Ключевые слова: alert, amplifier, amplify, announcement, asphalt, audio, blue, boulevard, broadcast, buildings, call to action, campaign, city, cityscape, concept, convey, downtown, downtown area, electronics, equipment, expression, information, infrastructure, loudspeaker, megaphone, message, modern, noise, outdoor, propaganda, protest, public, public address system, road, roadside, signal, skyscrapers, sound, sound equipment, speak, speak out, street, technology, traffic, urban, urban scene, vocal, voice, warning,