93 cadillac deville, 4.9 touring. drives fine, no vibrations. i speed up to say 60 miles and hour, goes fine, when i let my foot off of the gas i can hear a very faint hum when i get to 45 mph or close to...im deaf in one ear so its hard to pin point where its coming from. tires are fine, not enough tread on them to have that kind of road noise. i thought maybe the cv axle???? description again, not loud at all, very lov humming. never done it before and ive had the car for almost 2 and a half years now. your help will be appreciated, thanks.