Ключевые слова: advertisement, alert, amplifier, announce, announcement, attention, audible, audio, background, broadcasting, bullhorn, call, communication, concept, cutout, device, electric, electronic, emergency, equipment, horn, isolated, loud, loudspeaker, mega, megaphone, message, music, nobody, object, one, phone, portable, power, proclaim, public, shout, single, sound, speak, speaker, support, symbol, voice, volume, white,