A fundamental problem in understanding speech production is how the temporal coherence of the speech units associated with a given lexical unit is maintained despite changes due to speaking rate, prosodic embedding, and transient perturbations. To address this, a dynamical model of temporal planning of speech has been developed (Nam & Saltzman, 2003; Goldstein et al, 2006; Nam, in press). In this model, each speech unit (constriction gesture) is associated with a planning oscillator, or clock, and the oscillators within the ensemble associated with a particular lexical item are coupled to one another in a pattern represented as a coupling graph.

I will introduce this model and show how it is possible to account for syllable structure in terms of intrinsic modes of coupling that require no learning . Onset consonant gestures are hypothesized to be coupled in-phase to the tautosyllabic vowel gesture (regardless of how many consonants there are in an onset), while coda consonant gestures are coupled in an anti-phase pattern. This hypothesis can account for the universality of CV syllables, the relatively free combinatoriality that onsets and rimes typically exhibit in languages, and the seemingly paradoxical finding that single consonants are acquired by children earlier in onset than coda, but consonant clusters are acquired earlier in coda than in onset. In addition, the topology of the coupling graph can account simultaneously for regularities in relative timing and the patterns of stochastic variability that they exhibit.

References

Goldstein, L., Byrd, D., and Saltzman, E. (2006) The role of vocal tract gestural action units in understanding the evolution of phonology. In M. Arbib (Ed.) From Action to Language: The Mirror Neuron System. Cambridge: Cambridge University Press. pp. 215-249.

Nam, H. (in press). A competitive, coupled oscillator model of moraic structure: Split-gesture dynamics focusing on positional asymmetry. In Cole, J. and Hualde, J. (eds). Papers in Laboratory phonology 9. Berlin: Mouton deGruyter.

Nam, H. and Saltzman, E. 2003. A Competitive, Coupled Oscillator Model of Syllable Structure. Proceeding 15th ICPhS 2003, Barcelona, 2253-2256.