Earlier today, I was watching youtube and my sound was working fine. I then closed my laptop and went to go do stuff for a couple hours. When I came back, the sound wasn't working. It isn't working with headphones nor with the internal speakers. I have turned my computer off and on, no luck. I have an aluminum MacBook, 13''. OS X 10.5.8. 2GHz Intel Core 2 Duo and 2GB 1067 MHz DDR3. EDIT: Fixed it! No idea how... I went into system preferences and started playin' around with the sound stuff.