How to Sync Animated sound source to Video Playback ?

Hey Guys, first of all I am pretty new to Unity and I am working on a demo video playback with animated sound sources, but i struggle to find a way to sync the animated sound source to the video. I can only see the video playback when I start the scene, is that right or is there a solution to start the video already in Editing mode so that i can freely animate and sync the animation to the video ?

I am looking for something like this: http://www.bing.com/videos/search?q=spatial+audio+mix+&&view=detail∣=F0151D74E7B7E057A2E3F0151D74E7B7E057A2E3&FORM=VRDGAR

which would be prestine, but a solution within the editor mode is also superb.

So does anyone of you know a solution ?

Greetz,

Paul