Major report produced by a VIP (3,5)
I believe the answer is:
'a vip' is the definition.
(I've seen this before)
'major report produced by' is the wordplay.
'major' becomes 'big' (I've seen this in other clues).
'report' becomes 'noise' (a report is a loud sound like an explosion).
'produced by' says to put letters next to each other.
(Other definitions for big noise that I've seen before include "Important person (colloq.)" , "VIP" , "An important person, sounds loud" , "uproar" , "Important man (colloq.)" .)