PURPOSE: To automatically reduce or mute a voice signal outputted from a VTR, a television receiver or a stereo set or the like when a radio wave is generated from a cordless phone by providing a circuit receiving the radio wave of the cordless phone and a control signal generating circuit discriminating the signal to reduce or mute the voice signal to a receiver.

CONSTITUTION: A radio wave 2 generated from a cordless phone 1 is received by an antenna 3 and inputted to a receiver 4. When a discrimination circuit 5 discriminates a signal outputted from the receiver 4 to be a signal generated from the cordless phone 1, the voice signal 7 inputted to an audio circuit 8 is reduced or muted to provide an output by a control signal 6 to reduce or mute the voice signal.