| 摘要 |
PURPOSE:To easily adjust a speech voice through subscriber's operation, by providing a voice level converting circuit and sound volume selection control circuit in the trunk circuit of an automatic telephone switchboard. CONSTITUTION:To the trunk circuit of an automatic switchboard which has monitoring circuit 14 and 15 for monitoring a switchboard-side station and an opposite station and a sequence control circuit 16 for controlling the monitoring circuits 14 and 15, voice level converting circuits 12 and 13 for converting voice levels of a transmission side and reception side and a sound volume selection control circuit 11 which controls said circuits 12 and 13 on the basis of a number dialed by a subscriber are added. Therefore, a speech voice is adjusted easily through the dialing of the subscriber. |
