Mathematical Models for Speech Technology

284 Pages·2005·1.603 MB·English

by  Stephen Levinson

Mathematical Models
for Speech Technology
Stephen E. Levinson
UniversityofIllinois atUrbana-Champaign,USA

Mathematical Models
for Speech Technology

Mathematical Models
for Speech Technology
Stephen E. Levinson
UniversityofIllinois atUrbana-Champaign,USA
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LibraryofCongressCataloging-in-PublicationData
Levinson,StephenC.
Mathematicalmodelsforspeechtechnology/StephenLevinson.
p.cm.
Includesbibliographicalreferencesandindex.
ISBN0-470-84407-8(cloth)
1.Speechprocessingsystems.2.Computationallinguistics.3.Applied
linguistics–Mathematics.4.Stochasticprocesses.5.Knowledge,Theory
of.I.Title.
TK7882.S65L482005
006.4(cid:1)54(cid:1)015118–dc22
2004026215
BritishLibraryCataloguinginPublicationData
AcataloguerecordforthisbookisavailablefromtheBritishLibrary
ISBN0-470-84407-8
Typesetin10/12TimesbyLaserwordsPrivateLimited,Chennai,India
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To my parents
Doris R. Levinson
and
Benjamin A. Levinson

Contents
Preface xi
1 Introduction 1
1.1 Milestones in the history of speech technology 1
1.2 Prospects for the future 3
1.3 Technical synopsis 4
2 Preliminaries 9
2.1 The physics of speech production 9
2.1.1 The human vocalapparatus 9
2.1.2 Boundary conditions 14
2.1.3 Non-stationarity 16
2.1.4 Fluid dynamicaleffects 16
2.2 The source–filter model 17
2.3 Information-bearing features of the speech signal 17
2.3.1 Fourier methods 19
2.3.2 Linear prediction andthe Websterequation 21
2.4 Time–frequency representations 23
2.5 Classification of acoustic patterns in speech 27
2.5.1 Statistical decisiontheory 28
2.5.2 Estimation of class-conditional probability density functions 30
2.5.3 Information-preserving transformations 39
2.5.4 Unsupervised density estimation –quantization 42
2.5.5 A note on connectionism 43
2.6 Temporal invariance and stationarity 44
2.6.1 A variational problem 45
2.6.2 A solution by dynamic programming 47
2.7 Taxonomy of linguistic structure 51
2.7.1 Acoustic phonetics, phonology, and phonotactics 52
2.7.2 Morphology and lexicalstructure 55
2.7.3 Prosody, syntax, and semantics 55
2.7.4 Pragmatics anddialog 56