Audial (auditory) illusions

It has been estimated that among young adults 24% are susceptible to illusory discontinuity. The most susceptible listeners describe their sensations in terms of the sound actually containing a physical gap. The illusory discontinuity is strongest when the interrupting sound is short (50ms). Longer sounds elicit weaker illusory discontinuity; this effect may be related to better auditory segregation.

Auditory illusions

References:

• an auditory illusion is an illusion of hearing, the sound equivalent of an optical illusion;
• the listener hears either sounds which are not present in the stimulus, or "impossible" sounds;
• audio illusions highlight areas where the human ear and brain, as organic, makeshift tools, differ from perfect audio receptors

http://en.wikipedia.org/wiki/Illusion

http://bcs.worthpublishers.com/psychsim5/Auditory%20System/PsychSim_Shell.html

http://en.wikipedia.org/wiki/Illusory_discontinuity

http://en.wikipedia.org/wiki/Franssen_effect

https://en.wikipedia.org/wiki/McGurk_effect

Auditory system

• the sensory system for the sense of hearing
• picks up stimulus energy from the outer world
• changes that energy into a pattern of neural impulses
• carries those impulses to the proper location in the brain
• processes the information contained in the pattern of impulses so that the stimulus can be identified

Shepard Tone

• Roger N. Shepard, a Psychologist who in 1964 experimented with the frequencies that make pitches sound either high or low from tones and then analyzed how the brain would process these tones.
• Shepard created a “pitchless” cycle of Shepard Tones and looped them over and over again.
• Each preceding Shepard Tone sounds as if it is lower than the next, while the proceeding tones sound higher than the last, even though we are actually just hearing a loop of the same tones over and over.

Illusory discontinuity

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 hearing abilities.

http://en.wikipedia.org/wiki/Illusory_discontinuity

Franssen effect

The term illusion refers to a specific form of sensory distortion. Unlike a hallucination (which is a distortion in the absence of a stimulus) an illusion describes a misinterpretation of a true sensation.

For example, hearing voices regardless of the environment would be a hallucination, while hearing voices in the sound of running water (or any other auditory source) would be an illusion.

• found in 1960 by Nico Valentinus Franssen (1926 – 1979), a Dutch Physicist and Inventor;
• an auditory illusion where the listener incorrectly localizes a sound;
• two classical experiments, which are related to the Franssen effect, called Franssen effect F1 and Franssen effect F2.

Illusions

• an illusion is a distortion of the senses, revealing how the brain normally organizes and interprets sensory stimulation;
• though illusions distort reality, they are generally shared by most people;
• illusions may occur with any of the human senses.

McGurk effect

The McGurk effect is a perceptual phenomenon that demonstrates an interaction between hearing and vision in speech perception. The illusion occurs when the auditory component of one sound is paired with the visual component of another sound, leading to the perception of a third sound.

Audial (auditory) illusions