| 摘要 |
PROBLEM TO BE SOLVED: To actualize the more efficient quantization of the voice waveform in a voiceless section as to linear predictive encoding using a noise series as an exciting signal. SOLUTION: By this voice encoding method, a linear predictive analysis coefficient is found by taking a linear predictive analysis of the voice signal for each frame, and a code obtained by quantizing the feature quantity of a residual signal obtained by driving a linear predictive synthesis filter using a filter coefficient based upon the linear predictive analysis coefficient is determined. The periodicity of the residual signal is decided as the feature quantity and when the periodicity is smaller than a predetermined threshold, the residual signal is divided by bands into a low-frequency component and a high-frequency component, a noise code corresponding to a noise code vector having the shortest distance to the low-frequency component is selected to generate the code of a code vector, and the the mean power of the high-frequency component is calculated for each subframe constituting the frame to generate a voiceless part code according to the mean power. |
