Computation of the acoustic characteristics of simpli. ed vocal-tract models by 3-D finite element method

The acoustic characteristics of vocal-tract models are investigated using a three-dimensional. nite element method. Several. nite element models are created in order to examine the in.uence of the simplication of the vocal-tract shapes on the. ner acoustic characteristics up to the higher frequencies of around 8 kHz. The simpli. cation takes into account the following aspects: cross-sectional shape, bend, branches of the pyriform fossa and the valleculla, and lip protrusion. The effects of the yielding vocal-tract wall are also studied. The results indicate that with the frequency range up to around the third formant, the simpti. cation of the cross section and the bend is considered to be an effective approximation. It is shown that the use of soft walls suppresses the appearance of sharp peaks and zeros in the frequencies above 3 kHz It is suggested that the lips and the branches independently affect the shifts of the. rst three formant frequencies.