I want to still be able to speak and hear my PTT key, text messages, etc., but otherwise be "deafened." Hearing people changing channels/connecting/etc. is optional--Vent has that audible when the sound is muted, but I don't really care since I only "deafen" if someone else in the room is also in the channel (but it's uncommon enough that dual audio for it isn't too annoying).
Maybe add some check box options for what occurs when you deafen? "Mute yourself" could be an option that is selected by default.