| 摘要 |
<p>Foe executing the code excitation linear prediction (CELP) coding, for example, alpha -parameters are taken out from the input speech signal by a linear prediction coding (LPC) analysis circuit 12. The alpha -parameters are then converted by an alpha -parameter to LSP converting circuit 13 into linear spectral pair (LSP) parameters and a vector of these line spectral pair (LSP) parameters is vector-quantized by a quantizer 14. The changeover switch 16 is controlled depending upon the pitch value detected by a pitch detection circuit 22 for selecting and using one of the codebook 15M for male voice and the codebook 15F for female voice for improving quantization characteristics without increasing the transmission bit rate. <IMAGE></p> |
