1998 Dodge Stratus driver's side whining

My car has been making a very high pitched whine for over a year, coming from the driver's side front wheel area. It starts when the car gets to about 35 mph, and becomes more instense the faster you're driving. It does not matter whether your accelerating or coasting, the noise continues until you dip below about 20 mph, whether breaking or not. Our mechanic has repacked the ball bearings and checked the suspension, but neither seems to have been the issue. It was mentioned that the problem could be a u-joint, but I didn't think my front-wheel drive vehicle had them. It is definitely not a belt issue, either; in 2006 we replaced the timing and serpentine belts, and just recently replaced the timing belt again due to a failed pulley that shredded it. Is this a noise I should learn to live with, or should I get it fixed?