The noise only happens at 56mph or higher. I don't hear it before 56mph but I do it after. It sounds like the same humming sound you would hear if you are driving over semi rough pavement and your hear your tires hum. This happens on any road and it sounds like it is coming from the drivers side tire. It seems unlikely that it is a tire issue or even a bearing issue if the sound doesn't increase with speed and it only starts at around 56mph.... Anyone have any suggestions?