I'm not entirely convinced that your problem is the same as mine, but it may be.
My problem is that sounds and general media functions fail to work. Things don't just suddenly cut out during usage - they just don't work when I go to use them.
Over the last couple of weeks while I've been on Christmas break the problem has not arisen, whereas previously it was recurring every few days. At this stage I'm becoming increasingly convinced that it's because the problem is being triggered by a particular app that I would normally use routinely, but haven't needed to use over the last couple of weeks. The most likely culprit is Nightstand which is an alarm clock app, and my theory is that a bug in the app is causing it to hog the media API and hence prevent any other app from playing media. I'm going to start using this app again next week and if the problem starts occurring again then I think I've cracked it.
When you experience the problem yourself you may want to check which apps you've been using recently (the home button is an easy way to check this) and temporarily discontinue the use of particular apps to see if the problem goes away. If it is a rogue app causing your problem then you should be able to identify it by process of elimination.