Ключевые слова: alarm, alert, amplifier, announce, announcement, broadcast, cctv, city, concept, electric, electronics, gray, green, guard, industry, information, lens, light, loud, loudspeaker, megaphone, modern, object, office, pole, power, privacy, protection, retro, round, safety, security, shout, sky, sound, speak, speaker, speech, steel, street, symbol, system, technology, video, vintage,