Synthesis of Voiced Sound with a One-Dimensional Unsteady Glottal Flow Model

Abstract

A one-dimensional glottal flow model is presented to shed light upon the mechanism of speech production, from a mechanical point of view. The vocal cords are modeled by a pair of membranes supported by nonlinear springs. The equation of the vocal cord is coupled with those of incompressible separated flow through the glottis and compressible flow in the vocal tract. Numerical results show that the glottal source-vocal tract interaction induces high-frequency components in flow rate and pressure because of acoustic resonance. The synthesized sound of the vowels depending on the vocal tract shape agrees qualitatively in waveform with that of measured human voice. The effect of pulmonary pressure and stiffness of the vocal cord on the fundamental frequency of the vocal cord vibration is examined.