The intercom mute switch is one of the round knobs on the bottom of the radio unit, labeled "Mute". It controls how sensitive the mics are. It controls how loud you have to speak before the intercom cuts into the music.SB in SC: My neighbor and I have tried every setting of the buttons that we know and cannot get any response. Yet everything else works. I am not sure how to set these buttons. Where is the mute switch/button you are referring to?