You want to add compression to the sounds in your Flash movie to optimize both the quality of the sounds as well as the file size of the exported movie.
Adjust the compression settings for each sound and/or the global compression settings for the movie.
How you choose to compress and export the sound in your Flash movies makes a tremendous difference in the quality and file size of the resulting movie. And Flash gives you quite a lot of control over how you want to handle the sounds. You can affect the compression for each sound individually, and you can also apply moviewide, global sound compression settings. You can apply settings to each sound individually in order to assure that you maximize the quality of your sounds while also minimizing the required file size. Because each sound is generally quite different from another, no one setting will necessarily work best for all sounds. For example, you can generally apply much more compression to sounds that are voice-only than you can to sounds that include music.
In order to apply compression settings to each sound individually:
Locate the sound symbol in the library, and open the Sound Properties dialog box for that symbol. You can do this either by selecting Properties…from the menu that appears when you right-click/Control-click on the symbol in the library. Or you can select the symbol by clicking on it once in the library, and then ...