2001 Taurus with 171,000 miles makes a noise that sounds like a worn wheel bearing. This is loudest at about 1800 RPM and occurs whether I accelerate in Park or while in gear. Slight vibration while driving at highway speeds.

Bearings are good.
Tires are in balance.

 

Sometimes we loosen the serpentine belt and rotate each pulley it contacts to see if we can fine one that isn't rotating smoothly or find one that is actually making the unusual noise.