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Reverberation
In acoustics, reverberation (commonly shortened to reverb) is a persistence of sound after it is produced. It is often created when a sound is reflection (physics), reflected on surfaces, causing multiple reflections that build up and then decay as the sound is absorbed by the surfaces of objects in the space – which could include furniture, people, and air. This is most noticeable when the sound source stops but the reflections continue, their amplitude decreasing, until zero is reached. Reverberation is frequency dependent: the length of the decay, or reverberation time, receives special consideration in the architectural design of spaces which need to have specific reverberation times to achieve optimum performance for their intended activity. In comparison to a distinct echo, that is detectable at a minimum of 50 to 100 millisecond, ms after the previous sound, reverberation is the occurrence of reflections that arrive in a sequence of less than approximately 50 ms. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverberation Time Diagram
In acoustics, reverberation (commonly shortened to reverb) is a persistence of sound after it is produced. It is often created when a sound is reflected on surfaces, causing multiple reflections that build up and then decay as the sound is absorbed by the surfaces of objects in the space – which could include furniture, people, and air. This is most noticeable when the sound source stops but the reflections continue, their amplitude decreasing, until zero is reached. Reverberation is frequency dependent: the length of the decay, or reverberation time, receives special consideration in the architectural design of spaces which need to have specific reverberation times to achieve optimum performance for their intended activity. In comparison to a distinct echo, that is detectable at a minimum of 50 to 100 ms after the previous sound, reverberation is the occurrence of reflections that arrive in a sequence of less than approximately 50 ms. As time passes, the amplitude of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dereverberation
Dereverberation is the process by which the effects of reverberation are removed from sound, after such reverberant sound has been picked up by microphones. Dereverberation is a subtopic of acoustic digital signal processing and is most commonly applied to speech but also has relevance in some aspects of music processing. Dereverberation of audio (speech or music) is a corresponding function to blind deconvolution of images, although the techniques used are usually very different. Reverberation itself is caused by sound reflections in a room (or other enclosed space) and is quantified by the room reverberation time and the direct-to-reverberant ratio. The effect of dereverberation is to increase the direct-to-reverberant ratio so that the sound is perceived as closer and clearer. A main application of dereverberation is in hands-free phones and desktop conferencing terminals because, in these cases, the microphones are not close to the source of sound – the talker’s mouth � ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverb Effect
A reverb effect, or reverb, is an effects unit, audio effect applied to a sound signal to simulate reverberation. It may be created through physical means, such as echo chambers, or electronically through audio signal processing. The American producer Bill Putnam is credited for the first artistic use of artificial reverb in music, on the 1947 song "Peg o' My Heart" by the Harmonicats. Plate reverb uses electromechanical transducers to create vibrations in large plates of sheet metal. Spring reverb, created with a series of mounted springs, is popular in surf music and dub reggae. Shimmer reverb, which Pitch shift, alters the pitch of the reverberated sound, is often used in ambient music. Convolution reverb uses impulse responses to record the reverberation of physical spaces and recreate them digitally. Gated reverb became a staple of 1980s pop music, used by drummers including Phil Collins. Varieties Echo chambers The first reverb effects, introduced in the 1930s, were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wallace Clement Sabine
Wallace Clement Sabine (June 13, 1868 – January 10, 1919) was an American physicist who founded the field of architectural acoustics. Sabine was the architectural acoustician of Boston's Symphony Hall, widely considered one of the two or three best concert halls in the world for its acoustics. Early life Wallace Clement Sabine was born on June 13, 1868, in Richwood, Ohio, of Dutch, English, French, and Scottish descent. He graduated with a Bachelor of Arts from Ohio State University in 1886 at the age of 18. He then attended Harvard University and graduated with a Master of Arts in 1888. His sister was Annie W. S. Siebert. Career After graduating, Sabine became an assistant professor of physics at Harvard in 1889. He became an instructor in 1890 and a member of the faculty in 1892. In 1895, he became an assistant professor and in 1905, he was promoted to professor of physics. In October 1906, he became dean of the Lawrence Scientific School, succeeding Nathani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colors Of Noise
In audio engineering, electronics, physics, and many other fields, the color of noise or noise spectrum refers to the power spectrum of a noise signal (a signal produced by a stochastic process). Different colors of noise have significantly different properties. For example, as audio signals they will sound different to human ears, and as images they will have a visibly different texture. Therefore, each application typically requires noise of a specific color. This sense of 'color' for noise signals is similar to the concept of timbre in music (which is also called "tone color"; however, the latter is almost always used for sound, and may consider detailed features of the spectrum). The practice of naming kinds of noise after colors started with white noise, a signal whose spectrum has equal power within any equal interval of frequencies. That name was given by analogy with white light, which was (incorrectly) assumed to have such a flat power spectrum over the visible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound
In physics, sound is a vibration that propagates as an acoustic wave through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the brain. Only acoustic waves that have frequency, frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of to . Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges, allowing some to even hear ultrasounds. Definition Sound is defined as "(a) Oscillation in pressure, stress, particle displacement, particle velocity, etc., propagated in a medium with internal forces (e.g., elastic or viscous), or the superposition of such propagated oscillation. (b) Auditory sen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Level Meter
A sound level meter (also called sound pressure level meter (SPL)) is used for acoustics, acoustic measurements. It is commonly a hand-held instrument with a microphone. The best type of microphone for sound level meters is the condenser microphone, which combines precision with stability and reliability. The Diaphragm (acoustics), diaphragm of the microphone responds to changes in air pressure caused by sound waves. That is why the instrument is sometimes referred to as a sound pressure level meter (SPL). This movement of the diaphragm, i.e. the sound pressure (unit Pascal (unit), pascal, Pa), is converted into an electrical signal (unit volt, volt, V). While describing sound in terms of sound pressure, a logarithmic conversion is usually applied and the sound pressure ''level'' is stated instead, in decibels (dB), with 0 dB SPL equal to 20 micropascals. A microphone is distinguishable by the voltage value produced when a known, constant root mean square sound pressure is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echo Chamber
Echo chamber of the Dresden University of Technology Hamilton Mausoleum has a long-lasting unplanned echo An echo chamber is a hollow enclosure used to produce reverberation, usually for recording purposes. A traditional echo chamber is covered in highly acoustically reflective surfaces. By using directional microphones pointed away from the speakers, echo capture is maximized. Some portions of the room can be moved to vary the room's decay time. Nowadays, effects units are more widely used to create such effects, but echo chambers are still used today, such as the famous echo chambers at Capitol Studios. In music, the use of acoustic echo and reverberation effects has taken many forms and dates back many hundreds of years. Sacred music of the Medieval and Renaissance periods relied heavily on the composers' extensive understanding and use of the complex natural reverberation and echoes inside churches and cathedrals. This early acoustical knowledge informed the design of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impulse Noise (audio)
Impulse noise is a category of (Acoustics, acoustic) noise that includes unwanted, almost instantaneous (thus impulse function, impulse-like) sharp sounds (like clicks and pops)—typically caused by electromagnetic interference, scratches on disks, gunfire, explosions, pickleball play, and synchronization issues in digital audio. High levels of such a noise (200+ decibels) may damage internal organs, while impulses exceeding 180 decibels begin to present a risk of rupturing the tympanic membrane if hearing protection is not worn. The U.S. Department of Defense has established criteria for equipment that produces impulse noise at levels above 140 dB peak SPL and requires hearing protection be worn to prevent damage human ears. An impulse noise filter can enhance the quality of noisy signals to achieve robustness in pattern recognition and adaptive control systems. A classic filter used to remove impulse noise is the median filter, at the expense of signal degradation. Thus it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blank (cartridge)
A blank is a firearm cartridge that, when fired, does not shoot a projectile like a bullet or pellet, but generates a muzzle flash and an explosive sound ( muzzle report) like a normal gunshot would. Firearms may need to be modified to allow a blank to cycle the action, and the shooter experiences less recoil with a blank than with a live round. Blanks are often used in prop guns for shooting simulations that have no need for ballistic results, but still demand light and sound effects, such as in historical reenactments, special effects for theatre, movie and television productions, combat training, for signaling (see starting pistol), and cowboy mounted shooting. Specialised blank cartridges are also used for their propellant force in fields as varied as construction, shooting sports, and fishing and general recreation. While blanks are less dangerous than live ammunition, they can still be dangerous and can still cause fatal injuries. Beside the explosive gases, any o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Noise
In signal processing, white noise is a random signal having equal intensity at different frequencies, giving it a constant power spectral density. The term is used with this or similar meanings in many scientific and technical disciplines, including physics, acoustical engineering, telecommunications, and statistical forecasting. White noise refers to a statistical model for signals and signal sources, not to any specific signal. White noise draws its name from white light, although light that appears white generally does not have a flat power spectral density over the visible band. In discrete time, white noise is a discrete signal whose samples are regarded as a sequence of serially uncorrelated random variables with zero mean and finite variance; a single realization of white noise is a random shock. In some contexts, it is also required that the samples be independent and have identical probability distribution (in other words independent and identically distribu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pink Noise
Pink noise, noise, fractional noise or fractal noise is a signal (information theory), signal or process with a frequency spectrum such that the power spectral density (power per frequency interval) is inversely proportional to the frequency of the signal. In pink noise, each Octave (electronics), octave interval (halving or doubling in frequency) carries an equal amount of noise energy. Pink noise sounds like a waterfall. It is often used to tune loudspeaker systems in professional audio. Pink noise is one of the most commonly observed signals in biological systems. The name arises from the pink appearance of visible light with this power spectrum. This is in contrast with white noise which has equal intensity per frequency interval. Definition Within the scientific literature, the term "1/f noise" is sometimes used loosely to refer to any noise with a power spectral density of the form S(f) \propto \frac, where is frequency, and , with exponent usually close to 1. On ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
