Beginner's Guide to Adobe Flash/Sound/Importing
The first step to adding sound to Flash is importing a sound file. Flash can import many different sound file types including MP3, WAV, AIF, and QuickTime. Once imported these files will be compressed to .fla format in Flash before eventually becoming part of the final movie .swf file. Although Flash can import and convert these file formats, its often better to convert your sound to MP3 before importing it into Flash.
In Flash, the simplest way to import a sound file into your library is to access the file menu and choose import, then import to library. At this point the sound file is not a part of the timeline or the active layer of your presentation. It remains in the library until you assign it to a keyframe, as an instance of that sound or if it is used in ActionScript. Another method of importing sound files into Flash is by simply clicking and dragging the file from your desktop or file folder and placing it in the library or on the stage.
If you select the audio file in the library, you can click the play button located at the top of the window to sample the sound of the file.