Answer:

earplug

Answer	Crossword Clue
EARPLUG	Swimmer's stopper
EARPLUG	Noise blocker
EARPLUG	One of a swimmer's pair

EARPLUG	Sound stopper
EARPLUG	Stick it in your auditory canal
EARPLUG	Noise reducer
EARPLUG	Sleeping aid
EARPLUG	Radio addendum.
EARPLUG	Swimmer's protection
EARPLUG	Din deadener
EARPLUG	Silencer of a sort

EARPLUG	Silencer?
EARPLUG	Noise blocker-outer
EARPLUG	Sound barrier
EARPLUG	Sleep aid