Since last night I've been noticing this strange noise. It's a humming with a very faint vibration when driving. When I cross over bridges you can hear it more audibly which sounds like a tire rubber flapping like it's blown. I have checked all tires and all the pressure is good at 110 psi, 120 steers. Tread only has 50k on them and there are no missing tread spots or wear on any tires.
Ideas?