We take our noise measurements with the sound meter positioned 1 foot from the graphics card. I measured the noise floor to be 32 dBA, thus anything above this level can be attributed to the graphics cards. The power supply is passive for the entire power output range we tested all graphics cards in, while all CPU and system fans were disabled.
A reading under load comes from running the 3DMark Fire Strike Ultra stress test for 30 minutes. An idle reading comes after leaving the system on the Windows desktop for 30 minutes.
Noise output is the one area where PNY could have done a bit better. The XLR8 isn't a loud card – it's still about 1dB quieter than the Founders Edition – but it is still audible and we have tested significantly quieter aftermarket cards in the past.
For reference, under load we observed the three fans spinning at around 1890rpm, or 58%. I think there is definitely scope to slow the fans a bit given the impressive thermal performance of the card, resulting in lower noise levels.