| 摘要 |
PURPOSE:To apply in-room echo cancellation during conference talking stably by stopping the adaptive correction of a characteristic of each echo canceller after the end of training. CONSTITUTION:In receiving a signal commanding the start of training, a control circuit 10 sends a control signal commanding the execution of adaptive correction of a pseudo echo generating characteristic to echo cancellers 4A-4D respectively. Moreover, a control signal is sent to a noise generation circuit 11 to generate a training signal. Thus, the echo cancellers 4A-4D correct adaptively the pseudo echo generation characteristic of each adaptive filter 42 so as to erase the in-room echo. After the end of training period, the control circuit 10 sends the control signal to command the stop of the adaptive operation to the echo cancellers 4A-4D and also sends the control signal to the generation circuit 11 to stop the production of the training signal and the state is transited to the state capable of conference communication. |
