Find out about noise (6)
I believe the answer is:
rumble
This clue is a double definition.
'find out about' is the first definition.
(I've seen this before)
'noise' is the second definition.
(I know that rumble is a type of noise)
(Other definitions for rumble that I've seen before include "be wise to" , "Make a continuous resonant sound" , "Find out the truth" , "Sound of distant thunder" , "Thunder, perhaps" .)