Hack 59. Hear with Your Eyes: The McGurk Effect
Listen with your eyes closed and you’ll hear one sound; listen and watch the speaker at the same time and you’ll hear another.
If there were ever a way of showing that your senses combine to completely change your ultimate experience, it’s the McGurk Effect. This classic illusion, invented by Harry McGurk (and originally published in 19761, makes you hear different sounds being spoken depending on whether or not you can see the speaker’s lips. Knowing what’s going to happen doesn’t help: the effect just isn’t as strong.
5.8.1. In Action
Watch Arnt Maas’s McGurk Effect video (http://www.media.uio.no/personer/arntm/McGurk_english.html; QuickTime with sound). You can see a freeze frame of the video in Figure 5-3.
When you play it with your eyes closed, the voice says “ba ba.” Play the video again, and watch the mouth: the voice says “da da.” Try to hear “ba ba” while you watch the lips move. It can’t be done.
Taken from : Mind Hacks
