Truck vexing vibration and sound

My 2009 Dodge Ram 2500 with diesel engine, intermittantly makes a noise similar to the sound knobby tires make. It also sounds similar to the exhaust brake, but louder. A vibration accompanies the noise. Two mechanics (one a tire expert, one at a Dodge dealer) test drove it and examined it on their racks and said it’s the right front wheel bearing/hub assembly. I replaced that, despite not hearing or feeling any problem when rotating the wheel by hand. I’ve examined all tires and turned the wheels by hand while listening for odd sounds or roughness, and examined all drive shafts and joints which have not apparent problem, to no avail. When this issue first started, I heard a sound like rubber squeaking while driving at very low speed, especially in reverse. Please help!

The noise speeds up and slows down with road speed. Engine speed has no effect.