| 摘要 |
An uncomfortable feeling due to lack of the speech of a far end speaker and a convergence signal voice (sound) is prevented, and the echo of the far end speaker is removed. A pseudo signal generating circuit has a phase inverter (10) for inverting the phase of a signal, a pseudo hybrid circuit (11) for generating a pseudo echo having the same or substantially the same characteristic as that of the true signal, and a pseudo telephone set (5-2). By generating a pseudo echo having the phase opposite to that of the true signal and having the same or substantially the same characteristics as that of the true signal, the uncomfortable signals (echo, etc.) are cancelled out. When a telephone set is connected to a caller or when an extension transfer occurs, an adaptive filter convergence signal is generated for a predetermined constant time only during “no-voice (sound) (silence)” of the far end speaker's signal. |
