Safe noise level in decibels. Noise pollution: how to protect yourself? Sanctions for non-compliance with the Silence Law

The apartment is our fortress, our haven of peace and comfort. But very often extraneous noise prevents us from calmly relaxing and unwinding after a hard day's work. Especially often residents of large cities suffer from such problems, whom even new soundproof plastic windows do not save from the penetration of street noise into the room. The problem is aggravated by the summer heat, when it is not possible to close the window in a residential building or apartment, because not everyone has air conditioners. And if in the daytime the noise can still be somehow tolerated, then at night it is simply impossible to deal with it. But there are still neighbors who, looking at night, begin to drill, knock, sort things out, have fun with guests and listen to music loudly. And on the other side of the house there is a round-the-clock construction, in comparison with which the noise from the neighbors seems like a moment of silence.

What law protects citizens from increased noise in residential premises? What hygiene standards must be followed? What level in dB is acceptable in the apartment? Who can complain about a noisy cafe or construction next to your house? What noise level will not violate the established norms and harm your health? Yes, yes, you heard right. Constant presence in a noisy room is quite harmful to the human ear and the whole organism as a whole. Is it possible to measure the noise level at home and which competent authority to contact if the dB sanitary standard for residential premises is exceeded? How can you influence your neighbors to stop making noise? All these pressing questions are asked every day by about seventy percent of the townspeople. The Internet will do little to help you find answers. It is better to immediately turn to experienced professionals who have experience in solving such problems.

The consultants of our website are ready to help you competently, quickly and, most importantly, free of charge at any time.

In order to answer the above questions, you must first understand the basic concepts of the topic. What is noise, most likely, is clear to every person, so now we will not give a scientific justification for it. But the loudness of sound refers to the level of its (in the sense of sound) pressure in units of measurement, which are dB (decibels). The maximum noise level in the apartment is understood as an increase in the norm by 15 dB. That is, if the law establishes a sanitary norm of 40 dB during the daytime, then the permissible level will be 55 dB. At night, the maximum rate in residential apartments is 40 decibels and cannot be exceeded. Why does the law establish different indicators for premises at night and during the day? Because at night, the auricles become the main organ of perception, there is even such a thing as light sleep. The level of noise susceptibility increases by about 10-15 dB. So, sharp, loud sounds interfere with sleep.

Constant violation of the noise limits in decibels can lead to disruption of the normal functioning of your body. Regular noise in the apartment, for example, from the actions of neighbors, in the amount of 70 dB will already adversely affect your health (the nervous system does not rest, irritability, headaches, etc. appear). In some cases, you don’t even want to stay in residential premises for a long time due to the increased background noise. No need to try to swear with the people responsible for the roar and screams. And on neighbors, and on builders, and even on the management of a neighboring cafe, who violate the law on permissible noise during the day and at night, you can always find justice. To get started, contact the experts and you will be prompted by the algorithm of actions in accordance with the law and justice.

Noise levels with examples

It is not enough to measure dB in residential areas. It is also necessary to understand how much exceeding the permissible sound can affect your health and what degree of violation of the law is observed in this case (with a standard norm of 40 sound units).

Comparative list of sound vibrations (the unit of measurement here will naturally be dB):

• from 0 to 10 almost nothing is heard, it can be compared with a very quiet rustle of leaves;
• from 25 to 20 a barely audible sound, can be compared with a human whisper in residential apartments at a distance of one meter;
• from 25 to 30 a quiet sound (clock ticking, for example);
• from 35 to 45 noise effect from a calm (perhaps even muffled) conversation, for residential buildings the legal standard is 40 dB;
• from 50 to 55 a distinct sound wave, acceptable for non-residential premises, for example, for offices or workrooms using technical means (typewriters, fax, printer, etc.);
• 60 to 75 noisy room, can be compared with loud conversations, laughter, shouting, etc. I would like to remind you that 70 dB is already dangerous for your healthy state;
• from 80 to 95 very noisy sounds, in residential areas a powerful vacuum cleaner can work this way, in non-residential areas (including on the street) such sounds are emitted by the subway, the roar of a motorcycle, very loud screams, etc .;
• 100 to 115 maximum sound for headphones, thunder, helicopter, chainsaw, etc.;
• 130 - sound pressure level falling under the pain threshold (for example, the sound of aircraft engines when it starts);
• from 135 to 145 such sound pressure can lead to concussion;
• from 150 to 160, such sound pressure can lead not only to concussion, but also to injuries, as well as to the introduction of a person into a state of shock;
• over 160 it is possible to rupture not only the eardrums, but also the lungs of a person.

In addition to audible sounds, health is also affected by those that are inaudible to the ear (ultrasound, infrasound). For details, please contact our consultants.

Noise legislation

In our country there is no specific law that protects the peace of citizens in the daytime and at night. For example, the standards for maximum sound pressures (40 and 50 dB) are not established by civil or criminal proceedings, but by sanitary standards. You will also not find the definition of noise at 70 dB as harmful to health in modern legislation. And the people themselves do not respect each other's needs for rest. Regardless of age (a neighbor can turn on loud music at night, even if he is 18 years old, at least 40, at least 70) and social status. Construction work is also carried out day and night, bypassing the law on the basis of permission from the parliamentary bodies. It's easier to deal with neighbors. At night, you can call the police and hold them accountable for disturbing the peace. In the daytime, if someone bothers you, and you are sure that you are right, you can call the employees of the SES or Rospotrebnadzor, who are required to measure the noise level and record your complaint.

There are provisions on which premises are recognized as residential and the permissible conditions for living are prescribed in it. There you can find information about the violation of the norms of sound pressure in the daytime as well.

In order not to get into a mess, calling the police, you need to understand what day and night time means. So, the norms of SanPiN tell us that the daytime is from 7.00 am to 11.00 pm, respectively, the night lasts from 23.00 to 7.00. in accordance with the Federal Law on the maintenance of normal living conditions, violations of these very norms are subject to administrative liability.

The law also prohibits construction work that violates the norms for the admissibility of noise at night. If construction is still underway in a residential area, you can contact the municipal authorities or Rospotrebnadzor. Each situation is individual and therefore, before doing something, contact the experts for advice.

Hearing preservation

In order not to harm your hearing, you must follow certain rules:

• no need to drown out extraneous noise from the outside with loud music in headphones, you can only make it worse;
• if you need frequent and long stays in noisy places (or at work), use special earplugs (they are called earplugs);
• noise reduction in the room is possible with the use of special materials for sound insulation;
• follow the safety rules when diving, skydiving, flying on an airplane, shooting at a shooting range, etc.;
• take care of your ears if you get a runny nose or catch rhinitis (all the actions listed in the line above are prohibited);
• even with a great love for loud music, you do not need to listen to it for days on end;
• Give your hearing a break from time to time if noisy places are still unavoidable.

Take care of your health, because no one will do this except you and your loved ones. And in case of difficult situations, if you need legal assistance, please contact our lawyers. This can be done on the site without leaving your home and without any financial costs.

To feel comfortable and peaceful, a person does not need absolute silence. The complete absence of sounds will not bring peace of mind, and such a state of the environment is not silence (in the usual sense of the word). The world, filled with subtle, often not perceived by the consciousness, rustles and halftones allows you to take a break from the noise and bustle of the mind and body. However, many sounds of different strength and beauty fill people's lives, bringing joy, providing information, simply accompanying the necessary actions.

How to understand that while enjoying you do not interfere with others and do not harm yourself? How to eliminate annoying and negative influence from the outside? To do this, it is useful to know and understand scientifically established noise standards.

What is noise

Noise is a physical and multi-valued quantity (for example, digital noise in images). In modern science, this term denotes non-periodic oscillations of a different nature - sound, radio, electromagnetic. Previously, in science, this concept included only sound waves, but then it became wider.

Most often, noise means a complex of irregular sounds of different frequencies and heights, and from the point of view of physiology, any adversely perceived acoustic phenomenon.

Noise unit

The noise level is measured in decibels. A decibel is a tenth of a bela, which is practically not used. It characterizes the relationship to each other of two physical (energy or power) quantities of the same name - that is, power to power, current to current. One of the indicators is taken as the initial one. It can be simply a reference or generally accepted, and then they talk about the level of the phenomenon (an example is the power level).

For those unfamiliar with mathematics, it will be clearer that an increase of any initial value by 10 dB for the human ear means twice as loud as the initial sound, by 20 dB - four times, and so on. It turns out that the sound heard by a person is a billion times weaker than the loudest. The use of such a notation greatly simplifies the recording, eliminating many zeros, and facilitates the perception of information.

Bel originates from the methods used to estimate the attenuation of the telephone and telegraph signal in the respective transmission lines. Named after an American scientist of Canadian origin Alexander Graham Bell, who is one of the pioneers of telephony, the author of many inventions and the founder of the world's largest media conglomerate American Telephone and Telegraph Company, as well as a large research center Bell Laboratories.

The ratio of numbers and life phenomena

To understand the numerical expression of the noise level, you need to have accurate guidelines. Without application to familiar life phenomena, numbers will remain abstract signs.

The impact of noise on the human body

The negative impact of noise on people has been confirmed by many studies. In ecology, a very eloquent concept of "noise pollution" has even formed.

Noise levels above 70 dB with long-term exposure are likely to cause disorders of the central nervous system, changes in blood pressure, headaches, metabolic disorders, malfunctions of the thyroid gland and digestive organs, impair memory, the ability to concentrate and, of course, reduce hearing . Noise exceeding 100 dB can lead to absolute deafness. Intense and prolonged exposure can provoke

Every 10 dB increase in average noise raises blood pressure by 1.5-2 mmHg, and the risk of stroke increases by 10%. Noise leads to earlier aging, reducing the lives of the population of large cities by 8-12 years. According to experts, the permissible noise level in megacities is significantly exceeded: by 10-20 dB near iron roads and by 20-25 dB near medium-sized highways, by 30-35 dB in apartments whose windows do not have sound insulation and overlook major highways.

The results of studies by the World Health Organization showed that 2% of all human deaths were the result of diseases caused by excessive noise. The danger is also those sounds that are not perceived by the human ear - lower or higher than a person is able to hear. The degree of impact depends on their strength and duration.

Noise level during the day

In addition to federal laws, it is also possible to adopt local legislative acts that tighten the nationwide regulations. Russian legislation provides for a noise level limit that differs during the day and night, as well as on weekdays and weekends / holidays.

On weekdays, daytime will be from 7.00 to 23.00 - noise up to 40 dB is allowed (exceeding a maximum of 15 dB is allowed).

From 13.00 to 15.00 the noise level in the apartment should be minimal (complete silence is recommended) - this is the official afternoon rest time.

On weekends, the schedule also changes slightly - daily rates are valid from 10.00 to 22.00.

Repair work in residential apartment buildings is allowed only on weekdays during the time period from 9.00 to 19.00 with a mandatory one-hour lunch break (in addition to complete silence from 13.00 to 15.00), and their total duration should not exceed 6 hours. Complete renovation in the apartment should be within 3 months.

• industrial premises - noise level up to 70 dB;
• open-type offices (partitions between workplaces do not reach the ceiling) - up to 45 dB;
• closed type offices - up to 40 dB;
• conference rooms - up to 35 dB.

Is it possible to make noise at night?

During sleep, human hearing sensitivity increases by almost 15 dB. According to the World Health Organization, people become irritable if they are affected by sounds of only 35 dB in their sleep, 42 dB noise leads to insomnia, and 50 dB leads to diseases of the cardiovascular system.

Night time on weekdays is considered part of the day from 23.00 to 7.00, on weekends and holidays from 22.00 to 10.00. The noise level should not exceed 30 dB (exceeding a maximum of 15 dB is permissible).

In exceptional cases, violation of established norms is allowed, these include:

• capture of criminals;
• actions taken under force majeure circumstances, during emergency situations and natural disasters, as well as to eliminate their consequences;
• holding city-wide celebrations with the launch of fireworks, concerts.

Noise level measurement

Is it possible to independently determine the number of dB? Determining the noise level is very simple on your own, without professional instruments. For this you can:

• apply a special program for a computer;
• install the appropriate mobile application on the phone.

True, the results of these measurements can be used only for personal needs.

For a more accurate study, it is better to use the equipment designed for this - a sound level meter (often it can also be found under the name "sound level meter"). However, if you need to prove a violation of the rules for official proceedings, you will have to call a specialist with the same device.

There are sound level meters of 4 classes of accuracy and, accordingly, cost.

In order to most accurately determine the noise level in the measurement area, it must be taken into account that the device should not be used at temperatures below -10 °C and above +50 °C. Humidity in the room should not exceed 90%, and atmospheric pressure should not be between 645 and 810 millimeters of mercury.

Where to go if you need to measure the noise

Measurements can be carried out by representatives of forensic organizations, but only on the basis of a court order. Research is carried out by representatives of Rospotrebnadzor or third-party organizations accredited by it for this activity. Design organizations, members of builders' organizations working on the principles of self-regulation (SRO) will help - for the legitimate activities of construction companies, joining such non-profit associations is a prerequisite.

Who to complain to if the noise bothers you

You can contact the police - by calling the duty phone or by calling the district police officer. In some cases, especially when it comes to noise disturbances during repairs, it makes sense to call the representatives of the utility company servicing the house. Sometimes it is advisable to contact the prosecutor's office. You can also complain to Rospotrebnadzor or the authorities of the sanitary and epidemiological station.

Excessively loud noise that exceeds sanitary standards and barograms (injuries due to pressure drop) lead to partial or even complete hearing loss.

To be fully aware of the dangers of noise to hearing aids, it is necessary to become familiar with the maximum allowable noise levels both during the day and at night. Find out which sounds produce the most decibels. With the help of such knowledge, it is possible to clearly distinguish what is absolutely impossible for hearing, and what is safe.

Permissible noise standards

The permitted noise level, which does not have a harmful or destructive effect on hearing during prolonged exposure to the ears, is considered to be: 55 decibels (dB) during the day and 40 decibels (dB) at night. These thresholds are considered normal for the human ear, but alas, they are constantly violated, especially in large cities.

Noise level in decibels (dB)

The reality is that the noise level is often above the norm. Below we will analyze a small part of the sounds that appear in the daily life of each person and understand how many decibels these sounds can contain:

• human speechfrom 40 decibel (dB) up to 65 decibel (dB) ;
• Automotivesignal gets to 12 5 decibel (dB);
• Noisecity ​​road flow- before9 0 decibel (dB);
• Crying children – 75 decibel (dB);
• Noiseoffice space equipment – 8 5 decibel (dB);
• motorcycle noiseortrains -100 decibel (dB);
• Musical sounds in nightclubs - 125 decibel (dB);
• flying noisein the skyaircraft - 145 decibel (dB);
• Repair noise- to 105 decibel (dB);
• The noise of cooking – 35 decibel (dB);
• forest noisefrom 10 to30 decibel (dB);
• Criticalnoise levelfor a person,- 200 decibels (dB).

Now you know that many of the noises that surround you in everyday life are significantly higher than the norm. And these are only external noises, noises that we cannot influence in any way. The noise of the TV or loud music in the speakers is something that we ourselves do and deliberately load the hearing aid.

What noise level is harmful?

If the noise reaches up to 75-100 decibels (dB) and lasts for a long time, then with prolonged exposure it will lead to disorders of the central nervous system of our body. And exceeding these numbers will lead to significant hearing loss or, in the worst case, to deafness. So think about the next time you listen to music too loudly.

What happens to hearing when exposed to noise?

A strong and prolonged noise load on hearing leads to a rupture of the eardrum. As a result, hearing and even deafness decrease. However, the consequences of a ruptured eardrum can be restored, but this process is quite lengthy and depends on the degree of severity. Like it or not, the treatment of this disease takes place under the strict guidance of a doctor.

How to avoid hearing loss?

Knowing the causes of hearing loss, comes the understanding that it is important to avoid long-term strong exposure to noise on the eardrums. It is clear that it is almost impossible to remove the full load on the hearing aid in our time. But it is enough to give your ears more time to rest: to be in silence more often, to limit listening to music loudly. The point is to give your ears as much rest and silence as possible, so you can restore your hearing and keep it normal.

In the last article, we touched on the topic of cleaning the ears with cotton swabs. It turned out that, despite the prevalence of such a procedure, self-cleaning of the ears can lead to perforation (rupture) of the eardrum and a significant decrease in hearing, up to complete deafness. However, improper ear cleaning is not the only thing that can damage our hearing. Excessive noise that exceeds sanitary standards, as well as barotrauma (pressure-related injuries) can also lead to hearing loss.

To have an idea of ​​the danger that noise poses to hearing, it is necessary to familiarize yourself with the permissible noise standards for different times of the day, as well as find out what level of noise in decibels certain sounds produce. In this way, you can begin to understand what is safe for hearing and what is dangerous. And with understanding comes the ability to avoid the harmful effects of sound on hearing.

Permissible noise standards

According to sanitary standards, the permissible noise level, which does not harm hearing even with prolonged exposure to the hearing aid, is considered to be: 55 decibels (dB) during the day and 40 decibels (dB) at night. Such values ​​are normal for our ear, but, unfortunately, they are very often violated, especially within large cities.

Noise level in decibels (dB)

Indeed, often the normal noise level is significantly exceeded. Here are examples of just some of the sounds we encounter in our lives and how many decibels (dB) these sounds actually contain:

• Spoken speech ranges from 45 decibels (dB) to 60 decibels (dB), depending on the volume of the voice;
• Car horn reaches 120 decibels (dB);
• Heavy traffic noise - up to 80 decibels (dB);
• Baby crying - 80 decibels (dB);
• The noise of a variety of office equipment, a vacuum cleaner - 80 decibels (dB);
• Noise of a running motorcycle, train - 90 decibels (dB);
• The sound of dance music in a nightclub - 110 decibels (dB);
• Airplane noise - 140 decibels (dB);
• Repair work noise - up to 100 decibels (dB);
• Cooking on a stove - 40 decibels (dB);
• Forest noise 10 to 24 decibels (dB);
• Lethal noise level for humans, the sound of an explosion - 200 decibels (dB).

As you can see, most of the noises that we encounter literally every day significantly exceed the acceptable threshold of the norm. And these are just natural noises that we can't do anything about. But there is also the noise from the TV, loud music, which we ourselves expose our hearing aid to. And with our own hands we cause great harm to our hearing.

What level of noise is harmful?

If the noise level reaches 70-90 decibels (dB) and lasts for quite a long time, then such noise with prolonged exposure can lead to diseases of the central nervous system. And prolonged exposure to noise levels of more than 100 decibels (dB) can lead to significant hearing loss up to complete deafness. Therefore, we get much more harm from loud music than pleasure and benefit.

What happens to hearing when exposed to noise?

Aggressive and prolonged noise exposure to the hearing aid can lead to perforation (rupture) of the eardrum. The consequence of this is a decrease in hearing and, as an extreme case, complete deafness. And although perforation (rupture) of the eardrum is a reversible disease (i.e., the eardrum can recover), but the recovery process is long and depends on the severity of the perforation. In any case, the treatment of perforation of the tympanic membrane takes place under the supervision of a doctor who chooses a treatment regimen after an examination.

How to prevent hearing loss?

Now that we know the causes of hearing loss, we can easily say that if you avoid prolonged aggressive exposure to noise on the hearing aid, then this alone will be enough to prevent hearing loss. However, it is necessary to give our ears a rest: to be in silence, to go to places where the noise level is low, not to listen to loud music, TV, etc.
As a result, the more time we can spend in calm, relaxing places, the more we can restore our hearing, which will serve us faithfully for a long time.

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 volume of 10-15 dB and higher. The maximum frequency range for the human ear, on average, is from 20 to 20,000 Hz (possible range of values: from 12-24 to 18000-24000 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 1000-3000 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 eyes closed, increases by 10-14 dB (up to the first 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

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.

inaudible noise- sounds with frequencies less than 16-20 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.

High-frequency sound and ultrasound with a frequency of 20-50 kilohertz, reproduced with a modulation of several hertz, are used to scare away birds from airfields, animals (dogs, for example) and insects (mosquitoes, midges).

Workplaces maximum allowable, by law, equivalent sound levels for intermittent noise: the maximum sound level should not exceed 110 dBA, and for impulse noise - 125 dBAI. Even a short stay in areas with sound pressure levels above 135 dB in any octave band is prohibited.

The noise emitted by a computer, printer and fax machine in a room without sound absorbing materials can exceed 70 db. Therefore, it is not recommended to place a lot of office equipment in one room. Too noisy equipment should be moved outside the premises where the workplaces are located. You can reduce the noise level if you use noise-absorbing materials as room decoration and thick fabric curtains. Earplugs will also help.

The cry of a child, in comparison with other sounds of the same volume, has a much stronger effect on the human psyche, as an irritant and incentive for active physical actions (to calm, feed, etc.)

In the construction of buildings and structures, in accordance with modern, more stringent requirements for sound insulation, technologies and materials capable of providing reliable noise protection should be used.

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 NPB 104-03).

High power siren and ship's howler - presses more than 120-130 decibels.

Special Signals(sirens and "quacks" - Air Horn), installed on official vehicles, are regulated by GOST R 50574 - 2002. The sound pressure level of the signaling device when a special sound is given. signal, at a distance of 2 meters along the axis of the horn, should not be lower than:
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.

The civil car horn, according to GOST R 41.28-99 and UNECE Regulation No. 28, must emit a continuous and monotonous sound with an acoustic pressure level of not more than 118 decibels. The maximum permissible values ​​\u200b\u200bof this order are also for car alarms.

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

A device is used to measure the noise level sound level meter(pictured), which is produced in various modifications: household (estimated price - 3-4 tr, measurement ranges: 30-130 dB, 31.5 Hz - 8 kHz, filters A and C), industrial (integrating, etc. .d.) 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, which are tuned to the filters of two- or three-way acoustic systems: low-frequency - vibrations up to 400 hertz;
mid-frequency - 400-5000 Hz;
high frequency - 5000-20000Hz

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.

At 20 ° C., the speed of sound in fresh water is 1484 m / s (at 17 ° - 1430), in sea - 1490 m / s.

The speed of sound in metals and other solids (only the values ​​of the fastest, longitudinal elastic waves are given):
in stainless steel - 5.8 kilometers per second.
Cast iron - 4.5
Ice - 3-4km/s
Copper - 4.7 km/s
Aluminum - 6.3km/s
Polystyrene - 2.4 kilometers per second.

As temperature and pressure increase, the speed of sound in air increases. In liquids, the temperature is inversely related.

Velocity of propagation of elastic longitudinal waves in rock masses, m/s:
soil - 200-800
sand dry / wet - 300-1000 / 700-1300
clay - 1800-2400
limestone - 3200-5500

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), up to 300-800 m - in open areas (with a favorable 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 attenuation intensity (absorption coefficient) of medium frequency sound (of the order of 1-8 kHz), at normal atmospheric pressure and temperature, above the ground with low grass, in the steppe is approximately 10-20 dB for every 100 meters. Absorption is proportional to the square of the acoustic wave frequency.

// comment of the author of the site KAKRAS.RU
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.

The line of propagation of sound waves deviates in the direction of decreasing the speed of sound (refraction on the temperature gradient), that is, on a sunny day, when the air near the earth's surface is warmer than the overlying one, the line of propagation of sound waves bends upwards, but if the upper layer of the atmosphere turns out to be warmer than the surface layer, then the sound will go back down from there and it will be heard better.

Diffraction of sound is the wave bending around an obstacle when its dimensions are comparable to the wavelength or less than it. If it is much longer than the wavelength, then the sound is reflected (the angle of reflection is equal to the angle of incidence), and an acoustic shadow zone is formed behind the obstacles.

Reflections of a sound wave, its refraction and diffraction - cause multiple echo (reverberation), which has a significant impact on the audibility of speech and music in a room or outside it, which is taken into account when recording, to obtain live sound (by placing small-sized microphones with a sharp directional characteristic, for recording direct sound, followed by mixing and mixing of the “dry” recording by the processor into digital or using far-equidistant, well-tuned ambient microphones with additional recording of reflected sounds).

Ordinary soundproofing does not save from infrasound.

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, альфа - 8-13Гц, бета - 13-30 Гц). 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.

// with the binaural effect, not three, but two sounds are "heard": the first is the arithmetic mean, in frequency, from two real ones, and the second is a clock, modeled by the brain. With an increase in the frequency difference (> 20-30 hertz), 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.

Schumann resonance

In those places of the ionosphere where electromagnetic waves of sufficient power hit, 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 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, highly 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 80-90 decibels can lead to partial or complete hearing loss (at concerts, the power of acoustic systems can reach tens of kilowatts). Also, pathological changes in the cardiovascular and nervous system can occur. 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 specialist doctor (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, electromagnetic radiation to the brain from the earpiece speaker also increases;
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 cast "active earplugs" 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;
use soundproofing environmentally friendly materials in rooms 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 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 the 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.

Common Causes of Hearing Loss: water getting into the ears, infections (including respiratory organs), injuries and tumors, the formation of a sulfuric plug and its swelling upon contact with water, prolonged exposure to a noisy environment, barotrauma with a sharp pressure drop, inflammation of the middle ear - otitis (accumulation fluid behind the eardrum).

Ear diseases are treated by an otolaryngologist.

In apartment buildings, the maximum permissible noise level in the apartment in decibels during the daytime is 55 units. Exceeding the equivalent noise level in the daytime is allowed no more than 5 decibels.

Why are the norms on the noise level in residential premises of MKD fixed by law

It has been proven that prolonged exposure to noise above 100 dB leads to hearing loss. The expressions “deaf from the noise”, “burst eardrums” are not a common cliché, as many people think, but a possible injury.

The legislator regulates the permitted noise level in the apartment. The norm according to the law has a certain numerical maximum, obligatory for execution by all, without exception, individuals, legal entities and officials, organizations. In order not to be tempted to ignore the requirements of laws, serious administrative liability is provided for non-compliance, especially for enterprises.

Noise issues in residential premises are regulated by:

1. The Constitution of the Russian Federation guarantees the right to the inviolability of the home.
2. "Rules for the use of residential premises of 21.01.2006" Paragraph 6 of the rules requires that the interests of other residents of the premises or house be taken into account.
3. Federal Law No. 52 “On the sanitary and epidemiological well-being of the population” obliges to comply with the provisions of regulatory acts, not to take actions that infringe on the rights of other citizens to protect health and comfortable living conditions (Article 10).
4. SanPiN 2.1.2.2645-10 "Sanitary and epidemiological requirements for living conditions in residential buildings and premises" regulates noise levels.

To better understand what a noise of 40 decibels is, you can compare it with the volume of the most common sounds in everyday life:

As the above figures show, in many cases in the human environment there is an increased background noise that is hazardous to health. The maximum permissible sound levels in and around the dwelling are also limited.

The maximum permissible sound volume in residential buildings

According to paragraph 6.2.1 of SanPiN 2.1.2.2645-10, the excess of noise in the apartment during the daytime is permissible by 5 dB. That is, if in your region the time of day from 7.00 to 23.00 is designated as daytime, then the standard noise level in this time interval should not be higher than (40 + 5) = 45 dB.

The maximum possible noise level during the day can be no more than 55 decibels (clause 3 of article 23 of the Federal Law No. 52).

As mentioned earlier, sanitary and epidemiological standards establish an equivalent noise level in an apartment. At night, the norm according to the law is not higher than 30 dB. There will be no negative health effects even with prolonged exposure to the hearing organs of sounds of such volume. The maximum possible volume at night is 45 dB.

Excess at night is not allowed. If in your region night time starts, for example, from 22.00 and after its onset in a neighboring apartment, listening to your favorite performers with a sound level clearly not up to 45 dB continues, it is your legal right to demand to turn down the volume.

Exceeding the equivalent and maximum noise levels for adjacent areas facing highways and railways is allowed by 10 dB.

Deviation from the optimal sound volume values ​​established by law is unacceptable.

What to do if the apartment is noisy? Watch the video:

Sanctions for non-compliance with the Silence Law

In your apartment, you can do everything 24/7, if this does not qualify as an illegal act.

If you violate the legal rights of neighbors by allowing loud music to be heard at night, noisy repairs on weekends, or other actions that are qualified as illegal according to the norms of the law on silence, the rules provide for up to 500 rubles (Article 6.4 of the Code of Administrative Offenses of the Russian Federation) .

Legal entities will pay more - from 20 to 40 thousand rubles. In case of repeated violation, the fine is doubled. In case of systematic violations, you will have to pay up to 2 minimum wages.

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