Glissando illusion
Encyclopedia
The 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 both switched back and forth between stereo
loudspeakers. The effect is that the oboe is heard as switching between loudspeakers while the sine wave is heard as joined together seamlessly, and as moving around in space in accordance with its pitch motion. Right-handers often hear the glissando
as traveling from left to right as its pitch glides from low to high, and then back from right to left as its pitch glides from high to low. Left-handers often obtain different illusions.
Diana Deutsch
Diana Deutsch is a British-American perceptual and cognitive psychologist, born in London, England. She is currently Professor of Psychology at the University of California, San Diego, and is one of the most prominent researchers on the psychology of music...
in Musical Illusions and Paradoxes, 1995. An auditory illusion
Auditory illusion
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...
, it is created when a sound with a fixed pitch, such as a synthesized oboe
Oboe
The oboe is a double reed musical instrument of the woodwind family. In English, prior to 1770, the instrument was called "hautbois" , "hoboy", or "French hoboy". The spelling "oboe" was adopted into English ca...
tone, is played together with a sine wave
Sine wave
The sine wave or sinusoid is a mathematical function that describes a smooth repetitive oscillation. It occurs often in pure mathematics, as well as physics, signal processing, electrical engineering and many other fields...
gliding up and down in pitch, and they are both switched back and forth between stereo
Stereophonic sound
The term Stereophonic, commonly called stereo, sound refers to any method of sound reproduction in which an attempt is made to create an illusion of directionality and audible perspective...
loudspeakers. The effect is that the oboe is heard as switching between loudspeakers while the sine wave is heard as joined together seamlessly, and as moving around in space in accordance with its pitch motion. Right-handers often hear the glissando
Glissando
In music, a glissando is a glide from one pitch to another. It is an Italianized musical term derived from the French glisser, to glide. In some contexts it is distinguished from the continuous portamento...
as traveling from left to right as its pitch glides from low to high, and then back from right to left as its pitch glides from high to low. Left-handers often obtain different illusions.