Listen to these two sounds:
Is the second sound higher or lower than the first sound? (let us know in the comments). Play it again if you're not sure.
Ask a few other people to do the same. You'll find that some people hear the second note as higher and some hear it as lower!
(mini update: so far 5 commenters hear the second note as lower and 8 hear it as higher)
That's because it's an audio illusion. And just like an optical illusion an audio illusion can tell us something about the way we perceive the world around us. Continue reading →