Ключевые слова: activism, advertising, alert, amplification, announcement, attention, audio, broadcasting, close up, communication, communication device, communication equipment, crowd control, demonstration, detail, emergency, information, loud, marketing, megaphone, message, news, old, political campaign, promotion, propaganda, protest, public address, public speaking, rally, retro, revolution, riot, social movement, sound, speaker, speech, technology, vintage, voice, volume, warning, yellow,