Sound illusion

Audio illusions can occur in perfectly healthy people under the influence of stress, excitement, unusual conditions. In each case, psychologists find an explanation.

Such illusions there are many. This, for example, sound barriers (or, as scientists call them, the sound of the mirror) is the distortion associated with the different length of the sound wave.

Will give some well-known illusions with examples taken from the site molomo.ru

Hidden stairs

Sound illusion called "the hidden stairs", was discovered by Diana Deutsch (Diana Deutsch's), Professor of psychology, which obviously proves that the human brain can group together adjacent notes.

To demonstrate this effect, you lose two songs, increasing and decreasing in tone, the notes are for the ears of a man with different perception. For example, one ear may hear, as if alternately - first the first note of the first melody, then the second note of the second melody.

The brain of most of the students groups high and low notes together, so different ears, one hears decreasing, increasing sequence of sounds (in one ear) and Vice versa, increasing, decreasing - the other ear.

Right-handed right ear hears the first - rising tone, left-handed - the opposite is true. Out of this chaotic set of notes and tones, the brain selects the appropriate melody and takes with it our consciousness (the perception of sound).

Increasing sequence

The opening of the "increasing sequence" or the paradox of the shepherd belongs to the French composer Jean-Claude RISS (Jean-Claude Risset), and is reflected in the fact that the two notes following in succession, create the illusion of ascending sound (like when you press a key on a piano from left to right).

In reality, the rising tone is missing, and if you run this tune countless times in a row, people will perceive a constant increase in tone, although it can't be, it's an audio illusion created by the brain "on my own".

Falling bells

Sound illusion called "falling" bells, is that heard in a recording of the ringing of the bells "falling down" with decreasing pitch.

However, listening carefully, one understands that the tone increases. That is, the initial pitch is lower than at the end.

Accelerating drums

The meaning of the illusion of "accelerating" the drums is that they actually sound the same, although it seems that the pace is constantly increasing. Listen carefully!

Virtual Barber shop

The illusion called experts "virtual Barber shop" is a phenomenon of the binaural effect, and is the ability of humans and animals to determine which side of them is the source of the sound due to having two ears, performing the function of a sound receiver (the source located in front or rear, is defined poorly and inaccurately).

Due to the fact that the sound goes to the ear closest to its source, the shorter the path, the sound waves in the ear canals have different phases (through this phase) and amplitude (force) of sound vibrations. Therefore, the perception of sound of varying heights will be different. The direction of the sound source for low sounds (up to 1500 oscillations/second) is determined by the human mind the most accurate and almost entirely on the transit-time difference of the phase of the sound waves.

And for high sounds, due to the fact that the main importance is the difference in the strength of the sound from right and left ear, the direction will be less accurate. The ability to determine the direction of the sound occurs, due to the fact that the difference of the phase and intensity of the sounds perceived by the ear, leads to the distinction of pulses which act in the Central nervous system from the right and left ear.

Matchbox

Well-known specialists of the stereo effect, a kind of audio illusion - "matchbox". To achieve the result of its origin, it is necessary to close eyes.

Three notes

The paradox called "three notes" researched and also Diana Deutsch (Diana Deutsch's), in the sound recording you can listen to several grouped the notes for each listener perceives differently.

The difference is that some people perceive them as falling tone as rising. This phenomenon is known since ancient times, then it was considered the devil's work.

Phantom melodies

Phantom melodies is called audio illusion that can be created with the help of some tunes, consisting of quick losses, and only very slightly different from each other. With the rapid loss tunes the brain is able to "highlight" at the speed of some single notes and "compose" their own tune.

The slow loss of the same composition, a similar sound illusion does not occur due to the ability of the mind to have time to take all the right part of the losses.

An illustration of this phenomenon can serve the song Rustle of Spring, performed quickly, in this case in consciousness will occur about the melody, the slow performance of the sound the illusion disappears.

Phantom words

This illusion was first demonstrated by Diana Deutsch at the University of California in San Diego. The entry is similar to overlapping sequences of repeating words or phrases, located in different points of space.

Listening to them, you start to recognize certain phrases. Although in fact, no phrases, no. Your brain is their own, with the goal to give meaning to meaningless noise.

How young we were ...

With age, people lose the ability to hear high frequencies. This sound can only be heard by those who have not yet celebrated its own coming-of-age (though even among older people, there are exceptions, but they are quite rare) - its frequency is 18,000 Hz (by the way, your dog is absolutely sure to hear this sound).

Some teenagers set the sound as ringtone of the mobile phone, so only they (and of course their peers) can hear the call. In some countries this sound is very loud in those places in which you do not want the appearance of youth.

Stonehenge

Very interesting history of giant stones, in Stonehenge (England), they have an amazing ability to create sonic illusions that are not mirages acoustic character. The discovery and justification of this phenomenon belongs to the American researcher Steven Waller archaeoacoustics scientist who conducted research about the acoustics of the famous architectural ensemble, built in the South of England more than 5000 years ago.

If two musicians are playing the trumpet, standing in the center of this structure, there is an amazing sound effect in some places around the musicians, the sounds of their game are not heard, the observers "hear" the silence. Waller explains this by the fact that sound waves reflected from the rocks and devour each other, resulting in around musicians formed a "magic circle" of complete silence.

People invited by the researcher to conduct the experiment with a blindfold stood in the center of this circle and listen to the two trumpeters. Falling in a dead sound area, they began to hear sounds, and then told me that they imagined the obstacle (in reality it was absent) between them and the trumpeters.

Sound illusion for mentally ill people

Completely different origins and explanations are sound illusion for mentally ill people. As a rule, audible illusions take the form of cries, voices and abuse, suspicious (for the patient) whisper, shots and entire cannonading, singing, orchestral music. Sometimes the patient is in an obscure extraneous noise can "hear" private conversations involving different people, sometimes it "hears" those voices, sometimes he hears it strangers to him. These audio illusions "invents" sick mind, giving a completely foreign sound stimuli for distinct speech.

As in other cases of illusions of various types, doctors try to separate the illusion from the sound of auditory hallucinations. In the first case is the alleged erroneous perception of patients of extraneous noise, and in the second by mereschatsya sounds. And in one, and in another case, there is a unifying phenomenon - all "conversations" are, as a rule, the guilty and condemning the sick person's character.

Rarely, there is a phenomenon in which sound illusion calm the patient and get him to calm down. Usually sound illusion amplified in a noisy environment, when a large amount of sound and noise provokes the consciousness of the sick person to "hear" conversations. In case of wrong perception of sounds there is an effect of sound illusion.

Translated by «Yandex.Translator»