Giving my mom is in a small cottage in a perfect wilderness. I rarely visit there a couple of times a year for mushrooms. Why? It's very simple - I can't sleep there. I miss the noise of the road under the window, the sound of footsteps neighbor above, the creaking of the Elevator and slamming doors. "You here, as in the grave is dark and quiet! " - I laugh, once again refusing to spend the night at the cottage. And it's not a whim.What is the noise?
In absolute silence you only live deaf. In a healthy person, absolute silence is depressing: we used to hear different noises. When we are in nature, we hear the birds singing, the creaking of the trees, the rustle of leaves, the sound of the surf. And it pacifies us.
In the city of the same sounds much more - this car honking, and the rustle of tires and the roar of the nearest building, and wailing car alarms, and the laughter of kids on the Playground. You could even say that the noise is necessary - it people and animals Orient themselves in space.
Studies have shown that the noise intensity has a positive effect on productivity, stimulate the thinking process. In addition, the hearing allow us to determine the nature of the noise and develop a response. For example, we may not always see driving up from behind the car, but we will hear it and will react instinctively. In General, noise is a collection of sounds of different intensity and frequency. As is known, the noise level is measured in decibels. Natural background noise is about 20-30 decibels. Such noise is safe for our nervous system and organs of hearing.
But when people - especially those who live in large cities in recent times heard these same 20-30 decibels? Probably never. Loud sounds - up to 80 decibels is also harmless to humans, but the background noise of the metropolis - a rarity.
Loud!
... Now, you walk down the street and suddenly hear a car horn. "Beep! "and you have brought down 100 decibels. Heart jumped in surprise, hands were sweating is a response reaction to a loud sound. And such a shaking we get not just once or twice a day. Meanwhile, the sound in 130 decibel already makes people very real pain!
In the middle ages in some European countries, prisoners were executed in the following way: sentenced to death tied to a pole beneath continuously ringing bell. Ivan IV the terrible was ordered to plant accident under a large bell and hitting it with hammers in a few hours. With this method of execution was bad and the victims and executioners: a bell is about 180 decibels. Now, of course, sounds such force we rarely hear, but people working in the premises, daily subjected to prolonged exposure to noise in the 90-110 dB.
People working in, say, airport runways, several times a day feel 120 decibels. Office workers are constantly affected by background noise in 50-70 dB - like less range, but permanently. And in the evening all these people meet in the transport and go home within 1, 5-2 hours at constant same noise at 80 decibels. Long-term noise exposure cannot but affect our health in General.
What are the consequences of noise
As you know, "every action is equal to counteraction". Being in adverse noise conditions, our body begins to defend himself, because the noise has a negative impact on our hearing AIDS and the nervous system: development of various kinds of neurosis and insomnia. Moreover, suffers from noise vestibular apparatus, decreased reflex activity, increased blood pressure, developing various diseases of the organs, it would seem, is not associated with the hearing aid, for example, long-term noise exposure may cause metabolic disorders and even stomach ulcers. And, of course, the noise inhibits the human psyche: under the influence of noise people become more aggressive.
Noise different effect on people depending on their age, overall health and hearing sensitivity, but in varying degrees of intense noise affects all. Of course, the human body must defend itself, and therefore as a result of exposure to a strong acoustic oscillations we begin to lose... hearing. Intense noise first cause temporary hearing loss, which is restored after some time. But long-term effects of different noise temporary shift in hearing threshold becomes constant. For example, when working on a production with no additional means of protection from noise, irreversible reduction of the threshold of hearing occurs within 2-3 years. By the way, in order to lose your hearing, do not necessarily work in the lathe is quite often to listen to loud music.
Especially it is relevant to younger generations: riding the bus and clearly hear some young man with headphones "Rammstein" is listening. In 1-2 years this young man audiogram reveals a reduction in the threshold of audibility of 20-30 percent, and to restore hearing will be impossible: the nerve cells of the inner ear atrophy. But the negative consequences of intensive noise is not apparent immediately, but after a long time, so we are not accustomed to consider the noise of something dangerous to our health, and appeared irritability and insomnia retiring at high atmospheric pressure, magnetic storms and moon phase.
The noise that we hear
The human ear can perceive sound vibrations at a frequency of 16 Hz to 20 kHz. Oscillations, whose frequencies are below the lower threshold of perception (less than 16 Hz) are called infrasound. Ultrasound is sound oscillations, whose frequencies are above the upper threshold of perception (greater than 20 kHz).
Our hearing aid does not allow to distinguish between these sounds, but they still affect our body. Ultrasound certain frequencies of causes of human anxiety and anxiety. To prove this, it is enough to recall how most people feel in the aircraft. In addition to high-rise overloads, we can feel the effect of ultrasound 130 decibels, but our ears are not able to discern.
It is also known that the ultrasound power above 135 decibels causes of human condition contusion, at 160 burst eardrums, and at the sound of 200 decibels, possibly fatal, because the basis of the biological effects of ultrasound lies molecular heating of body tissue or the formation of gas bubbles in natural fluids. In addition, long-term systematic effects of ultrasound on the human body causes pathological changes in the nervous, endocrine and cardiovascular systems, and, of course, the auditory and vestibular apparatus.
But short-term use of ultrasound as a therapeutic agent has analgesic, anti-inflammatory and antispasmodic effect, improves blood circulation and tissue regeneration, stimulates the immune and metabolic processes. Therefore, ultrasound is widely used in medicine and in hardware cosmetology.
As infrasound, for some people it can cause attack of sea-sickness. Infrasound also causes headaches, impaired function and dysfunction of the vestibular apparatus. Often prolonged exposure to infrasound causes of thrombosis, due to the direct impact on the walls of blood vessels. Infrasound frequency of 6-7 Hz deadly to humans. The fact that the frequency of oscillation of the many processes in our body are in the infrasonic range and rhythms of the brain, and heart contractions.
The natural frequency of oscillation of the body is about 8-12 Hz. By the way, the alpha rhythm of the brain emits vibrations, is 8-13 Hz. When the body feels the effects of infrasound, the vibrations of the body are in resonance with the sound vibrations that can lead to disorder of the organs and tissues, and even break them. At low fluctuations in the body begin to break the internal organs, blood vessels and capillaries. Interestingly, nervous diseases residents of industrial cities scientists also associated with long-term impacts of infraslow different wavelengths: infrasound to hear they can't but feel a sense of anxiety. By the way, natural waves emitted by earthquakes and volcanic eruptions, are also in the range of 7-13 Hz.
Yes, constant high level of noise in the modern city is a disaster, which is why it pays insufficient attention on the part of the competent authorities of all countries. So - "the rescue of drowning - the handiwork of drowning". You should take some security measures that will allow at least partly to protect themselves from the noise of the metropolis.
Not cheap, but you need to install the apartment soundproof Windows and doors for residents of large cities it is not a luxury. Well, in everyday life it would be good to learn how to Express even the most strong emotions, without creating a strong acoustic oscillations. Loud music in headphones or stereo speakers, screaming TV - all this will exacerbate the negative impact of noise not only on us personally, but also on others. So let's take care - about themselves and about each other.
Between dream and reality: what can alpha rhythms
Author:
Stogniew M
Source:
Леди@mail.ru
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