I agree with Pedro on the bearing/tire noise. When a bearing goes bad it's because grease has escape and the bearing is overheating from friction and is beginning to breakup. The sound is something like driving on a paved country road with those little rocks at the surface. You also should here it about 20-30 mph miles an hour...loudest at about 50-60. Also check your trans-axle. Have you had your alignment checked.
