I pitched noise. Think it might be rodar. on 2004 Honda Civic

When I back up or I am driving for awhile a get a high pitched grinding steel noise that only lasts for about 10 seconds and then disappears.

Asked by for the 2004 Honda Civic
I suspect the sound may indicate the rear brake pads are worn. There is a metal finger attached to the brake pads, as the pads wear the finger is allowed to touch the brake disc emitting a loud high pitched squeal.