Introduction 1

Part I Fundamentals 5

1 Basic Acoustics and Acoustic Filters 7

1.1 The Sensation of Sound 7

1.2 The Propagation of Sound 8

1.3 Types of Sounds 11

1.3.1 Simple periodic waves 11

1.3.2 Complex periodic waves 12

1.3.3 Aperiodic waves 17

1.4 Acoustic Filters 19

Recommended Reading 22

Exercises 23

2 The Acoustic Theory of Speech Production: Deriving Schwa 25

2.1 Voicing 25

2.2 Voicing Quanta 28

2.3 Vocal Tract Filtering 30

2.4 Pendulums, Standing Waves, and Vowel Formants 32

2.5 Discovering Nodes and Antinodes in an Acoustic Tube 45

Recommended Reading 47

Exercises 48

3 Digital Signal Processing 49

3.1 Continuous versus Discrete Signals 49

3.2 Analog-to-Digital Conversion 50

3.2.1 Sampling 51

3.2.2 Quantization 55

3.3 Signal Analysis Methods 59

3.3.1 RMS amplitude 59

3.3.2 Fast Fourier transform (FFT) 60

3.3.3 Auto-correlation pitch tracking 64

3.3.4 Digital filters 68

3.3.5 Linear predictive coding (LPC) 71

3.3.6 Spectra and spectrograms 77

Recommended Reading 79

Exercises 80

4 Basic Audition 82

4.1 Anatomy of the Peripheral Auditory System 82

4.2 The Auditory Sensation of Loudness 83

4.3 Frequency Response of the Auditory System 88

4.4 Saturation and Masking 90

4.5 Auditory Representations 93

Rcommended Reading 97

Exercises 98

5 Speech Perception 100

5.1 Auditory Ability Shapes Speech Perception 101

5.2 Phonetic Knowledge Shapes Speech Perception 104

5.2.1 Categorical perception 104

5.2.2 Phonetic coherence 109

5.3 Linguistic Knowledge Shapes Speech Perception 112

5.4 Perceptual Similarity 115

5.4.1 Maps from distances 116

5.4.2 The perceptual map of fricatives 119

Recommended Reading 124

Exercises 126

Part II Speech Analysis 129

6 Vowels 131

6.1 Tube Models of Vowel Production 131

6.2 Perturbation Theory 137

6.3 "Preferred" Vowels - Quantal Theory and Adaptive Dispersion 141

6.4 Vowel Formants and the Acoustic Vowel Space 142

6.5 Auditory and Acoustic Representations of Vowels 144

6.6 Cross-linguistic Vowel Perception 146

Recommended Reading 149

Exercises 150

7 Fricatives 152

7.1 Turbulence 152

7.2 Place of Articulation in Fricatives 157

7.3 Quantal Theory and Fricatives 159

7.4 Fricative Auditory Spectra 162

7.5 Dimensions of Fricative Perception 165

Recommended Reading 166

Exercises 167

8 Stops and Affricates 169

8.1 Source Functions For Stops and Affricates 170

8.1.1 Phonation types 170

8.1.2 Sound sources in stops and affricates 172

8.2 Vocal Tract Filter Functions in Stops 176

8.3 Affricates 179

8.4 Auditory Properties of Stops 180

8.5 Stop Perception in Different Vowel Contexts 182

Recommended Reading 183

Exercises 184

9 Nasals and Laterals 185

9.1 Bandwidth 185

9.2 Nasal Stops 187

9.3 Laterals 196

9.4 Nasalization 198

9.5 Nasal Consonant Perception 202

Recommended Reading 204

Exercises 205

References 206

Answers to Selected Short-answer Questions 212

Index 218