Auditory Illusions

I have alerady shown you some optical illusions before, but did you know there are auditory illusions as well?

And, if some of those aren't really that impressive, this one certainly is. :)

Just listen to the following clip:



Did you listen to it? Now, keep playing it whenever it ends, and listen closely.
It seems it is alwasy going higher and higher every single time - even thought it's always the same clip.

That's known as Shepard's scale and it's pretty impressive, isn't it?