Brain Waves & Sound Waves

Here's another review of The Music Instinct which has a bit of info I'd not seen before. 

Recent studies by Professor Nina Kraus, a neuroscientists at Northwestern University in Evanston, Illinois, have shown that the electrical activity inside the brain while listening to music closely matches the physical properties of sound waves.

Using brain scanning equipment Professor Kraus, who presented her findings at the American Association for the Advancement of Science in San Diego on Saturday, said the brainwaves recorded from volunteers listening to music could be converted back to sound.

In one example where volunteers listened to Deep Purple's Smoke on the Water, when the brainwaves were played back the song was clearly recognizable.

She said: "When we play the brainwaves back as sound, although they don't sound exactly like the song, it is pretty similar. It shows that the brain matches the physical properties of sound very closely."

UPDATE - Here's a post on some people turning brain waves into sound waves