Synching sounds with animations.

[Glenjamin]

I'm currently working on a game where the player speaks through audio clips.  He has an animation where he's talking, and one where he's not. I am not using speech views.
I figured I'd use a bool variable to indicate whether a sound clip is playing or not, and if it's false, the not talking animation would play.
What functions can be used for if any sounds are playing or if none at all are? Thanks.