Have you ever wondered which of the next generation consoles is the noisest? I hadn't, but somebody has wondered about it enough to run a few tests to erase any doubts people might have. The first test is the location test. The tester believed that maybe the location had something to do with the noise, as when the consoles turns hot, the fans turn on to reduce the heat. However, he didn't quite get the chance to move around his consoles to conduct this test. But, let's move on, there are other methods.

Base dB testing
This test had no games running. Here are the results :

The results for Xbox 360 read 55 dB

The PS3 clocked at a dB of 53/54.

So far, the Wii seems to be leading with its dB reading of around 51.

After playing games on the hard drive

The tester playing Live Arcade Titles on the 360 and Tekken 5 on the PS3. The 360 showed no change in dB, but the PS3 was a different story. Now the dB reading was 64, quite an increase don't you think?

Media Games Test

This test includes running a media based game on each console, and then measuring the dB.

He played Gears of War on the Xbox 360, and the sound output read 61 dB.

After running Ridge Racer 7 on the PS3, the dB reading was 65, an increase of 11 dB.

After loading up Wii sports on the Wii, the results were quite surprising. The sound output increased from 51 dB to 70 dB.

In conclusion, the Xbox is the quietest of them all. The PS3 does make a fair bit of noise, and Wii is the noisiest after loading up games.

Source