Together with the development of industry and with the growth of cities, a huge number of invisible factors began to influence a person. We are not even aware of the dangers of many of them and perceive them as not very pleasant, but an integral part of life. Sound also belongs to invisible, but very harmful factors. Or a cacophonous accumulation of sounds - noise. Man is never completely silent. If you are alone at home right 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 state.
What is sound and noise?
Sound is a physical phenomenon. Sound is invisible elastic waves propagating in solid, liquid and gaseous media. It does not propagate only in a vacuum. As a rule, bodies are the sources of sound,vibrating at different frequencies: strings of musical instruments, human and animal vocal apparatus, membranes in various types of devices, etc.
Noise is the random fluctuations of physical objects in nature. This is a discordant combination of sounds. In modern science, sound, radio and electrical noise are distinguished. 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 kilo). Hertz is a unit of 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 this frequency. A frequency above 20,000 Hz is also not perceived by a human hearing aid and is called ultrasound (from Latin ultra - over, beyond).
Sound volume
The volume of a sound is a subjective value, since its value depends entirely on how it is perceived by our ears. Sound volume is measured in sons. This is an internationally recognized unit of measurement. But if we are talking specifically about the effect of sound on a person, its intensity and pressure on our hearing aid is measured in decibels. The unit of loudness (including noise) in this case is 1 bel, but since it is quite large for convenient measurement, a decibel is used, which is 1/10 of a bel.
Sounds andnoises in everyday life
In ordinary life, we rarely hear a clear sound. Most often, we are surrounded by their totality, that is, noise. Often we do not suspect that it exceeds the permissible safe rate for our hearing. The average and safest noise level for our he alth is 55–70 dB. The impact of sound and noise on a person with greater intensity can be detrimental. To better navigate the numerical values, let's write the strength of the main sources.
Safe noise level:
- 10 dB - whisper;
- 20-30 dB - natural background noise in the room;
- 50dB - talking in a calm tone;
- 70 dB is the noise level on a busy street.
Unsafe noise level:
- 80 dB - truck engine running;
- 90dB - subway train noise;
- 110 dB on average - the sound of equipment at concerts and discos.
Some rock musicians at their concerts gave the sound volume over 130 dB, not taking into account the fact that starting from this figure a person begins to experience physical pain from noise exposure. Dangerously loud noise starts at 70 dB. Sound with an intensity of more than 130 dB causes physical pain, and 150 dB or more can be fatal for a person. But not only the volume of sound affects a person. Low-frequency and high-frequency sounds can become an invisible weapon. Those that are not perceived by our hearing aid.
Infrasound
Infrasound is a sound with a low frequency, inaudible to humans, butposing a great danger to him. Infrasound is the one that is caused by the oscillation frequency from 0.001 to 16 Hz. This type of noise is used by the police of some countries when dispersing an aggressive crowd.
Today, many states are developing infrasonic weapons. It should be an inexpensive but effective weapon of mass destruction. Infrasound is widely used in science and even medicine. With it, they study the oceans and atmosphere, predict natural disasters. And doctors also use the effect of sound on human he alth. 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, meteorite falls emit a powerful sound wave. But the power of infrasound generated by a nuclear bomb explosion is much greater.
When there are periods of great geomagnetic activity on Earth, infrasonic waves also fly around the globe. And also sources are large-sized structures and mechanisms, whose fluctuation due to size cannot exceed 16 times per minute. It's technology and buildings. Subsonic frequencies are also emitted by the largest organ pipes in churches. But these frequencies are close to human hearing.
Influence of infrasound on humans
When exposed to frequencies equal to 4–8 Hz, a person begins to vibrate internal organs, and at 12 Hz, an attack of seasickness occurs. The effect of sound on a person can vary greatly independing on frequency indicators. If 12 Hz have a negative impact on he alth, 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, when this frequency influences it, processes incoming information more easily.
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. The person feels like his head is being torn apart. In order for the effect of sounds and noises on the human body to be noticeable, it is necessary that a certain frequency be combined with a dangerous loudness. The stronger the sound intensity, the more permanent damage to organs.
Low SPL infrasound can cause tinnitus, nausea, blurred vision and fear. Sound of medium intensity affects the digestive system and the brain, causing weakness, and in some cases, paralysis and complete loss of vision. The effect of sound on a person can be fatal. If its intensity exceeds 130 dB, cardiac arrest is possible.
Frequency of human organs
Almost all organs of our body operate at the infrasonic frequency. The average frequency of the whole organism is 6 Hz, head - 20-30 Hz, abdominal cavity and chest - 5-8 Hz, heart - 4-6 Hz, stomach - 2-3 Hz. The rhythm of the intestines is 2-4 Hz, the rhythm of the kidneys is 6-8 Hz, the vestibular apparatus is from 0.5 to 13 Hz. And so on.
When the frequency of infrasound enters into resonance with the rhythm of any organ, the effect of sound on the human body occurs. Hebegins to vibrate, which can be accompanied by severe pain and cause damage to this organ. When exposed to infrasound, a person increases energy consumption in the body. 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 influence, just like the similar influence 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 make life much easier in our time.
Ultrasound is widely used in medicine for both research and treatment. In production, it does an excellent job of making small holes of complex shape in metal. Ultrasound can make holes in the hardest materials, even diamond. It is used to connect liquids that are immiscible in other ways (for example, water and oil).
In biology, ultrasound is used to destroy cells and study their individual parts. With the help of such waves, mutations are caused, which 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. In production, ultrasonic welding is used, which makes it possible to connect 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. With it, you can examine in detail the tissues of soft organs, identify their damage, the presence of tumors, see changes in size and shape. This study is the safest method, since the effect of sound frequency on a person does not lead to dangerous consequences. Therefore, ultrasound is used in studies of the heart, female genital organs and breasts.
Unlike X-rays, ultrasound does not carry dangerous 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 tissues recover faster.
Ultrasonic sources
In nature, the sound of rain, wind, pebbles on the seashore can serve as sources of ultrasound. And also they are accompanied by lightning discharges. Many animals use ultrasound 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's called the G alton whistle. Commonly used for training dogs and cats. Later, a liquid ultrasonic whistle was invented. Its scheme of action is that a high-pressure fluid stream hits a metal plate,causing the plate to oscillate. 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 compression and stretching of body tissues, and acceleration of metabolic processes. Prolonged and intense exposure can cause destruction of living cells. In the blood, erythrocytes and leukocytes are destroyed, viscosity and clotting increase. The greater the intensity, the more dangerous the physics of the effect of sound on a person.
High power ultrasound has not been tested on humans. All experiments were performed on animals. When exposed to it, severe pain, burns, baldness, clouding of the lenses and pupils of the eyes were observed. High frequencies cause death by small hemorrhages in the organs. And also prolonged exposure to ultrasound can lead to hearing changes and symptoms of vegetovascular dystonia.
The influence of musical sounds on a person
The positive and negative influence of music on a person has been known since ancient times. Nowadays, it has been proven that music therapy has a very good effect on the mental and physical he alth of people. It has the greatest effect on children. Music stimulates the parts of the brain responsible for memory, motor functions and speech, improves motor skills.
Children who start playing instruments from an early age are characterized by a high level of enthusiasm, sociability and ability to assimilate knowledge. The influence of the sounds of music on a person is also manifested in the acceleration of brain activity, whichfavorably 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, irritability, mental retardation, etc. And music also has a positive effect during pregnancy, both for the mother and for the fetus.
It makes it easier to learn foreign languages, 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, and sometimes even restore damaged parts of the brain.
What to listen to?
Many projects have been written on the effect of sound on the human body, thanks to which researchers have found out what kind of 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, the sound has a similar frequency to the diseased organ.
All musical instruments affect our state in different ways, since each organ has its own instrument that resonates with it. For peace of mind, it is useful to listen to the violin and piano. To normalize the functioning of the liver and gallbladder, clarinet and oboe are advised. In diseases of the cardiovascular system, it is good to listen to melodies of stringed instruments.
MusicMozart
According to researchers, it is Mozart's music that has healing and therapeutic properties. Scientists conducted an experiment in which they gave the subjects to listen to various melodies. Only when listening to Mozart's works did the entire area of the cerebral cortex become active, while from other songs only one or several of its departments.
There are many works on the topic of the healing effect of the works of this classic. Stores sell CDs with selections from his repertoire to be listened to on certain occasions.
