PURPOSE: To shorten significantly the time required for stoppage of audible sounds by stopping the audible sound output with the control signal which is delivered from a trunk circuit or a subscriber circuit which is under reception of the audible sounds.

CONSTITUTION: A CPU103 monitors the state of a subscriber circuit LC101 via a signal line bus 114. When the LC101 needs reception of the audible sounds, an audible sound signal line 110 and a connection conrol signal 111 of the LC101 and an audible sound generating circuit TOT102 are connected to a main channel network SW100 via the bus 114. When the LC101 which is under reception of audible sounds is changed to an audible sound stop state, an audible sound stop signal is delivered to the line 111 from a control signal transmission circuit 104 and supplied to a reception circuit 105 of the TOT102. The circuit 105 receives the audible sound stop information and delivers it to 112 to control an audible sound stop circuit 106.