| 摘要 |
PROBLEM TO BE SOLVED: To obtain a natural reproduced sound even in a condition in which a background noise is large with a simple constitution by setting the gain of a random signal expressing the sound source signal of data to be encoded by a non-voice sound source estimating part to a specific suppressed value. SOLUTION: A switch control circuit 3 selects which of encodings of a voice signal and of a non-voice signal is to be performed by a linear prediction encoding means based on a discrimination result with a voice discriminator 2. Data to be encoded by the non-voice sound estimating part includes a linear prediction parameter anal the gain of the random signal expressing a sound signal. Then, the gain of the random signal is set to the suppressed value by multiplying a value making the error between the energy of the linear prediction residual signal of the non-voice signal being the input signal at that time and the energy of the random signal a value equal to or lower than a prescribed value by a prescribed suppression coefficient based on the energy of the non-voice signal being the input signal at that time. |
