a gap in the area of loanword and phonetics and phonology in general.

320 8.5 Summary

This chapter elaborated on the three major areas of research of the present study: phonetic properties of the vowels in isolation, phonetic properties of the vowels in context and phonetic properties of the vowel /ɯ/. The chapter also outlined possible further research questions which could not have been answered in this dissertation, as well as possible research topics that stemmed from the results of the study themselves.

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