Ключевые слова: alert, amp, amplification, amplifier, announce, announcement, antenna, audio, blue, broadcast, bunch, cable, calling, column, communication, electric, emit, information, isolated, light, loud, loudspeaker, many, masts, megaphone, music, noise, old, outdoor, pillar, power, public, red, relay, shout, sky, sound, speaker, system, trumpets, voice, volume, warning, white,