Decibel as approximately noise
In the last article, we touched on the theme cleaning with cotton wools. It turned out that, despite the prevalence of such a procedure, self.Cleaning of the ears can lead to an infusion (rupture) of the eardrum and a significant decrease in hearing, up to complete deafness.
However, improper ears cleaning is not the only thing that our hearing can ruin.
Excessive noise exceeding sanitary norms, as well as barotraumas (injuries associated with a pressure drop) can also lead to hearing losses.In order to have an idea of the danger that the noise is for hearing, it is necessary to familiarize with the permissible noise standards for different times of the day, and also find out what level of noise in decibels certain sounds are produced. Thus, you can begin to understand what is safe for hearing and what is a danger.
Permissible noise standards
According to sanitary standards, the permissible noise level that does not harm hearing even with prolonged exposure to the hearing aid, it is generally accepted: 55 decibels (dB) in the daytime and 40 decibels (dB) at night. Such values are normal for our ear, but, unfortunately, they are very often violated, especially within large cities.
Indeed, often a normal noise level is significantly exceeded. Here are examples of only some sounds that we encounter in our lives and how much decibel (dB) in reality these sounds contain:
- Colloquial speech ranges from 45 decibels (dB) to 60 decibels (dB), depending on the volume of the voice;
- Automobile beep reaches 120 decibels (dB);
- Noise of intensive street movement. Up to 80 decibels (dB);
- Children’s crying. 80 decibel (dB);
- The noise of a variety of office equipment, vacuum cleaner. 80 decibels (DB);
- The noise of a working motorcycle, trains. 90 decibels (dB);
- The sound of dance music in a nightclub is 110 decibels (dB);
- The noise of a flying aircraft. 140 decibels (dB);
- Noise of repair work. Up to 100 decibels (dB);
- Cooking on the stove. 40 decibels (dB);
- Forest noise from 10 to 24 decibels (dB);
- A fatal noise level for a person, the sound of an explosion is 200 decibels (dB).
As you can see, most of the noise that we encounter literally every day significantly exceed the permissible threshold of the norm. And these are only natural noises with which we cannot do anything. But there is still noise from the TV, loud music, which we ourselves expose our hearing aid. And we do our own hearing great harm with our own hearing.
What noise level does harm?
If the noise level reaches 70-90 decibels (dB) and lasts quite a long time, then such noise with prolonged exposure can lead to diseases of the central nervous system. And the long.Term exposure to noise with a level of more than 100 decibels (DB) can lead to a significant decrease in hearing to complete deafness. Therefore, we get much more harm from loud music than pleasure and benefits.
Aggressive and long.Term noise effect on the hearing aid can lead to an infusion (rupture) of the eardrum. The consequence of this is a decrease in hearing and, as an extreme case, complete deafness. And although the oral (gap) of the eardrum is a reversible disease (t.E. The eardrum may be restored), however, the restoration process is long and depends on the severity of the penetration. In any case, the treatment of the alarm of the eardrum takes place under the supervision of a doctor who selects a treatment regimen after examination.
Measurement of Noise | Sound Level Intensity | Decibel | Sound Level Meter | SLM
What sounds are dangerous for humans?
A sound that exceeds 100 decibels if it occurs regularly and for a long time, can seriously harm a person and even cause damage to sensory cells, which leads to an irreversible hearing loss. Therefore, on the recommendation of WHO, the maximum permissible noise level is 85 dB.
45 decibel is the average volume of human speech. About the same sound level. The noise of water from the crane along the sink, the smooth gross rumble of a car, the noise of a working Soviet refrigerator, the sound of an epilator or a washing machine.
Acceptable noise standards, or how much decibel in.?
/ / / In order to have an idea of the danger that noise is for hearing, it is necessary to familiarize with the permissible noise standards for different times of the day, and also find out what level of noise in decibels certain sounds are produced.
Thus, you can begin to understand what is safe for hearing and what is a danger. And with understanding, the ability to avoid the harmful effects of sound on the ear will come and. The permissible noise standards for sanitary standards, the permissible noise level that does not harm hearing even with a long effect on the hearing aid, is considered to be: 55 decibels (dB) in the daytime and 40 decibels (dB) at night.
Such values are normal for our ear, but, unfortunately, they are very often violated, especially within large cities.
The noise level in decibels (DB) really, often the normal noise level is significantly exceeded.
Here are examples of only some sounds that we encounter in our lives and how much decibel (dB) in reality these sounds contain:
Permissible levels of noise in residential premises
It is regulated by legislative acts, according to which the time of day is divided into periods and for each period the permissible noise level is different.
- 22.00. 08.00 The period of silence, during which the specified level should not exceed 35-40 decibels (this indicator is considered in them).
- From eight in the morning to ten in the evening, according to the law, it refers to the bright time of the day and you can make noise a little stronger-40-50 dB.
Many are interested in why such a spread in dB. The thing is that the federal authorities gave only approximate values, and each region establishes them on its own. For example, in some regions, in particular, in the metropolitan, there are additional periods of silence during the day. This is usually a gap from 13.00 to 15.00. Non.Compliance with silence at this time is a violation.
It is worth saying that norms are understood as the level that cannot cause any harm to human hearing. But many do not understand what these indicators mean. Therefore, we give a comparative table with noise levels and with what to compare.
- 0-5 dB-nothing or nothing is heard.
- 10. This level can be compared with a slight rustle of foliage on a tree.
- 15. Rustle of foliage.
- 20. Barely audible human whisper (at an approximate distance of one meter).
- 25. Level when a person speaks in a whisper at a distance of a couple of meters.
- 30 decibels with what to compare?. Loud whisper, the move on the wall. According to SNiP standards, this level is the most acceptable at night in premises belonging to residential.
- 35. Approximately at this level, a conversation is being held, however, in muffled tones.
- 40 decibel. Ordinary speech. Snip defines this level as permissible for daytime.
- 45. Also a standard conversation.
- 50. Sound that the writing machine makes (the older generation will understand).
- 55. With what you can compare this level? Yes, the same as the upper line. By the way, according to Euro.Norms, this level is the most acceptable for class A offices.
- 60. A level determined by law for ordinary offices.
- 65-70-loud conversations at a distance of one meter.
- 75. Human cry, laughter.
- 80 is a working motorcycle with a silencer, it is also the level of a working vacuum cleaner with an engine of 2 kW or more.
- 90. A sound made by a freight car when moving along the piece of iron and heard at seven meters distances.
- 95 is the sound of a subway car when moving.
- 100. At this level the winding orchestra plays, a chainsaw works. The sound of the same power makes thunder. In European standards, this is the maximum allowable level of headphones player.
- 105-such a level was allowed in passenger airliners until the 80s. Last century.
- 110. Noise published by a flying helicopter.
- 120-125 —walk working at a distance of one meter of the chipper.
- 130. So much decibel gives a starting plane.
- 135-145-a reactive plane or rocket takes off with such a noise.
- 150-160-a supersonic plane intersects a sound barrier.
All of the above is conditionally divided by the level of influence on human hearing:
- 0-10-nothing or nothing is heard.
- 15-20-barely audible.
- 35-45-already quite noisy.
- 50-55-clearly audible.
- 85-95-very noisy.
- 100-115-extremely noisy.
- 120-125-almost unbearable noise level for human hearing. Working workers working with a jackhand must put on special headphones, otherwise hearing loss is provided.
- 130 is the so.Called pain threshold, the sound higher for human hearing is already fatal.
- 135-155-Without protective equipment (headphones, helmets), a person has a shelter, brain injuries.
- 160-200-the rupture of eardrums and, attention, lungs is guaranteed.
Over 200 decibels can not even be considered, as this is a deadly sound level. It is at that level that the so.Called noise weapon acts.
With what to compare the noise in 40 decibels?
We are used to thinking that silence is the lack of sounds, but, as it turned out, our brain clearly hears it and perceives it in the same way as other sounds. This was found out by scientists from the University of Oregon in the United States.
With an increase in temperature and pressure, the speed of sound in the air increases. In liquids. The opposite dependence on temperature.
This line of our hit parade is occupied by vacuum cleaners. In fact, the range of their sound also changed over time, manufacturers optimize the operation of engines, introduce new cleaning systems and additional filters, which allowed the noise of a standard modern vacuum cleaner from 85 to 72 dB and raised these devices to the 6th line of our top.
Noise of a drill how many decibels
Sound volume. Noise level and its sources
Physical characteristics of the sound volume. Sound pressure level, in decibels (dB). “Noise” is a random mixing of sounds.
Sounds with a low and high frequency seem quieter than medium.Frequency of the same intensity. Given this, the uneven sensitivity of the human ear to the sounds of different frequencies is modulated using a special electronic frequency filter, obtaining, as a result of the standardization of measurements, the so.Called equivalent (in energy, “balanced”) sound level with dimensions of the DB (A), then there is. 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-from 20 to 20,000 Hz (possible scatter of values: from 12-24 to 18000-24000 Herz). In youth-a medium-frequency sound with a frequency of 3 kHz is better heard, in the middle age-2-3kHz, in old age-1 kHz. Such frequencies, in the first Killer (up to 1000-3000 Hz-a zone of speech communication)-are common in phones and on radio on SV and DV ranges. With age, the sound range perceived by ear is narrowed: for high.Frequency sounds. Decreasing to 18 Killerz or less (in older people, every ten years. About 1000Hz), and for low.Frequency. Increasing from 20 Hz or more.
In a sleeping person, the main source of sensory information about the environment. Ears become (“sensitive sleep”). Hearing sensitivity, at night and with closed eyes. Increases by 10-14 dB (until the first decibels, on the scale of DBA), compared with daytime days, therefore-a loud, sharp noise with large volume jumps, can wake up sleeping people.
In the absence of sound-absorbing materials (carpets, special coatings) on the walls, the sound will be louder due to repeated reflection (reverb, that is, an echo from walls, ceiling and furniture), which will increase the noise level by several decibels.
Noise scale (sound levels, decibel), in the table
The maximum allowable sound pressure for the headphones of the player (according to European standards)
In regions, in large cities, at the local level, their restrictive norms and rules can apply, on the basis of legislative amendments to the law on silence adopted by regional legislators, the implementation of which is controlled by local authorities.
The maximum allowable sound levels (Lamax, DBA) are more “normal” for 15 decibels. For example, for residential rooms of apartments, the permissible constant level of sound in the daytime is 40 decibels, and the temporary maximum is 55. With constantly working engineering equipment. The amendment is taken into account. Minus 5.
Inaudible noise. Sounds, with frequencies of less than 16-20 Hz (infrasound) and more than 20 kHz (ultrasound). Low-frequency fluctuations of 5-10 Herz can cause resonance, vibration of internal organs and influence the brain of the brain. Low.Frequency acoustic fluctuations enhance the aching pains in the bones and joints in sick people. Sources of infrasound: cars, wagons, thunder from lightning, etc.D.
At workplaces, Extremely permissible, according to the law, equivalent levels of sound, for intermittent noise: the maximum level of sound should not exceed 110 dBA, and for pulsed noise. 125 dBAI. Even a short.Term stay in zones with deafening sound pressure is prohibited. Over 135 dB, in any octave strip.
The noise published by a computer, printer and fax in a room without sound.Absorbing materials can exceed the level of 70 DB. Therefore, it is not recommended to place a lot of office equipment in one room where people can be located. Too noisy equipment should be carried out outside the room where staff workplaces are located. You can reduce the noise level if noise.Absorbing materials as a decoration of the room and curtains made of dense fabric. Soft (foamy (foamy sold in pharmacies) anti.Shift bers for ears will also help if their sound reduction parameter (SNR) is at least 30 decibels. Explosive sounds are extinguished using special mechanical membranes. High.Quality insulating headphones (acceptable, in terms of price and quality ratio, can be found, for example, in construction stores). They provide maximum hearing protection, reliably closing not only the auricle, but also the adjacent temporal bone of the skull.
Crying a child, in comparison with other sounds of the same volume, acts much more on the human psyche, as an irritant and an incentive to active physical actions (calm, feed, etc.D.) For noisy children, neighbors from above, they are unlikely to be fined if the cause of noise is not connected with domestic violence, dysfunction in the family. Not too loud, the stomp of ordinary steps, too, is unlikely to be the basis for holding accountable.
When erecting buildings and structures, in accordance with modern, more stringent sound insulation requirements, technologies and materials that can provide reliable protection against noise should be used.
For fire alarm: The level of sound pressure of the useful audio signal, provided by the Erternator, should be at least 75 dBA at a distance of 3 m from the warmer and no more than 120 dBA at any point in the protected room (p (p.3.14 NPB 104-03).
Large power siren and ship Revun-presses more than 120-130 decibels.
Special signals (sirens and “cracks”-Air Horn), installed by service transport, are regulated by GOST R 50574-2002. The level of sound pressure of the signal device, when the special sound of the signal is supplied, at a distance of 2 meters along the axis of the rope, should not be lower: 116 dB (a)-when installing the emitter of sound on the roof of the vehicle; 122 DBA-when installing the emitting in the engine compartment of vehicles. Changes in the main frequency should be from 150 to 2000 Hz. The duration of the cycle is from 0.5 to 6.0 s.
Claron of a civilian car, according to GOST R 41.28-99 and UN EC Rules 8, must make a continuous and monotonous sound with an acoustic pressure level-not more than 118 decibels. Such an order, the most acceptable values - and for car ashlarization.
If a city resident, accustomed to a constant noise, turns out, for some time, in complete silence (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.
How Loud Should You Master Your Music?
Noise level. What and how. Article on the website of the company “Professi Climate”.
In the parameters of climatic equipment, the noise level is indicated separately for the external and internal unit. The noise of the inner block is due to the sound of the air of the passing fan. Therefore, more expensive models of air conditioners, as a rule, have a larger size of the internal unit compared to more budgetary power. The explanation of this is simple: a similar volume of air, passing through a larger fan rotating with lower speed creates less noise.
The noise of the external block is primarily due to the noise of the compressor. Inverter models of air conditioners won significantly here. Although the level of noise of air conditioners type on/off (not inverter) has recently also significantly decreased.
|Mitsubishi Electric MSZ-EF35VEW||3.5||895 × 299 × 195||630||21|
|DAIKIN ATXN35MB / ARXN35MB||3.41||800 × 288 × 206||608||22|
|Zanussi ZACS-12 HPR/A15/N1||3.5||800 × 300 × 197||560||23|
|Electrolux Eacs/I-12 HM/N3_15Y||3.37||790 × 275 × 200||560||24|
|Ballu BSA-12HN1_15Y||3.5||816 × 265 × 200||550||27|
|LSSAR LS-H22KJA2 / LU-H22KJA2||3.51||790 × 265 × 198||580||32|
Note: The table is compiled according to manufacturers
From the point of view of the human ear, “noise” is a random mixing of sounds unfavorable for human perception. Physical characteristics of the sound volume. Sound pressure level, in decibels (dB).
Decibel is a dimensionless unit used to measure the relationship of certain values, in our case. Sound volume. It is important to remember that this is not an absolute value, such as watts or volt, but as relative as multiplicity (“three.Fold increase”) or interest intended to measure the relationship of two other values. Over, unlike interest or multiplicity to the resulting attitude, a logarithmic scale is used.
Decibels are widely used in areas of technology, where the measurement of values that change in a wide range is required: in radio engineering, antenna technology, in information transmission systems, automatic control and control, in optics, acoustics, etc.
For a better understanding, consider two cases:
What happens if 25 dB is to increase by 25 dB noise? Noise with a total intensity of 50 dB? No. After all, when doubling the number of its logarithm, it increases by ~ 0.3 (with an accuracy of two decimal signs). Then, when a sound intensity is doubling, the intensity level increases by ~ 0.3 white, that is, by ~ 3 dB, up to 28db. This is true for any level of intensity: doubling of sound intensity leads to an increase in the level of intensity by 3 dB.
How much is the different noise level of 20 and 32 dB? If we dealt with linear growth, the answer would be simple: 32 /20 = ~ 1.5 times. It is such a mistake that the buyers make the most often,
|× 1||~ × 2||~ × 8||~ × 16||~ × 32|
Note: draw your attention to the difference between DB and DBA. DBA. Acoustic decibel, unit measurement of noise level, taking into account the perception of the sound of a person. When measuring in the DBA, doubling rudely corresponds to an increase in the noise level by 10 dBa.
|× 1||~ × 2||~ × 8||~ × 16||~ × 32|
Sounds with a low and high frequency seem quieter than medium.Frequency of the same intensity.
A person, in the daytime, can hear sounds with a volume of 10. 15 dB and above. The maximum frequency range for the human ear, on average from 20 to 20,000 Hz (possible scatter of values: from 12. 24 to 18000. 24000 Herz). In youth, a medium.Frequency sound with a frequency of 3 kHz is better heard, in an average age of 2. 3 kHz, in old age 1 kHz. Such frequencies, in the first Killer (up to 1000. 3000 Hz zone of speech communication). Are common in phones. With age, the sound range perceived by ear is narrowed: for high.Frequency sounds, it decreasing to 18 Killers or less (in older people, every ten years by about 1000 Hz), and for low.Frequency. Increasing from 20 Hz or more.
In a sleeping person, the main source of information about the surrounding world is the ears. Hearing sensitivity is sharply aggravated by the daytime day, therefore noise to noise, and especially noise with volume surges, can easily wake sleeping people.
The absence of sound-absorbing materials (carpets, special coatings) on the walls of the premises, the sound will be louder due to multiple reflection (echo) from walls, ceiling, furniture), which will increase the final level of noise by several decibels.
Noise scale (sound levels in the DBA. Acoustic decibel, unit measurement of noise level, taking into account the perception of the sound of a person)
|From 0 to 28 DBA. Minimum noise level.The noise is poorly distinguished already at a distance of one meter from the source, even with a very low level of background noise.|
|0||Can not hear anything|
|ten||Almost inaudible||Quiet rustle of leaves|
|fifteen||Barely audible||The rustle of foliage|
|20||Barely audible||Whisper of a person at a distance of 1 meter.|
|25||Quiet||Whisper of a person at a distance of 1 meter.|
|From 29 to 34 DBA. The noise of the lowshum is already distinguished from two meters from the source, but does not give much attention.Lego is tolerated for a long time and does not interfere with work.|
|Thirty||Quiet||Whisper, ticking wall clock. Permissible maximum according to residential standards at night, from 23 to 7 hours. (SNiP 23-03-2003 “Noise Protection”).|
|From 35 to 39 DBA. Average noise level.The noise is confident and noticeably attracts attention, especially with the general low level of background noise.It is possible to work with this level of noise in general. Definitely interferes with rest and calm sleep.|
|35||Pretty audible||A muffled conversation|
|From 40 DBA and above. High noise level.The constant noise of this level for a long time begins to annoy and tire.When in a room with this noise level, there is a desire to leave the room or turn off the source of noise.|
|40||Pretty audible||Ordinary speech. Norm for residential premises during the day, from 7 to 23 hours. (SNiP 23-03-2003 “Noise Protection”).|
|45||Pretty audible||The usual conversation.|
|Fifty||It is distinctly audible||Writing.|
|55||It is distinctly audible||The upper norm for class A office premises.|
|65. 75||Noisy||Loud conversation, loud laughter at a distance of 1m.|
|80. 85||Very noisy||Noise of intense street movement, children’s crying, working vacuum cleaner.|
|90||Very noisy||Loud cries, cargo railway carriage.|
|95||Very noisy||Underground carriage.|
|100||Extremely noisy||Granding of thunder, screech of a working chainsaw.The maximum permissible sound pressure for the headphones of the player.|
|115||Extremely noisy||Sandblasting apparatus at a distance of 1m, the sound of specialized operational services.|
|120||Almost unbearable||Jumping hammer at a distance of 1m.|
|125||Almost unbearable||Large power siren or shipright.|
|145||Contusion||The start of the space rocket.|
|150. 155||Contusion, injuries|
|160||Shock, injuries||Shock wave from supersonic aircraft.|