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Apparent Source Width
Apparent source width (ASW) is the audible impression of a spatially extended sound source. This psychoacoustic impression results from sound radiation characteristics and properties of an acoustic space. Wide sources are desired by listeners of music because these are associated with sound of acoustic music, opera, classical music, historically informed performance. Research concerning ASW comes from the field of room acoustics, architectural acoustics and auralization as well as musical acoustics, psychoacoustics and systematic musicology. Physics and perception Apparent source width is the aurally perceived extent of a sound source. Sometimes, it is defined as the impression that a source sounds larger than its visible size. The impression results from several auditory cues, which are affected by sound radiation characteristics of the source itself and by characteristics of the room. Since the term ''apparent source width'' has been used a lot in the field of subjective room a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psychoacoustic
Psychoacoustics is the branch of psychophysics involving the scientific study of sound perception and audiology—how humans perceive various sounds. More specifically, it is the branch of science studying the psychological responses associated with sound (including noise, speech, and music). Psychoacoustics is an interdisciplinary field of many areas, including psychology, acoustics, electronic engineering, physics, biology, physiology, and computer science. Background Hearing is not a purely mechanical phenomenon of wave propagation, but is also a sensory and perceptual event; in other words, when a person hears something, that something arrives at the ear as a mechanical sound wave traveling through the air, but within the ear it is transformed into neural action potentials. The outer hair cells (OHC) of a mammalian cochlea give rise to enhanced sensitivity and better frequency resolution of the mechanical response of the cochlear partition. These nerve pulses then travel to the ... [...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] |
Audio Mastering
Mastering, a form of audio post production, is the process of preparing and transferring recorded audio from a source containing the final mix to a data storage device (the master), the source from which all copies will be produced (via methods such as pressing, duplication or replication). In recent years digital masters have become usual, although analog masters—such as audio tapes—are still being used by the manufacturing industry, particularly by a few engineers who specialize in analog mastering. Mastering requires critical listening; however, software tools exist to facilitate the process. Results depend upon the intent of the engineer, the skills of the engineer, the accuracy of the speaker monitors, and the listening environment. Mastering engineers often apply equalization and dynamic range compression in order to optimize sound translation on all playback systems. It is standard practice to make a copy of a master recording—known as a safety copy—in cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loudness
In acoustics, loudness is the subjectivity, subjective perception of sound pressure. More formally, it is defined as, "That attribute of auditory sensation in terms of which sounds can be ordered on a scale extending from quiet to loud". The relation of physical attributes of sound to perceived loudness consists of physical, physiological and psychological components. The study of apparent loudness is included in the topic of psychoacoustics and employs methods of psychophysics. In different industries, loudness may have different meanings and different measurement standards. Some definitions, such as LKFS, ITU-R BS.1770 refer to the relative loudness of different segments of electronically reproduced sounds, such as for broadcasting and cinema. Others, such as ISO 532A (Stevens loudness, measured in sones), ISO 532B (Eberhard Zwicker, Zwicker loudness), DIN 45631 and ASA/ANSI S3.4, have a more general scope and are often used to characterize loudness of environmental noise. More ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impulse Response
In signal processing and control theory, the impulse response, or impulse response function (IRF), of a dynamic system is its output when presented with a brief input signal, called an Dirac delta function, impulse (). More generally, an impulse response is the reaction of any dynamic system in response to some external change. In both cases, the impulse response describes the reaction of the system as a Function (mathematics), function of time (or possibly as a function of some other independent variable that parameterizes the dynamic behavior of the system). In all these cases, the dynamic system and its impulse response may be actual physical objects, or may be mathematical systems of equations describing such objects. Since the impulse function contains all frequencies (see Dirac delta function#Fourier transform, the Fourier transform of the Dirac delta function, showing infinite frequency bandwidth that the Dirac delta function has), the impulse response defines the response ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Music Critic
''The Oxford Companion to Music'' defines music criticism as "the intellectual activity of formulating judgments on the value and degree of excellence of individual works of music, or whole groups or genres". In this sense, it is a branch of musical aesthetics. With the concurrent expansion of interest in music and information media over the past century, the term has come to acquire the conventional meaning of journalistic reporting on musical performances. Nature of music criticism The musicologist Winton Dean has suggested that "music is probably the most difficult of the arts to criticise." Unlike the plastic or literary arts, the 'language' of music does not specifically relate to human sensory experience – Dean's words, "the word 'love' is common coin in life and literature: the note C has nothing to do with breakfast or railway journeys or marital harmony." Like dramatic art, music is recreated at every performance, and criticism may, therefore, be directed both at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conducting
Conducting is the art of directing a musical performance, such as an orchestral or choral concert. It has been defined as "the art of directing the simultaneous performance of several players or singers by the use of gesture." The primary duties of the conductor are to interpret the score in a way which reflects the specific indications in that score, set the tempo, ensure correct entries by ensemble members, and "shape" the phrasing where appropriate. Conductors communicate with their musicians primarily through hand gestures, usually with the aid of a baton, and may use other gestures or signals such as eye contact. A conductor usually supplements their direction with verbal instructions to their musicians in rehearsal. The conductor typically stands on a raised podium with a large music stand for the full score, which contains the musical notation for all the instruments or voices. Since the mid-19th century, most conductors have not played an instrument when conducting, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polar Coordinate System
In mathematics, the polar coordinate system is a two-dimensional coordinate system in which each point on a plane is determined by a distance from a reference point and an angle from a reference direction. The reference point (analogous to the origin of a Cartesian coordinate system) is called the ''pole'', and the ray from the pole in the reference direction is the ''polar axis''. The distance from the pole is called the ''radial coordinate'', ''radial distance'' or simply ''radius'', and the angle is called the ''angular coordinate'', ''polar angle'', or ''azimuth''. Angles in polar notation are generally expressed in either degrees or radians (2 rad being equal to 360°). Grégoire de Saint-Vincent and Bonaventura Cavalieri independently introduced the concepts in the mid-17th century, though the actual term "polar coordinates" has been attributed to Gregorio Fontana in the 18th century. The initial motivation for the introduction of the polar system was the study of circula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Pattern
In the field of antenna design the term radiation pattern (or antenna pattern or far-field pattern) refers to the ''directional'' (angular) dependence of the strength of the radio waves from the antenna or other source.Constantine A. Balanis: “Antenna Theory, Analysis and Design”, John Wiley & Sons, Inc., 2nd ed. 1982 David K Cheng: “Field and Wave Electromagnetics”, Addison-Wesley Publishing Company Inc., Edition 2, 1998. Edward C. Jordan & Keith G. Balmain; “Electromagnetic Waves and Radiating Systems” (2nd ed. 1968) Prentice-Hall. Particularly in the fields of fiber optics, lasers, and integrated optics, the term radiation pattern may also be used as a synonym for the near-field pattern or Fresnel pattern.Institute of Electrical and Electronics Engineers, “The IEEE standard dictionary of electrical and electronics terms”; 6th ed. New York, N.Y., Institute of Electrical and Electronics Engineers, c1997. IEEE Std 100-1996. d. Standards Coordinating Committee 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Spectrum
The power spectrum S_(f) of a time series x(t) describes the distribution of power into frequency components composing that signal. According to Fourier analysis, any physical signal can be decomposed into a number of discrete frequencies, or a spectrum of frequencies over a continuous range. The statistical average of a certain signal or sort of signal (including noise) as analyzed in terms of its frequency content, is called its spectrum. When the energy of the signal is concentrated around a finite time interval, especially if its total energy is finite, one may compute the energy spectral density. More commonly used is the power spectral density (or simply power spectrum), which applies to signals existing over ''all'' time, or over a time period large enough (especially in relation to the duration of a measurement) that it could as well have been over an infinite time interval. The power spectral density (PSD) then refers to the spectral energy distribution that would b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplitude
The amplitude of a periodic variable is a measure of its change in a single period (such as time or spatial period). The amplitude of a non-periodic signal is its magnitude compared with a reference value. There are various definitions of amplitude (see below), which are all functions of the magnitude of the differences between the variable's extreme values. In older texts, the phase of a periodic function is sometimes called the amplitude. Definitions Peak amplitude & semi-amplitude For symmetric periodic waves, like sine waves, square waves or triangle waves ''peak amplitude'' and ''semi amplitude'' are the same. Peak amplitude In audio system measurements, telecommunications and others where the measurand is a signal that swings above and below a reference value but is not sinusoidal, peak amplitude is often used. If the reference is zero, this is the maximum absolute value of the signal; if the reference is a mean value (DC component), the peak amplitude is the maximu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Point Source
A point source is a single identifiable ''localised'' source of something. A point source has negligible extent, distinguishing it from other source geometries. Sources are called point sources because in mathematical modeling, these sources can usually be approximated as a mathematical point to simplify analysis. The actual source need not be physically small, if its size is negligible relative to other length scales in the problem. For example, in astronomy, stars are routinely treated as point sources, even though they are in actuality much larger than the Earth. In three dimensions, the density of something leaving a point source decreases in proportion to the inverse square of the distance from the source, if the distribution is isotropic, and there is no absorption or other loss. Mathematics In mathematics, a point source is a singularity from which flux or flow is emanating. Although singularities such as this do not exist in the observable universe, mathematical po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
