- (from the Greek akustikos auditory, listening), a field of physics that studies elastic vibrations and waves from the lowest frequencies (conditionally from 0 Hz) to extremely high frequencies (1011 1013 Hz), their effects on the body and various applications. A. one of ... ... Physical Encyclopedia

Acoustics- Acoustics. Sound spectra of various musical instruments. ACOUSTICS (from the Greek akustikos auditory), in a broad sense, a branch of physics that studies elastic waves from the lowest frequencies to the highest (1012 1013 Hz); in a narrow sense, the doctrine of ... ... Illustrated Encyclopedic Dictionary

ACOUSTICS- (from the Greek akustikos auditory), in a broad sense, a branch of physics that studies elastic waves from the lowest frequencies to the highest (1012 1013 Hz); in a narrow sense, the doctrine of sound. General and theoretical acoustics are engaged in the study of ... ... Modern Encyclopedia

ACOUSTICS- (from the Greek akustikos auditory) in a broad sense, a branch of physics that studies elastic waves from the lowest frequencies to the highest (1012 1013 Hz); in a narrow sense, the doctrine of sound. General and theoretical acoustics are engaged in the study of patterns ... ... Big Encyclopedic Dictionary

ACOUSTICS- (from the Greek akuein to hear). The part of physics that sets out the laws and properties of sounds. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. ACOUSTICS 1) the doctrine of sound (part of physics); 2) condition for hearing; e.g. hall acoustics… Dictionary of foreign words of the Russian language

ACOUSTICS- (from the Greek akouo I listen), the doctrine of sound, one of the oldest and most developed branches of physics. Acoustics can be divided into 1) general, 2) physiological, 3) atmospheric, 4) architectural, 5) musical. General acoustics studies the processes ... ... Big Medical Encyclopedia

acoustics- sonic Dictionary of Russian synonyms. acoustics noun, number of synonyms: 12 auto acoustics (1) … Synonym dictionary

acoustics- and well. acoustic f., German. Akustik lat. acustica. gr. 1700. Lexis. 1. physical. The science. The properties of sound, the doctrine of the resurrection of the voice, the pipes through which they speak, and others are offered in acoustics. Uch. P. 2 54. Acoustics or the science of ringing, ... ... Historical Dictionary of Gallicisms of the Russian Language

ACOUSTICS- ACOUSTICS, the science of sound, mainly about the properties of sound waves. Architects consider acoustic requirements when designing public buildings, such as concert halls and lecture halls, to provide a clearer sound. Engineers... ... Scientific and technical encyclopedic dictionary

ACOUSTICS- ACOUSTICS, acoustics, pl. no, female (from Greek akustikos auditory). 1. Department of physics that studies sound. 2. Conditions for hearing music or speech in the premises. Concerts cannot be held in this hall due to its poor acoustics. Explanatory Dictionary of Ushakov ... Explanatory Dictionary of Ushakov

ACOUSTICS- ACOUSTICS, and, for women. 1. The branch of physics that studies sound. 2. The audibility of the sounds of music, speech in which n. special room. Good a. hall. | adj. acoustic, oh, oh. Explanatory dictionary of Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Explanatory dictionary of Ozhegov

Books

• Acoustics, Sh. Ya. Vakhitov, Yu. A. Kovalgin, A. A. Fadeev, Yu. P. Shchevev. The main characteristics of the sound field are considered; primary acoustic signals; hearing properties and perception of acoustic signals; acoustics of rooms, concert halls, studios…

ACOUSTICS(from Greek akustikos - auditory) - a field of physics in which elastic and waves are studied from the lowest frequencies (conditionally from 0 Hz) to extremely high (10 12 -10 13 Hz), the processes of their excitation and propagation, their interaction with substance and various applications.

A. is one of the most ancient areas of knowledge. It arose for several centuries BC e. as the doctrine of sound, i.e., about elastic waves perceived by the human ear (hence the origin of the name "A."). The beginning of the formation of A. as a physical. science (17th century) is associated with the study of the system, musical tones, their sources (strings, pipes), with measurements of the speed of sound propagation. Before the beginning 20th century A. developed as a branch of mechanics. A general theory of mechanics was created. oscillations, and propagation of sound waves in the medium, methods were developed for measuring the parameters of sound waves - sound pressure, energy flow, propagation velocity. The range of the studied elastic waves has expanded and covered the regions below (infrasound) and above () the region of audible frequencies. Creation of methods for the decomposition of complex oscillations. process into simple components (Fourier method) laid the foundation for the analysis of sound and the synthesis of complex sound from simple components. All this classic. stage of development A. summed up to the beginning. 20th century Rayleigh (J. W. Strutt, J. W. Strutt).

A new stage in the development of A. began in the 1920s. 20th century in connection with the development of radio engineering and broadcasting, to-rye necessitated the development of methods and means of converting e-magn. energy into acoustic, and vice versa. In connection with the development of electronics and the structure of matter, new directions have arisen in A.

In modern A. can be divided into a number of sections. The general laws governing the emission, propagation, and reception of elastic oscillations of n waves are studied by the theory of sound, which makes extensive use of Math. methods developed in the general theory of oscillations and waves. Along with the wave approach to consider the problems of sound propagation in the def. conditions (the smallness of the wavelength compared to the scale of the obstacles) the concepts of sound rays are also used. According to this methodological a feature from the general theory of sound, a section of radial A. is distinguished, or geometric acoustics(similar to geom. optics).

As applied to various characteristic models of wave propagation media and adequate methods for considering acoustic. fields formed such areas of sound theory as statistical. BUT., acoustics of moving media, crystal acoustics. Rapidly developing nonlinear acoustics, associated with the study of waves of large amplitude, for which the properties of the medium are impossible, as with the classical. approach, consider unchanged; high-intensity sound waves themselves perturb the medium, as a result of which the interaction of decomp. wave modes. The development of non-linear A. is due, in particular, to powerful tech. progress and the need to consider sound radiation from sources of high power.

The most important section A., Naib. closely associated with other leading areas of modern. physics, physical A., engaged in the study of the features of the propagation of elastic waves in a substance - gaseous, solid or liquid, the study of the interaction of waves with matter at different levels, in particular acoustoelectronic interaction, acousto-optical, phonon-phonon interaction and other types of interaction of elastic waves with quasiparticles. Subdivisions of physical A. are molecular acoustics, quantum A., optoacoustics and other Methods of physical. A. is an integral part of the arsenal of experiments. means of modern physics.

Acoustic propagation. waves in nature. environments - the atmosphere, the waters of the World Ocean, in the earth's crust and related phenomena are studied in atmospheric acoustics, hydroacoustics, geoacoustics. Acoustic waves are the most important means of probing these media, a means of obtaining information about their structure and the presence of various inclusions in them. Closely adjacent to hydroacoustics is such an important and widely developed applied area as sonar.

Huge applied value as in the technique of physical. experiment, and in industry, transport, medicine, etc. has a so-called. Ultrasound technology (see. Ultrasound). In ultrasonic devices, both ultrasonic and hypersonic, and partially sonic frequency ranges are used. Ultrasound is used as a means of influencing a substance (for example, ultrasound technology in industry, therapy and surgery in medicine), to obtain information (control and measurement applications of ultrasound, ultrasound diagnostics, sonar), signal processing ( acoustoelectronics, acousto-optics).

A special section A. - biol. A. - dealing with the distribution of acoustic. waves in living tissues, the impact of ultrasound on biological tissue, the study of sound-emitting and sound-receiving organs in living organisms. The study of organs and processes of sound perception and sound radiation in humans, as well as the problems of speech formation, transmission and perception of speech, is carried out by physiological. and psychological. A. The results of these studies are used in sound engineering, architectural acoustics, in the development of speech transmission systems, in information and communication theory, in music, medicine, biophysics, etc.

Lit.: Strett, J. W. (Lord Rayleigh), The Theory of Sound, trans. from English, 2nd ed., vol. 1-2, M., 1955; Mikhailov I. G., Solovyov V. A., Syrnikov Yu. P., Fundamentals of molecular acoustics, Moscow, 1964; Physical acoustics, [ed. W. Mason and R. Thurston], trans. from English, vol. 1-7, M., 1966-74; Physics and Technology of Powerful Ultrasound, ed. L. D. Rozenberg, [book. 1-3], M., 1967-70; Isakovich M.A., General acoustics, M., 1973; Elpiner I. E., Biophysics of ultrasound, M., 1973; Rudenko O. V., Soluyan S. I., Theoretical foundations of nonlinear acoustics, M., 1975; Skuchik E., Fundamentals of acoustics, trans. from English, vol. 1-2, M., 1976; Taylor R., Noise, [trans. from English], M., 1978; Urik R. D., Fundamentals of hydroacoustics, trans. from English, L., 1978; Brekhovskikh L. M., Lysanov Yu. P., Theoretical foundations of ocean acoustics, L., 1982; Hayasaka T., Electroacoustics, trans. from Japanese., M., 1982. I. P. Golyamina.