Some excellent examples of sinusoidal waves, that mean nothing, until you hear a bit of speech. Listening to the same gibberish again, the speech patterns in the waves become evident.

A great way to show that human brains are wired to perceive order when chaos exists, known as apophenia, or pareidolia. Pareidolia is the natural or rational explanation to such phenomena as EVP, satanic messages, and all those ‘virgin mary on a piece of toast’ kind of things.