Noise level unit. Noise, sanitary and hygienic level standards and harmful effects of noise on the human body

"Noise" is a random mixing of sounds.

Low and high frequency sounds seem quieter than mid-range sounds of the same intensity. With this in mind, the uneven sensitivity of the human ear to sounds of different frequencies is modulated using a special electronic frequency filter, obtaining, as a result of measurement normalization, the so-called equivalent (in terms of energy, "weighted") sound level with the dimension dBA (dB (A), then yes - with filter "A").

A person, in the daytime, can hear sounds with a loudness of otdB and higher. The maximum frequency range for the human ear, on average, is from 20 kHz (possible range of values: from up to 00 hertz). In youth, a mid-frequency sound with a frequency of 3 kHz is better heard, in middle age - 2-3 kHz, in old age - 1 kHz. Such frequencies, in the first kilohertz (up to Hz - the zone of speech communication) - are common in telephones and radio on the MW and LW bands. With age, the sound range perceived by ear narrows: for high-frequency sounds - decreasing to 18 kilohertz or less (in older people, every ten years - by about 1000 Hz), and for low-frequency sounds - increasing from 20 Hz or more.

In a sleeping person, the main source of sensory information about the environment is the ears ("light sleep"). Hearing sensitivity, at night and with closed eyes, increases nadB (up to a few decibels, on the dBA scale), compared to daytime, therefore, loud, sharp noise with large volume jumps can wake up sleeping people.

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(SNiP3 "Protection from noise").

moredeath (noise weapon)

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The maximum allowable sound levels (LAmax, dBA) are 15 decibels higher than the "normal" ones. For example, for living rooms of apartments, the permissible constant sound level in the daytime is 40 decibels, and the temporary maximum is 55. With constantly working engineering equipment, an amendment is taken into account - minus 5.

inaudible noise- sounds with frequencies less than Hz (infrasound) and more than 20 kHz (ultrasound). Low-frequency oscillations of 5-10 hertz can cause resonance, vibration of internal organs and affect the functioning of the brain. Low-frequency acoustic vibrations increase aching pains in bones and joints in sick people. Sources of infrasound: cars, wagons, thunder from lightning, etc.

Workplaces maximum permissible, according to the law, equivalent sound levels for intermittent noise: the maximum sound level should not exceed 110 dBA, and for impulse noise - BAI. Even a short stay in areas with sound pressure levels above 135 dB in any octave band is prohibited.

For fire alarm: the sound pressure level of the useful audio signal provided by the siren must be at least 75 dBA at a distance of 3 m from the siren and not more than 120 dba at any point of the protected premises (clause 3.14 of the airbag).

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A device is used to measure the noise level sound level meter(pictured), which is produced in various modifications: household (approximate price, measurement ranges: dB, 31.5 Hz - 8 kHz, filters A and C), industrial (integrating, etc.) The most common models: SL, octave, svan. To measure infrasonic and ultrasonic noise, wide-range noise meters are used.

Sound frequency ranges

midrange0 Hz;

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sand dry / wet0 /

They reduce the range of sound propagation along the surface of the earth - high obstacles (mountains, buildings and structures), the opposite direction of the wind and its speed, as well as other factors (low atmospheric pressure, high temperature and humidity). Distances at which the source of loud noise is almost inaudible - usually from 100 meters (in the presence of high obstacles or in a dense forest), home. - in open areas (with a fair average wind - the range increases to a kilometer or more). With distance, higher frequencies are “lost” (quickly extinguished and dissipated) and low-frequency sounds remain. The maximum range of propagation of infrasound of medium intensity (a person does not hear it, but there is an effect on the body) is tens and hundreds of kilometers from the source.

The noisiest cities in Russia

These are many regional and district centers of the country, practically all the territories of large transport hubs and urban residential buildings along avenues and near airports. This category includes: Moscow, St. Petersburg, Krasnoyarsk, Rostov-on-Don, Chelyabinsk, Yekaterinburg, Perm, Irkutsk, Yaroslavl, Voronezh, Novokuznetsk, Nizhny Tagil, Magnitogorsk, Omsk, Ufa, Samara, Nizhny Novgorod, Novosibirsk, Murmansk , Perm, Tula, Ulyanovsk, Kemerovo and others.

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When the right and left ears hear sounds (for example, from the player's headphones, fHz) - the sounds break up, in perception, into the original ones, with their actual frequency, and the bin. effect disappears. The phase difference of the sound waves coming to the right and left ear - allows you to determine the direction to the source of sound / noise, volume and timbre - the distance to it.

International standardization of physical parameters

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A reaction to prolonged and strong noise exposure is "tinnitus" - ringing in the ears, "noise in the head", which can develop into a progressive hearing loss. It is typical for ages over 30 years old, with a weakened body, stress, alcohol abuse and smoking. In the simplest case, the cause of tinnitus or hearing loss can be a wax plug in the ear, which is easily removed by a medical specialist (washing or extraction). If the auditory nerve is inflamed, this can be cured, also relatively easily (with medicines, acupuncture). Pulsating noise is a more difficult case to treat ( possible reasons: narrowing of blood vessels in atherosclerosis or tumors, as well as subluxation of the cervical vertebrae).

To protect your hearing:

In a noisy place, to protect your hearing - use anti-noise soft "ear plugs", earbuds or headphones (noise reduction is more effective at high sound frequencies). They need to be customized to fit your ear. In the field, they also use light bulbs from a flashlight (they are not for everyone, but they are suitable in size). In shooting sports, individually molded "active ear plugs" with electronic filling are used, at a price - like a telephone. They must be kept in their packaging. It is better to choose bershes made from a hypoallergenic polymer that have good SNR (noise reduction) of 30 dB or more. With sudden pressure drops (in an airplane), to equalize it and reduce pain, you need to use special earplugs with micro-holes;

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Techniques usually used to equalize pressure on both sides of the eardrum: swallowing, yawning, blowing with a closed nose. Frenzel's method - holding the nostrils, with an effort to take the tongue back, along the palate (when the muscles contract, the nasal cavities and Eustachian tubes will open). Artillerymen, firing a shot, open their mouths or cover their ears with the palms of their hands.

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Sound level meter SL. Household and industrial noise meters.

Noise level - what and how

In the parameters of the climatic equipment, the noise level is indicated separately for the outdoor and indoor units. The noise of the indoor unit is caused by the sound of the air passing through the fan. Therefore, more expensive models of air conditioners, as a rule, have a larger size of the indoor unit compared to more budgetary models of the same capacity. The explanation for this is simple: the same volume of air passing through a larger fan rotating at a lower speed creates less noise.

The noise of the outdoor unit is primarily due to the noise of the compressor. This is where inverter air conditioners come in handy. Although the noise level of on/off (non-inverter) type air conditioners has also decreased significantly recently.

Note: The table is based on manufacturers' data.

From the point of view of the human ear, "noise" is a random mixture of sounds that is unfavorable for human perception. Physical characteristic sound loudness - sound pressure level, in decibels (dB).

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A decibel is a dimensionless unit used to measure the ratio of certain quantities, in our case, the loudness of a sound. It is important to remember that this is not an absolute value, such as, for example, a watt or a volt, but the same relative one, like a multiplicity (“threefold increase”) or percentage, designed to measure the ratio of two other quantities. In this case, unlike percentages or multiplicity, a logarithmic scale is applied to the resulting ratio.

Decibels are widely used in areas of technology that require the measurement of quantities that vary over a wide range: in radio engineering, antenna technology, in information transmission systems, automatic regulation and control, in optics, acoustics, etc.

For a better understanding, consider two cases:

1. What happens if the noise of 25 dB is increased by another 25 dB? Noise overall intensity at 50 dB? No - after all, when a number is doubled, its logarithm increases by

0.3 (accurate to two decimal places). Then, when the sound intensity is doubled, the intensity level increases by

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0.3 bela, that is,

3dB, up to 28dB. This is true for any level of intensity: doubling the sound intensity results in a 3 dB increase in the intensity level.

2. How many times does the noise level differ between 20 and 32 dB? If we were dealing with linear growth, then the answer would be simple: 32 / 20 =

1.5 times. This is the most common mistake buyers make.

Note: Please note the difference between dB and dBA. dBA - acoustic decibel, a unit of measurement of the noise level, taking into account the perception of sound by a person. When measured in dBA, a doubling of loudness roughly corresponds to a 10 dBA increase in noise level. Those. for 25 dBA increase by 25 dBA

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Low and high frequency sounds seem quieter than mid-range sounds of the same intensity.

A person, in the daytime, can hear sounds with a volume of 10 - 15 dB and higher. The maximum frequency range for the human ear, on average, is from 20 kHz (possible range of values: from 12 - 24 to - hertz). In youth, a mid-frequency sound with a frequency of 3 kHz is better heard, in the middle age 2-3 kHz, in old age 1 kHz. Such frequencies, in the first kilohertz (up to 1000 - 3000 Hz voice communication zone) are common in telephones. With age, the sound range perceived by ear narrows: for high-frequency sounds, it decreases to 18 kilohertz or less (in older people, every ten years by about 1000 Hz), and for low-frequency sounds, it increases from 20 Hz or more.

For a sleeping person, the main source of information about the world around us is the ears. Hearing sensitivity is sharply aggravated compared to the daytime, so noise that is imperceptible during the day, and especially noise with volume jumps, can easily wake up sleeping people.

The absence of sound-absorbing materials (carpets, special coatings) on the walls of the premises, the sound will be louder due to repeated reflection (echo) from walls, ceiling, furniture), which will increase the final noise level by several decibels.

Noise scale (sound levels in dBA - acoustic decibel, a unit of noise level measurement taking into account human perception of sound)

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Permissible maximum according to the norms for residential premises at night, from 23 to 7 hours.

(SNiP3 "Protection from noise").

Norm for living quarters during the day, from 7 am to 11 pm (SNiP3 "Protection from noise").

The maximum allowable sound pressure for the player's headphones.

At sound levels above 160 decibels, rupture of the eardrums and lungs is possible, more than 200 - death

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Spoken speech ranges from 45 decibels (dB) to 60 decibels (dB), depending on the loudness of the voice;

The maximum allowable sound levels are 15 decibels higher than "normal". For example, for living rooms of apartments, the permissible constant sound level in the daytime is 40 decibels, and the temporary maximum is 55. With constantly working engineering equipment, an amendment is taken into account: minus 5.

Inaudible noise - sounds with frequencies less than Hz (infrasound) and more than 20 kHz (ultrasound). Low-frequency oscillations of 5-10 hertz can cause resonance, vibration of internal organs and affect the functioning of the brain. Low-frequency acoustic vibrations increase aching pains in bones and joints in sick people. Sources of infrasound: cars, wagons, thunder from lightning, etc.

How is noise measured?

A sound level meter is used to measure the noise level. Sound level meters are household (measurement ranges 30 - 130 dB, 31.5 Hz - 8 kHz,) and industrial. Wide-range sound level meters are used to measure infrasonic and ultrasonic noise.

One of the most important issues is the dependence of the sound level on its frequency. The lower frequency limit of human sound perception is about 30 Hz, and the upper one is not higher than 18 kHz; therefore, the sound level meter would have to register sounds in the same frequency range. But here a serious difficulty arises. The fact is that the sensitivity of the human ear for different frequencies is not the same; so, for example, in order for sounds with a frequency of 30 Hz and 1 kHz to sound equally loud, the sound pressure level of the first of them must be 40 dB higher than the second. And therefore, the readings of the sound level meter in themselves are not worth much.

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Therefore, all modern sound level meters are equipped with corrective circuits, thanks to which it is possible to reduce the sensitivity of the sound level meter to low-frequency and very high-frequency sounds and thereby bring the frequency characteristics of the device closer to the properties of the human ear. Typically, a sound level meter contains three correction circuits, designated A, B and C; correction A is most useful; correction B is used only occasionally; and even more rarely correction C.

Most often, the level of domestic and industrial noise is taken equal to the level measured in dB using an A-corrected sound level meter and expressed in units of dBA. Although the human ear perceives sound incomparably more refined than a sound level meter, and therefore sound levels expressed in dBA do not in any way correspond to an exact physiological response, the simplicity of this unit makes it extremely convenient for practical use.

Another advantage of the dBA scale is that doubling the volume roughly corresponds to a 10 dBA increase in noise level.

For an approximate estimate of the noise level, you can use the "improvised tools" in the form of a desktop computer, laptop, tablet and or smartphone. Of course, such a measurement will be rougher than that performed at least with the help of a specialized household sound level meter, but practically free of charge.

We measure the noise level using desktop computer or laptop:

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For a PC with MS Windows 8, you can use free application Decibel Meter or Asa Tempo. They can be downloaded from Microsoft App Store(https://www.microsoft.com/en-us/store/apps/windows). These applications use a microphone connected to your computer, external or built-in, and can measure sounds up to 96 dB (Decibel Meter).
For Apple products, there are similar programs in iTunes App Store (Decibel 10th - Professional Noise Meter).
You can also use sound editors to measure the volume of noise. The main thing is that the program can work with a microphone as a sound source. For example in Audacity, free sound editor(GNU GPL v2 license), there is a level measurement function input signal. It is available for a variety of operating systems: MS Windows (10/8/7/Vista/XP), GNU/Linux, Mac OS X. You can download it from the developers' website at http://www.audacityteam.org/ Users of the OS family GNU/Linux can in most cases install it directly from their distribution's repository.

For tablet and smartphone:

Microphone in mobile device Of course, it will not give the same quality as an external microphone, but you will get the ability to measure the sound level almost anywhere. Nevertheless, this accuracy will be sufficient to estimate the noise level in most domestic cases.

For Apple devices: Decibel 10th, Decibel Meter Pro, dB Meter, Sound Level Meter;
For devices under Android control: deciBel, Decibel Meter, Noise Meter, Sound Meter;
For devices running MS Windows phone: Cyberx Decibel Meter, Decibel Meter Free, Decibel Meter Pro.

What and how noisy in the air conditioner

Compressor. It is also a source of low-frequency (including infra-low, propagating primarily through building structures) noise.

In split systems, its contribution is lower than in window or mobile models. Also in mobile and window systems, it is added to the noise of the fan and the noise of the air flow.

2. Fan of the indoor unit. The motor should not be heard.

3. Swinging sash. If you hear it, contact the service

4. Relay for switching modes. Heard on non-inverter ("on/off") models

Refrigerant noise: only heard on the lines during heating, if heard during cooling, then there are some problems

What and how noisy in heaters

In convectors (fan heaters) and heat guns: fans and air flow. The smaller the fan diameter, the more noise. The shape of the ventilation grill also affects the noise level.
In oil coolers - oil movement at high power
In gas and diesel heat guns: flame

Hygienic noise standards

To determine the permissible noise level at workplaces, in residential premises, public buildings and residential areas, GOST 12.1.003-83 is used. SSBT "Noise. General requirements safety", SN 2.2.4 / 2.1.8. "Noise at workplaces, in the premises of residential, public buildings and in residential areas". Normalization of noise in the audio range is carried out according to the limiting spectrum of the noise level and according to dBA. This method sets the maximum permissible levels (MPL) in nine octave bands with geometric mean frequencies of 31, 63, 125, 250, 500, 1000, 2000, 4000, 8000 Hz.

Noise at workplaces, in the premises of residential, public buildings and in residential areas

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About decibels, Sound volume. Noise level and its sources

The physical characteristic of sound loudness is the sound pressure level, in decibels (dB). "Noise" is a random mixing of sounds.

Low and high frequency sounds seem quieter than mid-range sounds of the same intensity. With this in mind, the uneven sensitivity of the human ear to sounds of different frequencies is modulated using a special electronic frequency filter, obtaining, as a result of measurement normalization, the so-called equivalent (in terms of energy, “weighted”) sound level with the dimension dBA (dB (A), then yes - with filter "A").

A person, in the daytime, can hear sounds with a loudness of otdB and higher. The maximum frequency range for the human ear, on average, is from 20 kHz (possible range of values: from up to 00 hertz). In youth, a mid-frequency sound with a frequency of 3 kHz is better heard, in middle age - 2-3 kHz, in old age - 1 kHz. Such frequencies, in the first kilohertz (up to Hz - the zone of speech communication) - are common in telephones and radio on the MW and LW bands. With age, the sound range perceived by ear narrows: for high-frequency sounds - decreasing to 18 kilohertz or less (in older people, every ten years - by about 1000 Hz), and for low-frequency sounds - increasing from 20 Hz or more.

In a sleeping person, the main source of sensory information about the environment is the ears (“light sleep”). Hearing sensitivity, at night and with closed eyes, increases nadB (up to a few decibels, on the dBA scale), compared to daytime, therefore, loud, sharp noise with large volume jumps can wake up sleeping people.

If there are no sound-absorbing materials on the walls of the premises (carpets, special coatings), the sound will be louder due to multiple reflections (reverberation, that is, echoes from walls, ceilings and furniture), which will increase the noise level by several decibels.

Noise scale (sound levels, decibel), in the table

Permissible maximum according to the norms for residential premises at night, from 23 to 7 hours.

The norm for residential premises during the day, from 7 to 23 hours.

The maximum allowable sound pressure for the player's headphones (according to European standards)

At sound levels above 160 decibels, eardrums and lungs may rupture,

moredeath (noise weapon)

The maximum allowable sound levels (LAmax, dBA) are 15 decibels more than "normal". For example, for living rooms of apartments, the permissible constant sound level in the daytime is 40 decibels, and the temporary maximum is 55.

At workplaces, the maximum permissible, by law, equivalent sound levels for intermittent noise: the maximum sound level should not exceed 110 dBA, and for impulse noise, BAI. Even a short stay in areas with sound pressure levels above 135 dB in any octave band is prohibited.

When erecting buildings and structures, in accordance with modern, more stringent sound insulation requirements, technologies and materials capable of providing reliable protection from noise.

For fire alarms: the sound pressure level of the useful audio signal provided by the siren must be at least 75 dBA at a distance of 3 m from the siren and not more than 120 dba at any point of the protected premises (clause 3.14 of the airbag).

116 dB(A) - when installing the sound emitter on the roof of the vehicle;

122 dBA - when installing the emitter in the engine compartment of vehicles.

Changes in fundamental frequency should be between 150 and 2000 Hz. Cycle duration - from 0.5 to 6.0 s.

If a city dweller, accustomed to constant noise, finds himself in complete silence for some time (in a dry cave, for example, where the noise level is less than 20 db), then he may well experience depressive states instead of rest.

Noise meter for measuring sound level, noise

To measure the noise level, a sound level meter is used (pictured), which is produced in various modifications: household (approximate price, measurement ranges: dB, 31.5 Hz - 8 kHz, filters A and C), industrial (integrating, etc.). e.) The most common models: SL, octave, svan. Wide-range noise meters are used to measure infrasonic and ultrasonic noise.

Sound frequency ranges

Sub-bands of the audio frequency spectrum to which two- or three-band filters are tuned acoustic systems: low-frequency - fluctuations up to 400 hertz;

midrange0 Hz;

The speed of sound and its range

Approximate speed of audible, mid-frequency sound (with a frequency of about 1-2 kHz) and the maximum range of its propagation in various environments:

in air - 344.4 meters per second (at a temperature of 21.1 Celsius) and approximately 332 m / s - at zero degrees;

in water - approximately 1.5 kilometers per second;

in a tree of hard varieties - about 4-5 km / s along the fibers and one and a half times less - across.

in stainless steel - 5.8 kilometers per second.

Polystyrene - 2.4 kilometers per second.

sand dry / wet0 /

If during a thunderstorm you saw strong lightning and after 12 seconds you heard the first peals of thunder, this means that the lightning struck four kilometers from you (340 * 12 = 4080 m.) In approximate calculations, it is assumed that three seconds per kilometer of distance (in air space) to the sound source.

Binaural Beat Frequency

When the right and left ears hear sounds (for example, from the player's headphones, f< 1000 герц, f1 - f2 < 25 Гц) двух различных частот - мозг, в результате обработки этих сигналов, получает третью, разностную частоту биения (бинауральный ритм, который равен арифметической разнице их частоты), «слышимую» как низкочастотные колебания, совпадающие с диапазоном обычных мозговых волн (дельта - до 4 Гц, тета - 4-8Гц, альфаГц, бетаГц). Этот биологический эффект учитывается и используется в студиях звукозаписи - для передачи низких частот, не воспроизводимых напрямую динамиками обычных стереосистем (вследствие конструкционных ограничений), но эти способы и методы, при неумелом применении, могут негативно сказаться на психологическом состоянии и настроении слушателя, так как отличаются от естественного, природного восприятия человеческим ухом шумов и звуков.

In those places of the ionosphere where they hit electromagnetic waves of sufficient power, with a stable (with a high quality factor of the signal) Schumann resonance, especially at the frequencies of its first harmonics - the plasma bunches that have appeared, at the same time, begin to radiate infrasonic acoustic (sound) waves. Specific ionospheric emitters exist as long as lightning discharges continue in the initiating thunderstorm source - approximately, up to the first tens of minutes. For an eight hertz frequency, these radiating points are located on the opposite side of the globe, from the electromagnetic source. waves. At 14 hertz - in a triangle. Local, strongly ionized regions in the lower layers of the ionosphere (sporadic Es layer) and plasma reflectors - can be interconnected or spatially coincide.

Prolonged exposure to noise with a level of more than a decibel can lead to partial or complete hearing loss (at concerts, the power of acoustic systems can reach tens of kilowatts). Likewise, it may happen pathological changes in the cardiovascular and nervous systems. Only sounds up to 35 dB are safe.

A reaction to prolonged and strong noise exposure is "tinnitus" - ringing in the ears, "noise in the head", which can develop into a progressive hearing loss. It is typical for ages over 30 years old, with a weakened body, stress, alcohol abuse and smoking. In the simplest case, the cause of tinnitus or hearing loss can be a wax plug in the ear, which is easily removed by a medical specialist (washing or extraction). If the auditory nerve is inflamed, this can be cured, also relatively easily (with medicines, acupuncture). Pulsating noise is a more difficult case to treat (possible causes: narrowing of blood vessels in atherosclerosis or tumors, as well as subluxation of the cervical vertebrae).

To protect your hearing:

Do not increase the volume of the sound in the player's headphones, trying to drown out external noise (in the subway or on the street). At the same time, it also increases electromagnetic radiation on the brain from the earpiece speaker;

In a noisy place, to protect your hearing organs, use anti-noise soft "ear plugs", earbuds or headphones (noise reduction is more effective at high sound frequencies). They need to be customized to fit your ear. In the field, they also use light bulbs from a flashlight (they are not for everyone, but they are suitable in size). In shooting sports, individually molded "active earplugs" with electronic filling are used, at a price - like a phone. They must be kept in their packaging. It is better to choose bershes made from a hypoallergenic polymer that have good SNR (noise reduction) of 30 dB or more. With sudden pressure drops (in an airplane), to equalize it and reduce pain, you need to use special earplugs with micro-holes;

In rooms, use soundproofing environmentally friendly materials to reduce noise;

When diving, so that the tympanic membrane does not rupture, blow out in time (blow out the ears by holding the nose or swallowing). Immediately after diving - you can not go on a plane. Jumping with a parachute - you also need to equalize the pressure in a timely manner so as not to get barotrauma. Consequences of barotrauma: noise and ringing in the ears (subjective "tinnitus"), hearing loss, ear pain, nausea and dizziness, in severe cases - loss of consciousness.

With a cold and a runny nose, when the nose and maxillary sinuses are stuffy, sudden pressure drops are unacceptable: diving (hydrostatic pressure - 1 atmosphere per 10 meters of immersion depth in water, that is: two - at ten, three - at around 20 m. and etc.), parachute jumps (0.01 atm. per 100 m. height, rapidly increasing, with acceleration).

// about seven and a half millimeters of mercury column of a barometer - for every hundred meters, in height.

Give your ears a rest from loud noise.

Techniques usually used to equalize pressure on both sides of the eardrum: swallowing, yawning, blowing with a closed nose. Artillerymen, firing a shot, open their mouths or cover their ears with the palms of their hands.

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Noise level. What does 35 dB mean and how can it be compared?

The noise characteristics of the equipment are given in the form of tables, which contain:

Level sound power noise level LWA in dB(A) broken down by frequency bands, sound power levels at the inlet, outlet and surroundings of the fan.
Total sound pressure level dB(A) at 3m.

The frequency band is divided into 8 groups of waves. In each group, the average frequency is determined: 63 Hz, 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2 kHz, 4 kHz and 8 kHz. Any noise is decomposed into groups of frequencies and it is possible to find the distribution of sound energy over various frequencies.

The noise from the fan propagates through the air duct (air duct), partially attenuates in its elements and penetrates into the serviced room through the air distribution and air intake grilles.

The basis for the design of ventilation systems is acoustic calculation - a mandatory application to the ventilation project of any object.

The main tasks of such a calculation are: determination of the octave spectrum of ventilation noise at the calculated points and its required reduction by comparing this spectrum with the permissible spectrum according to hygienic standards. After the selection of construction and acoustic measures to ensure the required noise reduction, a verification calculation of the expected sound pressure levels at the same design points is carried out, taking into account the effectiveness of these measures.

Can not hear anything

almost inaudible

the soft rustle of leaves

whisper of a person (at a distance of 1m).

human whisper (1m)

whisper, ticking of the wall clock.

the norm for residential premises at night, from 23 to 7 in the morning

norm for residential premises, from 7 to 23 hours

normal conversation

conversation, typewriter

Norm for class A office premises (according to European standards)

norm for offices

loud conversation (at a distance of 1m)

loud conversations (1m)

scream, the sound of a motorcycle with a silencer

loud scream, the sound of a motorcycle with a silencer

loud screams, freight rail car (at a distance of 7 m)

the sound of a passing subway car (7m)

the sound of an orchestra, the intermittent sounds of a passing subway car, thunder

maximum allowable sound pressure for the player's headphones (according to European standards)

At the household level, noise is sound that does not carry useful information. Although for any of us usefulness is a relative concept. For a taxi passenger, incomprehensible sounds under the hood may be just noise, but they signal to the driver about a possible malfunction of the car. Let's define what noise is and learn as much as we can about this physical phenomenon.

What is noise?

For any physicist, noise is an oscillatory process. It can be depicted on paper as an alternation of density waves: condensation waves change places with rarefaction waves. This process is possible only in an elastic medium: sound vibrations, for example, do not propagate in a vacuum. If the bodies do not perform their vibrations in the prescribed order, the human ear perceives these sounds as noise.

Noise Options

All sounds have their own, unique set of parameters, thanks to which we can identify them. Sound vibrations can be measured by:

the strength of sound, which is directly dependent on the pressure that the sound wave produces;
sound frequency. The higher the oscillation frequency, the higher the sound we hear.

For sound in general and for noise in particular, scientists have created their own measurement parameter - "bel". This unit was named after Alexander Bell, the famous inventor of the telephone.

Hearing and noise

For the human ear, all noise sources lie in the range from 45 to 11,000 Hz. If we use a musical term, then the whole variety of sounds (including noise) was included in nine octave bands.

Our hearing organs are not able to distinguish between the entire range of sound vibrations - it is too large. But evolution provides for an instinctive reaction not to the noise itself, but to its change. That is why the human ear has learned to distinguish the multiplicity of changes in the sound wave.

In order for noise classification to be adequate and scientifically assessable, the change in sound pressure is expressed in logarithmic units. It's much easier to portray sound processes graphically. The commonly used unit for measuring noise is the decibel, which is one tenth of a bela. The range of change in sound pressure from the threshold of hearing to the pain that noise causes is millions of dB.

Types of noise

For technical descriptions, all noise can be divided into temporal and spectral parameters. According to the nature of the spectral bands, noise is distinguished:

broadband (the width of the continuous spectrum exceeds the width of an octave);
tonal (exceeding noise in one third-octave band compared to the rest by more than 10 dB).

Classification of noise can also occur according to temporal characteristics. Constant noise changes its frequency by no more than 5 dBA. Intermittent sound vibrations have a greater amplitude of changes and are divided into:

fluctuating - continuous changes in time;
intermittent - changes occur in steps often, there are intervals of constant noise of one or more seconds;
impulse - alternation of noise and silence

Noise level is measured by special devices - sound level meters.

How a sound level meter works

The device for measuring noise has a fairly simple device: a voltmeter calibrated in decibels and electrical filters are connected to a small microphone. Sound signal is perceived by the microphone and translated into an electrical impulse, equal in strength and frequency to the original wave. The increase in the electric field is recorded by a voltmeter and displayed on the display. According to its characteristics, a noise measuring device must be “on the same sound wave” with human hearing. This simple device serves as a reliable indicator of noise pollution in the home or workplace.

Noise sources and comparative noise levels

The modern technological world contains many sources of noise. These are: various types of transport, the sounds of the operation of any devices or equipment, sound equipment, and so on.

All the sounds we hear during the day merge into a cacophony, which we perceive as noise. At home, the noise is many times less than at work (even if your neighbor is a fan of indigestible loud sounds, which he calls songs). Industrial sources today are the main "culprits" of noise pollution of the earth. Among the main "villains" are the metallurgical, mining, coal, petrochemical, and defense industries. Least of all sounds are heard by workers serving the food industry.

Some industrial processes, such as those producing reinforced concrete structures, testing or shooting ranges, spaceports, can be sources of noise reaching up to 120 dBA.

The permissible noise level is determined by the GOST 12.1.003-83 standards. SSBT. Rationing of noise pollution is carried out according to the permissible range of noise levels and dBa. This method helps to set the noise exposure limit in nine octave bands.

What are the noises

Scientists could not get past the whole variety of sound stimuli and came up with various classifications of what noise is. Physics studies these sound phenomena and classifies them for ease of study. We have already familiarized ourselves with some types of noise earlier. Here are a few more options for ranking various sound phenomena according to the nature of their occurrence:

mechanical - sounds that occur during the operation of various mechanisms;
aerodynamic. This includes noise generated during takeoff;
hydraulic. We hear these noises when there are malfunctions in our own plumbing system: a sharp pressure drop in the system can cause water hammer, which is perceived as a sharp, unpleasant noise;
electromagnetic. Occur during the operation of devices and devices of the same name.

In a separate category, we can distinguish the "color" classification of noise. Thus, the “white” noise of technology is called a stationary sound stream, in which the spectral components are evenly distributed over the entire range. The rest of the noise of technology is classified as color. Such an analogy arose when comparing the spectrum of sound waves with the spectral bands of visible light. So, "pink" noise is often present in the heart rate, in the radiation of space, in electronic or mechanical devices. "Orange" noise corresponds to the frequencies of musical notes. "Red Noise" is the melody of various natural bodies of water on Earth. Well, "green" noises are emitted by all green plants of our planet.

Noises around us

Every day, all people who are able to distinguish sounds are faced with various types of sound vibrations. Offhand, you can determine the strength of the sound emitted by various sources of noise that surround us in everyday life.

Normal conversation: 40-45 dB.
The noise of work in the office, the office of a doctor, a lawyer: 50-60dB.
Street sounds: voices of passers-by, traffic flows: 70-80 dB.
Noise at the factory (tyazhprom): 70-110 dB.
Start of a modern airliner: 120 dB.
Maximum vuvuzela volume: 130 dB.

The human body quickly adapts to noise. Suffice it to say that the sound background that has become familiar to us, our ancestors would have regarded as an unbearable sound cacophony. But the human body is not able to withstand a constant noise load. Noises in the audio range dull a person's response to signals coming from outside. This leads to a decrease in the speed of an adequate response and an increase in errors when performing certain types of work.

Noise is the cause of depression of the central nervous system. A constant sound stream causes noticeable changes in the frequency of the pulse and respiration, disrupts metabolism. Noise exposure leads to a number of cardiovascular diseases, hypertension and stomach ulcers. When exposed to "high" noises with a volume above 140 dB, contusion, rupture of the eardrum is possible. Noise louder than 160 dB causes a fatal cerebral hemorrhage.

Noise and nature

Noise pollution is dangerous not only for humans. Scientific research confirm that the powerful engines of modern ships and submarines disorientate aquatic inhabitants who use sonar to find food and communicate. Dolphins and some cetaceans especially suffer from constant fluctuations in the sound background of the ocean. It is possible that reliable, but inexplicable cases of collective suicide of whales are somehow connected with a violation of their orientation skills. In a number of cases, mass beaching of whales was recorded near the places where military exercises were held, which means that noise pollution in this region was extremely high.

Noise and space

As mentioned earlier, noise cannot occur in an inelastic medium. And the vacuum of space is the most inelastic medium of all possible. However, in 2006, NASA researchers discovered an effect that was later named "cosmic noise". Of course, the detected effect is not noise in the usual sense of the word. That was the name of the mysterious radio waves penetrating the entire space of the Universe. Their frequency, strength and amplitude coincided so well with known sound sources that scientists did not hesitate to record radio waves as noise.

Cosmic noise is radio waves emitted by stars billions of light years away from us. Alternative sources of noise phenomena can be bursts of supernova waves, turbulence of gaseous nebulae, and so on. Any cosmic process is accompanied by the release of radio waves into vacuum, which can be studied and classified. Thanks to the phenomenon of cosmic noise, we can learn how stars formed and what fate, in the end, awaits our Universe.

Instruments and methods for measuring noise. In order to compare the characteristics of the noise generated by machines and mechanisms with acceptable sanitary standards, as well as to develop methods for combating noise, it is necessary to know the level of its intensity and spectral composition.

There are two methods for measuring noise levels: subjective and objective. The subjective method of measurement is phonometers, in which the measured sound or noise is compared with a pure tone of a certain frequency, excited by a special generator. However, due to the complexity of the measurements and the dependence of their results on the characteristics of the operator's hearing, they are of very limited use.

To measure noise levels by an objective method, sound level meters are widely used. In these devices, noise is perceived using a broadband microphone, which converts sound vibrations into electrical ones. The latter are amplified and fed to the rectifier of the pointer device (meter). Frequency analyzers, recorders and other devices can be connected to the amplifier output.

Objective sound level meters make it possible to determine only approximate values of noise volume levels due to the limited frequency characteristics of sensitivity.

Noise measurements in industry are made by sound level meters of various types, of which the Sh-63 sound level meter with an PF-1 octave band-pass filter attached to it and the Sh-3M sound level meter with a 1/3-octave LIOT analyzer are most widely used. On fig. 30 given general form sound level meter Sh-63.

Rice. thirty.

The sound level meter has three scales (A, B and C) that take into account the frequency composition of the measured noise. The noise characteristic on the A scale corresponds to the loudness curve of 40 phon, i.e., to some extent, to the subjective perception of the loudness level and allows for an approximate assessment of the “nuisance” or “harmfulness” of noise. Therefore, the noise level, measured on the A scale in decibels (dBA), is of great importance for the hygienic practice of assessing industrial noise.

The noise characteristic on the B scale corresponds to a curve equal to the loudness of 70 phon.

To obtain the noise spectrum, measurements must be made on the C scale. Rectilinear frequency response C in the range of 60-5000 Hz will show a purely physical value - the sound pressure level.

The spectral composition of noise is studied by special instruments called noise analyzers. The most commonly used octave analyzers are used to measure sound pressure levels in octave bands.

Octave band- this is a band in which the upper cut-off frequency is equal to twice the lower frequency (for example, 45-90; 90-180, etc.). The octave band is characterized by an average frequency (geometric mean of the upper f 1 and lower f 2 boundary frequencies

To measure constant (stationary) noise, noise levels are measured with a sound level meter for 5–10 minutes. during this time, several readings of the instrument pointer are taken. From all readings find the minimum and maximum values and calculate the average noise level. In the hygienic assessment of the noise source, they are guided by the maximum values. The obtained noise levels are expressed in decibels or decibels A, depending on the frequency correction on which the measurements were made - C or A.

Impulse noise (explosive, shock, etc.) cannot be measured with conventional sound level meters, since the latter have a large inertia. To measure the energy level of the pulse, special sound level meters 2203 "Brüel and Kjær", PSJ 201, RFT-GDR (Fig. 31), etc. are used.

The normalized values of the maximum permissible sound pressure levels are given in the Sanitary Design Standards for Industrial Enterprises SN 245-71. The maximum permissible sound pressure levels are normalized in octave frequency bands with geometric mean frequencies of 63, 125, 250, 500, 1000, 2000, 4000, 8000 Hz.

In table. 6 shows the current limiting noise spectra. The values indicated in the table must be adjusted depending on the nature of the noise and the time of its exposure. So, for example, indicated in the table. 6 values can be increased for broadband noise by 6 dB if the total duration of noise exposure to a person is from 1 to 4 hours per shift, by 12 dB - with an exposure duration of 15 minutes to 1 hour, by 18 dB - with an exposure duration of from 5 to 15 minutes and by 24 dB - with a duration of exposure to noise less than 5 minutes. When developing measures to combat industrial noise, it should be borne in mind that the maximum permissible noise levels established by sanitary standards are not focused on eliminating the tiring effect of noise, but only to exclude the possibility of developing an occupational disease (the standards take into account technical difficulties in reducing the noise level during various production processes).

Therefore, in all cases, where possible, lower noise levels should be achieved compared to those established by sanitary standards. Thus, noise not exceeding 30-35 dB is not felt as tiresome or noticeable and can be recommended as the maximum allowable for reading rooms, design and technology offices, as well as for mental work rooms.

Table 6 Permissible sound pressure levels and sound levels at permanent workplaces

Name	Geometric mean frequencies of octave bands in Hz								Sound levels in dBA
	63	125	250	500	1000	2000	4000	8000
	Sound pressure levels in dB
1. In case of noise penetrating from outside the premises located on the territory of enterprises:
a) design bureaus, rooms for calculators and programmers of electronic counting machines, laboratories for theoretical work and processing of experimental data, rooms for receiving patients, health centers	71	61	54	49	45	42	40	38	50
b) control rooms (workrooms)	79	70	63	58	55	52	50	49	60
c) observation cabins and remote control	94	87	82	78	75	73	71	70	80
d) the same, with voice communication by telephone	83	74	68	63	60	57	55	54	65
2. In case of noise that occurs inside the premises and penetrates into the premises located on the territory of enterprises:
a) premises and areas for precise assembly, typewriting bureaus	83	74	68	63	60	57	55	54	65
b) laboratory premises, premises for placing "noisy" units of calculating machines (tabulators, perforators, magnetic drums, etc.)	94	87	82	78	75	73	71	70	80
3. Permanent jobs in production premises and on the territory of enterprises	103	96	91	88	85	83	81	80	90

Noise- a random combination of sounds of different strength and frequency; can have an adverse effect on the body. The noise source is any process that causes a local change in pressure or mechanical vibrations in solid, liquid or gaseous media. Noise sources can be engines, pumps, compressors, turbines, pneumatic and electric tools, hammers, crushers, machine tools, centrifuges, hoppers and other installations with moving parts.

For a person, the region of audible sounds is determined in the range from 16 to 20,000 Hz. The auditory analyzer is most sensitive to the perception of sounds with a frequency of 1000-3000 Hz (speech zone).

As for any wave-like oscillatory motion, the main physical parameters characterizing sound are sound pressure, amplitude and period of oscillation, propagation velocity, wavelength.

Sound pressure is a variable pressure that occurs in addition to atmospheric pressure in the medium through which sound waves pass. It is expressed in Pa. The strength of sound - noise - depends on the magnitude of sound pressure.

The time during which an oscillating body makes one complete oscillation is called the oscillation period (T) and is measured in seconds. The oscillation period is related to its frequency by the following relationship:

Oscillation frequency (f) - the number of complete oscillations made within one second. The unit of frequency is hertz (Hz), equal to one oscillation per second.

Effect of noise on the human body. Noise regulation. Noise control methods.

The impact of noise on the human body

1) influence on auditory function, causing auditory adaptation, auditory fatigue, temporary or permanent hearing loss;

2) impaired ability to transmit and perceive the sounds of verbal communication;

3) irritability, anxiety, sleep disturbance;

4) changes in human physiological responses to stress signals and signals that are not specific to noise exposure;

5) impact on mental and somatic health;

6) influence on production activity, mental work.

Noise regulation

Noise regulation is carried out by two methods: 1) by the limiting noise spectrum in dB; 2) according to the integral indicator (sound level) in dBA.

The first method is used to normalize constant noise. The norms are based on the limitation of the sound pressure level within octaves, the nature of the noise and the characteristics of labor (Table 19.1) for nine octave bands with geometric mean frequencies from 31.5 to 8000 Hz. The band with fc = 16 000 Hz is not taken into account, since the sounds of this frequency are weakly audible.

The second method is to normalize the integral (over the entire frequency range) noise level measured on the A scale of the sound level meter. This indicator is called the sound level and denoted by dBA. Scale A of the sound level meter is intended for an approximate assessment of constant and intermittent noise, approximately corresponding to the lines of equal loudness of sounds, and reflects its subjective perception by a person

Noise protection includes the following measures.

1) Sound absorption. Sound absorption is the process of transferring part of the energy of a sound wave into the thermal energy of the medium in which the sound propagates. For sound absorption, porous (pores must be open from the side of sound incidence and interconnected) and loose fibrous materials (felt, mineral wool, cork, etc.) are used.

Sound-absorbing materials or structures made of them are fixed on the enclosing structures of the room without an air gap or at some distance from them.

2) Soundproofing. Soundproofing refers to the process of reducing the level of noise penetrating through the fence into the room.

The main parameter for assessing the sound insulation of any structure is the Rw index. It shows how many decibels the noise level is reduced when using a soundproof structure. To achieve a noise level comfortable for a person (no more than 30 dB), interior partitions must have an Rw index of at least 50 dB.

Vibration, its types and parameters. Measures to limit the spread of vibration.

Vibration- mechanical vibrations. Vibration - oscillation of solid bodies. The sources of occurrence are working electric motors, especially poorly balanced ones, working wood and metalworking equipment, gas turbine engines of vehicles, diesel engines, internal combustion engines and transmission, poor condition of the road surface, hand-held power tools - drills, jackhammers, etc.

Classification

Vibration is classified according to:

– From time characteristics

Permanent- For which the value of the normalized parameters changes by no more than 2 times (by 6 dB) during the observation time

Fickle, including - For which the value of the normalized parameters changes by at least 2 times (by 6 dB) during the observation time of at least 10 minutes when measured with a time constant of 1 s, including

Fluctuating in time - For which the value of the normalized parameters continuously changes in time

intermittent- When human contact with vibration is interrupted, and the duration of the intervals during which contact takes place is more than 1 second

Pulse- Consisting of one or more vibration impacts (for example, shocks), each lasting less than 1 s

- From the mode of transmission

General vibration- Transmitted through the supporting surfaces to the body of a seated or standing person

local vibration- Transmitted through human hands

- From the origin

local vibration- Transmitted to humans from hand-held power tools (with motors), manual controls of machines and equipment. Transmitted to humans from non-mechanized hand tools (without motors), such as straightening hammers different models and workpieces

General vibration - 1 category - transport vibration. Affects a person at the workplace of self-propelled and trailed machines, vehicles. The sources of transport vibration include: tractors, self-propelled vehicles, trucks (including tractors, scrapers, graders, rollers, etc.); snow plows, self-propelled mining rail transport

2 categories– transport and technological vibration. It affects a person at the workplace of machines moving along specially prepared surfaces of industrial premises, industrial sites. Sources of transport and technological vibration include: excavators (including rotary ones), industrial and construction cranes, loading machines, self-propelled drilling carriages; track machines, concrete pavers, floor production vehicles

3 categories– technological vibration. It affects a person at the workplace of stationary machines or is transmitted to workplaces that do not have sources of vibration. The sources of technological vibration include: metal and woodworking machines, forging and pressing equipment, foundry machines, electrical machines, stationary electrical installations, pumping units and fans, etc.

– From direction of action

In the direction of action, the total vibration is divided into vertical, propagating along the Z axis, perpendicular to the supporting surface; horizontal, extending along the X axis from the back to the chest; horizontal, extending along the Y axis from the right shoulder to the left

– On the nature of the spectrum

Narrowband- For which the controlled parameters in one 1/3 octave frequency band are more than 15 dB higher than the values in adjacent 1/3 octave bands

broadband- With a continuous spectrum more than one octave wide

– From the frequency composition

Low frequency- With a predominance of maximum levels in the octave frequency bands 1 - 4 Hz for general vibrations, 8 - 16 Hz - for local vibrations

midrange- 8 - 16 Hz - for general vibrations, 31.5 - 63 Hz - for local vibrations

high frequency- 31.5 - 63 Hz - for general vibrations, 125 - 1000 Hz - for local vibrations

Noise level measurements

To understand whether the noise level is a physical quantity, it is necessary to understand what a decibel is, which measures the sound itself. By the way, this value got its name in honor of Alexander Graham Bell, who invented the telephone, and had nothing to do with the sound pressure level. But that's how it has historically been.

Noise level in dB

So it is believed that the decibel is a unit of noise measurement. Although it is not. Why? The thing is that a sound wave can be measured by several parameters, one of which is the energy per specific area. That is, noise is measured, or rather, its intensity of action in watts per square meter W / m². But with this unit of measurement, difficulties arise of the following plan.

Influence of strong noise

For example, the noise intensity of the quietest conversation is 0.000000000001 W/m². but the sound of a rocket taking off is 1000 W / m². that is, it turns out a fairly wide range, which is simply inconvenient to record. Therefore, scientists adopted a completely different measurement unit, which denoted the ratio, where the lowest conversation, which mathematically can be denoted as 10 −12 W / m 2, acted as the standard or face value. If we compare this value with the noise of a rocket launch, it turns out that the latter exceeds the reference one by 15 times. So a change in the indicator by 10 began to be called white. And its tenths of decibels. That is, any change in the intensity of noise is its ratio to the reference indicator.

Important. Decibels are not a quantity like, for example, volts or amps, kilometers and centimeters. In order to understand this, it is necessary to give an example. If you add 20 m to 1 km, then in total you get 1.02 km or 1020 m. If you add the same amount to 10 dB, you will not get 20 dB. It's essentially a logarithmic function, so doubling the number only increases it by 0.3. That is, it will turn out in total not 20 dB, but 13 dB.

That is why, when choosing a soundproofing material, it is necessary to measure the noise level, and then compare it with the material. And one moment. Let's take an example for comparison. Soundproof boards ISOPLAAT, in the model range of which there are panels with a thickness of 10 and 25 mm. So, for the first one, the sound protection has a value of 22 dB, for the second, 26 dB. This is again to the question why the sound (noise) level is not determined in direct proportion to the auxiliary criteria.

It is quite difficult to determine the level or intensity of noise, therefore, pressure fluctuations of the sound flow are measured. In this case, one can trace the pattern that the sound pressure range is much smaller than the intensity limits. Hence the conclusion: the pressure grows much more slowly than the intensity, almost twice. That is, if the sound pressure indicator is doubled, then the level or intensity of the noise will increase four times.

On this scientific proceedings can be left. We turn to the main issue of the topic - the permissible noise level.

Noise level limits

Why are these indicators introduced? The whole thing, as always, rests on human health. There are special hygienic standards that clearly define how strong the noise should be (of a long-term nature) so that it does not harm a person's hearing aid. So here it is:

during the day, the permissible noise level should not exceed 55 dB;
at night 40 dB.

To make it easier for you to navigate the various noises, we suggest that you familiarize yourself with the table, which describes all kinds of noises, as well as their magnitudes in decibels (dB):

Noise intensity

What conclusion can be drawn by looking at the presented table? All the noises that we hear every day exceed the maximum permissible norm. But these are almost all natural sounds, from which it is very difficult to hide in our daily life. And there are others that we can control. For example, noise from a TV or music center. With a strong sound, there is more harm than the pleasure that both devices bring.

70-90 dB with prolonged exposure dramatically reduces hearing.
Above 100 dB can cause complete deafness.

How to measure sound (noise) level

There are certain maximum allowable standards that guarantee the protection of people living in cities in apartment buildings. So in this document it is clearly stated that the maximum permissible level of the sound background at night should not exceed 30 dB. But if your neighbor is doing repairs, and negligent craftsmen work at night, then you can measure the pressure level of the noise emitted in order to hold both the neighbor and the craftsmen accountable and pay a fine.

How can this be done, what device is needed for this? To find out, you need:

Call a specialist who has a special device available. This device comes with a very sensitive microphone that records sounds and transfers them to a monitor that shows the level in decibels. Such a service is not cheap, like the device itself.
Use a computer, tablet, iPhone and other gadgets. To do this, you need to download from the Internet special application. There are several. Some paid, some free. Since there is no need for high accuracy in determining the maximum permissible sound pressure, an approximate measurement already guarantees some success in your endeavor. So this is the easiest and most affordable option. The main thing, as always, is to understand and use the device correctly.

How to calculate the sound (noise) level

It is impossible to independently calculate the noise level (its pressure), if you are a layman in this matter. Why? Because for the calculation it is necessary to take into account a fairly large number of various conditions. Eg:

The noise source itself is determined, as well as all its characteristics and properties.
Noise is measured in each room separately, for which a professional device is used.
The points where the calculation will be made are selected.

After that, the specialist will need other data.

Indicators of the room (dimensions, what material it is built from, and so on).
Sound pressure spectrum.
Are there noise barriers and their characteristics.
The distance from the calculated point where the meter will be installed to the sound source.

What is included in the calculations? In principle, this is a rather voluminous and serious document.

Collection data and their analysis.
List of sources.
Calculation of sound pressure.
Calculation of sound power.
Full analysis of the situation.

Advice. Such calculations are much easier to carry out at the stage of building design, at the stage of major repairs or before soundproofing work.

Conclusion

Everything that is connected with the noise level, with the concept of sound pressure, measured in decibels, it is necessary to understand that both measurement and calculation are carried out according to special standards. It is their consideration that allows us to determine the atmosphere in which we live. And if the indicators exceed the maximum permissible norms, then this situation will have to be fought. How? Firstly, for this, the market offers a huge range of different soundproofing materials. Secondly, this topic is another article.