Third International Conference on Spoken Language Processing (ICSLP 94)

Yokohama, Japan
September 18-22, 1994

3D FEM Analysis of Vocal Tract Model of Elliptic Tube with Inhomogeneous-Wall Impedance

Hiroki Matsuzaki (1), Nobuhiro Miki (1), Nobuo Nagai (2), Tohru Hirohku (3), Yoshihiko Ogawa (1)

(1) Faculty of Engineering, Hokkaido University, Sapporo-shi, Japan
(2) Research Institute for Electronic Science, Hokkaido University, Sapporo-shi, Japan
(3) Faculty of Business Administration and Information Science, Hokkaido Information University, Ebetsu-shi, Japan

Acoustic characteristics of sound tubes as a simplified model of vocal tracts are simulated by a three dimensional Finite Element Method(3D FEM). The results suggest some new facts as follows; if the area of the wall impedance distribution is spread or the cross section is flattened more, then the formant band widths are increase more, and the amplitude of sound pressure is decreased near formant frequencies. The sound wave propagates as a non-plane wave along the soft wall, and the inhomogeneous distribution causes distortion of surface wavefront. The pressure ampletude in the bent tube is reduced along the direction from the driving surface to the radiational surface. Moreover, as the effect of radiation, the sound wave is a non-plane wave at the radiational part.

Full Paper

Bibliographic reference.  Matsuzaki, Hiroki / Miki, Nobuhiro / Nagai, Nobuo / Hirohku, Tohru / Ogawa, Yoshihiko (1994): "3d FEM analysis of vocal tract model of elliptic tube with inhomogeneous-wall impedance", In ICSLP-1994, 635-638.