Auditory illusion
Encyclopedia
An auditory illusion is an illusion
of hearing
, the aural equivalent of an optical illusion
: the listener hears
either sounds which are not present in the stimulus
, or "impossible" sounds. In short, auditory illusions highlight areas where the human ear and brain
, as organic, makeshift tools, differ from perfect audio receptors (for better or for worse).
Examples of auditory illusions:
Illusion
An illusion is a distortion of the senses, revealing how the brain normally organizes and interprets sensory stimulation. While illusions distort reality, they are generally shared by most people....
of hearing
Hearing (sense)
Hearing is the ability to perceive sound by detecting vibrations through an organ such as the ear. It is one of the traditional five senses...
, the aural equivalent of an optical illusion
Optical illusion
An optical illusion is characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a perception that does not tally with a physical measurement of the stimulus source...
: the listener hears
Hearing (sense)
Hearing is the ability to perceive sound by detecting vibrations through an organ such as the ear. It is one of the traditional five senses...
either sounds which are not present in the stimulus
Stimulus (physiology)
In physiology, a stimulus is a detectable change in the internal or external environment. The ability of an organism or organ to respond to external stimuli is called sensitivity....
, or "impossible" sounds. In short, auditory illusions highlight areas where the human ear and brain
Human brain
The human brain has the same general structure as the brains of other mammals, but is over three times larger than the brain of a typical mammal with an equivalent body size. Estimates for the number of neurons in the human brain range from 80 to 120 billion...
, as organic, makeshift tools, differ from perfect audio receptors (for better or for worse).
Examples of auditory illusions:
- hearing a missing fundamentalMissing fundamentalA sound is said to have a missing fundamental, suppressed fundamental, or phantom fundamental when its overtones suggest a fundamental frequency but the sound lacks a component at the fundamental frequency itself....
frequency, given other parts of the harmonic seriesHarmonic series (music)Pitched musical instruments are often based on an approximate harmonic oscillator such as a string or a column of air, which oscillates at numerous frequencies simultaneously. At these resonant frequencies, waves travel in both directions along the string or air column, reinforcing and canceling... - Various psychoacoustic tricks of lossy Audio compressionAudio compressionAudio compression may refer to:*Audio compression , a type of lossy compression in which the amount of data in a recorded waveform is reduced for transmission with some loss of quality, used in CD and MP3 encoding, Internet radio, and the like...
- Binaural beatsBinaural beatsBinaural beats or binaural tones are auditory processing artifacts, or apparent sounds, the perception of which arises in the brain for specific physical stimuli...
- Deutsch's scale illusionDeutsch's scale illusionDiscovered by Diana Deutsch in 1973, Deutsch's "scale illusion" is an auditory illusion in which principles of grouping by frequency proximity and spatial location are put into conflict with each other and in which frequency proximity wins out...
- Glissando illusionGlissando illusionThe glissando illusion was first reported and demonstrated by Diana Deutsch in Musical Illusions and Paradoxes, 1995. An auditory illusion, it is created when a sound with a fixed pitch, such as a synthesized oboe tone, is played together with a sine wave gliding up and down in pitch, and they are...
- Illusory continuity of tonesIllusory continuity of tonesThe illusory continuity of tones is the auditory illusion caused when a tone is interrupted for a short time , during which a narrow band of noise is played...
- McGurk effectMcGurk effectThe McGurk effect is a perceptual phenomenon which demonstrates an interaction between hearing and vision in speech perception. "It is a compelling illusion in which humans perceive mismatched audiovisual speech as a completely different syllable". The visual information a person gets from seeing a...
- Octave illusionOctave illusionDiscovered by Diana Deutsch in 1973, the octave illusion is an auditory illusion produced by simultaneously playing two sequences of two notes that are spaced an octave apart, high to low, and low to high, in separate stereo channels over headphones...
/Deutsch's High-Low Illusion - Phantom rings
- the Shepard toneShepard toneA Shepard tone, named after Roger Shepard, is a sound consisting of a superposition of sine waves separated by octaves. When played with the base pitch of the tone moving upward or downward, it is referred to as the Shepard scale. This creates the auditory illusion of a tone that continually...
or scale, and the Deutsch tritone paradox
See also
- Auditory systemAuditory systemThe auditory system is the sensory system for the sense of hearing.- Outer ear :The folds of cartilage surrounding the ear canal are called the pinna...
- Barber pole -- auditory illusions compared to visual illusions
- Doppler effectDoppler effectThe Doppler effect , named after Austrian physicist Christian Doppler who proposed it in 1842 in Prague, is the change in frequency of a wave for an observer moving relative to the source of the wave. It is commonly heard when a vehicle sounding a siren or horn approaches, passes, and recedes from...
– not an illusion, but real physical phenomenon - HolophonicsHolophonicsHolophonics is a binaural recording system created by Hugo Zuccarelli that is claimed to be based on the claim that the auditory system acts as an interferometer. The sound characteristics of Holophonics are most clearly heard through headphones, though can be demonstrated to be effective with 2...
- Pitch circularityPitch circularityPitch is often defined as extending along a one-dimensional continuum from high to low, as can be experienced by sweeping one’s hand up or down a piano keyboard. This continuum is known as pitch height...
- PsychoacousticsPsychoacousticsPsychoacoustics is the scientific study of sound perception. More specifically, it is the branch of science studying the psychological and physiological responses associated with sound...
- TinnitusTinnitusTinnitus |ringing]]") is the perception of sound within the human ear in the absence of corresponding external sound.Tinnitus is not a disease, but a symptom that can result from a wide range of underlying causes: abnormally loud sounds in the ear canal for even the briefest period , ear...
External links
- Demonstrations of various auditory illusions at Kyushu Institute of DesignKyushu Institute of DesignKyushu Institute of Design in Fukuoka, Japan is one of Japan's prestigious national universities and was founded in April, 1968...
- Diana Deutsch's Web Page
- The Virtual Barber - Selection of Auditory Illusions