| 摘要 |
PROBLEM TO BE SOLVED: To enable more properly controlling an operation and stop of an operation of an echo canceler, depending on changes in an echo state. SOLUTION: An apparatus is provided with a standard data holding means for holding estimation standard data about a signal attenuation amount and a delay time of a line echo signal in which the transmission sound of an own station is returned from another station through a telephone line; a line echo attenuation amount calculating means for calculating the signal attenuation amount of a line echo; a line echo delay time calculating means for calculating a delay time of the line echo; and a selecting means for selecting as a selected output any one of a received audio signal subjected to echo cancel from an echo cancel means and a received audio signal not subject to echo cancel, corresponding to a selection control signal. A selection control signal to be supplied to the selecting means is generated on the basis of the line echo attenuation amount calculated, the line echo delay time calculated and evaluation standard data. COPYRIGHT: (C)2005,JPO&NCIPI
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