| 摘要 |
PROBLEM TO BE SOLVED: To resolve the problem that the line efficiency is reduced due to special preparation of a channel in a method, which uses a common line or an unused line to transmit a reset signal in order to synchronously reset an encoder/decoder, and the problem that a method which transmits the reset signal at the time of detecting a silent state in the encoder/decoder cannot be generally used in all communication systems. SOLUTION: The encoder/decoder is provided with synthesizing filters and processing blocks, which perform gain forecasting calculation and linear forecast analysis, to encode and decode a sound signal, and the processing block which performs linear forecast analysis of the encoder/decoder or the processing block which performs gain forecasting calculation is provided with an abnormal state detection means which detects that a parameter has fallen into an abnormal state, and each filter is provided with a function which resets a filter coefficient to a prescribed value by an abnormality detection signal from the abnormal state detection means. |
