Along with the development of industry and the growth of cities, a huge number of invisible factors began to influence a person. We do not even suspect the dangers of many of them and perceive them as a not very pleasant, but integral part of life. Sound is also invisible, but very harmful. Or a cacophonic cluster of sounds - noise. Man is never in complete silence. If you are alone at home now - listen. Is it really quiet in the apartment? The influence of sound on a person occurs always and everywhere. And if you do not notice the monotonous noise that haunts you in seemingly complete silence, it does not mean that it does not currently affect your mental and physical states.
What is sound and noise?
Sound is a physical phenomenon. Sound is invisible elastic waves propagating in a solid, liquid, and gaseous medium. It does not spread only in a vacuum. As a rule, sound sources are bodies oscillating at different frequencies: strings of musical instruments, the vocal apparatus in humans and animals, membranes in various types of devices, etc.
Noise is the random fluctuations of physical objects in nature. This is a disparate set of sounds. In modern science, there are sound, radio and electrical noise. The main sources are a variety of mechanisms.
Sound frequency
The most important and strong influence of sound on the human body is through the frequency of sound vibrations. The human ear perceives a frequency from 16 Hz to 20,000 Hz (or 20 kHz, where "k" is a kilo). Hertz is a unit of measure for frequency. Sound with an oscillation frequency below 16 Hz is not audible to the human ear and is called infrasound from lat. Infra - below. Almost all human organs have such a frequency. A frequency above 20,000 Hz is also not perceived by the human hearing aid and is called ultrasound (from lat. Ultra - over, outside).
Sound volume
The volume of sound is a subjective quantity, since its value completely depends on how our hearing perceives it. Sound volume is measured in sones. This is an internationally recognized unit of measure. But if we are talking specifically about the effect of sound on a person, its intensity and pressure on our hearing system is measured in decibels. The unit of volume (including noise) in this case is 1 bel, but since it is quite large for convenient measurement, use the decibel, which is 1/10 of the bel.
Sounds and noises in everyday life
In ordinary life, we rarely hear a clear sound. Most often we are surrounded by their combination, that is, noise. Often we do not suspect that it exceeds the permissible safe norm for our hearing. The average and safest noise level for our health is 55–70 dB. The effect of sound and noise on humans with greater intensity can be detrimental. To better navigate in numerical values, we write the strength of the main sources.
Safe noise level:
- 10 dB - whisper;
- 20-30 dB - natural background noise in the room;
- 50 dB - conversation in a calm tone;
- 70 dB - noise level on a busy street.
Unsafe noise level:
- 80 dB - truck engine operation;
- 90 dB - train noise in the subway;
- 110 dB on average - the sound of equipment at concerts and discos.
Some rock musicians at their concerts gave out a sound volume of 130 dB, not taking into account the fact that starting with this figure a person begins to experience physical pain from noise exposure. The dangerously loud noise level starts at 70 dB. Sound with an intensity of more than 130 dB causes physical pain, and 150 dB or more can become fatal for a person. But not only the sound volume affects a person. Invisible weapons can be low-frequency and high-frequency sounds. Those that are not perceived by our hearing aid.
Infrasound
Infrasound is a sound with a low frequency, inaudible by a person, but representing a great danger to him. Infrasound is one that is caused by an oscillation frequency of 0.001 to 16 Hz. This type of noise is used by police in some countries to disperse an aggressive crowd.
Today, many states are developing infrasound weapons. It should be an inexpensive but effective weapon of mass destruction. Infrasound is quite widely used in science and even medicine. With it, oceans and the atmosphere are studied, natural disasters are predicted. And also doctors use the effect of sound on human health. With the help of infrasound, cancerous tumors are removed and the cornea of the eye is treated.
Infrasound sources
Infrasound often appears in nature. Volcanic eruptions, thunderstorms, tornadoes and earthquakes, meteorites fall emit a powerful sound wave. But the power of the infrasound formed by the explosion of a nuclear bomb is much greater.
When there are periods of great geomagnetic activity on Earth, infrasound waves also fly around the globe. And also the sources are large-sized constructions and mechanisms whose fluctuation due to size cannot exceed 16 times per minute. This is a technique and buildings. Infrasound frequencies also issue the largest organ pipes in churches. But these frequencies are close to those heard by a person.
Infrasound effects on humans
When exposed to frequencies of 4-8 Hz, a person begins to vibrate internal organs, and at 12 Hz an attack of motion sickness occurs. The effect of sound on a person can vary greatly depending on the frequency indicators. If 12 Hz have a negative impact on health, then 13-14 Hz contribute to the relaxation and concentration of all body systems. Such a frequency helps to tune in to creation and creative work, the brain, with the influence of a given frequency on it, is easier to process incoming information.
The most dangerous infrasound frequencies for humans are from 6 to 9 Hz. At a frequency of 7 Hz, which is consonant with the alpha rhythm of the brain, mental work is disrupted. It seems to a man that his head is torn apart. For the influence of sounds and noises on the human body to be noticeable, it is necessary that a certain frequency be combined with a dangerous volume. The stronger the sound intensity, the irreversible damage to organs.
Infrasound with low sound pressure can cause tinnitus, nausea, blurred vision, and fear. Sound of medium intensity affects the digestive system and the brain, causes weakness, and in some cases paralysis, and complete loss of vision. The effect of sound on a person can become fatal. If its intensity exceeds 130 dB, cardiac arrest is possible.
The frequency of human organs
Almost all organs of our body work at the infrasound frequency. The average frequency of the whole organism is 6 Hz, the head is 20–30 Hz, the abdominal cavity and chest are 5–8 Hz, the heart is 4–6 Hz, and the stomach is 2–3 Hz. The intestinal rhythm is 2–4 Hz, the kidneys are 6–8 Hz, and the vestibular apparatus is from 0.5 to 13 Hz. Etc.
When the frequency of infrasound resonates with the rhythm of an organ, the effect of sound on the human body occurs. It begins to vibrate, which can be accompanied by severe pain and cause damage to this organ. Under the influence of infrasound in humans, the energy expenditure in the body increases. Scientists believe that the state of the body under the influence of such waves is similar to the state during physical work.
Ultrasound
Ultrasound is characterized by a frequency of over 20,000 Hz, which is not included in the range of sounds perceived by our ear. Its effect, just like the similar effect of sounds and noises on the human body, is very noticeable. Ultrasound is used in almost all branches of science. Its properties are priceless and greatly facilitate life in our time.
Ultrasound is widely used in medicine for both research and treatment. In production, he copes with the manufacture of small holes of complex shape in metal. Ultrasound can make holes in the hardest substances, even in diamonds. Using it, liquids immiscible by other methods (for example, water and oil) are combined.
In biology, ultrasound is used to destroy cells and study their individual parts. With the help of such waves mutations are caused that are used in plant breeding. And also ultrasound helps people clean small parts and even wash things. In echolocation, he finds schools of fish. And also thanks to such waves, you can detect the smallest defects in parts and materials. Ultrasonic welding is used in the production , which allows joining parts that cannot be heated, metals with a strong oxide film and inhomogeneous metals.
The use of ultrasound in medicine
Ultrasound examination is the most famous and convenient type of examination. Using it, one can examine in detail the tissues of soft organs, reveal their damage, the presence of tumors, and see changes in sizes and shapes. This study is the safest method, since the influence of the frequency of sound on a person does not lead to dangerous consequences. Therefore, ultrasound is used in studies of the heart, female genital organs and breast.
Unlike x-rays, ultrasound does not carry hazardous radiation. And also ultrasound is used in treatment. In sports medicine, traumatology, dentistry, physiotherapy, it is used as an anti-inflammatory agent that can improve circulation in individual tissues, relieve swelling and pain. With the help of ultrasound, bone and cartilage tissue is restored faster.
Sources of Ultrasound
In nature, the sources of ultrasound can be the noise of rain, wind, pebbles on the seashore. And also they are accompanied by lightning discharges. Many animals use ultrasound in order to navigate in space, avoid obstacles and communicate with relatives. These are animals such as dolphins, bats, whales, rodents, etc.
People made the first ultrasonic whistle in 1883. It is called the Galton Whistle. Commonly used for training dogs and cats. Later invented a liquid ultrasonic whistle. Its action scheme consists in the fact that the fluid flow under high pressure hits a metal plate, so that the plate oscillates. Sirens are also used to produce ultrasound.
What effect can sounds have on a person: ultrasound
In the human body, ultrasound is converted into heat, which leads to the compression and stretching of body tissues, and the acceleration of metabolic processes. Prolonged and intense exposure can cause destruction of living cells. Red blood cells and white blood cells are destroyed, and viscosity and coagulability increase. The greater the intensity, the more dangerous the physics of the effect of sound on a person.
In humans, they did not experience ultrasound of strong power. All experiments were performed on animals. When exposed to severe pain, burns, baldness, clouding of the lenses and pupils of the eyes. High frequencies cause death through minor hemorrhages in the organs. And also, prolonged exposure to ultrasound can lead to hearing loss and symptoms of vegetative-vascular dystonia.
The effect of musical sounds on humans
The positive and negative effects of music on humans have been known since ancient times. Nowadays, it has been proven that music therapy has a very good effect on the mental and physical health of people. It has the greatest effect on children. Music stimulates the parts of the brain that are responsible for memory, motor functions and speech, improves motor skills.
Children from an early age who began to practice instruments have a high level of enthusiasm, sociability and the ability to absorb knowledge. The influence of music sounds on a person is also manifested in the acceleration of brain activity, which favorably affects our cognitive abilities.
Who needs music therapy?
Today, doctors successfully use music in the treatment of mental illness and disorders: depression, congenital mental illness, increased irritability, mental retardation, etc. And music also has a positive effect during pregnancy both for the mother and the fetus.
It is easier to learn foreign languages with it, it is used to prevent Alzheimer's disease and dementia. With the help of music, you can normalize blood pressure, improve the functioning of the heart and central nervous system, sometimes even restore damaged parts of the brain.
What to listen to?
Many projects have been written about the effect of sound on the human body, thanks to which researchers have found out exactly which music has a therapeutic effect. In China, albums are sold for the treatment of certain organs and disorders: “Heart”, “Depression”, “Liver”, “Migraine”, “Digestion”, etc. In them, sound has a frequency similar to a diseased organ.
All musical instruments have different effects on our condition, as each organ has its own resonating instrument. For peace of mind, it is useful to listen to the violin and piano. To normalize the liver and gallbladder, advise clarinet and oboe. For diseases of the cardiovascular system, it is good to listen to the melodies of stringed instruments.
Mozart's Music
According to the assurances of researchers, it is Mozart’s music that has healing and therapeutic properties. Scientists conducted an experiment in which subjects were allowed to listen to various tunes. Only when listening to Mozart’s works was the whole area of the cerebral cortex activated, while from other songs there was only one or several of its departments.
There are many works on the therapeutic effect of the works of this classic. The stores sell discs with samples from his repertoire, which you need to listen to in various cases.