Roaring sound at 30-40 MPH has appeared.

[ToddFord]

My '10 ES350, with 124,000 very smooth miles on it, has developed a sound that "resembles" a cupping sound from feathered-edge tires.  My tires were about 2/3rd's gone, so I purchased a new set of Michelins this weekend.  Had a 4-wheel alignment done, it was near perfect - no adjustments made.  Sound is still there.  First, while driving on asphalt, on a straight stretch, between 30-40 MPH, it is very evident.  Then, while driving through "s-curves" on smooth asphalt at 50 MPH, it is even louder.  I am at a loss for diagnosis.  Any experience with this from you all?  Any input is appreciated.

[gbhrps]

TddFord,

Sounds like a bad wheel bearing. To know for sure, get onto a road free of traffic and at various constant speeds, swerve the car back and forth. If the sound (roar) varies in volume or type of sound when swaying, the bearing is going south. To know for sure, have a good independent mechanic drive the car or put it on a hoist while idling and in gear. He'll be able to hear it with a stethoscope.

It is possible that you could also have a bad half axle shaft with a worn CV joint.