strange noise coming from the rear wheels

[matt4pl]

ok, so i was driving and i noticed this sound coming from the rear right wheel, its metallic sounding, but also kind of like air escaping, a mix, and its not always there, it seems to start after hitting a larger bump or accelerating from a stop to maybe over 30 or above, varies, it doesnt sound like breaks squealing, so i dunno, maybe a bearing? possibly the strut or maybe a warped rotor or bad alignment, but it just started suddenly from what i can tellalso, theres that sound again when going over bumps and whatnot, but its barely audiable, however, it gets a bit louder and more intense/frequent when braking, and doesnt start up until accelerating for a bit

[NISTECH]

check your backing plate see if its rubbing the rotor.