Fringe report? (4)
I believe the answer is:
bang
This clue is a double definition.
'fringe' is the first definition.
(I've seen this before)
'report?' is the second definition.
(report can mean a loud noise)
(Other definitions for bang that I've seen before include "Sound of a gunshot" , "Sudden noise; fringe" , "Loud noise; fringe" , "Straight fringe of hair" , "Completely modern" .)