Ключевые слова: abstract, adult, audience, auditorium, auditory, background, blur, blurred, boardroom, business, busy, class, classroom, college, concept, conference, corporate, crowd, education, group, hall, high, knowledge, large, learning, lecture, listening, meeting, men, people, person, presentation, public, room, row, school, seminar, sit, speaker, speaking, studying, teacher, teaching, technology, training, university, watching, women, world, young,