Abstract:

Previous work from our laboratory has suggested that certain acoustic measures may serve as indices of the extent of overlap for successive articulatory gestures. These experiments have employed speaking-rate variation as a means to vary the extent of articulatory gesture overlap, in a number of different syllable types. Explicit models have been used to predict how rate-induced variation in gesture overlap would be realized in the acoustic output of the vocal tract. Specifically, the F2 onset and offset values at CV and VC interfaces, respectively, where C and V are constant, have been shown to be sensitive to the rate variable, sometimes approaching the magnitude of variation associated with CV syllables where C is constant and V is varied (i.e., the classic vowel-induced coarticulation paradigm). However, the results to date appear to be dependent on specific syllables, but the reasons for this specificity are unknown. In the present study, some systematic analyses of vowel effects on the acoustic model of gesture overlap are presented. Results will be discussed in terms of the goodness of the model and theories of coarticulation.