I also hear a humming type noise that increases with speed and changes with cornering. Thought it might be tires except i just bought 4 new and noise is even a bit louder. Thought it was wind noise too but it sounds too mechanical. 6 months ago i took it to mr lube thinking maybe bearings or tie rods etc. I was told it could not be lubed as it was a sealed unit (which seems dumb), he could not even tell if. that was the problem.
Could a better mechanic tell if the sealed units are the problem?
Does the sound change when the steering wheel is turned off-center (i.e. changing lanes)? That is an indication of bad bearings. When both front bearings went bad on my 2000 Blazer right after new tires were installed, I thought the noise was the new tires. My mechanic diagnosed bad bearings at the next oil change.
Unfortunately, the entire hub has to be replaced at around $350 a pop (remanufactured). With labor and a new set of brake pads, the total was ~$900. The dealer would have been considerably more.