Auditory illusions are false perceptions of a real sound or outside stimulus. These false perceptions are the equivalent of an optical illusion: the listener hears either sounds which are not present in the

stimulus A stimulus is something that causes a physiological response. It may refer to: *Stimulation **Stimulus (physiology), something external that influences an activity **Stimulus (psychology), a concept in behaviorism and perception *Stimulus (economi ...

, or sounds that should not be possible given the circumstance on how they were created. Humans are fairly susceptible to illusions, despite an innate ability to process complex stimuli. Confirmation bias is believed to be largely responsible for the inaccurate judgments that people make when evaluating information, given that humans typically interpret and recall information that appeals to their own biases. Amongst these misinterpretations, known as illusions, falls the category of auditory illusions. The brain uses multiple senses simultaneously to process information, spatial information is processed with greater detail and accuracy in vision than in hearing. Auditory illusions highlight areas where the human ear and

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a ve ...

, as organic survival tools, differentiate from perfect audio receptors; this shows that it is possible for a human being to hear something that is not there and be able to react to the sound they supposedly heard. When someone is experiencing an auditory illusion, their brain is falsely interpreting its surroundings and distorting their perception of the world around them.

Causes

Many auditory illusions, particularly of music and of speech, result from hearing sound patterns that are highly probable, even though they are heard incorrectly. This is due to the influence of our knowledge and experience of many sounds we have heard. In order to prevent hearing echo created by perceiving multiple sounds coming from different spaces, the human auditory system relates the sounds as being from one source. However, that does not prevent people from being fooled by auditory illusions. Sounds that are found in words are called embedded sounds, and these sounds are the cause of some auditory illusions. A person's perception of a word can be influenced by the way they see the speaker's mouth move, even if the sound they hear is unchanged. For example, if someone is looking at two people saying "far" and "bar", the word they will hear will be determined by who they look at. If these sounds are played in a loop, the listener will be able to hear different words inside the same sound. People with brain damage can be more susceptible to auditory illusions and they can become more common for that person.

In music

Composers have long been using the spatial components of music to alter the overall sound experienced by the listener. One of the more common methods of sound synthesis is the use of combination tones. Combination tones are illusions that are not physically present as sound waves, but rather, they are created by one's own neuromechanics. According to Purwins, auditory illusions have been used effectively by the following:

Beethoven Ludwig van Beethoven (baptised 17 December 177026 March 1827) was a German composer and pianist. Beethoven remains one of the most admired composers in the history of Western music; his works rank amongst the most performed of the classic ...

(Leonore Overture),

Berg Berg may refer to: People *Berg (surname), a surname (including a list of people with the name) *Berg Ng (born 1960), Hong Kong actor * Berg (footballer) (born 1989), Brazilian footballer Former states * Berg (state), county and duchy of the Hol ...

(''

Wozzeck ''Wozzeck'' () is the first opera by the Austrian composer Alban Berg. It was composed between 1914 and 1922 and first performed in 1925. The opera is based on the drama '' Woyzeck'', which the German playwright Georg Büchner left incomplete at ...

''), Krenek (''Spiritus Intelligentiae, Sanctus''), Ligeti ( Études),

Violin Concerto A violin concerto is a concerto for solo violin (occasionally, two or more violins) and instrumental ensemble (customarily orchestra). Such works have been written since the Baroque period, when the solo concerto form was first developed, up thro ...

, Double Concerto, for flute, oboe and orchestra),

Honegger Arthur Honegger (; 10 March 1892 – 27 November 1955) was a Swiss composer who was born in France and lived a large part of his life in Paris. A member of Les Six, his best known work is probably ''Antigone'', composed between 1924 and 1927 to ...

(''

Pacific 231 ''Pacific 231'' is an orchestral work by Arthur Honegger, written in 1923. It is one of his most frequently performed works. Description The popular interpretation of the piece is that it depicts a steam locomotive, one that is supported by th ...

''), and Stahnke (Partota 12). In the 2017 film, Dunkirk, Hans Zimmer used a Shepard Tone to create a constant feeling of stress and tension.

Examples

There are a multitude of examples out in the world of auditory illusions. These are examples of some auditory illusions: * Binaural beats * The

constant spectrum melody A constant timbre at a constant pitch is characterized by a spectrum. Along a piece of music, the spectrum measured within a narrow time window varies with the melody and the possible effects of instruments. Therefore, it may seem paradoxical tha ...

Deutsch's scale illusion Deutsch's scale illusion is an auditory illusion in which two series of unconnected notes appear to combine into a single recognisable melody, when played simultaneously into the left and right ears of a listener. The illusion is produced by sim ...

Franssen effect The Franssen effect is an auditory illusion where the listener incorrectly localizes a sound. It was found in 1960 by Nico Valentinus Franssen (1926–1979), a Dutch physicist and inventor. There are two classical experiments, which are related ...

Glissando illusion The glissando illusion is an auditory illusion, 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 both switched back and forth between stereo lou ...

* Illusory continuity of tones *

Illusory discontinuity Illusory discontinuity is an auditory illusion in which a continuous ongoing sound becomes inaudible during a brief, non-masking noise. The illusion is perceived only by some listeners, but not by others, reflecting individual variation in he ...

* Hearing a

missing fundamental A harmonic 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. The brain perceives the ...

frequency, given other parts of the harmonic series *Various psychoacoustic tricks of

lossy audio compression In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compressio ...

* McGurk effect *

Octave illusion The octave illusion is an auditory illusion discovered by Diana Deutsch in 1973. It is produced when two tones that are an octave apart are repeatedly played in alternation ("high-low-high-low") through stereo headphones. The same sequence is p ...

/Deutsch's high–low illusion * Auditory

pareidolia Pareidolia (; ) is the tendency for perception to impose a meaningful interpretation on a nebulous stimulus, usually visual, so that one sees an object, pattern, or meaning where there is none. Common examples are perceived images of animals, ...

: hearing indistinct voices in random noise. * The Shepard–Risset tone or scale, and the

Deutsch tritone paradox __NOTOC__ The tritone paradox is an auditory illusion in which a sequentially played pair of Shepard tones separated by an interval of a tritone, or half octave, is heard as ascending by some people and as descending by others. Different populat ...

Speech-to-song illusion The speech-to-song illusion is an auditory illusion discovered by Diana Deutsch in 1995. A spoken phrase is repeated several times, without altering it in any way, and without providing any context. This repetition causes the phrase to transform p ...

* Yanny or Laurel

References

External links

Diana Deutsch's Web Page
{{Music cognition Music psychology Psychoacoustics

Causes

In music

Examples

See also

References

External links