| 摘要 |
PURPOSE:To realize the excellent reproduction of a voice with a small arithmetic quantity by representing the sound source signal of the voice signal in a frame section by using multipulses which are found by pitch prediction and multipulse which are found without the pitch prediction. CONSTITUTION:Pulses in one subframe section are found by the pitch prediction to represent pulses having high periodicity of each pitch efficiently and the multipulses are found without the pitch prediction to find pulses with not so high correlation of each pitch. Consequently, tone quality can be improved greatly at the part where the periodicity becomes slightly low like a vowel transition part and a transient part as compared with a conventional method which finds all the pulses by using the pitch prediction. Further, the arithmetic quantity required to search for the pitch-predicted multipulses can be reduced by finding some of the multipulses by the pitch prediction, so the arithmetic quantity is reducible. |
