I have an early Spring 2011 Macbook Pro running OS 10.8.3. I was working on a Rosetta Stone (the language learning software) lesson when an audio issue popped up. The application itself opened and closed and seemed to be functioning normally except that the audio from the lessons would not play (after clicking on different sections and stuff). I then noticed that audio in general from my laptop was off in general. The sound was muffled/distorted playing through my external speakers (running through a USB amplifier/DAC). I tried headphones out of the DAC, headphones out of the headphone jack and the built-in speakers and I heard the same issue each way. I've used iTunes and VLC with no difference. I've reset the NVRAM and SMC with no luck and I can't find anyone else online with this specific problem... Any help would be greatly, greatly appreciated... I basically can't listen to or watch anything... Thanks!