So a month later after replacing rotors and brakes I still hear this humming noise from the front drivers side. It's more of a constant squealing that doesnt go away until I slow down. I read various articles how you can really tell if its the wheel bearing if you do a couple of tests. One of them requires you to put your car in neutral and tap the gas pedal to see if it makes the noise. If you don't hear the noise then it's not your wheel bearings. Well, I didnt hear it when I tried it. So another article stated it could be the tranny!! UGH ... I dropped it off at Firestone this morning and the guy is arguing w/ me saying wheel bearings dont make humming noises. I said look just check it out, your growling could be my squealing/humming. If the damn thing can fall out due to a wheel bearing, I want to make sure we rule it out. I have no idea what it is, and when toyota had my car last month they couldnt figure out what it was. But that was because the noise occurred randomly. These past few days, I've heard it each time I drove the car.