Abstract
This paper presents a method to calculate the acoustic characteristics of three-dimensional vocal-tract models. A cascaded structure of rectangular acoustic tubes, connected asymmetrically with respect to their axes, is introduced as an approximation of the real vocal-tract geometry. Computation of the acoustic field in the models are performed using higher-order modes. A small change of the vocal-tract shape is regarded as a geometrical perturbation of the axis position of each vocal-tract section. The computational results of sound pressure distributions and
transfer characteristics for a large number of vocal-tract models are also presented. The results indicate that acoustic characteristics in the higher frequencies are highly sensitive to the small change of the vocal-tract shape.
