Ключевые слова: advertisement, alertness, amplifier, announcement message, audio electronics, audio equipment, broadcasting, business, communication, danger, dictionary, discussion, document, education, education training class, english language, french language, german language, language, learning, library, literature, megaphone, message, multilingual, music, noise, propaganda, protest, public speaker, screaming, shouting, solution, spanish language, speaker, speech, student, studying, symbol, talking, teaching, the media, tourism, translation, voice, wisdom,