MountainManMyke

Hey guys, I have a wierd humming sound coming from my truck. It makes this sound when my truck has sat in the driveway for 1 or 2 days. When I start to drive it humms, kind of like when you blow onto a beer bottle. After about ten minutes it starts to fade and eventually goes away. What can this be? One of my brake calipers? wheel bearing? I have no idea!! Thanks guys