Just a user here, so I do not know the actual mechanics of it, but I have seen many models mute their audio on occasion if they need to. (As
@yummybrownfox siad, usually when needing to take a phone call or as I alluded to in another very different thread, when talking -- briefly -- to fellow models in a studio who needed something)
So it is definitely possible, I just cannot tell you how, sorry.