Speech analysis‐synthesis system and quality of synthesized speech using mel‐cepstrum
Tadashi Kitamura, Satoshi Imai, Chieko Furuichi, Takao Kobayashi · Electronics and Communications in Japan (Part I Communications) · 1986
Abstract The quality of synthesized speech in the speech analysis‐synthesis system based on the mel‐cepstrum method is described. Mel‐cepstrum is defined as the Fourier coefficients of the log spectrum on a nonlinear frequency scale approximating the mel scale. The true mel‐log spectral envelope is estimated in this system by an improved cepstral method in the analysis part and a mel‐log spectrum approximating filter is used in the synthesis part. The preference score by pair comparison tests is used for subjective evaluation and spectral distortion on a nonlinear frequency scale is used for an objective evaluation. Using this system, 1.7 kbit/s, high‐quality synthesized speech is obtained.