Today i did a little research about acoustic illusion. I found some examples on one website, so maybe somebody will be interested. It requires lot of clicking, so I put everithing to one document. Perhaps lot of links on my post is considered as spam, I created a little HTML document.
wot no Shepard tone ... http://www.freesound.org/people/digifishmusic/sounds/65591/
That's great, I read about it but can not find relevant source. Thanks.