Sound (free)
Audacity
Audacity® is free, open source software for recording and editing sounds.
SFXR
sfxr is a generator for simple sound effects, created by DrPetter. You can use it to create easy retro sounds for remixing or video games.
Free
Official Site
cfxr
cfxr is a Mac port of DrPetter's sfxr. In his own words: Its original purpose was to provide a simple means of getting basic sound effects into a game for those people who were working hard to get their entries done within the 48 hours and didn't have time to spend looking for suitable ways of doing this. There already was a Mac port, but I felt a sudden urge to make one with a native Mac UI, add some proper save/load, and learn Core Data and Bindings while at it. My version's called cfxr (as in "Cocoa sfxr").
FREE
Official Site
