For the last few weeks I've had the humming sound that sounded very much like a failed bearing from the front drivers side. I took it in to have it replaced along with the ball joints on both front sides. I also had the tires rotated while it was in the shop.
However, once I pick it up and take it on the road I find that I am still getting the humming sound that starts getting louder as I speed up (although not as loud as before) coming from the front end.

Its not transmission or engine noise as I shifted to neutral and coasted at 100 kph...the humming was still there.

Is there something else that that could be producing this sound? Could it be the rotated tires just needing to "get settled in"?
Or could it be something with the trans axle?