Thanks for the replies!
kindred - It's not fan noise; it's coming from what sounds like maybe a regulator on the side of the card nearest to the display outputs.
Tho - Yeah, it does seem it will last despite the problem; it's just I'm sensitive to high frequencies so it's driving me a bit nuts >.<
weevil - It doesn't appear to be my PSU causing the noise as it's very localized around the card itself and scales with FPS. It almost sounds like maybe it's what looks like the digital supply making noise and hence the scaling with frequency. The card brand is eVGA.
Thanks again for the help, guys!