[Dave at Pelican Parts]

Hmmm....

Well, CV joints usually go click-click-click-click when they start to go. Wheel bearings usually start to roar. Both will change with road speed.

Since neither engine speed nor road speed seem to have anything to do with it, that would appear to rule out the common squeaks.

About the only guess I have is that you have a brake pad that is dragging on the rotor. Does the noise change when you hit the brakes? Does it change if you pull up on the handbrake?

--DD