Ключевые слова: above, abstract, acoustic, advertising, alert, amplification, announce, arrangement, attention, audio, black, broadcast, campaign, central, circle, cluster, communication, communication technology, concept, design, directional, dissemination, equipment, information, loud, marketing, megaphone, message, multiple, news, order, organization, pattern, perspective, propaganda, public address, public speaking, radial, repetitive, sound, speak, symmetrical, symmetry, technology, voice, volume, white,