Ключевые слова: address, advertising, alert, amplifier, announce, announcement, attention, audio, background, broadcast, broadcasting, building, cluster, communicate, communication, concepts, connected, doodles, equipment, guard, hanging, horn, image, industry, information, loud, loudspeaker, megaphone, message, microphone, music, news, old, out, projector, promotional, public, screaming, shout, siren, sound, speak, speaker, system, talk, talking, urban, voice, volume, wall,