| 摘要 |
PROBLEM TO BE SOLVED: To apply satisfactory coding to various voice configurations by using the code vector clipped with Gaussian random noises at multiple different threshold values for a code book for vector quantization. SOLUTION: The noise output corresponding to the LPC residue is fed to a weighted synthetic filter 122 from the noise code book 121 of the second coding section 120 via a gain circuit. The inputted noises are LPC-synthesized, and the obtained signal is fed to a subtracter 123. The error with the signal weighted by an acoustic sense weighting filter 125 is extracted, a distance calculation is made by a distance calculating circuit 124, and the central value vector minimizing the error is searched by the noise code book 121. The code vector clipped with Gaussian random noises at multiple different threshold values is used for the code book for the vector quantization of the time base wave- form. |
