I'm going to add a bouncing sound effect to the bouncing snowball animation from Lesson 14; I've already put a simple audio background on it, just a little looping holiday jingle imported into my library that helps to set the tone without being overpowering.
First you'll need to obtain an audio file for your sound effect. Short of recording your own, it's sometimes difficult to find the sound effects you need, especially with so many audio-related copyright issues at stake. I get mine from Freeze.com, which has a library of free sound effects for download. All you have to do is fill out a simple registration form, and accept or decline a couple of pages of offers.