Pulling out the TES 1350A Sound Level Meter we find ourselves quickly yelling into the top of it to see how loud we can be.
After five minutes of that we get a bit more serious and place the device two CM away from the fan on the card to find the maximum noise level of the card when idle (2D mode) and in load (3D mode).
Overclocking throws an extra 10dB onto the Quiet Mode number. Compared to the card in Uber Mode, the overclock brings no extra noise. Considering the overclock isn't all that much, this is what we'd hope and expect.