Aural Illusion

I'm guessing this is an example of top down processing (click that link to the left, it's a great explanation of TDP).

First, watch and listen to the video below.



Sounds sort of like "dada dada dada."

Now close your eyes and play it.

It switches to "baba baba baba." Not sure this works for everyone, but it did for me. My guess is seeing the hippie guy mouth the pronunciation of a "da" sound actually changes your perception of the sound. Close your eyes, and your hear the actual sound being made. The visual information is tricking your auditory perception. It's not an extraordinary example of top down processing, but it's pretty interesting.

(from Bad Astronomy)