Auditory illusion are false perceptions of a real sound/outside stimulus. These false perceptions are the equivalent of an optical illusion: the listener hears either sounds which are not present in the stimulus, or sounds that should not be possible given the circumstance on how they were created.  Auditory illusions highlight areas where the human ear and brain, 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.
Causes of Auditory Illusions
Sounds that are found in words are called embedded sounds and these sounds are the causation of auditory illusions. These sounds can be recreated simply by changing how you form your mouth while saying the word; same word yet someone could hear two different sounds. For example, if someone is looking at two different people saying "far" and "bar", the word they will hear will be determined by who they look at.
There are a multitude of different examples out in the world of auditory illusions. These are examples of some auditory illusions:
- Binaural beats
- The constant spectrum melody
- Deutsch's scale illusion
- Franssen effect
- Glissando illusion
- Illusory continuity of tones
- Illusory discontinuity
- Hearing a missing fundamental frequency, given other parts of the harmonic series
- Various psychoacoustic tricks of lossy audio compression
- McGurk effect
- Octave illusion/Deutsch's High-Low Illusion
- Auditory pareidolia: Hearing indistinct voices in random noise.
- The Shepard-Risset tone or scale, and the Deutsch tritone paradox
- Speech-to-Song illusion
- Yanny or Laurel
According to Purwins, auditory illusions have been used effectively by various composers, e.g. Beethoven (Leonore), Berg (Wozzek), Krenek (Spiritus Intelligentiae Sanctus), Ligeti (Piano etudes, Violin Concerto, Doppelkonzert für Flöte, Oboe und Orchester), Honegger (Pazific), Stahnke (Partota), Reutter (The Shephard's Flute from Orchestral Set No. 1).
- Auditory system
- Barber pole – auditory illusions compared to visual illusions
- Diana Deutsch
- Doppler effect – not an illusion, but real physical phenomenon
- Jean-Claude Risset
- Musical acoustics
- Phantom rings
- Pitch circularity
- Sharawadji effect
- "ScienceDirect". www.sciencedirect.com. Retrieved 2019-04-19.
- "Auditory illusion: How our brains can fill in the gaps to create continuous sound". Science Daily. Science Daily. Retrieved February 20, 2019.
- Massaro, Dominic W., ed. (2007). "What Are Musical Paradox and Illusion?" (PDF). American Journal of Psychology. University of California, Santa Cruz. 120 (1): 124, 132. Retrieved 15 November 2013.
- "Auditory Illusions: How your ears can be fooled". hear.com. Retrieved 2019-04-19.
- "Do You Hear What I Hear? Amazing Auditory Illusions Explained". IFLScience. Retrieved 2019-04-21.
- Purwins, Hendrik (2005). Profiles of pitch classes circularity of relative pitch and key-experiments, models, computational music analysis, and perspectives (PDF). pp. 110–120.