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Volley Theory
Volley theory states that groups of neurons of the auditory system respond to a sound by firing action potentials slightly out of phase with one another so that when combined, a greater frequency of sound can be encoded and sent to the brain to be analyzed. The theory was proposed by Ernest Wever and Charles Bray in 1930 as a supplement to the frequency theory of hearing. It was later discovered that this only occurs in response to sounds that are about 500 Hz to 5000 Hz. Description The volley theory was explained in depth in Ernest Wever's 1949 book, Theory of Hearing Groups of neurons in the cochlea individually fire at subharmonic frequencies of a sound being heard and collectively phase-lock to match the total frequencies of the sound. The reason for this is that neurons can only fire at a maximum of about 500 Hz but other theories of hearing did not explain for hearing sounds below about 5000 Hz. Harmonic spectrums Sounds are often sums of multiple fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurons
A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. Non-animals like plants and fungi do not have nerve cells. Neurons are typically classified into three types based on their function. Sensory neurons respond to stimuli such as touch, sound, or light that affect the cells of the sensory organs, and they send signals to the spinal cord or brain. Motor neurons receive signals from the brain and spinal cord to control everything from muscle contractions to glandular output. Interneurons connect neurons to other neurons within the same region of the brain or spinal cord. When multiple neurons are connected together, they form what is called a neural circuit. A typical neuron consists of a cell body (soma), dendrites, and a single axon. The soma is a compact structure, and the axon and dend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg Von Békésy
Georg von Békésy ( hu, Békésy György, ; 3 June 1899 – 13 June 1972) was a Hungarian-American biophysicist. By using strobe photography and silver flakes as a marker, he was able to observe that the basilar membrane moves like a surface wave when stimulated by sound. Because of the structure of the cochlea and the basilar membrane, different frequencies of sound cause the maximum amplitudes of the waves to occur at different places on the basilar membrane along the coil of the cochlea. High frequencies cause more vibration at the base of the cochlea while low frequencies create more vibration at the apex. He concluded that his observations showed how different sound wave frequencies are locally dispersed before exciting different nerve fibers that lead from the cochlea to the brain. In 1961, he was awarded the Nobel Prize in Physiology or Medicine for his research on the function of the cochlea in the mammalian hearing organ. Biography Békésy was born on 3 June 1899 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensorineural Hearing Loss
Sensorineural hearing loss (SNHL) is a type of hearing loss in which the root cause lies in the inner ear or sensory organ (cochlea and associated structures) or the vestibulocochlear nerve (cranial nerve VIII). SNHL accounts for about 90% of reported hearing loss . SNHL is usually permanent and can be mild, moderate, severe, profound, or total. Various other descriptors can be used depending on the shape of the audiogram, such as high frequency, low frequency, U-shaped, notched, peaked, or flat. ''Sensory'' hearing loss often occurs as a consequence of damaged or deficient cochlear hair cells. Hair cells may be abnormal at birth or damaged during the lifetime of an individual. There are both external causes of damage, including infection, and ototoxic drugs, as well as intrinsic causes, including genetic mutations. A common cause or exacerbating factor in SNHL is prolonged exposure to environmental noise, or noise-induced hearing loss. Exposure to a single very loud noise such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Missing Fundamental
A harmonic sound is said to have a missing fundamental, suppressed fundamental, or phantom fundamental when its overtones suggest a fundamental frequency but the sound lacks a component at the fundamental frequency itself. The brain perceives the pitch of a tone not only by its fundamental frequency, but also by the periodicity implied by the relationship between the higher harmonics; we may perceive the same pitch (perhaps with a different timbre) even if the fundamental frequency is missing from a tone. For example, when a note (that is not a pure tone) has a pitch of 100 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, and 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 (also known as the pitch of the missing fundamental ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illustration Of Common Periodicity Of Full Spectrum And Missing Fundamental Waveforms
An illustration is a decoration, interpretation or visual explanation of a text, concept or process, designed for integration in print and digital published media, such as posters, flyers, magazines, books, teaching materials, animations, video games and films. An illustration is typically created by an illustrator. Digital illustrations are often used to make websites and apps more user-friendly, such as the use of emojis to accompany digital type. llustration also means providing an example; either in writing or in picture form. The origin of the word "illustration" is late Middle English (in the sense ‘illumination; spiritual or intellectual enlightenment’): via Old French from Latin ''illustratio''(n-), from the verb ''illustrare''. Illustration styles Contemporary illustration uses a wide range of styles and techniques, including drawing, painting, printmaking, collage, montage, digital design, multimedia, 3D modelling. Depending on the purpose, illustration ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronic Oscillators
An electronic oscillator is an electronic circuit that produces a periodic, oscillating electronic signal, often a sine wave or a square wave or a triangle wave. Oscillators convert direct current (DC) from a power supply to an alternating current (AC) signal. They are widely used in many electronic devices ranging from simplest clock generators to digital instruments (like calculators) and complex computers and peripherals etc. Common examples of signals generated by oscillators include signals broadcast by radio and television transmitters, clock signals that regulate computers and quartz clocks, and the sounds produced by electronic beepers and video games. Oscillators are often characterized by the frequency of their output signal: *A low-frequency oscillator (LFO) is an electronic oscillator that generates a frequency below approximately 20 Hz. This term is typically used in the field of audio synthesizers, to distinguish it from an audio frequency oscillator. *An au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bad Reichenhall Rückpositiv
Bad or BAD may refer to: Common meanings *Evil, the opposite of moral good * Erroneous, inaccurate or incorrect *Unhealthy, or counter to well-being *Antagonist, the threat or obstacle of moral good Acronyms * BAD-2, a Soviet armored trolley car * Bank account debits tax, an Australian tax * Bcl-2-associated death promoter, a pro-apoptotic protein * Team B.A.D., a professional wrestling tag team Films * ''Andy Warhol's Bad'', a 1977 film * ''Bad'', an unfinished film by Theo van Gogh Music Performers * B. A. D., the Taiwanese boy band, who formed in 1998 * Big Audio Dynamite, Mick Jones' post-Clash band, from London * Royce da 5'9", the American rapper known as Bad, in the group Bad Meets Evil Albums * ''Bad'' (album), a 1987 album by Michael Jackson * ''BAD'', or ''Bigger and Deffer'', the second album by LL Cool J, 1987 Songs * "Bad" (U2 song), 1984 * "Bad" (Michael Jackson song), 1987 * "Bad", from the 2011 album ''Symphony Soldier'' by The Cab * "Bad" (Wale song), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Max Friedrich Meyer
Max Friedrich Meyer (June 14, 1873 – March 14, 1967) was the first psychology professor who worked on psychoacoustics and taught at the University of Missouri. He was the founder of the theory of cochlear function, and was also an advocate for behaviourism as he argued in his book "The Psychology of the Other". During his time at the University of Missouri, he opened an experimental lab for Psychology and taught a variety of courses. His lab focused on behavioural zeitgeist and the studies of nervous system and behaviour. Meyer eventually moved to Miami and lived there from 1932 until the late 1950s. Afterwards, he moved to Virginia to stay with his daughter until his death in 1967. Early life Max Friedrich Meyer was born in Germany in the city of Danzig on June 14, 1873. He was the son of a goldsmith and went to school in Germany. In 1892, he went to the University of Berlin where he enrolled in theology, but he studied other subjects. He became a professor of experimen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Rutherford (physiologist)
William Rutherford (20 April 1839, Ancrum Craig, Roxburghshire – 21 February 1899, 14 Douglas Crescent, Edinburgh) was a Scottish physician and physiologist. For 25 years he was professor of physiology at the University of Edinburgh, and contributed to the development of experimental physiology. He was Fullerian Professor of Physiology and Comparative Anatomy from 1872 to 1875. Life Rutherford was born at Ancrum Craig Farm near Ancrum in Roxburghshire, the son of Elizabeth (née Bunyan) Thomas Rutherford, a farmer and landowner. He was educated at Jedburgh Grammar School then studied medicine at the University of Edinburgh, gaining his doctorate (MD) in 1863. After studying in Berlin, Vienna, and Paris, he became assistant to John Hughes Bennett, professor of physiology at the University of Edinburgh. After the Edinburgh anatomist John Goodsir told Rutherford about the new experimental physiology in Germany, William Rutherford and the ophthalmologist Douglas Argyll Robert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heinrich Adolf Rinne
Heinrich Adolf Rinne (January 24, 1819 – July 26, 1868) was a German otologist born in Vlotho an der Weser. He received his doctorate from the University of Göttingen and practiced medicine in the city of Göttingen. Later he was a physician in Sandstadt near Stade (1857) and Hildesheim (1860). In 1855 Rinne described the combined conductive process of the tympanic membrane and the ossicles of the middle ear. He is known for the eponymous Rinne test. The Rinne test is a hearing test conducted with a tuning fork, and is used to test and compare a patients' hearing via air conduction (normal process) or by way of bone conduction (sound to the inner ear through the mastoid). He reasoned that if a person hears a sound for a longer period of time through bone conduction than through air conduction, a disease is present somewhere in the conduction apparatus. Despite his research, "Rinne's test" wasn't generally recognized until after his death — in the early 1880s, otologists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basilar Membrane
The basilar membrane is a stiff structural element within the cochlea of the inner ear which separates two liquid-filled tubes that run along the coil of the cochlea, the scala media and the scala tympani. The basilar membrane moves up and down in response to incoming sound waves, which are converted to traveling waves on the basilar membrane. Structure The basilar membrane is a pseudo-resonant structure that, like the strings on an instrument, varies in width and stiffness. But unlike the parallel strings of a guitar, the basilar membrane is not a discrete set of resonant structures, but a single structure with varying width, stiffness, mass, damping, and duct dimensions along its length. The motion of the basilar membrane is generally described as a traveling wave. The properties of the membrane at a given point along its length determine its characteristic frequency (CF), the frequency at which it is most sensitive to sound vibrations. The basilar membrane is widest (0.42– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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