The latest installment of AsapSCIENCE opens with a demonstration of the McGurk Effect, a powerful auditory illusion that demonstrates how what we see influences what we hear. But even more baffling is the Shepard tone illusion – a sort of sonic barber's pole that seems to continually ascend in pitch, without actually…

Diana Deutsch is a professor of psychology at the University of San Diego, and a master at manipulating people's ears. While researching quirks in the way humans hear things, she has invented many auditory illusions. Here are some of the weirdest, and why they work.