Noise colors- a mathematical abstraction that assigns a certain value to a signal based on the properties and parameters of this signal. One of these properties, which can be used to distinguish between types of noise, can be (power distribution over ). This abstraction is widely used in branches of technology dealing with noise ( , etc.).

Many of the following definitions consider the spectrum of a signal at all frequencies.

How white noise affects a person. By the nature of occurrence

Scientists have determined which films attract the attention of viewers more than others. It turned out that the most fascinating films are based on the so-called pink noise. The work of the researchers was accepted for publication in the journal Psychological Science. The New Scientist writes briefly about her.

For the starting point of their work, scientists took a study conducted in the 90s of the last century. A group of specialists watched the audience watching the movie. It turned out that the time periods during which their attention was occupied by the film were distributed in a very characteristic way. The researchers applied a mathematical operation known as Fourier transforms to the distribution and produced pink noise. This term refers to noise whose spectral density is inversely proportional to its frequency. You can listen to pink noise.

The authors of the new study decided to test whether the distribution of the duration of fragments from one splice to another has the characteristics of pink noise. Scientists analyzed 150 of the highest grossing Hollywood films made between 1935 and 2005. It turned out that when editing films recent years pink noise patterns are more commonly used.

According to the researchers, films based on patterns of pink noise are popular because they fit the distribution pattern of people's attention. The authors believe that filmmakers use pink noise unintentionally - they simply repeat the principles of building popular films in which a successful reception was found.

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Information sheet

JUST PROFESSIONALISM

Noise colors

Noise colors - a system of terms that ascribes certain colors to certain types of noise signals based on the analogy between the spectrum of a signal of arbitrary nature (more precisely, its spectral density or, mathematically speaking, the distribution parameters of a random process) and the spectra of various colors of visible light.

This abstraction is widely used in branches of technology dealing with noise (acoustics, electronics, physics, etc.).

White noise is a signal with a uniform spectral density at all frequencies and a dispersion equal to infinity. It is a stationary random process.

In other words, such a signal has the same power in any frequency band. For example, a 20 hertz signal band between 40 and 60 hertz has the same power as a band between 4000 and 4020 hertz. Unlimited in frequency White noise is possible only in theory, since in this case its power is infinite. In practice, a signal can only be white noise over a limited frequency band.

pink noise

The spectral density of pink noise is given by ~1/f (density is inversely proportional to frequency). Uniformly at any frequency. For example, the signal power in the frequency band between 40 and 60 hertz is equal to the power in the band between 4000 and 6000 hertz. The spectral density of such a signal, compared to white noise, attenuates by 3 decibels per octave.

An example of pink noise is the sound of a flying helicopter. Pink noise is found, for example, in heart rhythms, in graphs of the electrical activity of the brain, in electromagnetic radiation space bodies.
Pink noise is sometimes referred to as any noise whose spectral density decreases with increasing frequency.

Blue (cyan) noise

Blue noise is a type of signal whose spectral density increases by 3 dB per octave. That is, its spectral density is proportional to frequency and, like white noise, in practice it must be frequency limited. Blue noise is perceived as sharper than white noise. Blue noise is obtained by differentiating pink noise; their spectra are specular.

Brownian (red) noise

The spectral density of red noise is proportional to 1/f², where f is the frequency. This means that on low frequencies ah noise has more energy, even more than pink noise. Noise energy drops by 6 decibels per octave. Acoustic red noise is heard as muffled compared to white or pink noise. The red noise spectrum (on a logarithmic scale) is the mirror image of the violet spectrum.
By ear, Brownian noise is perceived as "warmer" than white noise.

purple noise

This is the kind of signal whose spectral density increases by 6 dB per octave. That is, its spectral density is proportional to the square of the frequency and, similarly to white noise, in practice it should be organic in frequency. Purple noise is obtained by differentiating white noise. The violet noise spectrum is the mirror image of the red noise spectrum.

gray noise

The term gray noise refers to a noise signal that has the same loudness for human ear over the entire frequency range. The spectrum of gray noise is obtained by adding the spectra of Brownian and purple noise. The spectrum of gray noise shows a large “dip” at medium frequencies, however human ear perceives gray noise in the same way as white noise.

There are other, "less official" colors:

Orange noise is noise with a finite spectral density. The spectrum of such noise has bands of zero energy scattered throughout the spectrum. These bands are located at the frequencies of musical notes.

Red noise - can be either a synonym for Brownian or pink noise, or a designation for natural noise characteristic of large bodies of water - seas and oceans that absorb high frequencies. Red noise is heard from the shore from distant objects in the ocean.

Green noise - noise natural environment. Similar to pink noise with a boosted frequency region around 500 Hz.

black noise
The term "black noise" has several definitions:

-Silence
Noise with a spectrum of 1/f, where > 2. Used to simulate various natural processes. It is considered a characteristic of "natural and man-made disasters, such as floods, landslides, etc."

-Ultrasonic white noise(with a frequency of more than 20 kHz), similar to the so-called. "black light" (with frequencies too high to be perceived, but capable of influencing the observer or instruments). Noise whose spectrum has predominantly zero energy except for a few peaks.

Definitions

Color matches various types noise signal are determined using similar types of electromagnetic signal. That is, if the noise signal is called "blue", then the corresponding electromagnetic signal with visible light wavelengths will have a blue color.

White noise is a signal with a smooth frequency spectrum at all frequencies. In other words, such a signal is the same in any frequency band. For example, a 20 hertz signal band between 40 and 60 hertz has the same power as a band between 4000 and 4020 hertz. Unlimited frequency white noise is possible only in theory, since in this case its power is infinite. In practice, a signal can only be white noise over a limited frequency band.

Pink Noise The frequency spectrum is smooth to scale. That is, the signal power in the frequency band between 40 and 60 hertz is equal to the power in the band between 4000 and 6000 hertz. The spectral density of such a signal, compared to white noise, is attenuated by 3 for each . That is, its spectral density is inversely proportional to frequency.

Blue Noise Blue noise is a type of signal whose spectral density increases by 3 dB per octave over a limited frequency band. That is, its spectral density is proportional to frequency.

Gray noise term refers to a noise signal that has the same loudness to the human ear over the entire frequency range.

	10 seconds of gray noise (description)

The Federal Telecommunications Standard 1037C Glossary defines white, pink, blue, and black noise.

Basic "colors" of noise

Color correspondences of various types of noise signal are determined using graphs (histograms) of spectral density, that is, the distribution of signal power over frequencies.

White noise

Other

There are other, "less official" colors:

orange noise

Orange noise is quasi-stationary noise with a finite spectral density. The spectrum of such noise has bands of zero energy scattered throughout the spectrum. These stripes are located at the frequencies of musical notes.

red noise

green noise

Green noise is the noise of the natural environment. Similar to pink noise with a boosted frequency region around 500 Hz.

black noise

The term "black noise" has several definitions:

Notes

Literature

Yellott, John I. Jr., "Spectral Consequences of Photoreceptor Sampling in the Rhesus Retina." Science, Volume 221, pp. 382-385, 1983.

White noise. What's the use?

Do you know what white noise is? Have you experienced its effects? What is the use of white noise, and is there such a thing in principle?

I will try to answer these questions now!

So, white noise is stationary noise, the spectral components of which are evenly distributed over the entire range of frequencies involved, as Wikipedia tells us. In other words, it is broadband radiation consisting of all wavelengths of approximately the same intensity or the maximum possible spectrum of such different wavelengths.

It got its name by analogy with white light - an effect observed in the visible part sunlight: If all the colors of the visible light spectrum are mixed, they will give a white color.

In the audible frequency region, an example of white noise is the noise of a waterfall.

In continuation of such a scientific metaphor!

There is also the concept of colored noise: noise different colors. And among all their diversity highest value has three types of noise: white noise, brown noise and pink noise.

All three main types of noise are widespread:

Where randomly mixed different factors, arises White noise- it can be heard, for example, by tuning an old radio receiver to a wave in which there are no radio stations. Another example is thermal noise in semiconductors. It is created by chaotic vibrations of atoms, and at high amplification it is quite audible in any sound-reproducing device. The origin of white noise is clear - it's just a game of chance.

brown noise. Noise has more energy at low frequencies than at high frequencies. Acoustic brown (or red) noise is heard as muffled compared to white or pink noise. Its color is not related to brown its corresponding light. Brown - from the word Brown, Brownian movement. To the ear, brown noise is perceived as “warmer” than white noise. It is also widespread in nature, and this is not surprising - it is generated by a random walk. For example, it corresponds to the waves of the sea surf and, of course, the Brownian motion of particles.

pink noise, despite its incomprehensible origin, is extremely widespread. He first drew attention to himself when physicists noticed that some semiconductor devices made a strange noise. In addition to the usual thermal white noise, they found the presence of noise that had more low and very low frequencies. It turned out that the power of this noise is inversely proportional to its frequency, and this relationship is true even for frequencies of thousandths of a hertz. This means that in semiconductors there are some processes that last several days or more, which generate this noise. It has been called "flicker noise", flickering noise - now another name for pink noise. Examples: the distant noise of a waterfall (since the high-frequency components of sound attenuate in the air more than the low-frequency ones), the sound of a flying helicopter, this noise is also found, for example, in heart rhythms, in graphs of the electrical activity of the brain, in the electromagnetic radiation of space bodies.

I would also like to highlight green noise- environmental noise. The spectrum is similar to that of pink noise with a "spike" around 500 Hz. Green noise also denotes the mid-range frequencies of white noise.

How does color noise affect a person?

As you probably already guessed - in different ways! Of course, all this is individual. The taste and color ... as they say! But many have noticed that this noise helps to concentrate, if there is a noisy environment around, helps to distract from any thoughts, relax, fall asleep, calm down crying baby and even take away headache!

Like these ones interesting characteristics I found on one English site:

White noise(at all frequencies) is an effective rogue noise masker because it covers a wide range of "spectrum". It's great for reading, studying, and any other activity that requires focus.

pink noise(a mixture of high and low frequencies) will help relieve stress, cope with tension. It creates a therapeutic environment that relaxes your mind and body.

brown noise(uses low audio frequencies) improves sleep, masks tinnitus, reduces headaches. It will also help calm your children and pets.

And here is an interesting video! Skeptics should consider

Of course, everything is individual. And, probably, one should not hope for the miraculous effect of these sounds at one hundred percent. Try it, see what suits you, but don't overdo it too much! Noises... sounds of nature... It's all good! But sometimes it’s better to go out into nature (and almost everyone can do it once a week!).