Muting and unmuting audio on the fly

After starting a stream, I’ve noticed that I can mute and unmute the audio using the “mute audio” check box in preferences. Is this the way it is supposed to work, on the fly after a stream has begun, or am I pressing my luck doing this? Also, is there a keyboard shortcut to mute/unmute during the stream instead of going through preferences?

Unfortunately there is no other way of muting/un-muting the audio sources. This current method would be the only one possible