Formant Deflection Directions of the Voiced Alveolar Stop Consonant in Different Vowel Contexts

Abstract

A parametric model of the vocal tract area function was used to synthesize a series of alveolar stop consonant constrictions imposed on nine /VV/ transitions (e.g., /idae/). The constrictions differed in spatial characteristics, places of occurrence along the vocal tract length, and the onset and release times to create different onglide and offglide formant deflection patterns. It was hypothesized that the formant deflection directions caused by the onset and release of the consonant constriction relative to the underlying vowel-to-vowel formant transitions (i.e., without consonant perturbations) provide information about the perceptual identity of the alveolar stop. Perceptual tests were conducted to assess the phonemic identities of the formant patterns produced by the model. The model parameter settings used to create the consonant constrictions that were perceived as /d/'s were analyzed to study the coarticulation between /d/ and different vowel contexts.