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Binaural Unmasking
Binaural unmasking is phenomenon of auditory perception discovered by Ira Hirsh. In binaural unmasking, the brain combines information from the two ears in order to improve signal detection and identification in noise. The phenomenon is most commonly observed when there is a difference between the interaural phase of the signal and the interaural phase of the noise. When such a difference is present there is an improvement in masking threshold compared to a reference situation in which the interaural phases are the same, or when the stimulus has been presented monaurally. Those two cases usually give very similar thresholds. The size of the improvement is known as the "binaural masking level difference" (BMLD), or simply as the "masking level difference". Binaural unmasking is most effective at low frequencies. The BMLD for pure tones in broadband noise reaches a maximum value of about 15 decibels (dB) at 250 Hz and progressively declines to 2-3 dB at 1500 Hz. The BM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ira Hirsh
Ira Hirsh (February 22, 1922 – January 12, 2010) was an American psychologist who made early contributions to the field of audiology. He was the Edward Mallinckrodt Distinguished University Professor of Psychology and Audiology at Washington University in St. Louis (WUSTL) and served as president of the Acoustical Society of America. Biography Born in New York, Hirsh earned an undergraduate degree from the University at Albany, SUNY, New York State College for Teachers. While earning a master's degree at the Northwestern University School of Communication, Northwestern University School of Speech, he worked for a CBS Radio station in Chicago as a staff announcer and radio drama actor. After serving in the United States Army Air Forces, US Army Air Force, Hirsh earned a Ph.D. at Harvard University, where he conducted research at the Psycho-Acoustics Laboratory (PAL) under Stanley Smith Stevens. He took a position at the PAL before joining the Central Institute for the Deaf (CID). H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noise
Noise is unwanted sound considered unpleasant, loud or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference arises when the brain receives and perceives a sound. Acoustic noise is any sound in the acoustic domain, either deliberate (e.g., music or speech) or unintended. In contrast, Noise (electronics), noise in electronics may not be audible to the human ear and may require instruments for detection. In audio engineering, noise can refer to the unwanted residual electronic noise signal that gives rise to acoustic noise heard as a Hiss (electromagnetic), hiss. This signal noise is commonly measured using A-weighting or ITU-R 468 noise weighting, ITU-R 468 weighting. In experimental sciences, noise can refer to any random fluctuations of data that hinders perception of a signal. Measurement Sound is measured based on the amplitude and frequency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decibels
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a Power, root-power, and field quantities, power or root-power quantity on a logarithmic scale. Two signals whose level (logarithmic quantity), levels differ by one decibel have a power ratio of 101/10 (approximately ) or root-power ratio of 10 (approximately ). The unit expresses a relative change or an absolute value. In the latter case, the numeric value expresses the ratio of a value to a fixed reference value; when used in this way, the unit symbol is often suffixed with letter codes that indicate the reference value. For example, for the reference value of 1 volt, a common suffix is "#Voltage, V" (e.g., "20 dBV"). Two principal types of scaling of the decibel are in common use. When expressing a power ratio, it is defined as ten times the Common logarithm, logarithm in base 10. That is, a change in ''power'' by a factor of 10 corresp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speech
Speech is a human vocal communication using language. Each language uses Phonetics, phonetic combinations of vowel and consonant sounds that form the sound of its words (that is, all English words sound different from all French words, even if they are the same word, e.g., "role" or "hotel"), and using those words in their semantic character as words in the lexicon of a language according to the Syntax, syntactic constraints that Governance, govern lexical words' function in a sentence. In speaking, speakers perform many different intentional speech acts, e.g., informing, declaring, asking, persuading, directing, and can use Elocution, enunciation, Intonation (linguistics), intonation, degrees of loudness, tempo, and other non-representational or Paralanguage, paralinguistic aspects of vocalization to convey meaning. In their speech, speakers also unintentionally communicate many aspects of their social position such as sex, age, place of origin (through Accent (sociolinguistics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interaural Time Difference
The interaural time difference (or ITD) when concerning humans or animals, is the difference in arrival time of a sound between two ears. It is important in the localization of sounds, as it provides a cue to the direction or angle of the sound source from the head. If a signal arrives at the head from one side, the signal has further to travel to reach the far ear than the near ear. This pathlength difference results in a time difference between the sound's arrivals at the ears, which is detected and aids the process of identifying the direction of sound source. When a signal is produced in the horizontal plane, its angle in relation to the head is referred to as its azimuth, with 0 degrees (0°) azimuth being directly in front of the listener, 90° to the right, and 180° being directly behind. Different methods for measuring ITDs *For an abrupt stimulus such as a click, onset ITDs are measured. An onset ITD is the time difference between the onset of the signal reaching two ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cocktail Party Effect
The cocktail party effect is the phenomenon of the brain's ability to focus one's auditory attention on a particular stimulus while filtering out a range of other stimuli, such as when a partygoer can focus on a single conversation in a noisy room. Listeners have the ability to both segregate different stimuli into different streams, and subsequently decide which streams are most pertinent to them. It has been proposed that one's sensory memory subconsciously parses all stimuli and identifies discrete pieces of information by classifying them by salience. This effect is what allows most people to "tune into" a single voice and "tune out" all others. This phenomenon is often described in terms of "selective attention" or "selective hearing". It may also describe a similar phenomenon that occurs when one may immediately detect words of importance originating from unattended stimuli, for instance hearing one's name among a wide range of auditory input. An inability to segregate stim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radian
The radian, denoted by the symbol rad, is the unit of angle in the International System of Units (SI) and is the standard unit of angular measure used in many areas of mathematics. The unit was formerly an SI supplementary unit (before that category was abolished in 1995). The radian is defined in the SI as being a dimensionless unit, with 1 rad = 1. Its symbol is accordingly often omitted, especially in mathematical writing. Definition One radian is defined as the angle subtended from the center of a circle which intercepts an arc equal in length to the radius of the circle. More generally, the magnitude in radians of a subtended angle is equal to the ratio of the arc length to the radius of the circle; that is, \theta = \frac, where is the subtended angle in radians, is arc length, and is radius. A right angle is exactly \frac radians. The rotation angle (360°) corresponding to one complete revolution is the length of the circumference divided by the radius, which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lloyd A
Lloyd, Lloyd's, or Lloyds may refer to: People * Lloyd (name), a variation of the Welsh word ' or ', which means "grey" or "brown" ** List of people with given name Lloyd ** List of people with surname Lloyd * Lloyd (singer) (born 1986), American singer Places United States * Lloyd, Florida * Lloyd, Kentucky * Lloyd, Montana * Lloyd, New York * Lloyd, Ohio * Lloyds, Alabama * Lloyds, Maryland * Lloyds, Virginia Elsewhere * Lloydminster, or "Lloyd", straddling the provincial border between Alberta and Saskatchewan, Canada Companies and businesses Derived from Lloyd's Coffee House *Lloyd's Coffee House, a London meeting place for merchants and shipowners between about 1688 and 1774 * Lloyd's of London, a British insurance market ** ''Lloyd's of London'' (film), a 1936 film about the insurance market ** Lloyd's building, its headquarters ** Lloyd's Agency Network * ''Lloyd's List'', a website and 275-year-old daily newspaper on shipping and global trade ** ''Lloyd's List In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Comparative And Physiological Psychology
The ''Journal of Comparative and Physiological Psychology'' was a peer-reviewed academic journal published by the American Psychological Association. It was established in 1921 as the result of a merger between two journals, ''Psychobiology'' (1918-1920) and the ''Journal of Animal Behavior'' (1911-1916), under the title ''Journal of Comparative Psychology''. It was renamed ''Journal of Comparative and Physiological Psychology'' in 1947. Publication ceased in 1982 when the journal was split into ''Behavioral Neuroscience'' and the re-instated ''Journal of Comparative Psychology''.Dewsbury, Donald A. (June 2012)Historical trends in American comparative psychology.''The Behavioral Neuroscientist and Comparative Psychologist'' From 1965 till 1982, the journal was abstracted and indexed in Index Medicus/MEDLINE/PubMed PubMed is a free search engine accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics. The United States Na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Localization
Sound localization is a listener's ability to identify the location or origin of a detected sound in direction and distance. The sound localization mechanisms of the mammalian auditory system have been extensively studied. The auditory system uses several cues for sound source localization, including time difference and level difference (or intensity difference) between the ears, and spectral information. These cues are also used by other animals, such as birds and reptiles, but there may be differences in usage, and there are also localization cues which are absent in the human auditory system, such as the effects of ear movements. Animals with the ability to localize sound have a clear evolutionary advantage. How sound reaches the brain Sound is the perceptual result of mechanical vibrations traveling through a medium such as air or water. Through the mechanisms of compression and rarefaction, sound waves travel through the air, bounce off the pinna and concha of the exte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Action Potential
An action potential occurs when the membrane potential of a specific cell location rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and in some plant cells. Certain endocrine cells such as pancreatic beta cells, and certain cells of the anterior pituitary gland are also excitable cells. In neurons, action potentials play a central role in cell-cell communication by providing for—or with regard to saltatory conduction, assisting—the propagation of signals along the neuron's axon toward synaptic boutons situated at the ends of an axon; these signals can then connect with other neurons at synapses, or to motor cells or glands. In other types of cells, their main function is to activate intracellular processes. In muscle cells, for example, an action potential is the first step in the chain of events l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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