It would be quite unusual for both sides of wheel bearings to go south at once. The classic tell for wheel bearings is that the growl or whine gets louder when cornering. And if you corner, more force is placed on the outer side of the turn - turn right and your left side wheel bearings have more force on them, so if it gets louder when turning one direction, the bearing is usually the one opposite the direction of the turn.

Rgds,
Chris W.
'95 E300D