As you just saw, one of the easiest customization tasks is to replace a sound file with one that has your own twist. For many applications, it is extremely simple to adapt or replace alert sounds. Mail is just one of these many easy-to-change apps, since it stores its alert sounds as Audio Interchange File Format (AIFF) files in the top Resources folder. Replace the sound file and you’ve replaced the sound. It’s as simple as that.
Unfortunately, not all applications are so standard. Unlike Mail, many of iChat’s sounds are stored outside the application bundle. They can sometimes be found in an external framework. Frameworks, which are discussed in Chapter 2, provide a modular way to program and deliver Mac OS X applications.
To locate iChat’s audio files, navigate to the /System/Library/PrivateFrameworks/InstantMessage.framework folder. Select the latest version (alphabetically) and open the Resources folder; for example, Versions/A/Resources (also known as Versions/Current/Resources). This directory contains iChat’s “missing” AIFF files.
Despite the complexity of location, both iChat and Mail use the same strategy for loading sounds. When you replace an AIFF file, you replace the sound used by that application. This works even when the sounds involved do not appear within the application bundle.
For some applications, however, replacing sounds is quite difficult. iTunes (at least up to Version 4.6) was built using a very Classic approach. Its ...