We experienced this on Xbox last night.  It was odd, 3 of us in a party, none could hear each other.  We all exited out, back in, still nothing.  We tried loading into our own separate matches, still nothing.  We decided to go ahead and play a game.  After the first match, we got back into the lobby and unplugged our headsets and re-plugged them in, and it started working fine.  Not sure what the problem was or what the actual solution would be, but that's what we did.