Stun with noise (6)
I believe the answer is:
deafen
'stun with noise' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for deafen that I've seen before include "Drown out" , "Overwhelm with sound" , "Cause to lose hearing as from explosion" , "Cause to lose sense of hearing" , "Cause to lose the power of hearing" .)