Deliver a forceful speech and hear a gun going off (8)
I believe the answer is:
harangue
'deliver a forceful speech' is the definition.
(I've seen this before)
'hear a gun going off' is the wordplay.
'going off' is an anagram indicator (letters go or move around).
'hear'+'a'+'gun'='hearagun'
'hearagun' with letters rearranged gives 'HARANGUE'.
'and' acts as a link.
(Other definitions for harangue that I've seen before include "Loud and agressive speech" , "Rant" , "Exhortation" , "urgent words" , "Loud angry speech" .)