Mobo beeps while in windows or during gameplay

for the life of me i can't figure out why i get these random long beeps while in windows(very high pitched, not a normal sounding error/post beep). usually happens when i'm playing games, it isn't multiple beeps like the ram error. it's just one long beep which doesn't even happen that often, usually it won't happen at all. my cpu(i7) @4.2ghz is liquid cooled and never goes above 55c-60c ish while gaming, my ram is running at 2005mhz (dominator gt) (is it possible that the extra 5mhz above the 2000mhz spec could be the problem?) i have a thermal probe(reads a constant 20c) and fans on the ram, my gpu(5970)@ 850/1200 has the fan set to 75% so that never gets above 65c while gaming. my motherboard is an ASUS p6t6 ws revolution, nb external temp- 41c-45c sb external temp- 45c-52c.
the beep doesn't sound like it would come from the mobo speaker. maybe my gpu has an error speaker? idk
note- everything is stable on prime95, memtest, and furmark

Its card squeal. I think its coming from capacitors or inductor coils on the card when its under heavy load. I hear it when my Nvidia GPUs when i'm running folding as well.