This is totally amazing.
First, watch this video. It's short -- just a guy saying a single word -- and try to figure out what he's actually saying.
OK, now the cool part: listen to the video again and close your eyes, or look away from the video. Seriously. Do it.
Isn't that awesome? I was blown away from this. I need to look into it more; I've never run into this before. I love illusions, and this must tie in somehow with aural pareidolia.
Tip o' the lobe to Way of the Woo.