Begin to bite back producing a nasal tone (5)
I believe the answer is:
twang
'a nasal tone' is the definition.
(I've seen this before)
'begin to bite back' is the wordplay.
'begin' says to take the initial letters.
'bite' becomes 'gnaw' (gnawing is a kind of biting).
'back' says the letters should be written backwards.
The initial letter of 'to' is 't'.
'gnaw' written backwards gives 'wang'.
't'+'wang'='TWANG'
'producing' is the link.
(Other definitions for twang that I've seen before include "Nasal tone or sound of plucked string" , "Local accent" , "way of speaking" , "ringing sound" , "Strongly nasal quality in speech" .)