| 摘要 |
PROBLEM TO BE SOLVED: To provide an echo canceler capable of immediately coping with a change in the echo path condition. SOLUTION: The echo canceler 1 is provided with an adaptive filter 18 the characteristic of which is controlled to be the same as that of an echo path including a loudspeaker 25 and a microphone 11 to eliminate echoes produced by a sound from the speaker 25 via the microphone 11 and a deviation arithmetic means 14 that conducts difference arithmetic operation between the echo and an output of the adaptive filter. The echo canceler 1 is also provided with a delay time measurement means 16 that measures the delay time of a sound signal outputted from the speaker, in response to a prescribed pulse signal outputted and specified by a pulse generating means, a storage means 17 that measures a delay time for an echo path for each position of the microphone with respect to the speaker in advance, by the delay time measurement means 16 and stores a filter coefficient of the adaptive filter calculated based on the delay time, and a control means 15 that controls the storage means selecting a filter coefficient of the microphone position corresponding to the delay time, based on the delay time from the delay time measurement means and providing an output of the selected coefficient to the adaptive filter.
|
