Kevin,

Had a similar problem once that turned out to be a front wheel bearing, it was very hard to try to pinpoint where this noise was coming from and I eventually lifted the front end and spun a front wheel with one hand with my fingers of the other hand on the front strut and I could actually feel a slight vibration in the strut of the offending wheel bearing. Replaced the bearing on that wheel and the noise was gone and then replaced the other front wheel bearing just in case.

Might be worth a try to see if you can feel any vibration at the strut.

Vincent.