2005 Chevy Silverado Cricket Noises Coming from under my tr

While riding down the road with my windows down, I can hear a noise that sounds like a handful of crickets coming from underneath the driver's side. I cannot tell if it is coming from the front or the rear, but it is on the driver's side. It seems to occur when I hit a bump or drive down a rough road.

The only thing that I have had done to my car is to have the torsion bars turned slightly to raise the front end.

Any ideas?