| 摘要 |
PROBLEM TO BE SOLVED: To extremely reduce the power consumption of a voice decoding device by driving no post-filter processing that requires a large processing quantity in a silent mode and instead carrying on an updating operation. SOLUTION: The received signals which are inputted via an input terminal 11 storing the codes showing the voice spectrum information, the voice signal level/pitch information, the noise information, etc., are stored in a sound/silent information storage part 122. A code control part c131 controls the operations of a background noise code generation part 131 and a code switching part s131 based on the sound/silent information inputted from the part 122, as follows. That is, the received codes stored in a received code storage part 521 are directly outputted to a decoding processing part 54 and also to the part 131 in a sound mode. In a silent mode, a post-filter control part c144 drives a post-filter state updating part 144. The part 144 directly outputs a background noise signal, i.e., a synthetic signal produced in the silent mode and outputted from a synthetic signal generation part 142. |
