Identifying defective wheel bearing

Hello, at speeds from approx. 70 km/h I have a loud, dry rolling noise while driving straight. In left turns nothing changes, in right turns it becomes quieter. Now I have the car in front, started and let the wheels blow. No noise. When rolling out on the bucks first the right wheel stops, without noises. After that the left wheel comes to a stop. But shortly before stop a audible rumor occurs. I am pretty sure that the noises ache is a wheel bearing. But how can I determine for sure which one it is?