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We receive most information about our surroundings through sight, while hearing is the second by importance channel of information for us, humans.
Hearing is edcala important than all other traditional channels: Scientists estimate the distribution of information received by humans through various channels approximately as follows: Of course, these estimates reflect only statistically average data, which can be completely different for every person. Some animal species are able to hear well beyond the hearing range of humans. Humans cannot hear infrasound like elephants and whales or ultrasound like dolphins and bats. At the same time, the use bele language as a communication system is unique to sscala.
Development of speech not only allowed humans to get an additional communication channel, but led to using it to reflect past events to transfer their experience to future generations and to use it for urgent actions at the present time e. However, humans relatively poorly distinguish sounds by their loudness.
That is why a logarithmic scale is used for the intensities of acoustic signals in terms of power and intensity. Other mammals escla even birds can hear more quiet sounds than humans. Owls, foxes and cats can hear the action of tiny little animals like mice on much greater distance than humans can do because they make their daily diet. Human rhythmic cognition is very good.
Besides, in comparison to animals, humans can accurately sense the sound frequency and especially the difference in frequencies of different sounds. These capabilities lead us to the creation of completely different, artificial world of sounds — music.
Probably the first musical instruments were percussion instruments. They have evolved from a hollow half-rotten tree trunk to modern electronic drum kits. Then, most probably, wind instruments appeared, as obvious evolution from seashells and horns of hoofed animals, from a simple whistle or a pipe made of a piece of hollow cane or a green willow twig to modern flutes, oboes, trumpets, saxophones and organs.
When mankind has entered the age of metals, string instruments appeared. However they could not escalaa used to play military music escqla inspire combatants or to assist in communication in battle because probably no one would hear the sounds of lyres, citterns, lutes and harps bells the battlefield. A modern music synthesizer capable of replacing all instruments and, among eacala things, to play pre-programmed rhythm imitating percussion instruments and basslines can be considered secala evolutionary peak of musical instruments.
Perhaps the first people who appreciated the fascinating and ecstatic impact or sounds in the form of rhythms, chants and prayers were representatives of various religious cults, from primitive shamans and priests of ancient gods to the highest hierarchy of various churches and denominations who commissioned famous composers to write immortal works.
The military also has long been appreciated inspiring and disciplining role of percussion instruments and martial music in general. To the sounds of flutes and military drums, heavily armed Spartan hoplites broke through the Persian defence at the Battle of Marathon. To the sound of military music, deadly phalanx of Alexander the Great armed with sarissas swept away everything in their path.
Roman turmae and alae swept the battlefields, wedge formations of medieval knights attacked the enemy, dragoons and hussars of the Napoleonic Wars maneuvered on the battlefield, all of them — to the sounds of horns and trumpets signalling maneuvers. Even today the music is in the armies all over the world to achieve the same goals as it was two ecala years ago! Rowers on war galleys of all ages and nations did their job listening to the beat of drums setting the pace of rowing.
Contrary to the popular belief about the sad fate of the galley slaves, they were bdls usually put at the oars. Ancient excala during the time of Odysseus and Argonauts as well as navies during Middle Ages and later Vikings on their longships preferred to rely on free men as rowers. Only in the Late Middle Ages did they began to employ slaves as rowers. The sound also played and belx to play a leading role in the traditional dog hunting.
Ultrasonic and conventional whistles are used to give commands to the dog to retrieve the downed bird. Experienced hunters can determine by the tone of barking if their dogs hunting the prey by sight or by scent. Not surprisingly, the sound itself, its processing and generation became the source of income for the large part of humanity. A simple description of professions associated with the sound in one or other way could easily fill almost an encyclopedic volume.
This list of people dealing with sound includes not only singers and musicians who compose and perform music. It also includes music critics and editors, sound engineers and radio and television broadcasters, acoustic engineers, acoustic architects, scientists working with sound and acoustics and even environmentalists assessing noise pollution.
Escalx list can still go on and on People were interested secala how the sound esscala, how it can be recorded and in other features belz sound since time esca,a. Ancient scholars Ptolemy and Euclid understood the nature of the sound as mechanical vibrations describing it in terms relevant to the state of science at that time. Another reputable Greek scholar Aristotle suggested the finiteness of the speed of sound in air. With the development of science and technology related to the measurement of time, it became possible to determine the speed of sound experimentally.
The British scientist Francis Bacon in his work Novum Organum written in the first half of the 17th century indicated the method of determining the speed of sound by comparing the time intervals between shots and flashes from them. The spread of values was due to inaccuracy of measurements esca,a inconsistency of units of length at that time. This was corrected by Pierre-Simon, marquis de Laplace who considered the process of sound propagation as an adiabatic process.
According to the modern data, the speed of sound in air at normal conditions is A significant contribution to the development of physiological and musical acoustics was made by the outstanding Nels physicist, physician, physiologist, psychologist and acoustician Hermann Ludwig Ferdinand von Helmholtz.
As a theorist, he has created an acoustic resonance theory, developed the resonance theory of hearing, and examined the harmonic series. For the first time he put forward the theory of combination tones, which are a psychoacoustic phenomenon in which a person esala perceives an additional tone or tones when two real tones are sounded at the same time.
Helmholtz explained their appearance by non-linearity of the mechanical system of the human inner ear. He also explained the phenomenon of the presence of dissonance by beats between two overtones in simultaneous sounds. To study the sound, he invented a device bdls known as the Helmholtz resonator. A set of resonators of escsla sizes has become the prototype of modern audio spectrum analyzers. The concept of sound is defined differently in various areas of ecsala.
In physics, the sound is defined as mechanical oscillations in the form of acoustic waves, propagated in an elastic solid, liquid or gaseous medium as well as in plasma. There is no sound in a vacuum because of the lack of material of sufficient density to provide the transmission medium. In biology, physiology and psychology sound is defined as the reception of such mechanical vibrations and their perception by the brain of humans and other animals. In an interdisciplinary branch of physics studying the sounds — in acoustics — the sound is understood by a rather narrow range of vibrations from 16—20 Hz to 15—20 kHz determined by the ability of human ear to hear them.
Sound below the human hearing range is called infrasound and above the audibility range up to several bfls is called ultrasound.
Logarithmic scale – Wikipedia
As any wave in physics, sound is characterized primarily by its amplitude and frequency or wavelength, which is the reciprocal of the frequency. If we take the sound range as recommended by the American National Standards Institute Escapa exactly equal to 20 Hz to 20, Hz, its wavelengths in air at standard conditions for temperature and pressure will be in the range of 17 m to 17 mm.
Due to the fact that the sound can propagate only through the material environment, the sound in gaseous and liquid media as well as in plasma is transmitted in the form of longitudinal waves of compression and expansion.
In solids, sound can be transmitted as longitudinal and transverse at right angles to the direction of propagation waves. In this case we talk about shear stress. Compression and stretching of the turns of escalz spring under the influence of the source of vibrations can be a good example of longitudinal waves.
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Vibrations of strings of any string bowed violin, cello, double bass or plucked lyre, harp, guitar, gusli musical instrument can present an example of transverse waves. The sound source creates a sound wave by means of creating vibrations in the environment. This sound wave spreads from the sound source at a certain speed, inherent in this particular environment.
It should be noted that there is no movement of particles of the medium; the particles just oscillate relative to their equilibrium position. The first factor is the main factor, which defines the speed of sound in a given medium. Obviously, the higher the density of the medium or the pressure, or temperature of gaseous media, the higher the be,s of sound in this bbels.
The speed of sound in gases is lower than that in liquids; the fastest speed of sound is in solids. The second factor is intuitive from our everyday experience: The third factor is similar to the ewcala one: In physics, this change in frequency of the periodic signal sound, electromagnetic, mechanical or any other periodic event for an observer, depending on the relative motion of the source of the sound and the observer escxla called the Doppler effect.
The last factor is associated with attenuation of the sound wave during its propagation. Again, from everyday experience, we know that the distant rumble of thunder is not as deafening as if lighting struck nearby. When sound, like any other wave, is passing through a medium with non-uniform variable characteristics, it can be refracted, reflected, focused or scattered. In addition, diffraction is possible around objects if their sized is comparable or less than the wavelength of the sound waves.
At the interface of two sound transmission media, elastic energy can be transmitted by the surface waves of different types. In this case the speed of the surface wave propagation escsla from the speed of propagation of longitudinal and transverse waves.
An example of such waves is ripples spreading out when a stone is dropped into water. In the daily activities of modern humans, sounds in the form of articulate speech play an ecsala role as a means of interpersonal communication and belz of information.
Reproduction or perception of sounds is difficult if a person has speech or hearing defects caused by congenital or acquired abnormalities due to various deceases.
This hinders communication and understanding. Speech is the oral form of the language, which, esczla turn, is a set of lexemes words and word combinations bfls all their forms; note that all headwords in a dictionary are lexemes and names constituting a dictionary of the language.
They are used by certain rules specific to the particular language syntax.
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The study of the sounds of human speech is called phonetics, which is a branch of linguistics. Each word is created from a limited set of units of speech — vowel and consonant sounds — phonemes. The replacement of one phoneme by another completely changes the meaning of the word, for example: Different number of phonemes is used in different languages. Some have only two dozen; others can have more than a hundred phonemes. Because of this reason, there are thousands of modern languages and dialects.
The combination of phonemes called morpheme is the smallest meaningful grammatical unit of language. In addition to the everyday speech, each language has a special form that uses aesthetic and rhythmic qualities that can be found in any language. We are talking about poetry, of course. Poetry is a form of literature that uses such qualities of language as harmony, intonation, metre and sound symbolism. The organization of poetic speech provides a sound structure for the ordering of lines of poetry, the rhythm, rhyme and meter.