| 摘要 |
PURPOSE: To attain echoless communication at a low cost without wasting an echo canceler by constituting a slave telephone set so as to execute calling through an echo canceler in an echo canceler trunk and two-wire analog communication. CONSTITUTION: An echo canceler trunk 9 constituted of plural echo cancelers is provided in a main device 1, and when each of slave telephone sets 17 to 20 is to execute calling through a two-wire analog communication line, the calling is executed through a corresponding echo canceler in the trunk 9 and the communication line. A receiving voice signal including an echo signal and outputted from an analog trunk line is inputted to the transmitting side input of the echo canceler and a transmitting voice signal from the slave set is inputted to the receiving side input. The voice signal from which an echo is erased by the echo canceler is outputted from the transmitting side output and transmitted as a receiving voice signal for the slave set concerned. |
