Vocally twangy (5)
I believe the answer is:
nasal
'vocally twangy' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for nasal that I've seen before include "Of sound, as if it came through the nose" , "of central feature" , "To do with nose, say sound" , "front piece of helmet" , "Sounding affected by cold" .)