How many decibels can a big stereo emit outdoors, and how many decibels can a small stereo emit outdoors? The intensity of sound produced by sound is related to the distance between sound and listener and the sound field produced by sound. As for big stereos, some can generate tens of kilowatts of power, while others can only generate tens of watts of power. There is a great difference in the field strength between them, and the measuring distance is also closely related to the frequency response of the sound, so it cannot be generalized. However, if you listen to the strong sound from high-power audio at close range, it will cause permanent damage to people's hearing.
See: 360doc. /content/ 1 1/ 123 1/2 1/7476588 _ 17638 1845 . s。
How many decibels of sound affect hearing medical research shows that any sound above 90 decibels will cause hearing loss to a certain extent if it suddenly "bombs" the ear. The sound played by headphones sometimes exceeds 100 dB, even as high as 120 dB, which is almost equivalent to the noise when a jet plane takes off. Generally speaking, noise above 120 decibels will lead to tinnitus, deafness, deafness and other symptoms, resulting in hard of hearing, which is clinically called "discos hard of hearing" and belongs to the scope of acute acoustic trauma. However, the overuse of MP3 and mobile phone earplugs has become an important factor that cannot be ignored.
100 decibels 100 meters away, how many decibels does the sound attenuate? 20logR 1/R2 (R2= 1)
Calculated at 100 meter, it is reduced by 40db and weakened to 60db.
What is the maximum sound in decibels? There is no maximum, as long as it is larger. According to the regulations of the Occupational Safety and Health Administration (OSHA), the human ear can withstand the maximum sound intensity of 85 decibels for 8 hours without negative effects. These laws and regulations have influenced the design of industrial headphones. However, in consumer products, there is no hard and fast regulation of the maximum sound intensity.
So what is the maximum volume of most MP3 players circulating in China market? Generally, the maximum volume of MP3 is around110dB.
Sound below 40 decibels has no effect on human body; When the sound is between 40 decibels and 60 decibels, the nervous system will be affected if the human body is in this environment for a long time. At this time, for every 3 decibels increase in noise, the noise energy will double; When the sound reaches 65 decibels to 80 decibels, the cardiovascular damage of people is more than 20% higher than that of people living in a noise environment of 50 decibels. When the noise exceeds 80 decibels, it will do great harm to people's hearing. When the noise exceeds 100 decibel, it is unbearable noise. The sound reaches 120 decibels, which is equivalent to a Boeing 747 flying over, and human health will be greatly damaged in a short time.
How many decibels does sound hurt your ears? At any time, the sound emitted by the stereo cannot exceed 120 decibels.
How many decibels can the maximum sound of Eustace mini speakers reach? How many decibels the sound can reach needs to be known: 1. Effective output power of stereo (root mean square power); 2. What is the endurance and sensitivity of the speakers (sound boxes) of the sound system? With these indicators, we can infer how many decibels the maximum sound of the sound system can reach.
How many decibels is the most suitable for rambler audio signal? Hello! When cooking the box, the speaker volume should not be too loud, just control it at half position.
How many decibels can a 5W stereo reach? With the main power index and without the sensitivity index, it is impossible to get the specific sound pressure level (decibel) index. If the sensitivity of a 5w speaker is about 80~85dB, the sound pressure level is about 92dB/ 1m when the power of 5w is input.
As for how to get this reference value, go to Baidu to find the calculation formula of sound pressure level!
How many decibels of sound affect sleep? Harm of noise pollution
Long-term exposure of pregnant women to noise exceeding 50 decibels will lead to endocrine gland dysfunction, mental stress and endocrine system disorder. Serious will raise blood pressure, fetal hypoxia and ischemia, leading to fetal malformation, and even abortion. However, high decibel noise will damage the hearing organs of the fetus and affect some cutting areas. It affects the development of the brain and leads to mental retardation in children.
The malignancy of noise seriously affects the quality of our sleep, which can lead to neurasthenia symptoms such as dizziness, headache, insomnia, dreaminess, memory loss, inattention, and digestive tract symptoms such as nausea, vomiting, stomachache, bloating and loss of appetite. Nutritionists have found that noise can also increase the consumption of vitamins, amino acids, glutamic acid, lysine and other trace elements in the human body, affecting health; Noise increases adrenal gland secretion, heart rate and blood pressure, which easily leads to heart attack; At the same time, noise can reduce the secretion of saliva, gastric juice and gastric acid, thus suffering from gastric ulcer and duodenal ulcer. It is harmful to people's cardiovascular system. According to the survey of urban noise and residents' health in China, the incidence of hypertension increases by 3% for every increase of 1 decibel in regional noise.
It affects people's nervous system and makes people irritable.
Affect sleep and cause fatigue.
way
1 build a soundproof forest
2. Move enterprises with serious noise pollution out of urban areas.
3 source prevention, reduce the transmission process
The physical and psychological damage caused by noise mainly includes the following aspects:
1, hearing loss. Relevant data show that people's hearing will be impaired after 8 hours of continuous listening to the sound of motorcycles; If you are in a rock concert hall, your hearing will be impaired after half an hour; If you live in a noise environment above 80 decibels, the possibility of deafness can reach 50%.
2. Noise impairs vision
As we all know, noise will seriously affect the hearing organs and even make people lose their hearing. However, there is a subtle internal "connection" between ears and eyes. When noise acts on the auditory organs, it will also "diffuse" the visual organs through the action of the nervous system, which will weaken people's vision.
It is pointed out that noise can make color vision and color gamut abnormal. The survey found that among 80 workers exposed to steady noise, the visual field of red, green and white was as high as 80%, which was 85% higher than that of the control group.
The influence of noise on eyesight can be seen everywhere in daily life. For example, when shopping in a quiet and bright store, it looks very pleasant and calm, so you can choose carefully and buy everything. When the tweeter plays high-tempo pop music loudly when shopping (some so-called pop music is just deafening noise), it is often annoying, dazzling and even confusing. I didn't buy what I should buy, and I was not satisfied with what I bought because I didn't recognize it carefully. The main reason is that dry sound affects vision.
3. It is harmful to people's cardiovascular system. According to the Survey of Urban Noise and Residents' Health in China, the incidence of hypertension increases by 3% for every increase of 1 decibel in regional noise.
4, affecting people's nervous system, making people irritable.
Scientific research has found that noise can inhibit the nervous system, and people who work in a noisy environment for a long time can also cause neurasthenia syndrome (such as headache, dizziness, tinnitus, memory loss, vision loss, etc.). ).
5, affecting sleep, causing fatigue.
Harm of noise to sleep: Sudden noise can wake up 10% of people at 40 decibels, and 70% of people at 60 decibels.
Psychologically speaking, noise will first cause psychological symptoms such as poor sleep, inattention, memory loss, etc., and then lead to irritability, emotional instability, and even decreased patience and bad temper, and finally produce a series of diseases such as hypertension, ulcer and diabetes. Psychologically, this disease is called psychosomatic disease, which refers to a physical disease caused by psychological factors. Dr. Li also introduced that the probability of psychosomatic diseases caused by noise is quite high, the treatment is difficult and it takes a long recovery period, which brings great troubles to people's daily life and work.
The direct harm of noise to human body includes: destroying human nerves, causing vasospasm, accelerating the metabolism of hair cells, thus accelerating the arrival of aging period. In clinical diagnosis, the external manifestations of patients are that the whole person is in a bad mood, emotional and speaks loudly; The most common symptoms are tinnitus, earache, hearing loss, dizziness, headache and noise deafness; For babies who are in the growth and development stage, the harm of noise is particularly obvious. Babies who are often in a noisy environment will not only suffer from hearing impairment, but also suffer from intellectual development. Because noise can cause sensory nerve damage and hair cell damage, it is difficult to repair.
Relevant experts believe that noise is very harmful to the human body, and the impact of noise (decibel) on the human body: for example, 0-50 decibels: comfortable, quiet; 50-90 decibels: it interferes with sleep, sadness and anxiety; 90- 130 dB: itchy ears and earache; /kloc-above 0/30 db: eardrum rupture, deafness.
Best groom's wedding speech 1
Distinguished guests, ladies and gentlemen,
Today is my son's wedding day with his wife. I would like to extend