2005 Chevy Cavalier humming noise

I have had a humming noise and a vibrating noise within the area of my hub bearing unit on the driver side. I thought if I was to replace the hub bearing the noises would go away. I had to do the same on the passenger side and the noise did go away. But on the driver it didnt, when i replaced the hub bearing the vibration went away but the humming noise did not. It normally gets a little louder when i reach past 45 mph. I have also checked the cupping of the tire and my tire is not cupping or wearing out other then normal wear and tear. I dont know what else the problem could be? could you help me