Few people think about how many different sounds exist in nature. Few people know that the sound itself does not exist, but what a person hears is just transformed waves of a certain frequency. The hearing aid that people have is able to convert some of these waves into sounds that we are used to. However, this is only a small fraction of all those frequencies that surround everyone. Some of them, which cannot be heard without special devices, can cause significant harm to the human body.
The concept
Infrasound is sound vibrations in which the frequency is less than 16 Hz. The existing world is full of sounds, and they all have a different range. The human hearing aid is designed to receive sounds in which the frequency is not less than 16 vibrations per second, but not more than 18-20. Such fluctuations are measured in hertz (Hz). However, such sound vibrations can be both above and below the specified range. Such frequencies, inaudible by people, are the so-called areas in which ultrasound and infrasound exist. These oscillatory processes are absolutely not audible to humans, however, at the same time, they can influence various processes, including the human body.
The human brain is designed in such a way that it is able to perceive only a small part of those phenomena occurring in the sound environment, which can reach the inner ear, its peripheral receptor devices. In this case, the perception of such acoustic waves will be determined by several factors, among which are the focus of attention, the resolution of the receptors, and the transmission rate along the nerve paths.
Sound
As mentioned, the frequency range of infrasound is below the range of perception of sounds by humans. The essence of infrasound is no different from other sounds. In general, elastic waves are called sound, which move in a certain medium and create mechanical vibrations with such movements. In other words, sound can be called the movement of air molecules that occurs as a result of an oscillation of a physical body. As an example, we can cite vibrations originating from stringed instruments. In order for the sound to spread, there must be an air environment. It is well known that silence always reigns in a vacuum. This is due to the fact that as a result of physical action, reciprocating air movements occur, which, in turn, cause compression and rarefaction waves.
Infrasound Features
Infrasound is a low-frequency wave process, and although its physical nature is the same as that of another sound, it has several features. So, low-frequency waves have great penetrating power. This is due to the fact that they are characterized by low absorption. Infrasound, distributed deep in the ocean or in the airspace near the earth, having a frequency of ten to twenty hertz, usually fades out, breaking a thousand kilometers by only a few decibels. The same insignificant dispersion of infrasound waves occurs in the natural environment. This is due to the huge wavelength. So, the last value, if the infrasound frequency is 3.5 Hz, will be about 100 meters. The only thing that can have a significant impact on the dispersion of these acoustic waves is large objects (high-rise buildings and structures, mountains, rocks, etc.). These two factors - low absorption and low scattering - contribute to the movement of infrasound over long distances.
For example, sounds such as volcanic eruptions or nuclear explosions can bypass the surface of the globe several times, and waves that appear as a result of some seismic vibrations can overcome the entire thickness of the planet. As a result of the above reasons, infrasound, the influence of which is very negative on a person, is practically impossible to isolate, and all materials used for sound insulation and sound absorption lose their properties at low frequencies.
Infrasound and processes in the human body
As already noted, the low-frequency wavelength is quite large, so its penetration into the human body, in its tissue can also be expressed to a large extent. Figuratively speaking, a man, although he does not hear infrasound with his ears, he hears it with his whole body. Infrasound can affect a person in different ways, it can coincide with many processes that occur in the human body. Indeed, many organs also create certain sounds. For example, the heart creates infrasound with a frequency of 1-2 Hz during contraction, the brain during sleep - from 0.5 to 3.5 Hz, and during its active work - from 14 to 35 Hz. Naturally, if external infrasonic vibrations somehow coincide with the vibrations occurring in the human body, then the latter will only intensify. And this increase can ultimately lead to damage to the organ, its frustration, or even to rupture.
Sources in nature. Sea waves
Infrasound literally pervades nature. This is caused by many phenomena, including sudden pressure drops, volcanic eruptions, seismic activity, and hurricanes, as well as many other factors. Numerous studies conducted on people who fell into the zone of low-frequency waves, gave scientists reason to believe that infrasound is dangerous for humans, for their health. These waves provoke the loss of sensitivity of organs designed to adjust the balance of the body. In turn, this loss is the cause for the occurrence of ear pain, brain damage, pain in the spine. Some scientists and psychologists believe that infrasound is the main and most serious cause of psychological disorders.
It always exists, even when people believe that silence reigns in the atmosphere. The sources of infrasound are varied and diverse. Shocks of sea waves on the shore, firstly, cause small seismic fluctuations in the bowels, and secondly, contribute to changes in air pressure. With the help of special barometers it is possible to catch such vibrations. Powerful gusts of wind, combined with sea waves, are a source of powerful low-frequency waves. They move at the speed of sound, and propagating through the waves of the sea, even more amplified.
Soothsayers
Such infrasounds are a harbinger of a storm or a hurricane. It is no secret that animals have a unique ability to predict such natural phenomena. For example, jellyfish, which even before the storm begins, are moving away from the coast. This prediction ability, according to some scientists, is also available to individuals. From ancient times, people were known who, looking at the calm and serene sea, could declare an imminent storm. When studying this fact, it turned out that such people feel pain in the ears, which are caused by infrasound waves. In addition, the low-frequency waves that appear as a result of a storm affect the behavior of a person, his psyche. This can be expressed both in malaise, memory impairment, and in an increase in the number of suicidal attempts.
Earthquakes and volcanic eruptions
Infrasound in nature can also occur as a result of an earthquake. With its help, for example, the Japanese predict the imminent occurrence of tsunamis resulting from underwater seismic activity. Boris Ostrovsky, a researcher in this field, claims that over fifty thousand underwater earthquakes occur annually in the oceans, and each of them creates infrasound. This phenomenon and its mechanism are characterized by the following. It is well known that seismic activity results from the accumulation of energy in the earth's crust. In the end, this energy is released, and the crust breaks. It is these forces that create low-frequency oscillations. The intensity of infrasound is directly proportional to the intensity of energy in the earth's crust. During an underwater earthquake, transverse low-frequency waves travel through the water column and further, reaching the ionosphere. A vessel entering the radiation region of such waves will be affected by infrasound. If such a vessel will be in the specified area for a long time, then it can become the so-called resonator. That is, in other words, the next source of low-frequency waves. This vessel will transmit, like dynamics, infrasound. The influence on a person of precisely this factor is sometimes the cause of the inexplicable fear in people on the ship, often turning into horror. Some researchers claim that this is the key to finding ships on the high seas without a crew. People in this situation are looking for a way out, escape from the ship, if only to hide from this inaudible sound, which drove them crazy.
The greater the intensity of low-frequency oscillations, the greater panic can seize people on the resonator ship. This inexplicable horror by the consciousness of man will be interpreted, his cause will be sought. Perhaps this is precisely what influenced the emergence of such common myths as calling sirens. If we study the ancient myths in more detail, then we can assume that the rowers who put their ears in soundproof devices, as well as other members of the ship’s crew who tied themselves to the masts, tried to protect themselves in this way. It was a kind of protection against infrasound.
In history there are many cases when a ship was discovered with the dead bodies of the crew. And here the theory of infrasound is applicable. As mentioned above, if it coincided with the frequencies published by the internal organs of a person, then, as a rule, it amplified many times. This enhanced infrasound was quite capable of tearing apart internal organs, hence causing sudden death. Murderous infrasound was most likely the culprit of several deaths that occurred in 1957 in Mongolia. Then, on December 4, a powerful earthquake occurred. According to eyewitnesses, some people, including shepherds grazing cattle, literally fell dead even before the Gobi-Altai earthquake.
Volcanic eruptions are another source of infrasound. The wave frequency of the resulting infrasound is about 0.1 Hz.
According to some statements, all kinds of ailments that appear in people during bad weather are caused by nothing more than infrasound.
Production sources
Unlike nature, which does not so often complicate a person’s life with its low-frequency sounds, the infrasound resulting from human activity has an increasingly negative effect on people. These low-frequency waves appear together with the same processes in which sounds heard by a person arise. One of these are shots from guns, explosions, sound radiation emanating from jet engines.
Factory compressors and fans, diesel engines, all kinds of slow-moving units, urban transport - these are all sources of infrasound. The most powerful low-frequency waves cause the meeting of two trains at speed, as well as the passage of a train in a tunnel.
The further humanity develops, the more powerful and voluminous machines and mechanisms are developed and produced. Accordingly, this is accompanied by an increase in the generated infrasound waves. Of particular danger is infrasound in production due to the fact that it has not been fully studied in this area.
Infrasound and human
The negative impact of infrasound on humans is confirmed by many studies. Some scientists believe that it has an undoubted negative effect not only on the body, but also on the psyche of people. Thus, the experiments to which the astronauts undergo allow us to say that subjects with low-frequency waves more slowly solve simple mathematical problems.
Scientists in the field of medicine have determined that a dangerous resonance of the abdominal cavity is detected at an oscillation frequency of 4-8 Hz. During the pulling of this area by belts, an increase in the frequency of sounds was observed, but the effect on the body of infrasound did not stop.
One of the largest resonating objects in the human body is the heart and lungs. In cases where their frequencies coincide with external low-frequency waves, they are subject to the most severe fluctuations, which ultimately can lead to cardiac arrest and lung damage.
Many works of scientists are devoted to the effects that infrasound has on the brain. Low-frequency waves can affect a person in different ways. Studies have shown that there is some similarity between the effects of alcohol and the effects of infrasound. So, in both cases, both of these factors actively inhibit mental work.
Low-frequency waves also have a negative effect on the circulatory system. Researchers have conducted experiments in this area. As a result of these, the subjects over whom the infrasound was applied showed a sharp decrease in blood pressure, arrhythmia, respiratory failure, fatigue and other disturbances in the normal functioning of the body were manifested.
Everyone met with a situation when, after a long and tiring trip by car or sailing in the sea, a bad condition occurs, in which a gag reflex is manifested. Usually people in such cases say that they are sick. However, this is the direct effect of infrasound, which manifests itself in the action on the vestibular apparatus. Interestingly, with the help of infrasound in ancient Egypt, priests tortured their captives. They tied them together and through a mirror and sun glare directed into the victim’s eyes, sought the appearance of last seizures. This was the influence of infrasound. The will of such captives was suppressed, and they were forced to answer the questions asked.
Conclusion
Although ultrasound and infrasound have not yet been fully studied, and there are many gaps in their understanding, the latter has been associated with some natural disasters in humans since ancient times. Their subconscious mind allowed them to avoid many troubles, and the infrasound itself was perceived by man as a harbinger of something bad. Over time, this feeling in humanity gradually atrophied. However, even now suddenly, where the inexplicable fear that came from can warn a person from something bad, forcing him to run away and hide from overwhelming horror.