英文關鍵字
address
alert
amp
amplification
amplifier
amplify
angry
announce
announcement
audio
background
blue
broadcast
bunch
communicate
communication
concept
deafening
electric
equipment
forest
green
horn
information
loud
loudspeaker
media
megaphone
message
music
noise
object
outdoor
power
public
siren
sky
sound
speak
speaker
sports
system
talk
technology
tree
trend
voice
volume
wall
warning