Notebook is a 15" SR MacBook Pro 2.4Ghz. I mostly pipe audio out to the speakers. But recently, I've been using headphones and have realized that every time a sound effect is played, such as a new mail notification or any system-related sound effect that there is white noise that accompanies it. The white noise remains for several seconds after the sound is played and than goes away I've also heard random tones from the audio output as well. Best way I can describe it are similar tones that you hear while getting a hearing test using different frequencies. Anyone else getting this? This is my first Intel Mac, and I don't recall ever getting this on a PowerPC machine. I'll probably try returning it to Apple before the 1yr. warranty but I can't part with it now as its my only machine.