I had the same problem with my 2009 ltz crew cab. Took off the bug deflector, noise gone.

 

I have the AVS bug screen and went to the dealer for the wind noise issue. They told me the procedure was to remove the bug screen and drive the truck, then add a GM bug screen and test drive again. I did some research and found a fix that GM recommends for the wind noise. I put some black 2 sided tape on each side of the windshield between the trim on the vertical side of the windshield. Wind noise solved... Now road noise is very noticeable from the rear corner of the truck. WTH!

 

My 2013 Silverado CC has a GM approved bug deflector and it makes noises on the passenger side in certain windy conditions and speeds over 60 mph. The noise was no were as annoying as the last one I commented on. Get rid of the deflector I guess.
Also had it undercoated for road noise/corrosion purposes.