Sleeper's noise (5)
I believe the answer is:
snore
'sleeper's noise' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for snore that I've seen before include "Make racous nocturnal sound" , "Sound made by sleeper" , "How to keep someone awake while sleeping?" , "Noise indicating sleep" , "Raucous sound while sleeping" .)