Towards an articulatory model of tone: a cross-linguistic investigation

Abstract

This thesis examines the role of timing information in phonological representation, focusing on how tone aligns with segmental material. On the basis of three acoustic studies, I present a novel gestural model of tone representation, where tone gestures are durationally underspecified and receive their timing information from the constellation of segmental gestures they are coordinated with. I also argue that the distributional and temporal characteristics of tone are the direct result of gestural coordination: phonological association can be analyzed as the existence of coordinative relationships between a tone gesture and a constellation of segmental gestures, and the precise nature of that coordinative relationship produces the cross-linguistically variable acoustics. Chapter 1 delineates two major approaches to tone representation: Autosegmental(-Metrical), which references point-like features and nominal time, and Articulatory Phonology, which uses gestures that unfold over time and space. I discuss the different ways in which each theory arrives at phonetic realization from underlying representation, as well as their differing notions of overlap. Chapter 2 presents the results of an acoustic study on contour tones in Thai (Tai-Kadai), a tone language where the mora serves as a licensing unit for tone. Counter previous hypotheses, tonal extrema do not map to moraic edges: both moraic edges and tone extrema instead independently refer to the syllable as a unit of timing. Based on these results, I argue that the apparent acoustic mismatches can be straightforwardly derived from the application of different coordinative modes between tonal and segmental gestures, while maintaining the phonological licensing relationship between moras and tones. The data also suggests that the F0 targets of tone gestures play a role in tone timing, indicating that there is an interaction between the tone gesture and segmental gestures when determining duration. Chapter 3 presents the results of an acoustic study focused on the realization of the falling accent in the Belgrade and Valjevo dialects of Serbian (Indo-European---Slavic), a tone language where one syllable per word is specified for tone. I compare the alignment and duration of pitch excursions across varying phonetic and phonological properties of the syllable onset of the tone-bearing syllable. I show that the duration of pitch excursions increases with phonetically longer syllable onsets, which indicates that tone gestures are durationally underspecified and receive their timing information from the constellation of segmental gestures they are coordinated with. The two dialects also exhibit distinct patterns of both the duration and the alignment of the pitch excursion, and I argue that this is due to differences in the type of coordination used. Chapter 4 focuses on the rising accents of the same dialects of Serbian, crucially examining the Valjevo dialect, which routinely retracts the pitch peak into the syllable preceding the H-bearing syllable. Despite this phonetic retraction, the patterns of alignment parallel those observed for the falling accent. This indicates that the tone gesture is still receiving timing information from the H-bearing syllable, and as such is still coordinated to it. Based on these results, I argue for the availability of gestural target coordination, in addition to gestural onset coordination. In Chapter 5 I synthesize the findings from the experimental chapters to present a gestural model of tone representation, and discuss its implications for Articulatory Phonology and avenues for future research.