| Ohnishi Lab. |
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Computer Audition Research Theme |
| Echo Canceler Using a Single Microphone |
Many studies have been done on removal or suppression of reverberation. Among them, the approach, in which the impulse-response in a room is measured beforehand, has obtained very satisfactory results. But an impulse-response is not invariant , and changes with time depending on the room temperature and humidity, and the relative location between a sound source and microphones. It is troublesome to measure an impulse-response exactly each time. So, we have tried to cancel echoes using only one signal with echoes, which is obtained through a signal microphone. In order to cancel echoes, we determine both delay time and amplitude ratio between direct wave and each of reflected waves. In the case that there are a few reflected waves, the result of simulation shows good recovery of an original sound. |
