By having two different temporal positive feedback loops or “ dual-time switches ” allows for ( a ) increased regulation: two switches that have independent changeable activation and deactivation times ; and ( b ) linked feedback loops on multiple timescales can filter noise.

Behavioral coordination and production of signalling substances is achieved through interpretation processes that enables the organism to differ between self or non-self, abiotic indicator, biotic message from similar, related, or non-related species, and even filter out " noise ", i. e. similar molecules without biotic content.

The thermal noise is given by k < sub > B </ sub > T B, where T is temperature, B is bandwidth ( post matched filter ) and k < sub > B </ sub > is Boltzmann's constant.

If a person ‘ synthesizes ’ a ‘ jet plane landing ’ sound, this is achieved mostly by altering the shape of the mouth to filter the white noise into pink noise by removing the higher frequencies.

Digital systems must manage noise and timing margins, parasitic inductances and capacitances, and filter power connections.

Most frequently ambient noise levels are measured using a frequency weighting filter, the most common being the A-weighting scale, such that resulting measurements are denoted dB ( A ), or decibels on the A-weighting scale.

A digital filter will introduce noise to a signal during analog low pass filtering, analog to digital conversion, digital to analog conversion and may introduce digital noise due to quantization.

With analog filters, every component is a source of thermal noise ( such as Johnson noise ), so as the filter complexity grows, so does the noise.

The coincidental formation of an audio frequency filter is also beneficial in that noise is reduced.

Real world loop filter design can be much more complex e. g. using higher order filters to reduce various types or source of phase noise.

Otherwise, when the characteristics of the noise are known and are different from the signals, it is possible to filter it or to process the signal.

For example, it is sometimes possible to use a lock-in amplifier to modulate and confine the signal within a very narrow bandwidth and then filter the detected signal to the narrow band where it resides, thereby eliminating most of the broadband noise.

The squelch control adjusts the gain of an amplifier which varies the level of noise coming out of the filter.

The audio output of the filter and amplifier is rectified and produces a DC voltage when noise is present.

The distortion of a waveform relative to a pure sinewave can be measured either by using a wave analyser to analyse the output wave into its constituent harmonics and noting the amplitude of each relative to the fundamental ; or by cancelling out the fundamental with a notch filter and measuring the remaining signal, which will be total aggregate harmonic distortion plus noise.

In double conversion mode the UPS can adjust for voltage variations without having to use battery power, can filter out line noise and control frequency.

Another way to generate a signal with the required Doppler power spectrum is to pass a white Gaussian noise signal through a Gaussian filter with a frequency response equal to the square-root of the Doppler spectrum required.

This results in an effective high-pass filter acting on the quantization ( signal processing ) noise, thus steering this noise out of the low frequencies of interest into the megahertz frequencies of little interest, which is called noise shaping.

The quantization noise at these high frequencies is removed or greatly attenuated by use of an analog low-pass filter at the output ( sometimes a simple RC low-pass circuit is sufficient ).

The analog output is connected to a low-pass filter, which filters out high-frequency aliases when the Amiga is using a lower sampling rate ( see Nyquist limit ).

On the subscriber's end of the circuit, inline low-pass DSL filters ( splitters ) are installed on each telephone to filter the high-frequency " hiss " that would otherwise be heard, but pass voice ( 5 kHz and below ) frequencies.

A high-pass filter ( HPF ) is an electronic filter that passes high-frequency signals but attenuates ( reduces the amplitude of ) signals with frequencies lower than the cutoff frequency.

* A low-pass filter is used to cut unwanted high-frequency signals.

A 2007 study by Nico F. Declercq and Cindy Dekeyser of the Georgia Institute of Technology indicates that the astonishing acoustic properties are the result of the advanced design: The rows of limestone seats filter out low-frequency sounds, such as the murmur of the crowd, and amplify high-frequency sounds from the stage.

From a signal-processing standpoint, an unsharp mask is generally a linear or nonlinear filter that amplifies high-frequency components.

A light beam enters the first prism ( A ) and the blue component of the beam is reflected from a low-pass filter coating ( F < sub > 1 </ sub >) that reflects blue light ( high-frequency ), but transmits longer wavelengths ( lower frequencies ).

Frequency filters and averaging functions ( such as those built into oscilloscopes ) are often used to filter out high-frequency components.

Since the Fourier transform of a Gaussian is another Gaussian, applying a Gaussian blur has the effect of reducing the image's high-frequency components ; a Gaussian blur is thus a low pass filter.

A filter in which the signal passes through an inductor, or in which a capacitor provides a path to ground, presents less attenuation to low-frequency signals than high-frequency signals and is therefore a low-pass filter.

If the signal passes through a capacitor, or has a path to ground through an inductor, then the filter presents less attenuation to high-frequency signals than low-frequency signals and therefore is a high-pass filter.

A passive low-pass filter removes the unwanted high-frequency components, i. e., smoothes the pulses out and recovers the desired low-frequency signal.

The output filter removes the high-frequency switching components of the PWM signal and recovers the audio information that the speaker can use.

The effects of capacitance and inductance, which filter out high-frequency signals, limit the speed.

The 3 dB bandwidth of an electronic filter or communication channel is the part of the system's frequency response that lies within 3 dB of the response at its peak, which in the passband filter case is typically at or near its center frequency, and in the lowpass filter is near 0 hertz.

The transform preserves stability and maps every point of the frequency response of the continuous-time filter, to a corresponding point in the frequency response of the discrete-time filter, although to a somewhat different frequency, as shown in the Frequency warping section below.

This means that for every feature that one sees in the frequency response of the analog filter, there is a corresponding feature, with identical gain and phase shift, in the frequency response of the digital filter but, perhaps, at a somewhat different frequency.

* A " finite impulse response " ( FIR ) filter uses only the input signals, while an " infinite impulse response " filter ( IIR ) uses both the input signal and previous samples of the output signal.

A filter may also be described as a difference equation, a collection of zeroes and poles or, if it is an FIR filter, an impulse response or step response.

The output of a linear digital filter to any given input may be calculated by convolving the input signal with the impulse response.

A linear time-invariant ( LTI ) filter can be uniquely specified by its impulse response h, and the output of any filter is mathematically expressed as the convolution of the input with that impulse response.

A color gel or color filter ( British spelling: colour gel or colour filter ), also known as lighting gel or simply gel, is a transparent colored material that is used in theatre, event production, photography, videography and cinematography to color light and for color correction.

In Shakesperean theatre, red wine was used in a glass container as a light filter.

North Bay's detachment and its filter centre, formally known as 50 Ground Observer Corps Detachment, were set up in an ex-movie theatre on the sixth and seventh floors of the Sibbett Building, a well-known North Bay downtown landmark.