Drive it down the road. If the left hand bearing is going then on a right hand corner (you load the left bearing in this bend) the bearing will be noisy. On a left hand bend (the left bearing is now not under load) then it will be quite.
Obviously this will be the opposite for the right hand wheel bearings.There does not need to be play in the bearing for it to be noisy but the wheel movement check is a good place to start
This works for the fronts as well.