I recently watched this Rupert Neve lecture where, among other things, he talked about the Hypersonic effect on the brain. According to Rupert, cutting off audio frequencies above 20k Hz or so, like CDs do, changes the way our brain responds to the music.
Here's the full lecture. It's long but if you like this sort of thing it's rather fun.
http://m.youtube.com/watch?v=SsgQcyXyzss
Rupert talks about the work of Professor Oohashi who measured the hypersonic effect.
Any thoughts on this.