This is kind of strange, and I had never noticed it before. I find that if I don't use the keyboard or trackpad (no peripherals plugged in) for 15-30 seconds while on battery power, the sound goes away. Once you press a key, or ouch the pad, it comes back. I haven't tried it while plugged in, but it definitely happens while on battery...at least with my MBP. The number of applications, or CPU usage doesn't seem to matter either.
Is this happening for anyone else?
EDIT: It also goes away after a few seconds while charging as well...
Is this happening for anyone else?
EDIT: It also goes away after a few seconds while charging as well...