All our judges have extensive experience working with digital music and compressed audio and they're all foolishly confident that they'll be able to tell the difference between the different formats.
Here's a little bit of info on them:
Techno producer Ben Long has had a string of releases on labels like Soma, NovaMute and Infonet, and he's been DJing for over a decade as one half of the Space DJz.
Fabric's Sanj Bhardwaj is the head sound engineer at the club, and has the pleasure of working with one of the finest club PAs in the world.
DJ Paddy Freeform started up the www.universalvibes.com radio show 2 years ago and has played a big part in promoting London's broken beat, and nu jazz scenes.
Matt Cheetham is the boss of one of the largest independent online radio stations in the world - Samurai.fm.
Simon Bull knows a thing or two about crystal clear audio, he works for Martin Audio, one of the finest club PA manufacturers in the world.
All the judges had extensive experience working with audio
The same song was compressed four times into mp3, Vorbis, WMA, and AAC, and then each of the compressed formats were pitched against the song's original format.
The judges had to guess which out of the two tracks was the compressed version.
There were three tests altogether; to represent the three compressed audio bit-rates - 300 Kbps (best quality), 192 Kbps, and 128 Kbps.
TEST 1: over 300Kbps
Joint 1st - MP3 & Vorbis
Joint 3rd - WMA & AAC
It was very difficult to tell the difference between the original and the lossy (techy word for compressed audio) at this bit rate, and only Simon Bull and Matt Samurai could spot the MP3 and Vorbis.
Clearly MP3's new codec technology has done wonders for its sound quality.
TEST 2: 192Kbps
Matt from Samurai.fm was amazed with MP3's new codec technology
1st Place - WMA
2nd Place - AAC
3rd Place - MP3
4th Place - VorbisThis was a shock result. Only Sanj spotted the WMA but all judges clocked the Vorbis.
TEST 3: 128Kbps
1st Place - AAC & Vorbis
3rd Place - MP3
4th Place - WMA
AAC & Vorbis were only spotted by one judge each (Matt and Ben), whereas the WMA compressed audio was spotted by all the judges.
After collating the test data, the results are a clear triumph for compressed audio.
The experts, who between them have some of the best ears in the business, could not consistently tell the difference between the original and the lossy.
Vorbis was the overall champion, topping the charts in two categories: 128Kbps and over 300Kbps.
But the results probably say more about individual perception then codec technology.
The fact that four out of the five judges thought Vorbis and AAC sounded better than the original WAV at 128Kbps is a curious thing indeed.
It's worth noting lossy's underlying technology is founded on perceptual coding, which is based around a psycho-acoustic model of human hearing.
In plain English, the bits of audio that are messed with in a compressed audio file are based on an opinion of how humans hear, rather than on any fundamental laws of maths or physics.
In the case of MP3, a group of scientists in Germany (The Franhofer Institute) decided amongst themselves what to chuck out and what to keep, so it's probable the sound will be coloured to a degree and therefore may actually sound better than the original to some people.