Harm of noise to people

Noise pollution is harmful to people, animals, instruments and buildings, and its degree of harm mainly depends on the frequency, intensity and exposure time of noise.

The hazards of noise mainly include: (1) hearing damage caused by noise. The most direct harm of noise to human body is hearing loss. When people enter a strong noise environment and are exposed for a period of time, they will feel uncomfortable in both ears and even have a headache.

Leave the noisy environment and have a rest in a quiet place, and your hearing will gradually return to normal. This phenomenon is called temporary hearing threshold shift, also known as hearing fatigue.

However, if people work in a strong noise environment for a long time and their hearing fatigue cannot be recovered in time, organic lesions will appear in the inner ear organs, that is, permanent hearing threshold deviation will be formed, also known as noise deafness. If people are suddenly exposed to a very strong noise environment, the auditory organs will suffer from acute trauma, which will cause tympanic membrane rupture and bleeding, labyrinth bleeding, and the spiral device will be peeled off from the basement membrane, which may make people completely lose their hearing, that is, sudden deafness.

Research shows that noise pollution is an important cause of presbycusis. In addition, hearing impairment is also related to living environment and occupation. For example, the incidence of senile deafness in rural areas is lower than that in cities, and textile workers, forgers and blacksmiths have more hearing impairment than their peers.

(2) Noise can induce many diseases, because noise acts on the central nervous system of the brain through the auditory organs, thus affecting all organs of the whole body. Therefore, noise not only damages people's hearing, but also harms other systems of the human body. Due to noise, there will be neurasthenia symptoms such as headache, brain swelling, tinnitus, insomnia, general fatigue and memory loss.

The incidence of hypertension, arteriosclerosis and coronary heart disease in people who work in high noise environment for a long time is 2~3 times higher than that in people who work in low noise environment. It can be seen that noise can lead to cardiovascular diseases.

Noise can also lead to digestive system dysfunction, causing indigestion, loss of appetite, nausea and vomiting, and increasing the incidence of gastrointestinal diseases and ulcers. In addition, noise will also have a certain impact on visual organs, endocrine function and the normal development of the fetus.

People who work and live in high noise, the general health level is declining year by year, and their resistance to diseases is weakened, which leads to some diseases, but it is also related to personal physical factors and cannot be generalized. (3) Noise interferes with normal life and work. Noise has a great influence on people's sleep. Even in sleep, people's hearing is subject to noise.

Noise can lead to dreaminess, easy waking, and decreased sleep quality. The impact of sudden noise on sleep is more prominent. Noise will interfere with people's conversation, work and study.

Experiments show that when people are disturbed by a sudden noise, they will be distracted for 4 seconds. According to statistics, noise will reduce labor productivity 10~50%, and with the increase of noise, the error rate will also increase.

It can be seen that noise will distract people's attention, leading to slow response, easy fatigue, decreased work efficiency and increased error rate. Noise will also cover up safety signals, such as alarm signals and vehicle driving signals, which will cause accidents.

(4) Effects of Noise on Animals Noise can cause pathological changes in the hearing organs, visual organs, internal organs and central nervous system of animals. Noise has a certain influence on the behavior of animals, which can make animals lose their ability to control their behavior, be agitated and lose their normal state. Strong noise will lead to the death of animals.

Birds will lose their hair in the noise, which will affect the spawning rate. 5. The experimental study on the harm of ultra-strong noise to instruments and equipment and building structure shows that ultra-strong noise will damage instruments and equipment and even make them ineffective.

The influence of noise on instruments and equipment is related to noise intensity, frequency, structure and installation mode of instruments and equipment. When the noise level exceeds 150dB, resistors, capacitors, transistors and other components will be seriously damaged.

When strong noise acts on mechanical structures such as rockets and spacecraft, materials will be fatigued and broken due to the repeated action of alternating audio load, which is called acoustic fatigue. General noise has little effect on buildings, but when the noise level exceeds 140dB, it will start to damage light buildings.

For example, when supersonic aircraft pass by at low altitude, there will be sudden changes in pressure and density at the head and tail of the aircraft, and N-type shock waves will be formed after being reflected by the ground. It sounded like an explosion when it reached the ground. This special noise is called rumble. Under the action of suspenders, buildings will be damaged to varying degrees, such as broken doors and windows, broken glass, cracked walls, gypsum falling off, chimney collapse and so on.

Boom has slow attenuation, long propagation distance and wide influence range. In addition, the use of air hammer, piling or blasting near buildings will also cause damage to buildings.

Noise is a kind of sound that causes people to be agitated or loud and is harmful to human health. Noise pollution mainly comes from social noise such as traffic, vehicle horn, industrial noise, building construction, concert hall, tweeter, morning market and people talking loudly.

The physical and psychological harm of noise mainly includes the following aspects: the damage to hearing. Experiments have shown that people's hearing will be impaired after 8 hours of continuous listening to motorcycle sounds; If you are in a rock concert hall, your hearing will be impaired in half an hour.

It is harmful to people's cardiovascular system. The survey of urban noise and residents' health in China shows that the incidence of hypertension increases by 3% for every increase of 1 decibel in regional noise. It affects people's nervous system and makes them irritable.

Affect sleep and cause fatigue. From the perspective of psychoacoustics, noise, also known as noise, generally refers to inappropriate or uncomfortable hearing.

It is a compound sound with many frequencies and aperiodic vibration. In short, noise is an aperiodic sound vibration.

Its sound wave shape is irregular and it sounds harsh. From the social and psychological point of view, any sound that interferes with people's study, work and rest and makes people feel uncomfortable is called noise.

For example, the sound of running water, knocking, rustling and the roar of machines are all noises. It is measured in decibels.

Zero decibel is the lowest intensity of audible sound. Noise can be divided into high intensity and low intensity.

Low-intensity noise is generally harmless to people's physical and mental health, and it is also beneficial to improve work efficiency in many cases. High-intensity noise mainly comes from work.

How harmful is noise to human body?

It is generally believed that 40 decibels is the normal environmental sound of human beings. If it is higher than this value, it may cause some harm, including affecting sleep and rest, interfering with work, hindering conversation, causing hearing damage, and even causing diseases such as cardiovascular system, nervous system and digestive system. Basically, it can be summarized as follows:

1) interferes with sleep, affecting the quality and quantity of sleep, causing frequent breathing, rapid pulse and nervous excitement. And fatigue and fatigue will appear the next day, which will affect work efficiency and cause insomnia, tinnitus, dreaminess, fatigue and memory loss for a long time. In the case of high noise, the incidence of this disease can reach 50-60%;

2) Hearing damage, noise below 85 decibels will not cause hearing damage, and noise above 85 decibels may cause hearing damage, but this damage is only temporary, as long as it is not living in such high noise conditions for a long time, it can still be recovered;

3) Physiological impact on human body, noise will cause nervous reaction of human body, and the secretion of adrenal gland will cause the change of heart rate and the increase of blood pressure. Noise can reduce the secretion of saliva, gastric juice and gastric acid, and is prone to gastric ulcer and duodenal ulcer;

4) Influence on children and fetus: Children's mental development is slow in noisy environment. Studies have shown that children's intellectual development in noisy environment is 20% lower than that in quiet environment. Noise will also have a nervous reaction to the mother, causing uterine blood vessels to contract, thus affecting the supply of nutrients and oxygen necessary for fetal development.

Zhu Lin's home reply time 2007-06-1610:11

Satisfied answer

It is generally believed that 40 decibels is the normal environmental sound of human beings. If it is higher than this value, it may cause some harm, including affecting sleep and rest, interfering with work, hindering conversation, causing hearing damage, and even causing diseases such as cardiovascular system, nervous system and digestive system. Basically, it can be summarized as follows:

1) interferes with sleep, affecting the quality and quantity of sleep, causing frequent breathing, rapid pulse and nervous excitement. And fatigue and fatigue will appear the next day, which will affect work efficiency and cause insomnia, tinnitus, dreaminess, fatigue and memory loss for a long time. In the case of high noise, the incidence of this disease can reach 50-60%;

2) Hearing damage, noise below 85 decibels will not cause hearing damage, and noise above 85 decibels may cause hearing damage, but this damage is only temporary, as long as it is not living in such high noise conditions for a long time, it can still be recovered;

3) Physiological impact on human body, noise will cause nervous reaction of human body, and the secretion of adrenal gland will cause the change of heart rate and the increase of blood pressure. Noise can reduce the secretion of saliva, gastric juice and gastric acid, and is prone to gastric ulcer and duodenal ulcer;

4) Influence on children and fetus: Children's mental development is slow in noisy environment. Studies have shown that children's intellectual development in noisy environment is 20% lower than that in quiet environment. Noise will also have a nervous reaction to the mother, causing uterine blood vessels to contract, thus affecting the supply of nutrients and oxygen necessary for fetal development.

The main harm of noise to people

Noise pollution (1) Noise is a kind of sound.

From a physical point of view, it is the sound produced by irregular and aperiodic vibration of sound source. From the perspective of environmental protection, it refers to those voices that people don't need, are disgusting, or hinder human life and work.

Noise not only has its objective physical characteristics, but also depends on the evaluation of subjective feeling. For example, when listening to music, good singing is not noise, but in the classroom where the teacher is lecturing, the music played in high notes can only be regarded as noise.

(2) The characteristics of noise The space we live in is full of all kinds of sounds, some of which are as weak as insects; Others are better than shelling; Some sounds are as sharp as whistles; Some are as heavy as muffled thunder; Some sounds are very pleasant; Some of them are so noisy that people can't stand it. How is the nature of sound determined? Whether the original sound is big or small is related to the "sound pressure"; The sharpness or heaviness of sound is related to the level of "audio"; Whether the sound is pleasant or noisy is related to whether the "tune" is harmonious.

(1) Audio Audio is the frequency of sound. The number of times a vibrating object vibrates per second is the vibration frequency of the object, and the unit of frequency is hertz.

Generally speaking, the fluctuation of vibration frequency between 20 Hz and 20000 Hz can be heard by human beings, so it is called sound wave, and the vibration source of sound wave is called sound source. Below 20 Hz and above 20000 Hz belong to infrasound and ultrasonic respectively, which can't be heard by human ears.

In the range of sound waves, the pitch changes from low to high with the increase of frequency, but in different frequency bands, the sensitivity of human ears is not consistent. Generally speaking, the audio frequency is below 1000 Hz. As the frequency decreases, the hearing will gradually become dull. Therefore, the human ear is more tolerant to low-frequency noise, but more sensitive to high-frequency noise and less tolerant.

If you live in a high-frequency and strong noise environment for a long time, it will cause partial or severe deafness in your ears. (2) Sound pressure acoustic energy spreads out in the air because the vibrating object causes the local pressure change of the surrounding air through vibration, causing the local density change of the surrounding air, and the local density change causes the pressure change of the far air. In this way, pressure changes will be transmitted to further parts, which will lead to sound transmission.

In the process of sound propagation, the pressure change of air pressure relative to atmospheric pressure is called sound pressure, and the unit is Pa. The field of human hearing is quite broad, with an average of about 2* 10-5-20 Pa.

In other words, we can hear the volume of the strongest sound source, which may be 200,000 times that of the weakest sound source. For the convenience of expression, scientists generally use the overwhelming logarithmic expression of sound as the expression unit, that is, the sound pressure level is used to express the volume.

The unit of sound pressure level is decibel. The sound pressure level of the sound we hear in our daily life is about 0- 140 dB.

The intensity of noise is also expressed by sound pressure level. The lowest sound level that normal people can feel is 1 dB.

Whispering softly is about 30 decibels. The conversation language separated by 1 m is about 60 decibels.

It's about 80 decibels on the bus. The noise in heavy trucks, weaving workshops and subways is about 100 dB.

The limit of sound pressure level that causes earache is called ear valve, and its value is 120 dB. The cannon roared and the jet plane took off at about 130 decibels.

There are three main sources of noise: traffic noise, industrial noise and living noise. Traffic noise Traffic noise is mainly emitted when vehicles are driving.

Such as cars, planes and trains, are all sources of traffic noise. Investigation shows that motor vehicle noise accounts for 85% of urban traffic noise.

The spread of vehicle noise is closely related to the number of roads and the size of traffic measurement. In a city with narrow passages and rows of tall buildings on both sides, the noise is reflected back and forth, which is more noisy.

The same noise source sounds 5- 10 decibels higher in the street than in the open space. In motor vehicles, the noise of heavy vehicles such as trucks and buses is 89-92 decibels, and the noise of light vehicles such as cars and jeeps is about 82-85 decibels. All the above sound levels were measured at a distance of 7.5 meters.

The speed of the car is also closely related to the noise level. The faster the speed, the greater the noise, the higher the speed 1 times the noise increases by 6- 10 dB. Automobile noise mainly comes from automobile exhaust noise.

If the muffler is not added, the noise can reach more than 100 decibel. Followed by engine noise and tire noise, the engine noise can reach more than 90 decibels when the car is driving normally, and the tire noise can reach about 95 decibels when the speed is above 90 km/h.

Therefore, installing a muffler in the exhaust system can reduce the exhaust noise of automobiles by 20-30 decibels. For engines, replacing diesel engines with gasoline engines can reduce engine noise by 6-8 decibels.

In addition, the railway passenger and freight station near the city center has a great influence, especially when the passenger flow is large, because the train has to pass through the urban area. The noise source of subway is similar to that of train.

Because the vehicle runs in the tunnel, the noise is not easy to dissipate, which greatly interferes with the people in the carriage. According to the actual measurement in Britain, the noise in the window is as high as 102 decibel.

Although land and water traffic noise has a wide influence, it is still air traffic noise in terms of direct and significant harm. The aircraft is in the period of internal combustion engine, and the noise of air transportation is not prominent.

However, after the jet plane appeared, the air transportation noise gradually had a greater impact. On the one hand, the jet noise level is high, on the other hand, it is also the result of the increasingly busy air transport.

In fact, the airport will not only produce noise when the plane takes off and lands, but also produce strong noise during airport ground maintenance and aircraft trial operation, which has a great impact on nearby residents. When a large jet plane took off, the language communication on both sides of the runway 1 km was disturbed, and people within 4 km could not rest and sleep.

Industrial Noise Industrial noise mainly comes from mechanical vibration, friction, impact and airflow disturbance in production and various working processes. Although the influence of noise and vibration produced by the production and operation of various factories and municipal and building construction in the city is not as wide as that of transportation, the pollution in some areas is much more serious than that of transportation.

Therefore, the influence of these noise vibrations on the surrounding environment should also be paid attention to. Living noise Living noise mainly refers to the sound generated by various living facilities and crowd activities in streets and buildings.

For example, in the living room, children cry and play radio, television and audio equipment loudly; People are noisy outdoors or in the street, so it is high to publicize or advertise.

The harm of noise to human beings?

According to the relevant regulations, the emission standard of regional environmental noise, which is mainly residential, cultural and educational institutions, is 55 decibels during the day and 45 decibels at night; Commercial and industrial mixed zone is 60 decibels during the day and 50 decibels at night. If the counterpart who is polluted by noise has evidence to prove that the actor has carried out pollution and the pollution has caused certain damage to the counterpart, the counterpart can directly sue the polluter to stop the infringement and compensate for the losses without the coordination of the competent administrative department of environmental protection.

Hazards of noise:

1. Strong noise can cause ear discomfort, such as tinnitus, earache and hearing loss.

2. Reduce work efficiency.

3. The cardiovascular system is damaged.

4. Noise can also cause nervous system dysfunction, mental disorders, endocrine disorders, and even increase the accident rate.

5. Interfere with rest and sleep.

6. Damage to women's physiological function.

7. Noise is more harmful to children's physical and mental health.

8. Noise impairs vision.

What harm does noise bring to human beings?

With the development of industrial production, transportation, urban architecture, and the increase of population density, the number of home facilities (audio, air conditioning, television, etc.). ) increase, environmental noise is becoming more and more serious, which has become a major public hazard that pollutes the human social environment.

Noise is local, temporal and frequency. Noise will not only affect hearing, but also have adverse effects on people's cardiovascular system, nervous system and endocrine system, so some people call noise "a chronic poison that kills people."

The physical and psychological harm of noise mainly includes the following aspects: (1) It interferes with rest and sleep and affects work efficiency. Rest and sleep are the necessary conditions for people to eliminate fatigue, restore physical strength and keep healthy.

But the noise makes people fidget, making it difficult to rest and fall asleep. When people can't sleep after tossing and turning, they will feel nervous, shortness of breath, increased pulse, excited brain, and feel tired or weak limbs the next day.

Thus affecting work and study, over time will get neurasthenia, manifested as insomnia, tinnitus, fatigue. After people fall asleep, even the noise of 40-50 decibels will change from a sleep state to a semi-sleep state.

When people sleep, their brain activities are slow and regular, and they can get enough rest. However, in the semi-sleep state, the brain is still in a tense and active stage, which will make people unable to get adequate rest and physical recovery. (2) reduce work efficiency.

The study found that noise exceeding 85 decibels can make people feel agitated, and people will feel noisy and unable to concentrate on their work, resulting in reduced work efficiency. (2) We all have the experience of damaging the hearing and visual organs. When I get off the plane or come out of the forging workshop, my ears are always buzzing, and I can't even hear the voice of the other party clearly, but I will recover after a while.

This phenomenon is called auditory fatigue, which is a protective response of human auditory organs to the external environment. If people are affected by strong noise for a long time, their hearing will be weakened, leading to organic damage of hearing organs and hearing loss.

① Strong noise can cause ear discomfort, such as tinnitus, earache and hearing loss. According to the measurement, noise exceeding 1 15 decibels can also cause deafness.

According to clinical medical statistics, if you live in a noise environment above 80 decibels, the number of deaf people can reach 50%. Medical experts believe that family noise is one of the reasons for children's deafness.

Noise is more harmful to children's physical and mental health. Because children are immature, tissues and organs are delicate and fragile. Whether it is a fetus or a newborn child in the body, noise will damage the hearing organs, leading to hearing loss or loss.

According to statistics, there are more than 70 million deaf people in the world today, and a considerable part of them are caused by noise. Expert research has proved that indoor noise is the main cause of children's deafness. If you live in noise above 85 decibels, the deaf can reach 5%.

(3) the damage of noise to vision. People only know that noise affects hearing, in fact, noise also affects vision.

Experiments show that when the noise intensity reaches 90 decibels, the sensitivity of human visual cells decreases and the reaction time to identify weak light is prolonged. When the noise reaches 95 decibels, 40% people have dilated pupils and blurred vision; When the noise reaches 1 15 shellfish, the adaptation of most people's eyeballs to light brightness is weakened to varying degrees. Therefore, people who are exposed to noise for a long time are prone to eye fatigue, eye pain, dizziness and tears.

At the same time, noise can also make color vision and visual field abnormal. It is found that noise reduces the visual field of red, blue and white by 80%.

(3) Physiological effects on human body Noise is a malignant substance, which acts on human central nervous system for a long time, causing imbalance of excitation and inhibition of cerebral cortex, abnormal conditioned reflex, dizziness, headache, tinnitus, dreaminess, insomnia and other symptoms. Palpitation, memory loss, inattention and other symptoms. In severe cases, it will lead to insanity.

This kind of symptoms, the curative effect of drug treatment is very poor, but when out of the noise environment, the symptoms will be significantly improved. Noise can cause dysfunction of autonomic nervous system, which is manifested as increase or decrease of blood pressure, change of heart rate and aggravation of heart disease.

Noise will reduce the secretion of saliva and gastric juice, reduce gastric acid, weaken gastric peristalsis, lose appetite and cause gastric ulcer. Noise will also have an impact on human endocrine function, such as: leading to female sexual dysfunction, menstrual disorder, increased abortion rate and so on.

Noise also has a negative impact on children's intellectual development. According to the survey, children living in 75 decibel noise environment before the age of 3 will suffer different degrees of damage to their heart and brain function development. Children living in a noisy environment are 20% less intelligent than children living in a quiet environment. The psychological impact of noise on people is mainly to make people anxious, excited, fidgety and even lose their minds.

In addition, noise is harmful to animals and buildings, and plants under noise do not grow well, and some even die. ① Damage to cardiovascular system.

Noise is a risk factor for cardiovascular diseases, which will accelerate heart aging and increase the incidence of myocardial infarction. Medical experts have proved through human and animal experiments that long-term exposure to noise will increase adrenal secretion in the body, thus raising blood pressure. People who live in noise with an average of 70 decibels for a long time can increase the incidence of myocardial infarction by about 30%, especially at night.

The survey found that the myocardial infarction rate of residents living beside the expressway increased by about 30%. 110/textile female workers were investigated. The incidence of hypertension was 7.2%, of which the contact intensity reached 100 dB noise, and the incidence of hypertension reached 15.2%.

② Damage to female physiological function. Women are threatened by noise, and there will be irregular menstruation, miscarriage, premature delivery, etc., such as causing female sexual dysfunction, menstrual disorder, and increased abortion rate.

Experts conducted a three-year systematic investigation in seven regions, including Harbin, Beijing and Changchun, and found that noise can not only make female workers suffer from noise deafness, but also have a negative impact on their menstruation and fertility. In addition, it can also lead to miscarriage, premature delivery and even teratogenesis.

Foreign countries have made a survey on the common situation of miscarriage and premature delivery of pregnant women in a certain area, and found that they live near an airport, and the culprit is the huge noise generated when the plane flies and lands. ③ Noise can also cause nervous system dysfunction, mental disorder, endocrine disorder, and even increase the accident rate.

It's noisy.

What effect does noise have on people's health?

The hazards of noise are manifold. Noise not only causes great interference to people's normal life and work, but also affects people's conversation and thinking, affects people's sleep, makes people fidgety, unresponsive, reduces work efficiency, distracts attention and causes work accidents. More seriously, noise will damage people's hearing and health. The greater the noise intensity, the higher the frequency, the longer the action time, the smaller the personal tolerance and the more serious the harm. Statistics show that noise below 80dB(A) will not cause noise-induced deafness; Noise of 80dB(A)~85dB(A) will cause slight hearing loss; Noise of 85dB(A)~ 100dB(A) will cause a certain amount of noise-induced deafness; When it is above 100dB(A), it will cause a considerable amount of noise deafness. When people are unprepared, intense noise with extremely high intensity (such as sudden shooting, explosion, etc.) will cause permanent hearing loss in an instant, that is, sudden deafness. At this time, people's hearing organs will be seriously injured.

Traffic noise has many effects on human health. Noise acts on people's central nervous system, making people's cerebral cortex excited and inhibited unbalanced, leading to abnormal conditioned reflex and damaging cerebrovascular tension. These physiological changes can be recovered in the early stage, but they will lead to pathological changes over time, causing headaches, brain swelling, tinnitus, insomnia, memory loss, general fatigue and other symptoms. If pregnant women ride noisy vehicles for a long time, noise will affect fetal development by acting on the central nervous system.

Noise also has a serious adverse effect on the digestive system and cardiovascular system, which will cause indigestion, loss of appetite, nausea and vomiting, thus leading to an increase in the incidence of stomach diseases and gastric ulcer diseases. The incidence of hypertension, arteriosclerosis and coronary heart disease is significantly higher than normal. Noise can also have a bad effect on the visual organs.

How harmful is noise to people?

The hazards of noise can be summarized as follows.

(1) Noise interferes with sleep. Humans spend nearly 1/3 of their time in sleep. Sleep is an important condition for human beings to eliminate fatigue, restore physical strength and keep healthy. However, environmental noise can make people unable to sleep or wake up. In this respect, the elderly and patients are more sensitive to noise interference. Sleep is disturbed, and work efficiency and health will be affected. The results show that continuous noise can accelerate the rotation from deep sleep to shallow sleep, make people dream more and shorten the time of deep sleep; Sudden noise will wake people up. Generally speaking, 40 decibels of continuous noise can affect 10% of people; 70 decibels can affect 50%; Sudden dynamic noise can wake up 10% people at 40 decibels and 70 people at 60 decibels. Long-term interference with sleep can cause insomnia, fatigue, memory loss, and even neurasthenia syndrome. In high noise environment, the incidence of this disease can reach more than 50-60%.

(2) Interference of noise on language communication The influence of noise on language communication comes from the influence of noise on listening. This kind of influence, from low communication efficiency to damage people's language listening. Research shows that the environment below 30 decibels belongs to a very quiet environment, such as radio studios, hospitals, etc., which should meet this condition. 40 decibels is a normal environment, such as the average office to maintain this level. 50-60 decibels belong to a noisy environment. At this time, mental work is affected and conversation is also disturbed. When making a phone call, it is difficult to talk when the ambient noise reaches 65 decibels; 80 decibels, I can't hear you clearly. When the noise reaches 80-90 decibels, the distance is about 0. 15 meters, and the conversation can only be carried out if the voice is raised. If the noise decibel is higher, it is almost impossible to have a dialogue.

(3) Noise Impairment When people with hearing loss are in a noisy environment for a short time, even if they leave the noisy environment, their ears will suffer from hearing loss for a short time, but when they return to a quiet environment, they can recover in a short time. This phenomenon is called auditory adaptation. If you work unprotected in a noisy environment for many years, the recovery of hearing sensitivity will be prolonged after leaving the noisy environment, and hearing will be restored after several hours or more. This loss that can restore hearing is called hearing fatigue. With the aggravation of hearing fatigue, hearing function will not fully recover. Therefore, to prevent noise-induced deafness, we must first prevent fatigue. Under normal circumstances, noise below 85 decibels will not harm hearing, and noise above 85 decibels may be dangerous. Statistics show that the incidence of deafness increases obviously after working in a noise environment above 90 decibels for a long time.

(4) Noise can cause many diseases. Besides hearing loss, noise can also cause other personal injuries. Noise can cause anxiety, nervousness, rapid heartbeat and high blood pressure. Noise can also reduce the secretion of saliva and gastric juice, reduce gastric acid, and easily suffer from gastric ulcer and duodenal ulcer. Some industrial noise survey results show that the incidence of personal circulatory system in steel workers and machinery workshop workers is higher than that in quiet conditions. There are many people with high blood pressure under strong tone. Many people think that noise in life in the 20th century is one of the causes of heart disease. Working in a noisy environment for a long time will also cause obstacles to nerve function. Human experiments under laboratory conditions prove that human brain waves will change under the influence of noise. Noise can cause the balance of excitement and inhibition in cerebral cortex, leading to abnormal reflex under conditions. Some patients may cause intractable headache, neurasthenia and cranial nerve insufficiency. Symptoms are closely related to the intensity of noise exposure. For example, when the noise is 80-85 decibels, it is often easy to get excited and feel tired, and the headache is mostly in the temporal frontal area; At 95- 120 dB, the operator often has dull pain in the front head, accompanied by restlessness, sleep disorder, dizziness and memory loss; When the noise is strong to 140- 150 dB, it will not only cause ear disease, but also cause fear and nervous system tension.

What harm does noise bring to our life?

Strong noise can cause ear discomfort, such as tinnitus, earache and hearing loss. According to the measurement, noise exceeding 1 15 decibels can also cause deafness.

When the noise exceeds 85 decibels, people will feel agitated, and they will feel noisy and unable to concentrate on their work, resulting in reduced work efficiency.

Cardiovascular system is damaged. Noise is a risk factor for cardiovascular diseases, which will accelerate heart aging and increase the incidence of myocardial infarction.

Causes such as nervous system dysfunction, mental disorders, endocrine disorders and so on may even increase the accident rate. Noisy working environment can cause dizziness, headache, insomnia, dreaminess, general fatigue, memory loss, fear, irritability, inferiority and even insanity, which interferes with rest and sleep.

Women are threatened by noise, and there will be irregular menstruation, miscarriage, premature delivery, etc., such as causing female sexual dysfunction, menstrual disorder, and increased abortion rate.

Noise is more harmful to children's physical and mental health. Because children are immature, tissues and organs are delicate and fragile. Whether it is a fetus or a newborn child in the body, noise will damage the hearing organs, leading to hearing loss or loss.

When the noise intensity reaches 90 decibels, the sensitivity of human visual cells decreases and the reaction time to identify weak light is prolonged. When the noise reaches 95 decibels, 40% people have dilated pupils and blurred vision; When the noise reaches 1 15 dB, the adaptation of most people's eyeballs to light brightness is weakened to varying degrees.