ADAPTIVE SOUND SOURCE GENERATOR, SPEECH CODING DEVICE, AND SPEECH DECODING DEVICE

摘要

PROBLEM TO BE SOLVED: To overcome the problem of a prior art such that the system is diffused or the offset DC components are superposed, if one or more adaptive sound source code directory gains continue, in the CELP voice coding device mounted on a mobile communication systems such as a digital portable telephone. SOLUTION: The mean of the adaptative sound source code directory gain is computed, and the adaptative sound source so that the mean is <1 is generated. Thus, one or more adaptive sound source code directory gains can be prevented from continuing, and the diffusion of the system or the superposition of the offset DC component can be suppressed.