Shepard Tone - Created by psychologist Roger Shepard at Bell Labs, this illusion is made of a list of tones that seem to perpetually increase or tumble. The illusion is designed by super-positioning pure tones (sine waves) an octave aside. An optical illusion. Equally circles are the same shade https://homeworld-352962.full-design.com/the-basic-principles-of-illusion-of-kundun-mu-online-78102878