Metal grill making a rasping sound (7)
I believe the answer is:
grating
I believe this is a double definition.
'metal grill' is the first definition.
(a grating is a metal framework)
'making a rasping sound' is the second definition.
(grate can mean to rasp or scrape)
(Other definitions for grating that I've seen before include "Harsh sounding" , "Lattice" , "Unpleasantly harsh in sound" , "Irritating - framework of bars" , "Wearing away" .)