1) Shutting off the audio 2) Silencing 
• (n.) Dung of birds.
(from the article `stringed instrument`) ...made from wood, the resonator of the present-day instrument is made of an easily available metal pan. The krar can be played in two ways: in the ...
the automatic suppression of the output signal of a radio receiver when either the input signal is less than some predetermined level, or the signal-to-noise ratio is below a predetermined value
Mut'ing noun Dung of birds. 
muted, muting, mutes 1. To soften or muffle the sound of. 2. To soften the tone, color, shade, or hue of.
Muting, some devices also provide muting and dimming.