Nasal sound (5)
I believe the answer is:
twang
'nasal sound' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for twang that I've seen before include "Pluck (a string)" , "A nasal intonation in speech, or sound of guitar" , "Distinctive nasal style of pronunciation" , "Nasal or musical sound" , "heard when listening to The Archers?" .)