Stopping a sound that's in the timeline of a movieClip?

I’ve got a situation where I’m trying to synch a camera sound with some flashing light effects that are contained in a movieClip on the stage. I only want the flashing sounds to go off twice. If I call the sound from actionscript using a timer, the results aren’t that accurate and seem to change base on internet connection speed. So I’ve thought about putting the sound in the timeline of the movieClip that contains the flashes.

Of course, this results in the sound going off every time the movieClip loops itself. Is there some way to access the sound and turn it off once the moveClip has looped twice?

Thanks for any advice.