Coding Method of LSP Residual Signals Using Wavelets for Speech Synthesis
Tadaaki Shimizu, Masaya Kimoto, Hiroki Yoshimura, Naoki Isu, Kazuhiro Sugata · IEEJ Transactions on Electronics Information and Systems · 2003
This paper presents a method to use wavelet analysis for speech coding and synthesis by rule. It is a coding system where LSP residual signal is transformed into wavelet coefficients. As wavelet analysis is implemented effectively by filter banks, our method is featured to require less computation than multipulse coding and others where complicated prediction procedures are essential. To achieve good quality speech at low bit rates, we verified to allocate the different bits onto the wavelet coefficients, with more bits in lower frequencies, and less in higher. The synthesized speech by Haar wavelet with 16.538kbits/s has nearly same perceptual quality with 6 bits μlog PCM (66.15kbits/s). We are convinced that coding method of LSP residual signals using wavelet analysis is an effective approach to synthesize speech.