Grinding Noise while Cruising

Hey y’all,
My 2000 Toyota Sienna has been making some concerning noises. It makes a periodic grinding noise, the period is related to the wheel speed…i.e. the noise happens once each time the wheel goes around. I can hear it while I drive, and it’s even louder when I roll down the windows. The weird thing is that the noise stops when I hit either the breaks or the gas. First mechanic says that the wheel bearings are shot, and the second says they’re fine. There is no “jet engine taking off” noise that I am told is typical of shot bearings, but there is a wump-wump-wump noise at higher speeds. Let me know what y’all think!
Giorgio

Perhaps, creaking is a better word to describe the noise…greaking?