Please Help!

I have a 2002 silhouette. There is a noise coming from the front. I can only hear it inside the van, not outside. The noise sounds like a small plane about to take off. My husband says it's a flapping noise. We cannot find the cause. I can't hear it when I make a hard right turn or when we are at a stop. Could it be a bad cv joint? Unbalanced tires? Please help.