英文關鍵字
background
calm
care
cone
deaf
ear
earplug
ears
equipment
explosion
foam
guard
hear
horizontal
industrial
isolated
loss
loud
medical
nobody
noise
object
orange
pair
peace
plug
plugs
pollution
prevention
protect
protection
protective
purple
reduction
regulation
round
rubber
safe
safety
shot
silence
soft
sound
sponge
swimming
tools
vertical
white
work
yellow