The acoustic consequences of time-dependent changes of the vocal tract shape

Abstract

During singing or speech production, the human vocal tract is a nearly continuously changing conduit through which sound propagates. As the vocal tract shape changes, its resonance frequencies also continuously vary, shaping an excitation signal into a sequence of vowels and consonants. This presentation will focus on modeling the time-dependent movements of the vocal tract shape and their acoustic consequences. Based on data collected with MRI and x-ray microbeam techniques, a kinematic model of the vocal tract area function has been developed that allows for efficient specification of time-dependent cross-sectional area changes in an acoustic waveguide. When coupled with a voice source, the result is a basic simulation of the sound production process from which pressures and airflows are generated. The components of the model will be presented and then used to demonstrate some time-dependent relations between the vocal tract shape and resulting acoustic characteristics. [Work supported by NIH R01-DC04789.]