Quote Originally Posted by unit View Post
You have not shared what the vehicle is. The advice given without specific details on the year make and model of the vehicle are shots on the dark.

Bad tire wear (cupping) can cause the same sort of noise. If you can swerve and the pitch changes it points to a bearing and not tires.

On a rear wheel drive a bad bearing can trickle into several other more expensive problems.

On a front wheel drive a bad rear bearings can erode quickly into serious safety issues in short order on some models...and sometimes they will howl for months without issues.

The safest course of action is to not drive it without solid advice from a qualified technician.

I could tell you all sorts of stories about bearings (good and bad).

I hope this helps, if you want to pm me with specifics, I'd be happy to try and help, but it's hard to be certain without inspecting it myself.
Exactly what he said. I would get it checked immediately can turn very serious or dangerous in very short order.