To synchronize a sound with animation, you
start and stop the sound at keyframes.
Add a sound to a document.
To synchronize this sound with an event in the scene,
select a beginning keyframe that corresponds to the keyframe of
the event in the scene. You can select any of the synchronization
options.
Create a keyframe in the sound layer’s Timeline at the
frame where you want the sound to end. A representation of the sound
file appears in the Timeline.
Select Window > Properties >
Properties, and click the arrow in the lower right-corner to expand
the Property inspector.
In the Property inspector, select the same sound from
the Sound pop-up menu.
Select Stop from the Sync pop-up menu.
When you play the SWF file, the sound stops playing when
it reaches the ending keyframe.