Volume not recovering after a FaceTime call
Quit coreaudiod:

Open app Activity Monitor (Utilities -&gt; Activity Monitor in your applications folder)
Search for &quot;coreaudiod&quot;
Click the (x) in the top left corner and quit the process normally.

It should restart automatically and if you hear no sound, restart the desired application. Note: All applications already playing audio might have to restart as well, not sure.
Warning:
Be aware if you've turned up the volume to max in frustration of the low sound. It might break your speakers or cause permanent hearing damage. I take no responsibility for following this advice. Consult with your IT technician before moving your curser.