Ever heard of Sine Wave Speech? It's where they take a clip of speech and distort it into a weird mess of mechanical squeaks.
Here's the strange part:
The distorted version doesn't sound like speech at all...
...until you hear the undistorted version. Then you can make out the words in the garbled sentence. It's weird!
Click "Play Garble" to hear the garbled sentence (you may need to boost the volume). Then click "Play Nice" to hear the ungarbled version. Then replay the Garble version to hear what you didn't hear before...
More examples (including the one I used) here.
p.s. I'm still working on my cartoon, this was just a quick diversion.
p.p.s. Yes, I know the "sound waves" on the screens aren't sine waves.