We're all familiar with "Optical Illusions", in which we're tricked by clever images into seeing things that aren't really there, or static images which appear to waver, and a host of other tricks played upon our notably visual sense. But fewer of us are familiar with "Auditory Illusions", (by which I don't mean the 1st date post-mortem in which one partner tries to recall if he/she heard "I love you". . .). For a quick introduction try this link:
http://deutsch.ucsd.edu/psychology/deutsch_research1.php#Introduction.php
Note: Laptop speakers won't suffice. Use proper speakers or headphones.