Free Beer & Hot Wings: An Amazing Audio Illusion [Audio]
Here's audio that is going to take multiple listens for it to make sense.
While it is just 10 seconds of a sound repeating over and over, the more you listen to it, it seems as though the sound keeps getting faster and faster and higher pitched.
This audio illusion is kind of a slow burn, but if you take the time follow through with multiple listens, it definitely works.
Source: Free Beer & Hot Wings