| 摘要 |
PURPOSE:To secure a relatively good tone quality even when an information transmission speed is small. CONSTITUTION:A mute processing section 30 is provided with a mute detection section which judges whether inputted voice to a voice coding section is generate from a mute section or a voiced sound section, a quantization bit number storage section which stores the number of bits to be assigned for auxiliary information and an auxiliary information quantization section. When the mute sections continue to operate, only the signals which indicate the purport situation and residual signals are quantized and sent to a coding section 16 and the auxiliary information is not quantized and is not sent to the section 16. Moreover, the number of bits to be assigned to the auxiliary information are stored in the quantization bit number storage section and are used for a voiced sound section. Furthermore, for the auxiliary information used in an adaptive prediction section 9 and a quantization bit number adaptive section, the same as the auxiliary information of an analysis frame that is judged as mute by a mute detection section is used as long as the mute section continues to operate. The same processing takes place in a voice decoding section. |
