| 摘要 |
PURPOSE:To transmit the waveforms with a relatively small information quantity and to improve the sound quality which is like the buzzer sound specific to a VOCODER system and lacks personality and naturalness by using optimum sound source vectors to form the sound source waveforms within an analysis frame and forming synthetic waves. CONSTITUTION:A representative sound source forming circuit 8 segments the representative sound source waveforms 2b of a pitch period length from the predicted residual waveforms 2a within the analysis frame of the specified length of the vocal voices. Sound source selecting circuits 10, 11 select the optimum sound source vectors to obtain the synthesized waveform synthesized from this representative sound source by using the envelope parameter of the above-mentioned frame and the synthesized waveform of the smallest waveform distortion from the sound source vector groups in code note memories 9, 18. A sound source forming circuit 19 forms the sound source waveforms 2d by arraying the optimum sound source vectors at every pitch period within the above-mentioned analysis frame. Synthesizing filter circuits 10, 11, 22 and driven by the predicted residual signal 2a, by which the efficient transmission of the predicted residual signal is executed. The synthetic sounds of good quality are efficiently synthesized in this way with the relatively small transmission information quantity and the synthetic sounds which are natural and have the ample personality is obtd. |
