I'm getting a cupping/ buffering sound whenever it's 60mph and up on the rear passenger tire. Threw it up on jacks and there seems to a slight wear down the center....tires were set at 35psi, which I normally do during winter to mitigate the Pothole bumps - especially with 20"s. I've set it around 34-35 for the last 12 years with no problem. However, the centers of both rear tires do have a bit more wear so I dropped the psi down to 32.

Not sure if the noise is tires or not.
Maybe when the sides wear down the noise will go away ?
I am only hearing it on the rear passenger side though.

Just short of throwing it up on the rack and getting the wheels turning with someone prying to confirm the slop on the wheel bearing , is there another way to diagnose this noise ?