Okay, I'm having a little problem that requires some explanation.

We are doing experiments on event representation that involves looking at videos. The videos I shot have sound that the participants do not need to hear. We also present what the main events of interest are in a video before we show it to them. Ideally, we could do this aurally. However, right now, we have to just turn the sound off so the videos cannot be heard, and participants just have to read the focus events aloud (so we are sure they have read them).

I have tried several techniques, including using a modified silence file as a backsound, and even trying to make a backsound that is exactly out of phase with the movie sound to cancel out the sound (I was proud of coming up with this idea, but in practice, it seems nearly impossible).

So, the question is, how do I make the sound for the video go away and still have audio availible for aural presentation of stimulus? Note that I cannot (with the software at hand) simply delete the sound track of the video, or else this would be no problem.

Thanks:-)