under hard braking i hear a humming noise come from the rear. i never noticed it til i changed the rear pads about a month ago but i listen to my music loud so it couldve done it before. is there anything i should check or be worried about? thanx in advance

 

nobody? it doesnt sound like its coming from the brakes and theres a slight vibration too. at first i passed it off as abs but from what i read here the abs noises come from the front.