Ключевые слова: advertisement, advertising, alert, amplifier, announce, announcement, attention, audio, broadcast, broadcasting, bullhorn, cartoon, communicate, communication, concept, design, equipment, graphic, icon, illustration, isolated, loud, loudspeaker, media, megaphone, message, news, object, promotion, propaganda, protest, public, red, scream, shout, sign, sound, speak, speaker, speech, symbol, vintage, voice, volume, warning, web,