The voice is carrying one right back (5)
I believe the answer is:
tenor
'the voice' is the definition.
(one of the voices in a choir say)
'carrying one right back' is the wordplay.
'carrying' is an insertion indicator.
'right' becomes 'rt' (abbreviation as in Rt Hon- the Right Honourable).
'back' says the letters should be written in reverse.
'one' inserted into 'rt' is 'ronet'.
'ronet' written backwards gives 'TENOR'.
'is' acts as a link.
(Other definitions for tenor that I've seen before include "Pavarotti, maybe" , "High male singing voice like Pavarotti" , "intent" , "Meaning - male singing voice" , "Placido Domingo, say" .)