Impulse noise is a category of (
acoustic)
noise
Noise is sound, chiefly unwanted, unintentional, or harmful sound considered unpleasant, loud, or disruptive to mental or hearing faculties. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrat ...
that includes unwanted, almost instantaneous (thus
impulse-like) sharp sounds (like clicks and pops)—typically caused by
electromagnetic interference, scratches on disks,
gunfire
A gunshot is a single discharge of a gun, typically a man-portable firearm, producing a visible flash, a powerful and loud shockwave and often chemical gunshot residue. The term can also refer to a ballistic wound caused by such a discharg ...
, explosions, pickleball play, and synchronization issues in digital audio. High levels of such a noise (200+
decibel
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 whos ...
s) may damage internal organs, while impulses exceeding 180
decibel
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 whos ...
s 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
The median filter is a non-linear digital filtering technique, often used to remove signal noise, noise from an image, signal, and video. Such noise reduction is a typical pre-processing step to improve the results of later processing (for example ...
, at the expense of signal degradation. Thus it's quite common to get better performing impulse noise filters with model-based systems, which are programmed with the time and frequency properties of the noise to remove only impulse obliterated samples.
See also
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Audio synchronizer
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Crackling noise
Crackling noise arises when a system is subject to an external force and it responds via events that appear very scale invariant, similar at many different scales. In a classical system there are usually two states, on and off. However, sometimes ...
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Rustle noise
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Click (acoustics)
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Record restoration
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Gaussian noise
Carl Friedrich Gauss (1777–1855) is the eponym of all of the topics listed below.
There are over 100 topics all named after this German mathematician and scientist, all in the fields of mathematics, physics, and astronomy. The English eponymo ...
References
Noise (electronics)
Acoustics
Sound
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