Order maintained initially in sound offensive (7)
I believe the answer is:
noisome
'offensive' is the definition.
('noisome' can be similar in meaning to 'offensive')
'order maintained initially in sound' is the wordplay.
'initially' suggests taking the first letters.
'in' is an insertion indicator.
'sound' becomes 'noise' (noising is a kind of sounding**).
The first letters of 'order maintained' is 'om'.
'om' going within 'noise' is 'NOISOME'.
(Other definitions for noisome that I've seen before include "Harmful - noxious" , "Evil-smelling, objectionable (7)" , "unhealthy" , "Foul-smelling, noxious" , "Harmful - offensive" .)