Volume not working on MacBook Pro?

So my volume recently hasn't been seeming to work recently. The volume is NOT locked and it has nothing to do with plugging in headphones. Regardless of having in headphones or not, the volume tends to cut out for about 20-30 seconds, be stuck at a random volume, or I may simple have no volume at all. I still have the ability to change the volume, but doing so will have no affect on any of these. Restarting my computer usually fixes this, but only for a few hours or so. I have not updated my OS recently, this just began happening out of the blue. Any tips?