What are the dangers of noise?

Noise pollution poses harm to people, animals, instruments and buildings. The degree of harm mainly depends on the frequency, intensity and exposure time of the noise. Noise hazards mainly include:

Hearing damage caused by noise

The most direct harm caused by noise to the human body is hearing damage. When people enter a strong noise environment and are exposed for a period of time, they will feel uncomfortable in their ears, and may even experience headaches and other symptoms. After leaving the noisy environment and resting in a quiet place for a period of time, your hearing will gradually return to normal. This phenomenon is called temporary hearing threshold shift, also known as auditory fatigue. However, if people work in a strong noise environment for a long time, auditory fatigue cannot be recovered in time, and organic lesions will occur in the inner ear organs, which will form a permanent hearing threshold shift, also known as noise-induced deafness. If a person is suddenly exposed to an extremely strong noise environment, the hearing organ will undergo severe trauma, causing tympanic membrane rupture and bleeding, labyrinth bleeding, and acute detachment of the spiral organ from the basilar membrane, which may cause the person's ear to completely lose hearing, that is, blast deafness. Studies have shown that noise pollution is an important cause of presbycusis. In addition, hearing loss is also related to the living environment and occupation. For example, the incidence of presbycusis in rural areas is lower than that in cities. Textile factory workers, blacksmiths and blacksmiths have more hearing loss than their peers.

Noise can induce a variety of diseases

Because noise acts on the central nervous system of the brain through the auditory organs, affecting various organs throughout the body. Therefore, in addition to causing damage to human hearing, noise also It can also cause harm to other systems of the human body. Due to the effect of noise, neurasthenic symptoms such as headache, brain swelling, tinnitus, insomnia, general fatigue and memory loss will occur. For people who work in a high-noise environment for a long time, the incidence of hypertension, arteriosclerosis and coronary heart disease is 2 to 3 times higher than in a low-noise environment. It can be seen that noise can cause cardiovascular system diseases. Noise can also cause 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 functions and the normal development of the fetus. For people who work and live in high noise, their general health level declines year by year, their resistance to diseases weakens, and some diseases are induced. However, this is also related to personal physical factors and cannot be generalized.

Noise’s interference with normal life and work

Noise has a great impact on people’s sleep. Even when people are sleeping, their hearing must be stimulated by the noise. Noise can cause excessive dreams, easy awakening, and decreased sleep quality. Sudden noise has a more prominent impact on sleep. Noise can interfere with people's conversation, work and study. Experiments show that when a person is disturbed by a sudden noise, he will lose 4 seconds of concentration. According to statistics, noise can reduce labor productivity by 10 to 50%. As noise increases, the error rate increases. It can be seen that noise can distract people's attention, lead to slow response, easy fatigue, reduced work efficiency, and increased error rate. Noise can also mask safety signals, such as alarm signals and vehicle driving signals, causing accidents.

The impact of noise on animals

Noise can cause pathological changes in the animals’ auditory organs, visual organs, internal organs and central nervous system. Noise has a certain impact on the behavior of animals

Noise pollution

It can cause animals to lose their ability to control their behavior, become restless, and lose their normalcy. Strong noise can cause the death of animals. Birds will lose their feathers when exposed to noise, which affects their egg-laying rate. Experiments on the effects of noise on animal behavior and sound-induced convulsions have proven that animals in noisy fields will lose their ability to control their behavior and become irritable and lose their normalcy. For example, in a 165 decibel noise field, rats will jump wildly, bite each other and twitch, and then lie down stiffly. Sound-induced spasm is a physiological-muscle disorder phenomenon induced by sound stimulation in animals (especially rodents). It is a physiological epilepsy caused by sound. It has similarities to human epilepsy and the various symptoms that may accompany it. The impact of noise on animal hearing and vision: When a guinea pig is exposed to a strong noise field of 150 to 160 decibels, its auricle's ability to reflect sound will decrease or even disappear. The attenuation value of the reflection ability in a strong noise field is about 50 decibels. When the noise exposure time remains unchanged, as the noise sound pressure level increases, the auricle's reflex ability is significantly reduced or disappeared, and the degree of hearing loss becomes more serious.

Experiments have shown that the auricle reflexes of guinea pigs exposed to 150 decibels of noise basically recovered after 24 hours, which was a temporary threshold shift; while the auricles of guinea pigs exposed to 156 or 162 decibels of noise fields declined. And disappearing is difficult to recover from, which may be a permanent damage. Anatomy of the middle ears of guinea pigs after exposure to strong noise fields showed that the middle ears and oval window membranes of guinea pigs were damaged to varying degrees. In severe cases, mild hemorrhage and crack-like damage to the tympanic membrane could be observed. Under the influence of stronger noise, the tympanic membrane of guinea pigs may even be perforated and the malleus handle may be damaged. Animals exposed to low-frequency noise fields above 150 decibels can cause eye vibrations and blurred vision. Noise-induced animal lesions: The body temperature of guinea pigs will increase in strong noise fields, and the electrocardiogram and electroencephalogram will be obviously abnormal. The electrocardiogram shows symptoms similar to heart rhythm failure. The electroencephalogram recorded before death of guinea pigs whose organs were severely damaged in a strong noise field showed that the wave rhythm slowed down and the wave amplitude tended to be low and flat. After being exposed to strong noise, the guinea pig appeared normal, with no abnormalities under the skin and limbs. However, an anatomical examination revealed that almost all internal organs were damaged. There were large areas of stasis, hemorrhage and stasis edema in each lobe of both lungs. There are large ecchymoses on the fundus and stomach, severe cases include diffuse bleeding and even gastric mucosal rupture, and even more serious cases include large-scale rupture of the stomach. There were patchy or diffuse stasis and bleeding in the cecum, and the entire cecum was purple-brown. Other organs also have varying degrees of blood stasis and bleeding. Noise causes animal death. A large number of experiments have shown that strong noise fields can cause animal death. The higher the noise pressure level, the shorter the time it takes for the animal to die. For example, a noise of 170 decibels could kill half of the guinea pigs tested in about 6 minutes. For guinea pigs, an increase in noise sound pressure level of 3 decibels reduces the half-time to death by half.

The harm of extremely strong noise to instruments, equipment and building structures

Experimental studies have shown that extremely strong noise can damage instruments and equipment, or even cause them to fail. The impact of noise on instruments and equipment is related to factors such as noise intensity, frequency, and the structure and installation method of the instrument and equipment itself. When the noise level exceeds 150dB, resistors, capacitors, transistors and other components will be seriously damaged. When extremely strong noise acts on mechanical structures such as rockets and spacecrafts, the material will fatigue and break due to repeated effects of alternating acoustic loads. This phenomenon is called acoustic fatigue. General noise has little impact on buildings, but when the noise level exceeds 140dB, it begins to have a damaging effect on light buildings. For example, when a supersonic aircraft passes by at low altitude, sudden changes in pressure and density will occur at the nose and tail of the aircraft, which will form an N-shaped shock wave after being reflected by the ground. When it reaches the ground, it will sound like an explosion. This special noise is called boom. . Under the action of the roar, buildings will be damaged to varying degrees, such as damage to doors and windows, broken glass, cracked walls, falling plaster, and collapse of chimneys. Because the roar attenuates slowly, it spreads farther and affects a wider range. In addition, the use of air hammers, piling, or blasting near buildings can also cause damage to buildings. Noise is a type of sound that arouses people's annoyance or is too loud and endangers human health. Noise pollution mainly comes from transportation, vehicle horns, industrial noise, construction, social noise such as concert halls, loudspeakers, morning markets and people talking loudly. Noise brings physical and psychological harm to people mainly in the following aspects: Damage to hearing. Tests have shown that when people continuously listen to the sound of motorcycles, their hearing will be damaged after 8 hours; if they are in a rock concert hall, their hearing will be damaged after half an hour. Harmful to the human cardiovascular system, China's survey on urban noise and residents' health shows that: for every decibel increase in regional noise, the incidence of hypertension increases by 3%. Affects people's nervous system, making people impatient and irritable. Affects sleep and causes fatigue. From a psychoacoustic perspective, noise, also known as noise, generally refers to inappropriate or uncomfortable auditory stimulation. It is a composite sound composed of numerous frequencies and having non-periodic vibrations. Simply put, noise is non-periodic sound vibrations. Its sound wave shape is irregular and sounds harsh. In a social and psychological sense, any sound that hinders people's study, work and rest and makes people feel uncomfortable is called noise. Such as the sound of running water, knocking, rustling, roaring of machines, etc., 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 not harmful to people's physical and mental health, and in many cases it is beneficial to improve work efficiency. High-intensity noise mainly comes from industrial machines (such as looms, lathes, air compressors, pneumatic picks, blowers, etc.), modern transportation (such as cars, trains, motorcycles, tractors, airplanes, etc.), tweeters, and construction sites As well as the noise from shopping malls, sports and entertainment venues, etc. These high-intensity noises harm people's bodies, make people feel tired, produce negative emotions, and even cause diseases. High-intensity noise not only damages human hearing, but also affects the nervous system, cardiovascular system, endocrine system, digestive system, vision, and intelligence to varying degrees. If people work and live in a noisy environment of 95 decibels for a long time, about 29% of people will lose their hearing;

Noise pollution

Even if the noise is only 85 decibels, 10% of people will lose their hearing. People will become deaf; noises of 120 to 130 decibels can make people feel pain in the ears; stronger noises can damage hearing organs. In terms of the nervous system, strong noise can cause symptoms such as headache, dizziness, fatigue, insomnia, emotional restlessness, memory loss, increased slow waves in the electroencephalogram, and autonomic nervous system dysfunction. In terms of the cardiovascular system, strong noise can cause It can cause changes in pulse and heart rate, increased blood pressure, irregular heartbeat, conduction block, changes in peripheral blood flow, etc. In terms of the endocrine system, strong noise can cause hyperthyroidism, enhanced adrenal cortex function, and increased basal metabolic rate. High noise, sexual dysfunction, menstrual disorders, etc.; in terms of the digestive system, strong noise can cause decreased digestive function, gastric dysfunction, reduced gastric acid, loss of appetite, etc. In short, strong noise can cause a series of physiological and pathological changes in the human body. Someone once conducted a survey on 202 people working in an environment with noise reaching 95 decibels. 39% suffered from dizziness, 32% from insomnia, 27% from headaches, 27% from stomachache, 27% from palpitation, and 27% from memory problems. 27% were depressed, 22% were upset, 18% had poor appetite, and 12% had high blood pressure. Therefore, we cannot take strong noise lightly and should take measures to prevent it. Of course, people are more sensitive to noise, and there are great differences between individuals. Some people are more sensitive to noise, and some people have strong adaptability to noise. It is also related to people's needs, emotions and other psychological factors. Regardless of the differences between people, loud noises always need to be prevented. Pregnant women exposed to noise exceeding 50 decibels for a long time can cause endocrine gland dysfunction, mental stress and endocrine system disorders. In severe cases, it will increase blood pressure, cause fetal hypoxia and ischemia, cause fetal malformations and even miscarriage. High-decibel noise can damage the fetal hearing organ, causing some areas to be affected. Affects brain development, leading to mental retardation in children. The malignant stimulation of noise seriously affects our sleep quality, and can cause neurasthenic symptoms such as dizziness, headache, insomnia, dreaminess, memory loss, and difficulty in concentration, as well as digestive tract symptoms such as nausea, vomiting, stomach pain, bloating, and sluggish appetite. symptom. Nutritionists have found that noise can also increase the consumption of essential nutrients such as vitamins, trace elements nitrogen, glutamic acid, and lysine in the human body, affecting health; noise can increase adrenal gland secretion, speed up the heartbeat, and Increased blood pressure can easily lead to heart attacks; at the same time, noise can reduce the secretion of saliva and gastric juice, and lower gastric acid, leading to gastric ulcers and duodenal ulcers. Affects people's nervous system, making people impatient and irritable. Affects sleep and causes fatigue.