bearings will shift pitch at speed. At a speed of 35 to 45 windows up, air off, radio off, listen as you drive straight down a smooth paved road. Now take a slow left, turn right, turn left shifting the cars weight from side to side.
Bad bearings will make noise as they become loaded. The right rear would likely make noise when you turn left and weight is transferred to the rightside.
Beyond that, block the car, jack the rear, have a helper spin the wheel (brake off), place stethoscope to the hub area. If it sounds like gravel, its bad or going bad. It more likely you hear the wisp of the brakes dragging. Try not to confuse the two.
Listen to the engines alternator for perspective on a bearing. It'll be loud with a stick to you ear.
hint: broom handles cut down, long screw drivers, and stethoscope are handy for listening to noises. Use a paper towel tube to listen to vacuum leaks, coil sparks jumping, ect. . .
How many miles on the 92?