Just about every kid in the United States has played with a See 'n Say®. These toys play a selection of sounds when you pull the string (or, on the modern ones, pull a lever).

If, for instance, you point the dial at the cow and pull the string, the toy says, "The cow says Moo." See 'n Says have been around forever; they use no batteries and they are nearly indestructible -- I've seen See 'n Says submerged in bathtubs, thrown down the steps, dropped onto concrete patios...and they work fine afterwards!

Have you ever wondered how one of these toys works? How can it make sound without a battery, and how can it have 26 different phrases stored inside? In this edition of HowStuffWorks, we will solve the mystery of the See 'n Say!