Jeff Hawkins has a hypothesis about universal neocortex algorithm (i.e. that all areas of cortex perform the same function and this function is as follows): perception (signals moving from senses towards cortex) always happens together with temptive recollection (feedback signals). cortex starts “empty” (without a way to successfully recall anything) and then learns to recall pattern sequences that it often experiences.

What we experience then is only partially defined by what our senses tell us, and partially by what our cortex predicts based on its “experience” (memory).

2peet: This can explain why not only your friend, first exposed to “decent” speakers discovers an entire new aspect, but you yourself when listening to the same track again often dicover something new, don’t tell me you don’t. That’s because the first time you listen to the track your perseption is coloured by the similar music your cortex knows about, while on each consequent listening (and even, on a different level, on each repeating musical figure during that first time) cortex can recall and predict the music on higher level, take some load off the lower cortical regions (the ones closer to the ear) and give them a chance to notice details that went ignored before.

As if higher region told to the lower one: “ignore the singer, I remember how the vocal goes”, and the lower region answers, “but have youo heard what the guitar was doing the whole time? this is incredible!”

Oh, I wish I could listen to some of my favorite tracks for the first time!

Of course this is very simplistic: your perception is affected by even higher cortical regionds and their memory, you listen to the music differently if you’re a critic or a musician or film director, some totally unexpected regions may be activated by association and affect attention of the lower regions to detail.

On the other hand the physical ear itself changes which again affects what you will hear. And that’s where earbuds (especially worn in metro ;-)) or live concerts can do irreversible damge. I recently spent a couple of days at friends place, the guy is a big pop music appreciator, the whole day he had radio on and sometimes he would sing with it. But the volume was so low I first thought the music was at his neighbours place - I’m sure he never had a walkman or an ipod. And it has little to do with my cortex either :(

P.S. http://www.onintelligence.org/

But try this for a mind experiment: How do those kids in the metro with inferior and ‘leaking’ headphones and mobile phone speakers remember their music?

I’m convinced they either already know the full bandwidth version of the songs and make up the rest in their minds, or their hearing is so damaged they don’t hear the difference.

I once played some music through my ‘decent’ speakers to a friend (it was her favorite, she only heard it on her laptop); it made her cry, she discovered an entire new aspect of the song.