英文關鍵字
noise
ear
person
protection
safety
earplug
loud
equipment
quiet
sound
silence
male
protective
care
man
hearing
prevention
people
hear
inserting
noisy
hand
plug
health
caucasian
adult
reduce
soft
decibel
calm
view
rest
quietness
muffled
home
wearing
human
bedtime
relaxation
comfort
foam
audible
eardrum
muted
industry
medical
hold
reduction
relax