Chevy Cobalt Clicking Noise - What is it?

My Cobalt has 38k miles on it. It's never been abused. My wife drives it and I maintain it. Yesterday, I was in it as a passenger and as we were traveling in a straight line on the interstate I could hear a distinct slapping sound. It's not brake related and it's not a front end problem. It sounded more like something flopping around erratically like a wire or a chain was hitting something. I jacked up each front wheel and spun them to and fro. The clicking noise can be head from either side. If it's a bearing it appears to be internal. My other guess is: It may be related to the traction control parts inside the case. Maybe a chain is hitting inside? Any other suggestions?