2004 Silverado, noise near windsield

I just picked up a 2004 Chevy Silvirado short box diesel and when I drive around 60 MPH I can hear this light rattle noise around the Bose speakers which are mounted on the windshields interior molding.
Has anyone ever come across this? I was wondering if it could be the speaker wires behind the molding where the speakers are mounted. It's like air is getting up there and moving the wires. I find it annoying.......
Looking forward to any replies. Thanks

Do you have a bugshield on the truck?

i tool have a noise kind of like that sort of sounds like a peice of ice is rattling on the outside cowl right in front of the windshield. I do have a bug deflector.

The reason I ask if you have a budshield is because I had this same problem after installing my bug shield. What happens is the bug shield changes the way the air flows around the truck and causes the weatherstripping around the windshield and the plastic inserts at the top of the hood to flap around. I fixed it by running a bead of silicone under the weatherstripping and around the plastic inserts (which were pretty loose). No more noise at highway speeds.