| 摘要 |
<p>A first false echo signal which approximates an echo of a receiving signal overlapping a transmitting signal is produced from a past delayed receiving signal according to a filter factor, and a first residual signal is produced from the first false echo signal and a delayed transmitting signal. A filter factor is updated so as to reduce the first residual signal. When a single-talk condition based on the voice of a far-end speaker for a receiving signal migrates to a double-talk condition based on an addition of a voice of a near-end speaker to a transmitting signal, a filter factor deteriorates. A second false echo signal is produced from a receiving signal currently received according to an updated filter factor. Since there exists a time-wise deviation between a signal related to filter factor updating and a signal related to the generation of the second false echo signal, a deterioration component is indicated in a delayed second residual signal produced from the second false echo signal to enable the detection of a double-talk condition according to the difference between the delayed second residual signal and the first residual signal.</p> |
