Ключевые слова: alarm, alert, amplifier, announce, announcement, argentiera, attention, audio, background, blue, broadcast, broadcasting, church, communicate, communication, electric, electronic, equipment, high, horn, information, italy, loud, loudspeaker, megaphone, message, metal, nobody, noise, object, old, outdoor, public, roof, sardegna, sardinia, siren, sky, sound, speak, speaker, street, symbol, system, technology, urban, vintage, voice, volume, warning,