| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem wherein it is difficult to calculate an accurate pitch period because of a sum signal being zero when channel signals are opposite in phase, since the pitch period is obtained from the sum signal of a plurality of channels before, and an audio signal after speed conversion has lower sound quality when the pitch period is obtained from either the sum signal or a difference signal, and different from pitch periods of the respective channel signals. SOLUTION: An audio speed converting device has a pitch period extracting means of calculating waveform similarities of the respective channels of an input multichannel signal by processing sections, finding the sum of the similarities of all the channels whose similarities are calculated at the same time, and extracting a position of the highest similarity as a pitch period from the sum of the similarities; and a speed conversion processing means of performs speed conversion of all the channels of the input signal, based on the pitch period extracted by the pitch period extracting means. COPYRIGHT: (C)2007,JPO&INPIT
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