Resounding sound of vocal group briefly dividing England (7)
I believe the answer is:
echoing
'resounding sound' is the definition.
(an echo is a repeating or resounding sound)
'vocal group briefly dividing england' is the wordplay.
'vocal group' becomes 'choir' (group of vocalists).
'briefly' means to remove the last letter.
'dividing' is an insertion indicator.
'england' becomes 'eng' (abbreviation).
'choir' with its final letter taken away is 'choi'.
'choi' going within 'eng' is 'ECHOING'.
'of' acts as a link.
(Other definitions for echoing that I've seen before include "Repetition" , "sending back imitations" , "Reverberating" , "Copying" , "Resounding" .)