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Auditory Illusions
Auditory illusions are illusions of 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, 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, as organic survival tools, differentiate from per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illusion
An illusion is a distortion of the senses, which can reveal how the mind normally organizes and interprets sensory stimulation. Although illusions distort the human perception of reality, they are generally shared by most people. Illusions may occur with any of the human senses, but visual illusions ( optical illusions) are the best-known and understood. The emphasis on visual illusions occurs because vision often dominates the other senses. For example, individuals watching a ventriloquist will perceive the voice as coming from the dummy since they are able to see the dummy mouth the words. Some illusions are based on general assumptions the brain makes during perception. These assumptions are made using organizational principles (e.g., Gestalt theory), an individual's capacity for depth perception and motion perception, and perceptual constancy. Other illusions occur due to biological sensory structures within the human body or conditions outside the body within one's phys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binaural Beats
In acoustics, a beat is an Interference (wave propagation), interference pattern between two sounds of slightly different frequency, frequencies, ''perceived'' as a periodic variation in amplitude (music), volume whose rate is the Difference (mathematics), difference of the two frequencies. With Musical tuning, tuning instruments that can produce sustained tones, beats can be readily recognized. Tuning two tones to a unison will present a peculiar effect: when the two tones are close in pitch but not identical, the difference in frequency generates the beating. The volume varies as in a tremolo as the sounds alternately interfere constructively and destructively. As the two tones gradually approach unison, the beating slows down and may become so slow as to be imperceptible. As the two tones get further apart, their beat frequency starts to approach the range of human pitch perception, the beating starts to sound like a note, and a combination tone is produced. Mathematics and phy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pareidolia
Pareidolia (; ) is the tendency for perception to impose a meaningful interpretation on a nebulous stimulus (physiology), stimulus, usually visual, so that one detects an object, pattern, or meaning where there is none. Pareidolia is a specific but common type of apophenia (the tendency to perceive meaningful connections between unrelated things or ideas). Common examples include Cloud#In culture and religion, perceived images of animals, faces, or objects in cloud formations; seeing faces in inanimate objects; or lunar pareidolia like the Man in the Moon or the Moon rabbit. The concept of pareidolia may extend to include hidden messages in recorded music played in reverse or at higher- or lower-than-normal speeds, and hearing voices (mainly indistinct) or music in random noise, such as that produced by air conditioners or by fans. Face pareidolia has also been demonstrated in Rhesus macaque, rhesus macaques. Etymology The word derives from the Greek words ''wikt:para-, pará'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 played to both ears simultaneously; however when the right ear receives the high tone, the left ear receives the low tone, and conversely. Instead of hearing two alternating pitches, most subjects instead hear a single tone that alternates between ears while at the same time its pitch alternates between high and low. First experiment The two tones used were pitched at 400 Hz and 800 Hz, corresponding roughly to G4 and G5 in modern pitch notation. Each tone was played for 250 ms before switching ears. No gaps were allowed between tones. Both tones were therefore always present during the experiment; only the ears perceiving the high and the low tone at any one time changed repeatedly. After the initial test, the headphones w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. The visual information a person gets from seeing a person speak changes the way they hear the sound. If a person is getting poor-quality auditory information but good-quality visual information, they may be more likely to experience the McGurk effect. Integration abilities for audio and visual information may also influence whether a person will experience the effect. People who are better at sensory integration have been shown to be more susceptible to the effect. Many people are affected differently by the McGurk effect based on many factors, including brain damage and other disorders. Background It was first described in 1976 in a paper by Harry McGurk and John MacDonald, titled "Hearing Lip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 compression reduces bits by identifying and eliminating Redundancy (information theory), statistical redundancy. No information is lost in lossless compression. Lossy compression reduces bits by removing unnecessary or less important information. Typically, a device that performs data compression is referred to as an encoder, and one that performs the reversal of the process (decompression) as a decoder. The process of reducing the size of a data file is often referred to as data compression. In the context of data transmission, it is called source coding: encoding is done at the source of the data before it is stored or transmitted. Source coding should not be confused with channel coding, for error detection and correction or line coding, the means ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harmonic Series (music)
The harmonic series (also overtone series) is the sequence of harmonics, musical tones, or pure tones whose frequency is an integer multiple of a ''fundamental frequency''. Definite pitch, Pitched musical instruments are often based on an Acoustics, acoustic resonator such as a String (music), string or a column of air, which Oscillation, oscillates at numerous Normal mode, modes simultaneously. As waves travel in both directions along the string or air column, they reinforce and cancel one another to form standing waves. Interaction with the surrounding air produces audible sound waves, which travel away from the instrument. These frequencies are generally integer multiples, or harmonics, of the Fundamental frequency, fundamental and such multiples form the Harmonic series (mathematics), harmonic series. The fundamental, which is usually perceived as the lowest #Partial, partial present, is generally perceived as the Pitch (music), pitch of a musical tone. The musical timbre of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Missing Fundamental
The pitch being perceived with the first harmonic being absent in the waveform is called the missing fundamental phenomenon. It is established in psychoacoustics that the auditory system, with its natural tendency to distinguish a tone from another, will persistently assign a pitch to a complex tone given that a sufficient set of harmonics are present in the spectrum. For example, when a note (that is not a pure tone) has a pitch (music), pitch of 100 hertz, Hz, it will consist of frequency components that are integer multiples of that value (e.g. 100, 200, 300, 400, 500.... Hz). However, smaller loudspeakers may not produce low frequencies, so in our example, the 100 Hz component may be missing. Nevertheless, a pitch corresponding to the fundamental may still be heard. Explanation A low pitch (psychophysics), pitch (also known as the pitch of the missing fundamental or virtual pitch) can sometimes be heard when there is no apparent source or component of that frequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 hearing abilities. It has been estimated that among young adults 24% are susceptible to illusory discontinuity.Vinnik E, Itskov PM, Balaban E (2011).Individual differences in sound-in-noise perception are related to the strength of short-latency neural responses to noise" PLoS One. 6(2): e17266. . 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 (50 ms). Longer sounds elicit weaker illusory discontinuity; this effect may be related to better auditory segregation. Relation to other auditory illusions Illusory discontinuity is antagonistic with illusory continuity of tones (auditory filling-in). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illusory Continuity Of Tones
The illusory continuity of tones is the auditory illusion caused when a tone is interrupted for a short time, during which a narrow band of noise is played. The noise has to be of a sufficiently high level to effectively mask the gap, unless it is a gap transfer illusion. Whether the tone is of constant, rising or decreasing pitch, the ear perceives the tone as continuous if the discontinuity is masked by noise. Because the human ear is very sensitive to sudden changes, however, it is necessary for the success of the illusion that the amplitude of the tone in the region of the discontinuity not decrease or increase too abruptly. While the inner mechanisms of this illusion is not well understood, there is evidence that supports activation of primarily the auditory cortex is present. Relation to Other Auditory Illusions Illusory continuity is antagonistic with illusory discontinuity. While illusory continuity restores perceptual continuity of obscured sounds, illusory disconti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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. The effect was first reported and demonstrated by Diana Deutsch Diana Deutsch (born 15 February 1938) is a British-American psychologist from London, England. She is a professor of psychology at the University of California, San Diego, and is a prominent researcher on the psychology of music. Deutsch is ... in ''Musical Illusions and Paradoxes'', 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 to the Franssen effect, called Franssen effect F1 and Franssen effect F2. Franssen effect F1 There are two loudspeakers to the left and right of the listener. Each is about 1 meter in distance from the listener, at approximately 45° angles. The left speaker suddenly begins to produce a sharp pure tone. The two speakers are complementary to each other: i.e., as one increases, the other decreases. The left one is decreased exponentially, and the right speaker becomes the main source of the sound. The listener mistakenly perceives the sound as only coming from the left speaker, although the right speaker has been on most of the time. Franssen effect F2 Experiment Inside a room (auditorium) there are two loudspeakers at different position ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
