MuteButton is an addon that temporarily mutes or dampens audio while a button is held, which helps Teamspeak or Ventrilo users using a push-to-talk keybind that may have regular desktop speakers.
Updated to WoW 2.0, based off the original version by Milena available here: http://wow-en.curse-gaming.com/files/details/363/mutebutton/
Use /mf or /mutefactor to specify factor of dampening. 0.0 indicates a full mute on keypress, 1.0 indicates no adjustment to sound. 0.5 indicates 50% reduction of sound.
Ex:
/mf 0.0
/mutefactor 0.45