Development of A Formant-Based Analysis-Synthesis System and generation of High Quality Liquid Sounds of Japanese

摘要

Although flexible control fo acoustic features is possible in formant-based speech synthesizers, their development requires precise estimation of parameters related to vocal tract and soruce. This requirement is difficult to satisfy and often results in limiting quality of the synthesized speech. The difficulty is derived from the fact that estimation of the parameters is a non-linear problem. Therefore, the completely automatic estimation of the parameters is quite difficult and some approxiamtions or manual modifications of parameters with a priori knowledge are required in the development. In this study, mainly to make the estimation more efficient and/or to assist developers doping the manual modifications of parameters, a formant-based analysis-synthesis system is build. The system introudces pitch-synchronous acoustic analysis to reduce fluctuation of the estimated parameters. Experiments show that quality of synthetic speech fo Japanese /r/ sound is significantly improved by uisng the proposed system.