Event Objects sound etc..

Im currently in the final stages of making my model I have the all other parts completed, the only problem I have right now is Event Objects. The art tutorials blizzard provided very briefly mention these things and give no "how-to" as far as I've seen. Anyway if anyone could tell me how/ and or link me to a tutorial. I would be a very happy man, and I could finish my current model who needs a rifle sound when he fires his gun.

This model is from scratch..