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Ambisonics
Ambisonics is a ''full-sphere'' surround sound format: in addition to the horizontal plane, it covers sound sources above and below the listener. Unlike some other multichannel surround formats, its transmission channels do not carry speaker signals. Instead, they contain a speaker-independent representation of a sound field called ''B-format'', which is then ''decoded'' to the listener's speaker setup. This extra step allows the producer to think in terms of source directions rather than loudspeaker positions, and offers the listener a considerable degree of flexibility as to the layout and number of speakers used for playback. Ambisonics was developed in the UK in the 1970s under the auspices of the British National Research Development Corporation. Despite its solid technical foundation and many advantages, Ambisonics had not until recently been a commercial success, and survived only in niche applications and among recording enthusiasts. With the easy availability of power ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambisonic UHJ Format
Ambisonic UHJ format is a development of the Ambisonic surround sound system designed to be compatible with mono and stereo media. It is a hierarchy of systems in which the recorded soundfield will be reproduced with a degree of accuracy that varies according to the available channels. Although UHJ permits the use of up to four channels (carrying full-sphere with-height surround), only the 2-channel variant is in current use (as it is compatible with currently-available 2-channel media). In Ambisonics, UHJ is also known as "C-Format". The UHJ hierarchy Ambisonic B-Format is the standard format for use in the studio. While it is possible to distribute B-Format recordings for decoding and listening by end-users, this is only starting to be more widespread with the advent of software-based players. Traditionally, Ambisonic recordings have been distributed in the form of 2-channel discs, CDs etc. using the 2-channel version of the UHJ encoding hierarchy, which, unlike B-Format, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambisonic Data Exchange Formats
Data exchange formats for Ambisonics have undergone radical changes since the early days of four-track magnetic tape. Researchers working on very high-order systems found no straightforward way to extend the traditional formats to suit their needs. Furthermore, there was no widely accepted formulation of spherical harmonics for acoustics, so one was borrowed from chemistry, quantum mechanics, computer graphics, or other fields, each of which had subtly different conventions. This led to an unfortunate proliferation of mutually incompatible ad hoc formats and much head-scratching. This page attempts to document the different existing formats, their rationales and history, for the terminally curious and those unfortunate enough to have to deal with them in detail. Most modern applications use ACN and SN3D, although ''traditional'' first order is still common. Spherical harmonics in Ambisonics A common formulation for spherical harmonics in the context of Ambisonics is : Y_\ell^m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surround Sound
Surround sound is a technique for enriching the fidelity and depth of sound reproduction by using multiple audio channels from speakers that surround the listener ( surround channels). Its first application was in movie theaters. Prior to surround sound, theater sound systems commonly had three ''screen channels'' of sound that played from three loudspeakers (left, center, and right) located in front of the audience. Surround sound adds one or more channels from loudspeakers to the side or behind the listener that are able to create the sensation of sound coming from any horizontal direction (at ground level) around the listener. The technique enhances the perception of sound spatialization by exploiting sound localization: a listener's ability to identify the location or origin of a detected sound in direction and distance. This is achieved by using multiple discrete audio channels routed to an array of loudspeakers. Surround sound typically has a listener location ( sweet sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadraphonics
Quadraphonic (or quadrophonic and sometimes quadrasonic) sound – equivalent to what is now called 4.0 surround sound – uses four audio channels in which speakers are positioned at the four corners of a listening space. The system allows for the reproduction of sound signals that are (wholly or in part) independent of one another. Four channel quadraphonic surround sound can be used to recreate the highly realistic effect of a three-dimensional live concert hall experience in the home. It can also be used to enhance the listener experience beyond the directional limitations of ordinary two channel stereo sound. Quadraphonic audio was the earliest consumer product in surround sound. Since it was introduced to the public in the early 1970s many thousands of quadraphonic recordings have been made. Quadraphonic sound was a commercial failure when first introduced due to a variety of technical issues and format incompatibilities. Four channel audio formats can be more expensive to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blumlein Pair
Blumlein pair is a stereo recording technique invented by Alan Blumlein for the creation of recordings that, upon replaying through headphones or loudspeakers, recreate the spatial characteristics of the recorded signal. The pair consists of an array of two matched microphones that have a bi-directional (figure-8) pickup pattern. They are positioned 90° from each other. Ideally, the transducers should occupy the same physical space; since this cannot be achieved, the microphone capsules are placed as close to each other as physically possible, generally with one centered directly above the other. The array is oriented so that the line bisecting the angle between the two microphones points towards the sound source to be recorded (see diagram). The pickup patterns of the pair, combined with their positioning, delivers a high degree of stereo separation in the source signal, as well as the room ambiance. The Blumlein pair produces an exceptionally realistic stereo image, but the qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auro 11
Auro may refer to: People *Auro de Moura Andrade (1915–1982), Brazilian politician * Auro Roselli (1921–2013), Italian journalist * Auro Jr. (born 1996), Brazilian footballer Other uses * Auro-3D, 3D audio format *Auro 11.1 Auro 11.1 is one of the cinematic speaker layouts of the Auro-3D format, invented in 2005 by Wilfried Van Baelen (CEO Auro Technologies, CEO Galaxy Studios). The Auro 11.1 cinema audio format is supported by Barco, a global visualization technol ..., cinematic speaker layout * AURO University, Indian private university {{hndis, Auro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Localisation
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 exter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delay (audio Effect)
Delay is an audio signal processing technique that records an input signal to a storage medium and then plays it back after a period of time. When the delayed playback is mixed with the live audio, it creates an echo-like effect, whereby the original audio is heard followed by the delayed audio. The delayed signal may be played back multiple times, or fed back into the recording, to create the sound of a repeating, decaying echo. Delay effects range from a subtle echo effect to a pronounced blending of previous sounds with new sounds. Delay effects can be created using tape loops, an approach developed in the 1940s and 1950s and used by artists including Elvis Presley and Buddy Holly. Analog effects units were introduced in the 1970s; digital effects pedals in 1984; and audio plug-in software in the 2000s. History The first delay effects were achieved using tape loops improvised on reel-to-reel audio tape recording systems. By shortening or lengthening the loop of tape and adj ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spherical Harmonic
In mathematics and physical science, spherical harmonics are special functions defined on the surface of a sphere. They are often employed in solving partial differential equations in many scientific fields. Since the spherical harmonics form a complete set of orthogonal functions and thus an orthonormal basis, each function defined on the surface of a sphere can be written as a sum of these spherical harmonics. This is similar to periodic functions defined on a circle that can be expressed as a sum of circular functions (sines and cosines) via Fourier series. Like the sines and cosines in Fourier series, the spherical harmonics may be organized by (spatial) angular frequency, as seen in the rows of functions in the illustration on the right. Further, spherical harmonics are basis functions for irreducible representations of SO(3), the group of rotations in three dimensions, and thus play a central role in the group theoretic discussion of SO(3). Spherical harmonics originat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinna (anatomy)
The auricle or auricula is the visible part of the ear that is outside the head. It is also called the pinna (Latin for "wing" or "fin", plural pinnae), a term that is used more in zoology. Structure The diagram shows the shape and location of most of these components: * ''antihelix'' forms a 'Y' shape where the upper parts are: ** ''Superior crus'' (to the left of the ''fossa triangularis'' in the diagram) ** ''Inferior crus'' (to the right of the ''fossa triangularis'' in the diagram) * ''Antitragus'' is below the ''tragus'' * ''Aperture'' is the entrance to the ear canal * ''Auricular sulcus'' is the depression behind the ear next to the head * ''Concha'' is the hollow next to the ear canal * Conchal angle is the angle that the back of the ''concha'' makes with the side of the head * ''Crus'' of the helix is just above the ''tragus'' * ''Cymba conchae'' is the narrowest end of the ''concha'' * External auditory meatus is the ear canal * ''Fossa triangularis'' is the depres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diffraction
Diffraction is defined as the interference or bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle/aperture. The diffracting object or aperture effectively becomes a secondary source of the propagating wave. Italian scientist Francesco Maria Grimaldi coined the word ''diffraction'' and was the first to record accurate observations of the phenomenon in 1660. In classical physics, the diffraction phenomenon is described by the Huygens–Fresnel principle that treats each point in a propagating wavefront as a collection of individual spherical wavelets. The characteristic bending pattern is most pronounced when a wave from a coherent source (such as a laser) encounters a slit/aperture that is comparable in size to its wavelength, as shown in the inserted image. This is due to the addition, or interference, of different points on the wavefront (or, equivalently, each wavelet) that travel by paths of d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
(quadrophonie)_label.svg "Click for more on -> Quadraphonics")
