Acoustics is the science of sound. The main directions of modern acoustics
Sound is a phenomenon that has stirred human minds from deep antiquity. In fact, the world of various sounds arose on Earth long before the appearance of human beings on it. The first sounds were heard even during the birth of our planet. They were caused by powerful blows, oscillations of matter and boiling of the hot substance.
Sound in a natural environment
When the first animals appeared on the planet, over time they had an urgent need to get as much information as possible about the surrounding reality. And since sound is one of the main information carriers, evolutionary changes in the brain began to occur in the fauna, which gradually led to the formation of hearing organs.
Now, primitive animals could obtain, by capturing sound vibrations, the necessary information about the danger, often coming from objects invisible to gaze.Later, living beings learned to use sounds for other purposes. The scope of application of audio information grew in the process of evolution of the animals themselves. Sound signals began to serve as a means of primitive communication between them. By sounds, they began to warn each other about the danger, he also served as a call to unite for creatures with herd instincts.
The man - master of sounds
But only a man managed to learn to fully use the sound for their own purposes. At one point, people were faced with the need to transfer knowledge to each other and from generation to generation. The man subordinated to these goals the variety of sounds that he learned to publish and perceive over time. From this multitude of sounds, speech subsequently arose. The sound has also become the filling of leisure. People discovered for themselves the melodiousness of the whistle of a descending bowstring of onions, the vigor of rhythmic beats of wooden objects against each other. Thus arose the first, most simple musical instruments, and hence the very art of music.
However, human communication and music are not the only sounds that appeared on Earth with the appearance of people.The sounds were accompanied by numerous labor processes: the manufacture of various objects from stone and wood. And with the advent of civilization, with the invention of the wheel, people for the first time faced the problem of loud noise. It is known that already in the ancient world, the knock of wheels on roads paved with stone often caused poor sleep among residents of roadside houses. In the fight against this noise, the first noise reduction tool was invented: straw was laid on the pavement.
Growing noise problem
When humanity knew the benefits of iron, the problem of noise began to take on a global scale. Having invented gunpowder, man thus created a sound source of such power, which is sufficient to cause noticeable damage to his own hearing aid. In the era of the industrial revolution, among such negative side effects as environmental pollution, depletion of natural resources, not the last place is the problem of high-volume industrial noise.
Anecdote from life
Nevertheless, even at present, not all manufacturers of industrial equipment pay at least some attention to this issue.The management of far from all plants and factories is concerned about the preservation of healthy hearing in their subordinates.
Sometimes you hear stories like this. The chief engineer of one of the large industrial enterprises ordered to install microphones connected to loudspeakers located outside buildings in the noisiest workshops. In his opinion, in this way the microphones will suck some of the noise out. Of course, with all the comicity of this story, it makes you think about the reasons for such illiteracy in matters relating to noise reduction and noise insulation. And the only reason for this is that only in the last decades they began to introduce special courses in acoustics in educational institutions of a higher, secondary professional and secondary specialized level of education.
The first attempts to understand the nature of sound were made by Pythagoras, who studied the vibrations of a string. After Pythagoras for many centuries, this area did not cause any interest among researchers. Of course, a number of ancient scholars were engaged in building their own acoustic theories, but these scientific investigations were not based on mathematical calculations, but were more like isolated philosophical arguments.
And only after more than a thousand years did Galileo start a new science of sound - acoustics. The most prominent pioneers in this field were Rayleigh and Helmholtz. In the nineteenth century, they created the theoretical basis of modern acoustics. Hermann Helmholtz is mainly famous for his study of the properties of resonators, and Rayleigh became the Nobel laureate due to his fundamental work on the theory of sound.
The main directions of modern acoustics
Numerous scientific studies on the nature of noise and the issues of noise reduction and noise insulation were published some time later. The first works in this area were mainly related to noise produced by aviation technology and ground transportation. But over time, the boundaries of these studies expanded significantly. At the moment, most industrialized countries have their own research institutes engaged in developing solutions to these problems.
Today, the following sections of acoustics are best known: general, geometric, architectural, construction, psychological, musical, biological, electrical, aviation, transport, medical, ultrasound, quantum, speech, digital.The following chapters will cover some of the listed sections of the science of sound.
First of all, it is necessary to give a definition of science, which is discussed in this article. Acoustics is a field of knowledge about the nature of sound. This science studies such phenomena as the appearance, distribution, sensation of sound and the various effects produced by sound on the organs of hearing. Like all other sciences, acoustics has its own conceptual apparatus.
Acoustics is a science that is considered one of the branches of physical science. However, it is also an interdisciplinary industry, that is, it has close ties with other areas of knowledge. The interaction of acoustics with mechanics, architecture, music theory, psychology, electronics, and mathematics is most clearly seen. The most important formulas of acoustics concern the properties of the propagation of sound waves under conditions of an elastic medium: the equation of plane and standing waves, the formula for calculating the velocity of waves.
Application in music
Musical acoustics - the branch investigating musical sounds from the point of view of physics. This industry is also interdisciplinary.In scientific works on musical acoustics, the achievements of mathematical science, musical theory and psychology are actively used. The basic concepts of this science: pitch, dynamic and timbre shades used in music sounds. This section of acoustics is mainly aimed at exploring the sensations that arise when a person perceives sounds, as well as the features of musical intonation (reproduction of sounds of a certain height). One of the most extensive research topics of musical acoustics is the topic of musical instruments.
Scientists engaged in the theory of music, used the results of studies of musical acoustics to build the concepts of music based on the natural sciences. Physicists and psychologists were engaged in issues of musical perception. Domestic scientists who worked in this field worked both to develop a theoretical base (N. Garbuzov is known for his theory of zones of musical perception) and to apply achievements in practice (L. Termen, A. Volodin, E. Murzin) were engaged in the design of electromusical instruments ).
In recent years, interdisciplinary scientific works have increasingly begun to appear, in which the acoustics of buildings belonging to different architectural styles and eras are comprehensively considered. The data obtained in studies in this field are used in the construction of techniques for the development of musical hearing and techniques for tuning musical instruments. Therefore, we can conclude that musical acoustics is a branch of science that has not lost its relevance today.
Not all sounds can be perceived by human organs of hearing. Ultrasonic acoustics - the acoustics section that studies sound vibrations with a range from twenty kHz. The sounds of this frequency are beyond human perception. Ultrasound is divided into three types: low-frequency, mid-frequency, high-frequency. Each species has its own specificity of reproduction and practical application. Ultrasounds can be created not only artificially. They are often found in wildlife. Thus, the noise emitted by the wind, partly consists of ultrasound.Also, such sounds are reproduced by some animals and captured by their organs of hearing. Everyone knows that a bat is one of these creatures.
Ultrasonic acoustics is a branch of acoustics that has found practical application in medicine, in various scientific experiments and research, in the military industry. In particular, in the early twentieth century in Russia, a device was invented for detecting underwater icebergs. The operation of this device was based on the generation and trapping of ultrasonic waves. From this example, it is clear that ultrasonic acoustics is a science whose achievements have been used in practice for over a hundred years.