Hearing no noise coming from The Nag's Head? (5)
I believe the answer is:
neigh
'noise coming from the nag's head?' is the definition.
'hearing no' is the wordplay.
'hearing' shows a homophone (sound like).
'no' becomes 'nay' (I've seen this before).
'nay' sounds like 'NEIGH'.
(Other definitions for neigh that I've seen before include "Whinnying sound" , "Animal noise (expressing 3?)" , "The noise of a bay" , "Comment from Arab" , "Comment from stallion" .)