Comment 26 for bug 1398560

Resetting User Configuration For some reason, pulseaudio's user configuration files can become corrupt(unsynced?) in some way, and deleting them (and forcing fresh ones to be generated) fixes a no sound condition. After using the command below, log out/in.

Ubuntu 12.10/Quantal (and earlier)

rm -r ~/.pulse*; pulseaudio -k

Ubuntu 13.04/Raring (and later)

rm -r ~/.config/pulse; pulseaudio -k