Sony® head units produce a beep sound when buttons are pressed. To mute the beep sounds, simultaneously press the SEL or SOUND button and the 6 button on the head unit at the same time. Pressing these buttons a second time will restore the beep function.
- The beep function can not be activated when connected to an external amplifier.
- This procedure encompasses most Sony head units. However, consult the instruction manual for specific information if necessary.