| This study claims that the basis of syllable structure can be found in the intrinsic stable modes of a system of coupled oscillators that control intergestural timing in speech: in-phase and anti-phase defining C-V and V-C, respectively. We propose a gestural coupling model where a planning oscillator acts as an underlying control clock in each gesture, and higher-order structures (i.e. syllables, words, phrases, etc) can be developed by a network of inter-oscillator coupling, coupling graph. Differences in coupling graph structures are hypothesized to be part of the phonological knowledge of particular word forms. In addition, the model provides a principled way of explicitly representing of temporal properties of phonetic units (gestures). The thesis illustrates the theoretical advantages of this model. First, we describe how the differences in intergestural timing can potentially be derived from various topologies of a coupling graph. Further, we show that intergestural timing can be understood within graph theory by employing a quantitative index of network connectivity. The inter-oscillator variability in the network can be captured as a function of graphical connectivity. Consequently, connectivity is shown to correlate strongly and nonlinearly with inter-oscillator variability across a range of graph topologies. Second, distinct coupling graphs for CV (in-phase) and VC (anti-phase) are tested within the coupling model that captures both qualitative and quantitative properties of sound patterns. Simulations show that the structural differences correctly predict differences in the mean and variability of intergestural timing patterns in the empirical data. Third, this approach provides a rationale, grounded in dynamic systems theory, for the acquisition preference of CV. We simulate the self-organization of syllable structure in phonological development using the coupling model and the Hebbian learning model. The differences in coordination between CV and VC can predict the two contradictory asymmetries in the acquisition of syllable structures: CV precedes VC but CCV follows VCC. Finally, intergestural coordination patterns can be incorporated as phonological constraints into OT grammar to account for language-particular syllable structure inventories and alternations. Analysis using the constraints predicts the syllable-final patterns by their factorial possibilities, accounts for phonological processes in each final type of language, and facilitates the understanding of unique geminate properties. |
