Third International Conference on Spoken Language Processing (ICSLP 94)

Yokohama, Japan
September 18-22, 1994

Flow Theory for Analysis of Phonation with a Membrane Model of Vocal Cord

Tadashige Ikeda (1), Yuji Matsuzaki (2)

(1) Fluid Engineering Division, Mechanical Engineering Laboratory, AIST, MITI, Tsukuba, Japan
(2) Department of Aerospace Engineering, Nagoya University, Nagoya, Japan

A membrane model of the vocal cord is presented to shed light upon the mechanism of phonation from a mechanical point of view. The vocal cords are modeled by a pair of membranes supported by external distributed dampers and nonlinear springs, which represent the viscoelasticity of the vocal cord. A one-dimensional unsteady separated flow theory is proposed and is applied to the flow through the trachea, the bronchi, the glottis, and the false glottis. The theory successfully represents flow separation and reattachment with sufficient accuracy. Then, the flow in the vocal tract is represented by a one-dimensional compressible flow theory, which can include resonance. The equation of motion for the vocal cord is coupled with the governing equations of the flow. When voiced sound is evaluated numerically, the waveforms of pressure at the sub- and the supra-glottis agree qualitatively with data measured during phonation. Therefore, the present model is suitable for understanding of the mechanical phenomena of phonation.

Full Paper

Bibliographic reference.  Ikeda, Tadashige / Matsuzaki, Yuji (1994): "Flow theory for analysis of phonation with a membrane model of vocal cord", In ICSLP-1994, 643-647.