3d
3d illustration
advertisement
alert
amplifier
announce
announcement
attention
audible
audio
be heard
blueprint
broadcasting
bullhorn
call
communication
concept
device
drawing
electric
electronic
emergency
equipment
frame
horn
illustration
industry
line
lines
loud
loudspeaker
megaphone
message
outline
portable
project
public
shout
shouting
sketch
sound
speak
speaker
structure
symbol
voice
volume
wireframe