Conclusions

Possibilities for future investigation/development include the refinement and expansion of the Tcl/Tk GUI allowing users to experiment with formant-filter-based vowel sounds, the use of higher-order filters to simulate the radiation of the lips and nose in Cook's vocal tract model, and the further investigation of noise sources in Cook's vocal tract model. Each of the vowel synthesis schemes examined in this paper could probably benefit from the incorporation of slowly-varying random-walk-like processes to give a more ``life-like'' quality to the sounds.