Gestural overlap and selforganizing phonological contrasts Alexei Kochetov

Gestural overlap and self-organizing phonological contrasts Alexei Kochetov Haskins Laboratories/ Yale University Contrast in Phonology, University of Toronto May 3 -5, 2002

Thanks to • The Project on Contrast in Phonology – SSHRC grants (410 -99 -1309 and 410 -96 -0842) to Elan Dresher and Keren Rice, University of Toronto – http: //www. chass. utoronto. ca/~contrast

Introduction • Restrictions on phonological contrasts – Backness and rounding in high vowels – Secondary articulations in consonants • Account: – These markedness effects emerge from lowlevel speaker-listener/learner interactions – The crucial role of production and perception of contrasts

Phonological contrasts • Focus: – Contrasts in high vowels • Front/back, rounded/unrounded • Inventories /i y u/, /i y u/, or /i u/ – Contrasts in consonant secondary articulations • Palatalized vs. non-palatalized: /C C( /w)/ • Labialized vs. non-labialized: /Cw C(w/ )/ • Velarized vs. non-velarized: /C C( )/

Observations • UPSID Database (Maddieson & Precoda 1990) – 451 languages

Observations • Languages with multiple vowel contrasts avoid distinctions in secondary consonant articulations – e. g. /y/ but */Cj/ (C = plosive; 2 exceptions)

Observations • Languages with distinctive secondary articulation contrasts tend to avoid multiple vowel contrasts, particularly distinctions in rounding/backness – e. g. /Cw/ but */y/ (C = plosive; 1 exception)

Observations • Inventories of languages of Northern and Eastern Europe – 37 languages (Celtic, Germanic, Baltic, Uralic and Turkic)

Observations Faroese Saami Icelandic Nenets Karelian Mari Mordva Chuvash Tatar Bashkir

Question • Why are these contrasts incompatible? ?

Explanation • Approach 1 – These markedness effects are pre-specified in Universal Grammar • Harmonic rankings of constraints (Optimality Theory; Prince & Smolensky 1993) • Phonological representations

Explanation • Approach 2 – These markedness effects arise due to lowerlevel factors -- limitations on production and perception – Work in phonology and phonetics: • Browman & Goldstein 1986, 2002; Ohala 1981; Hume & Johnson 2001, Pierrehumbert, Beckman, & Ladd 2001, among others • Cf. Jackendoff 2002 on markedness in general

Explanation • Approach 2 – These markedness effects arise due to lowerlevel factors -- limitations on production and perception – Work in phonology and phonetics: • Browman & Goldstein 1986, 2002; Ohala 1981; Hume & Johnson 2001, Pierrehumbert, Beckman, & Ladd 2001, among others • Cf. Jackendoff 2002 on markedness in general

Explanation • Approach 2 – Self-organization, or spontaneous emergence of order (see e. g. , Kauffman 1995) • dynamic systems • AI and ALife (see e. g. , Pfeifer & Scheier 2001)

Self-organization Simple local interaction Spontaneous emergence of order From www. swarm. org

Self-organization and phonology Phonological structure Speaker-listener interactions

Self-organization and phonology • Markedness effects • Unmarked: – stable with respect to production and/or perception, and/or higher-level processing – An equilibrium position • Marked: – unstable with respect to production, and/or perception, and/or higher-level processing – A non-equilibrium position

Simulation • Speaker-listener/learner interactions • Autonomous agents – Cf. Browman & Goldstein 1999, de Boer 2000, Lieberman 2000, Harrison, Dras & Kapicioglu 2002

A hypothetical language • Language X • Inventory: – {i y u} – {C C } • Lexicon: – C 1 VC 2 words, where C 1= C 2 – 16 items

Language X Lexical items

Speaker-listener interactions Agent A * From www. zabaware. com * Agent B

Speaker-listener interactions Agent A Agent B

Speaker-listener interactions Agent A Agent B

Speaker-listener interactions Agent A Agent B

Speaker-listener interactions Agent A Agent B

Speaker-listener interactions Agent A Agent B

Speaker-listener interactions Agent A Agent B

Speaker-listener interactions Agent A Agent B

Speaker-listener interactions Agent A Agent B

Speaker-listener interactions Agent A Agent B

Speaker-listener interactions Agent A Agent B

Speaker-listener interactions Agent A Agent B

Speaker-listener interactions Agent A Agent B

Production • Articulatory synthesizer (Maeda 1989, Vallée 1994) • Articulatory gestures (targets) • Vectors of numbers between 0 and 1 – Backness – Height – Rounding [0. . . 1]

Production • Rounding [1]

Production • Rounding [0. 75]

Production • Rounding [0. 5]

Production • Rounding [0. 25]

Production • Rounding [0]

Production • Vowels • • i Backness = [ 0 Height 1 Rounding 0 ]

Production • Vowels • Backness • y = [ 0 Height 1 Rounding 1 ]

Production • Consonants (secondary articulation) • Backness Height Rounding • C = [ 0 1 0 ]

Production • Consonants (secondary articulation) • Backness Height Rounding • C = [ 0 1 1 ]

Production • Words – Matrices of numbers between 0 and 1 e. g. , C u. C C 0 1 0 u 1 1 1 C 0 1 0

Production • Words: sequences of gestures overlapping in time C V C

Production: Gestural overlap • Gestures have conflicting targets • Physical limits on how well targets can be attained • An “undershoot” of at least one of the gestures (Lindblom 1963) • Stiffness (GEST, Computational gestural model; Browman & Goldstein 1990)

Production: Gestural overlap • Stiffness, k. C = 1, k. V = 1; • No reduction; physically impossible C V C

Production: Gestural overlap • Stiffness, k. C = 1, k. V = 0. 75 • Vowel gesture is reduced C V C

Production: Gestural overlap • Evidence: – In languages with secondary articulation vowels are strongly affected by the secondary articulation quality of neighboring consonants – Russian (Bolla 1981, Kochetov 2001) – Irish (Ó Dochartaigh 1992 ) – Marshallese (Choi 1992)

Production: Gestural overlap • Stiffness, k. C = 0. 75, k. V = 1 • Consonant gestures (secondary articulation) are reduced C V C

Production: Gestural overlap • Evidence: – In languages with multiple backness and rounding contrasts consonants are often allophonically palatalized and velarized/labialized – Turkic languages (Comrie 1981)

Simulation • Item: C u. C • Case 1: Vowel gesture is reduced – k. C = 1, k. V = 0. 5 • Case 2: Consonant gestures are reduced – k. C = 0. 5, k. V = 1

Case 1 • k. C = 1, k. V =. 5 • Input: C u. C • Output: C C or C y. C

Case 2 • k. C = 0. 5, k. V = 1 • Input: C u. C • Output: C u. C or C u. C

Case 1: Lexicon and grammar Agent A

Case 1: Lexicon and grammar Agent B

Case 1: Lexicon and grammar Agent B

Case 1: Lexicon and grammar Agent B

Case 1: Lexicon and grammar • Default grammar 1: – limited vowel contrasts (front vs. back) – multiple consonant contrasts in secondary articulation (restricted in distribution)

Case 2: Lexicon and grammar Agent A

Case 1: Lexicon and grammar Agent B

Case 2: Lexicon and grammar Agent B

Case 2: Lexicon and grammar Agent B

Lexicon and grammar • Default grammar 2: – multiple vowel contrasts (restricted in distribution) – limited consonant contrasts in secondary articulation (front vs. back) – consonants realizations are often close to neutral (non-palatalized, non-labialized, etc. )

Lexicon and grammar • Grammar 0: • Grammar 1: • Grammar 2: unstable more stable

Lexicon and grammar • Default grammar 3: – limited vowel contrasts – limited consonant contrasts in secondary articulation

Conclusion • The incompatibility of vowel and secondary articulation contrasts emerges through speaker-listener/learner interactions – Unstable (marked) Stable (unmarked) • No reference to pre-specified “knowledge” of markedness

Limitations • The simulation does not explain certain segmental markedness effects – e. g. – /y/ is more marked than /i/ / / is more marked than /u/ • Markedness is a by-product of multiple factors

Further directions • Implementation: additional factors – Other sequences, primary place of articulation – More realistic production and perception – More complex generalizations across the Lexicon and Grammar – Higher-level processing: morphological structure and alternations – Multiple agents: speakers/listeners • Other phonological contrasts

Further directions • Towards a better understanding of the phonological Grammar and markedness END