Rear Disc Brakes

I have a 2002 Honda Accord EX 4 Cyl with rear disc brakes. When I go in reverse and apply the brakes I hear a whinning or maybe a low sounding scraping or grinding noise. Could the problem be that I need new rear disc brakes?

Thank you

It would be a good idea to have the brakes checked. The noise could be a sign of worn brake pads.