Functional phonology - Phonetic Sciences, Amsterdam - Universiteit

509 Pages·1998·3.43 MB·English

Functional Phonology

Functional Phonology
Formalizing the interactions between
articulatory and perceptual drives
Academisch proefschrift
ter verkrijging van de graad van doctor
aan de Universiteit van Amsterdam,
op gezag van de Rector Magnificus
prof. dr. J.J.M. Franse
ten overstaan van een door het
college voor promoties ingestelde commissie
in het openbaar te verdedigen in de Aula der Universiteit
op maandag 14 september 1998 te 13.00 uur
door
Paulus Petrus Gerardus Boersma
geboren te Sint Nicolaasga
FaculteitderGeesteswetenschappen
UniversiteitvanAmsterdam
Promotor: prof.dr.ir.L.C.W.Pols
Overigecommissieleden: prof.dr.C.H.M.Gussenhoven
dr.V.J.vanHeuven
prof.dr.G.E.Booij
prof.dr.A.M.Bolkestein
dr.N.S.H.Smith
Uitgavevan
HollandAcademicGraphics phone:[phone]
P.O.Box53292 fax:[phone]
2505AG TheHague e-mail:[email protected]
TheNetherlands http:www.hag.nl
ISBN90-5569-54-6
NUGI941
Copyright©1998byPaulBoersma.Allerechtenvoorbehouden.
PrintedintheNetherlands.
Contents
INTRODUCTION ...........................................................................................................................................1
0.1 Articulatory and perceptual representations ............................................................................................1
0.2 Functional principles and constraints of articulation and perception ......................................................2
0.2.1 Functional principles of speech production ................................................................................2
0.2.2 Functional principle of the communication channel ...................................................................2
0.2.3 Functional principles of speech perception .................................................................................2
0.2.4 The functional hypothesis for phonology ...................................................................................2
0.2.5 Conflicts between functional principles ......................................................................................3
0.2.6 Formalizing functional principles ...............................................................................................4
0.2.7 Interactions between the constraints ...........................................................................................4
0.3 Production and perception grammars ......................................................................................................5
PART I: REPRESENTATIONS ..................................................................................................................7
1. REPRESENTATIONS AND FEATURES .................................................................................................9
1.1 Articulatory and perceptual representations of an utterance ...................................................................9
1.2 Articulatory, perceptual, and hybrid features ........................................................................................10
1.2.1 Articulation versus perception in speech production ................................................................10
1.2.2 The two targets of speech production: two levels of specification ...........................................13
1.2.3 Perceptual specifications ...........................................................................................................14
1.2.4 Articulatory specifications ........................................................................................................15
1.2.5 Perceptual versus articulatory features ......................................................................................16
1.2.6 The speech-neutral position and privative features ..................................................................22
1.2.7 Feature geometries ....................................................................................................................22
1.2.8 Conclusion ................................................................................................................................23
1.3 Hybrid, articulatory, and perceptual representations .............................................................................24
1.3.1 Hybrid representations ..............................................................................................................24
1.3.2 Articulatory phonology .............................................................................................................26
1.3.3 The specification – articulation – perception triad ....................................................................27
1.4 Formalization of functional principles ..................................................................................................30
2. ARTICULATION MODEL ......................................................................................................................31
2.1 Requirements .........................................................................................................................................31
2.1.1 Specification of the input: muscle activities or tasks? ..............................................................32
2.1.2 Controlling the muscles ............................................................................................................32
2.1.3 Smooth trajectories ...................................................................................................................33
2.1.4 Aerodynamic-myoelastic interaction ........................................................................................33
2.1.5 Timing .......................................................................................................................................34
2.1.6 Generating acoustic output ........................................................................................................34
2.2 Overview of the articulation model .......................................................................................................36
2.3 The springs and the masses ....................................................................................................................38
2.3.1 Equation of motion ....................................................................................................................38
2.3.2 The tension force .......................................................................................................................38
2.3.3 The collision force ....................................................................................................................40
2.3.4 The coupling force ....................................................................................................................42
2.3.5 The damping force ....................................................................................................................42
ii CONTENTS
2.3.6 The air pressure force ................................................................................................................43
2.3.7 Parallel subdivision ...................................................................................................................43
2.3.8 The z direction ..........................................................................................................................43
2.4 From muscles to tract shape ..................................................................................................................43
2.5 Speaker properties .................................................................................................................................44
2.5.1 Three sizes of speakers ..............................................................................................................45
2.5.2 Default values ...........................................................................................................................45
2.6 Sublaryngeal system ..............................................................................................................................46
2.7 Larynx ....................................................................................................................................................48
2.7.1 Conus elasticus ..........................................................................................................................48
2.7.2 Intermembranous glottis ...........................................................................................................48
2.7.3 Intercartilagenous glottis ...........................................................................................................51
2.8 Nasal cavities .........................................................................................................................................51
2.9 Pharyngeal and oral cavities ..................................................................................................................52
2.9.1 Upper part of the larynx ............................................................................................................52
2.9.2 Jaw and tongue body .................................................................................................................53
2.9.3 Tongue root ...............................................................................................................................54
2.9.4 Velum and palate ......................................................................................................................56
2.9.5 Tongue tip .................................................................................................................................56
2.9.6 Teeth ..........................................................................................................................................57
2.9.7 Lips ............................................................................................................................................57
2.10 Meshing of the vocal tract ...................................................................................................................57
2.10.1 Mesh points on the outer contour ............................................................................................58
2.10.2 The midlines of the tube sections ............................................................................................58
2.10.3 The lengths of the mesh lines ..................................................................................................60
2.10.4 Equilibrium widths of pharyngeal and oral tube sections .......................................................60
2.10.5 Equilibrium lengths of pharyngeal and oral tube sections ......................................................61
2.11 Other oral and pharyngeal properties ..................................................................................................62
2.12 Time .....................................................................................................................................................62
2.13 Conclusion ...........................................................................................................................................63
3. ACOUSTICAL SIMULATION ................................................................................................................65
3.1 The equation of continuity of mass flow ...............................................................................................65
3.1.1 The integral equation of continuity ...........................................................................................65
3.1.2 Pumping and sucking ................................................................................................................66
3.1.3 Others’ choices for the continuity equation ..............................................................................67
3.2 The equation of motion ..........................................................................................................................68
3.2.1 Pressure gradient .......................................................................................................................68
3.2.2 Bernoulli effect .........................................................................................................................69
3.2.3 Friction ......................................................................................................................................70
3.2.4 Complete equation of motion ....................................................................................................73
3.2.5 Others’ choices for the equation of motion ...............................................................................73
3.3 The equation of state ..............................................................................................................................73
3.4 Turbulence .............................................................................................................................................74
3.4.1 Energy loss ................................................................................................................................74
3.4.2 Turbulence noise .......................................................................................................................75
3.5 Boundary conditions ..............................................................................................................................76
3.5.1 At a closed boundary ................................................................................................................76
3.5.2 At a boundary open to the atmosphere ......................................................................................77
3.5.3 At a boundary between two tube sections .................................................................................77
3.5.4 At a three-way boundary ...........................................................................................................78
3.6 Simplifying the aerodynamic equations ................................................................................................79
3.6.1 The aerodynamic equations in terms of continuous quantities .................................................79
3.6.2 Eliminating the equation of state ..............................................................................................79
3.6.3 A paradoxical factor of one half ................................................................................................80
3.7 Acoustic output ......................................................................................................................................80
CONTENTS iii
3.8 Digital simulation ..................................................................................................................................81
3.9 The dissipative part of the equations .....................................................................................................82
3.9.1 The exponential method ............................................................................................................82
3.9.2 The first-order explicit method .................................................................................................83
3.9.3 The first-order implicit method .................................................................................................83
3.9.4 The second-order method ..........................................................................................................84
3.9.5 Which method should we use? ..................................................................................................85
3.10 The harmonic part of the myo-elastic equations ..................................................................................85
3.10.1 The “explicit” method .............................................................................................................86
3.10.2 The “exact” method ................................................................................................................87
3.10.3 The “implicit” method ............................................................................................................87
3.10.4 The “second-order” method ....................................................................................................88
3.10.5 The amplitude of the periodic motion .....................................................................................88
3.10.6 Which method should we use? ................................................................................................89
3.11 The hyperbolic part of the aerodynamic equations ..............................................................................89
3.11.1 The Lax-Wendroff method .....................................................................................................90
3.11.2 Stability, numerical damping, and frequency warping ...........................................................91
3.11.3 Four extensions to the Lax-Wendroff method ........................................................................94
3.11.4 Stability, frequency warping, and numerical damping ...........................................................97
3.11.5 Accuracy .................................................................................................................................97
3.12 The algorithm ......................................................................................................................................98
3.13 Conclusion .........................................................................................................................................102
4. PERCEPTION MODELS ........................................................................................................................103
4.1 Pitch .....................................................................................................................................................103
4.2 Perceptual spectrum .............................................................................................................................103
4.3 Intensity ...............................................................................................................................................109
4.4 Contrast and confusion ........................................................................................................................110
4.4.1 Discrete measures ...................................................................................................................110
4.4.2 Combining various perceptual dimensions to a global contrast measure ...............................110
4.4.3 Perceptual salience versus dissimilarity ..................................................................................112
4.5 Conclusion .............................................................................................................................................112
5. TEST OF THE ARTICULATION MODEL ...........................................................................................113
5.1 Silence ..................................................................................................................................................113
5.2 Sigh ......................................................................................................................................................113
5.3 Balloon ................................................................................................................................................116
5.4 The onset of phonation ........................................................................................................................118
5.5 During phonation .................................................................................................................................118
5.5.1 The motion of the vocal folds during phonation .....................................................................118
5.5.2 Air velocity in the glottis during phonation ............................................................................120
5.5.3 Air pressure in and around the glottis during phonation .........................................................120
5.6 Sustained phonation .............................................................................................................................122
5.7 Varying lung pressure ..........................................................................................................................124
5.8 Phonetogram ........................................................................................................................................127
5.9 Voicing in obstruents ...........................................................................................................................128
5.10 Voicing contrast using glottal width: aspiration ................................................................................130
5.11 Voicing contrast using tract-wall tension: fortis - lenis .....................................................................133
5.12 Place-dependent maintenance of voicing ..........................................................................................134
5.13 Voiceless by glottal constriction: ejectives ........................................................................................136
5.13.1 The production of ejectives ...................................................................................................136
5.13.2 Simulation of ejectives ..........................................................................................................137
5.14 Trills ..................................................................................................................................................138
5.15 Clicks .................................................................................................................................................138
5.16 Conclusion .........................................................................................................................................140
iv CONTENTS
PART II: CONSTRAINTS .......................................................................................................................141
6. FUNCTIONAL OPTIMALITY THEORY .............................................................................................143
6.1 Grammar model ...................................................................................................................................143
6.2 Constraint-ranking grammars and functionalism ................................................................................144
6.2.1 Explanation versus description ...............................................................................................144
6.2.2 Constraint-ranking grammars .................................................................................................145
6.3 The production grammar .....................................................................................................................146
6.4 The perception grammar ......................................................................................................................147
6.5 Conclusion ...........................................................................................................................................148
7. ARTICULATORY CONSTRAINTS ......................................................................................................149
7.1 Energy ..................................................................................................................................................149
7.2 Number of gestures ..............................................................................................................................151
7.3 Synchronization ...................................................................................................................................154
7.4 Precision ..............................................................................................................................................155
7.5 Coordination ........................................................................................................................................156
7.6 Global or local rankings of effort? ......................................................................................................158
7.7 Ranking by specificity .........................................................................................................................159
7.8 A restriction on functional rankings of articulatory constraints ..........................................................159
7.9 A comprehensive gestural constraint and additive ranking .................................................................159
7.10 Conclusion .........................................................................................................................................160
8. PERCEPTUAL CATEGORIZATION AND THE EMERGENCE OF FINITENESS ..........................161
8.1 Feature values are not innate ...............................................................................................................161
8.2 Constraints in speech production .........................................................................................................162
8.3 Functional constraints in speech perception: categorization ...............................................................163
8.4 Categorization along a single perceptual dimension ...........................................................................165
8.5 Special case: weak categories ..............................................................................................................168
8.6 Special case: unparsed features ...........................................................................................................169
8.7 Dependence on environment ...............................................................................................................170
8.8 Merger ..................................................................................................................................................170
8.9 Conclusion ...........................................................................................................................................171
9. PERCEPTUAL CONTRAST AND FAITHFULNESS ..........................................................................173
9.1 How to implement minimization of confusion ....................................................................................173
9.1.1 Global optimization ................................................................................................................173
9.1.2 The local-ranking principle .....................................................................................................174
9.1.3 Local implementation: faithfulness .........................................................................................174
9.1.4 Faithfulness in phonetic implementation ................................................................................175
9.2 Faithfulness in phonology ....................................................................................................................176
9.3 The emergence of equally spaced categories ......................................................................................179
9.4 Extreme feature values ........................................................................................................................180
9.5 Category strength: ranking *REPLACE by markedness ......................................................................180
9.6 Information ..........................................................................................................................................184
9.7 Binary features .....................................................................................................................................185
9.8 Correspondence strategy for binary features .......................................................................................186
9.9 Privative features .................................................................................................................................189
9.10 Ranking by specificity .......................................................................................................................192
9.11 Simultaneity constraints ....................................................................................................................193
9.12 Precedence constraints .......................................................................................................................194
9.13 Alignment constraints ........................................................................................................................196
9.14 Global or local ranking of faithfulness constraints? ..........................................................................201
9.15 Conclusion .........................................................................................................................................201
CONTENTS v
10. ACOUSTICAL FAITHFULNESS ........................................................................................................203
10.1 Interaction between articulation and perception ................................................................................203
10.1.1 Inherent conflicts ...................................................................................................................205
10.1.2 No interaction constraints .....................................................................................................206
10.2 Constraints for vowel height ..............................................................................................................206
10.2.1 Specification: perceptual constraints .....................................................................................206
10.2.2 Articulatory constraints .........................................................................................................207
10.3 Articulation-to-perception transformation .........................................................................................208
10.4 Interaction of articulatory and perceptual constraints .......................................................................208
10.5 Shifting the working point .................................................................................................................210
10.5.1 Dependence on stress ............................................................................................................210
10.5.2 Dependence on surrounding consonants ...............................................................................212
10.5.3 Dependence on duration ........................................................................................................212
10.5.4 Dependence on inventory size ..............................................................................................213
10.5.5 Comparison to other models .................................................................................................214
10.5.6 Lexical vowel reduction ........................................................................................................214
10.6 Typologies of vowel systems ............................................................................................................215
10.7 Conclusion .........................................................................................................................................216
11. TYPOLOGY AND THE LOCAL-RANKING HYPOTHESIS ............................................................217
11.1 Freedom of ranking ............................................................................................................................218
11.2 Combinatorial typology .....................................................................................................................219
11.3 Implicational universals .....................................................................................................................220
11.4 Case: place assimilation of nasal stops ..............................................................................................220
11.5 Optionality .........................................................................................................................................222
11.6 Problems with surface constraints .....................................................................................................222
11.7 Typology of place assimilation of nasals ..........................................................................................223
11.8 Perceptual versus acoustic faithfulness .............................................................................................225
11.9 Constraint generalization ...................................................................................................................226
11.10 Phonologization ...............................................................................................................................228
11.11 Homogeneous *GESTURE or homogeneous PARSE? .....................................................................232
11.12 Licensing ..........................................................................................................................................234
11.13 Assimilation of nasality ...................................................................................................................235
11.14 Conclusion .......................................................................................................................................236
12. CORRESPONDENCE: .........................................................................................................................237
12.1 Is perception segmental? ....................................................................................................................238
12.2 OCP-driven epenthesis ......................................................................................................................239
12.3 Horizontal and vertical correspondence ............................................................................................241
12.4 Floating features ................................................................................................................................247
12.5 Fusion ................................................................................................................................................249
12.6 Phonetic substance of epenthesis .......................................................................................................251
12.7 Subsegmental satisfaction by segmental deletion ..............................................................................251
12.8 Conclusion .........................................................................................................................................255
13. DEGREES OF SPECIFICATION ........................................................................................................257
13.1 Different feature systems for inventories and rules ...........................................................................257
13.2 Redundant features ............................................................................................................................258
13.3 Weak features ....................................................................................................................................262
13.4 The lexicon ........................................................................................................................................263
13.5 Optionality and stylistic variation ......................................................................................................265
13.6 Privative features ...............................................................................................................................265
13.7 “Trivial” underspecification ..............................................................................................................265
13.8 Invisible specifications ......................................................................................................................265
13.9 Conclusion .........................................................................................................................................266
vi CONTENTS
PART III: GRAMMAR ............................................................................................................................267
14. LEARNING A PRODUCTION GRAMMAR ......................................................................................269
14.1 Grammar model .................................................................................................................................269
14.2 Learning in functional phonology .....................................................................................................271
14.2.1 The grammar .........................................................................................................................271
14.2.2 Gradual learning algorithms ..................................................................................................273
14.2.3 Three production modes ........................................................................................................274
14.2.4 Stage 1: an empty grammar ..................................................................................................275
14.2.5 Step 1: perceptual categorization and faithfulness constraints .............................................276
14.2.6 Stage 2: violated faithfulness ................................................................................................279
14.2.7 Step 2: sensorimotor learning ...............................................................................................279
14.2.8 Stage 3: faithful imitation .....................................................................................................281
14.2.9 Step 3: the learning curve ......................................................................................................282
14.2.10 Stage 4: faithfulness outranks gestural constraints .............................................................287
14.2.11 Step 4: sentence-level phonology .......................................................................................288
14.2.12 Stage 5: alternating levels of constraints ............................................................................290
14.2.13 Step 5: emergence of underlying forms ..............................................................................291
14.2.14 Stage 6: the adult phase .......................................................................................................291
14.2.15 Second-language acquisition ..............................................................................................292
14.2.16 Acoustic versus linguistic faithfulness ................................................................................292
14.2.17 Puzzles ................................................................................................................................293
14.3 Example: acquisition of tongue-root harmony ..................................................................................294
14.3.1 Universal ranking of articulatory constraints ........................................................................296
14.3.2 Universal ranking of faithfulness constraints ........................................................................297
14.3.3 Typology of tongue-root systems .........................................................................................298
14.3.4 The learning process for continuous families .......................................................................300
14.3.5 The learning of simplified Wolof ..........................................................................................301
14.3.6 An alternative Wolof: articulatory versus perceptual candidates .........................................306
14.3.7 Wolof with schwa licensing ..................................................................................................307
14.3.8 Learning unnatural local rankings ........................................................................................308
14.3.9 Real Wolof ............................................................................................................................309
14.4 Principles-and-parameters learning algorithms .................................................................................310
14.4.1 Seven possible tongue-root-harmony systems ......................................................................310
14.4.2 The Triggering Learning Algorithm .....................................................................................311
14.4.3 The subset problem ...............................................................................................................312
14.4.4 Intermezzo: the correct P&P convergence criterion .............................................................316
14.4.5 Local maxima ........................................................................................................................318
14.4.6 Relaxing conservatism or greediness ....................................................................................318
14.4.7 Genetic algorithms ................................................................................................................319
14.4.8 TLA versus GLA ..................................................................................................................319
14.5 Optimality-theoretic learning ............................................................................................................320
14.5.1 The initial state in an Optimality-theoretic grammar ............................................................320
14.5.2 Innateness ..............................................................................................................................321
14.6 Algorithm ..........................................................................................................................................322
14.7 Proof of learnability ...........................................................................................................................323
14.8 Acquisition time ................................................................................................................................327
14.9 Conclusion .........................................................................................................................................328
15. HOW WE LEARN VARIATION, OPTIONALITY, AND PROBABILITY ......................................329
15.1 Continuous ranking scale and stochastic disharmony .......................................................................330
15.2 Learning optionality in production ....................................................................................................332
15.2.1 Learning that faithfulness can be violated in an adult grammar ...........................................332
15.2.2 The minimal gradual learning step: demoting the offender ..................................................333
15.2.3 A remedy for downdrift: symmetric demotion and promotion .............................................334