Acoustic effects of speaking rate changes in articulatory models

Abstract

Speaking rate effects on articulatory phasing, velocity, and magnitude have been reported in the speech-kinematic literature. Yet little is known about the acoustic consequences of manipulating these dimensions. Using an articulatory modeling method developed by Milenkovic, simulations of the acoustic effects of changes in articulatory phasing, velocity, and magnitude have been explored. Articulatory models have been optimized for speakers from the University of Wisconsin X-Ray Microbeam Speech Production Database. Preliminary work has revealed that models of rate change which use only a single dimension (e.g., phasing) may reveal less plausible acoustic solutions than models involving multiple dimensions. Using sample productions of ‘‘a boy’’ to determine articulatory parameter time histories, the acoustic consequences of rate change simulations have been described by the F2 value at onset (F2on), the maximum F2 value (F2tar), and the shape of the F2 trajectory throughout the diphthong. Speaking rate models that combine velocity and phase changes to articulatory parameters result in a reduction in the magnitude of the F2on effect, near elimination of any effect on F2tar, and a relative increase in the homogeneity of the F2 trajectory shapes across speaking rates when compared with phase-only models. [Work supported by NIH (NIDCD) P60 DC1409-10.]