I tried to respond to Andrew's post below several times, to offer an explanation before GBrowdy could show off. Alas! Sillytech thought I was spam! Even though I was logged in.
So I will offer you more auditory illusions thanks to the awesome Al Bregman AND another way cool video demonstrating the properties of sound using salt.
I will also remind Andrew- and any other readers who may or may not be named Gil- that he called me the better linguist. That's right... I'm the pettier better linguist!