| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that it is necessary to identify a double talk and an echo path variation using a predetermined identification parameter in order to apply an echo canceler to a system wherein the double talk and the echo path variation occur, but an overlap that occurs in distribution given by the double talk and the echo path variation is too great in a conventional identification parameter, so that identification is delayed, the securing of an echo erasure quantity is delayed and operation of the echo canceler becomes unstable. SOLUTION: In an adaptation algorithm of an echo canceler, a product of an error signal and an input signal to each of coefficient taps within a predetermined search range of an FIR filter 212 is calculated, and a representative tap is selected out of the coefficient taps within the search range based on a first value determined based on the product. It is then determined whether or not a double-talk state is generated based on a second value determined based on a product of a difference signal and an input signal to the representative tap, and a third value determined based on a power value of the difference signal. COPYRIGHT: (C)2006,JPO&NCIPI
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