| 摘要 |
The present invention aims to suppress an echo which occurs in a telephone system when a signal originating at a far-end, and output at a near-end loudspeaker, is picked up by a near-end microphone and transmitted back to the far end (see Fig. 1). A signal identifier 201 detects an echo of the far-end signal in a near-end microphone signal. The echo from the near-end microphone signal is preferably used in the estimation 202 of a characteristic of the echo path. For example, the microphone signal can be correlated with the received far-end signal to determine a measure of similarity between the signals, from which the degree of non-linearity of the echo path may be inferred (see table 1). In response to the signal identifier detecting a near-end talk signal in the near-end microphone signal, the gain of a far-end signal to be output at a near-end loudspeaker is adjusted. The gain is adjusted based on the estimated characteristic of the echo path (see table 2). |
