This has been driving me nuts for a few months now. My macbook keeps emitting a sound very much like static. Only today, I realized that this sound goes away when the processor is working. So if I scroll down in Safari, open a New Folder, etc, the sound briefly pauses before resuming again. Almost sounds like a refrigerator. It bugs me a lot lot. Anybody else having this issue? Or has Apple been able to fix this for anyone? Cheers!