My headphones stopped working on the macbook air

My headphones on my Macbook Air just stopped working! Like they are "stuck on mute". I take them out, no red light on the jack, and they work perfectly. But once I plug my Headphones in, the volume just stopped! I have tried messing around in preferences, nothing! I can't seem to find any solution for my problem. People have the jack red light problem, but I can't get my volume to work! In fact, just now while I'm writing this my volume isn't working! I can't seem to find anything to help me with this. Nor have I found anybody with the kind of problem I have. I would greatly appreciate your help anybody. But this has happened before, and simply restarting my computer worked. This time, nope. Zilch, Zero, No help at all.