There are two options for inserting sounds in an animation created using Flash™ Firestarter: track or sound clip. In either case, you must make sure the sound file is in WAV or MP3 format, The sound file must be recorded at a sampling rate of 16-bit 44.1KHz (also known as CD quality) in order to play properly in the software.
Inserting as a Sound Clip
First click the Add New Sound button to browse your computer for the sound you want to insert. When you insert a sound clip, you can have the clip play as many times as you want during the movie. You will notice in the cutting room, next to your sound, a green plus-sign icon appears. You can use that button to add more occurrences of your sound, which will appear in your timeline as blue arrows. These arrows can be moved in your movie, allow you to play the clip at any frame you choose.
Inserting a Sound Track
Just like when you're inserting a sound clip, you first click the Add New Sound button to browse your computer for the sound you want to insert. The difference is, you can only insert one sound track in the movie, and it will automatically start when the movie starts and stop when the movie stops.