My 2005 has a humming noise from the passenger side whenever I make a slight left turn at speeds above about 40 MPH. The sound level does not change whether I press accelerator or coasting. This existed for almost a year and it gets a little louder over the time. I always suspect the passenger side bearing but there is no detectable looseness or any play when I manually shake the wheel (car on jack stands), nor any roughness when manually spin the wheels. What else can this possibly be? I don't want to just replace the bearing if I am not sure of it. The tires have about 50K miles but look fairly even with enough tread left.