Sounds can be imported and added to a layer in the timeline.

1.Import the sound to the library

2. Add a sound layer, choose the frame you want the sound to start,  and choose the sound from the properties inspector.

3. Set the sync to start. This will allow the sound to start on the frame you have chosen.

4. Choose how many times you want it to repeat. The only problem is if your timeline is long, the sound may finish and not start for a while until the timeline loops around again.

Another way to have a sound play is to load it dynamically from outside the flash file. This will keep the flash file smaller. First place the sound in your flash project folder.

1. Click on your sound frame and open the action script editor

2. The script is simple and can be found here http://www.tozier.net/flashy1/mx_scripts.html