This is a recording of Shepard’s ascending tones, also called Shepard’s Paradox. When you listen to the recording two or more times in quick succession, the pairs of chords sound as if they’re advancing up the scale with each successive play.
Is it real, or are your ears deceiving you?
Auditory illusions are illusions of hearing -- the sound equivalent of an optical illusion where your eyes deceive you. Depending on the illusion created, you may hear sounds that are not present in the recording, or other “impossible” sounds. These illusions highlight areas where your ear and brain differ from perfect audio receptors, for better or worse.
In Shepard’s Paradox, the starting pair of chords is in fact the same as the finishing pair, creating an auditory illusion that the pitch gets higher with each play. If you looped this sample seamlessly, it should be impossible to tell where the sample begins and where it ends.
