Regular readers know that pareidolia is the psychological term for seeing faces and other familiar things in random patterns like clouds. There is an aural version of pareidolia as well. You're probably already familiar with it: silly claims that playing songs backwards reveals satanic worship, or very silly claims that you can record ghost voices on tape. In both cases, these are simply our goofy brains trying to tease information out of noise. The funny thing about this is that if someone primes you -- shows you what you are supposed to hear -- then man, you can really hear it. Don't believe me? Then check this out: I LOLed a lot listening to this! For about a billion more examples, head over to Kiss This Guy, which will provide hours of laughs.
Tip o' the mitre to The Friendly Atheist.