Ключевые слова: acoustic, alarm, alert, amplifier, announce, apartment, attention, audio, brick wall, broadcast, building, cloudy, communication, danger, disaster, earthquake, electric, emergency, emit, equipment, evacuation, event, horn, information, loudspeaker, megaphone, message, metallic, mouthpiece, news, no people, noise, notify, outdoor, population, public, safety, security, signal, siren, sky, sound, speaker, storm, system, tell, urgent, warning, weather,