Sentence:  Another related primary control is called a <WSD>"mute</WSD>", which is simply a switch that kills the signal altogether, allowing for a speedier turn-off than turning the fader all the way down rapidly. <WSD>Mutes</WSD> are probably more commonly used during multitrack music recording than during film mixing because in music all tracks are on practically all of the time, whereas workstations produce silence when there is no desired signal ... 
Meaning of the word marked with <WSD> tags:  An electronic switch or control that mutes the sound.