Sound recording
Sound recording – carried out with the help of special technical equipment. devices fixing sound vibrations (speech, music, noise) on a sound carrier, allowing you to play back the recorded. The real possibility of Z. appeared from 1688, when it. scientist G.K. Schelhammer found that sound is air vibrations. Z.’s first experiments captured sound vibrations, but did not ensure their reproduction. Sound vibrations were usually captured by the membrane and transmitted from it to a pin (needle), which left a wavy mark on the moving sooty surface (T. Jung in England, 1807; L. Scott in France and R. Koenig in Germany, 1857).
The first Z. apparatus, which made it possible to reproduce what was recorded, was developed by T. A. Edison (USA, 1876) and, independently of him, Ch. Cros (France, 1877). It was called the phonograph. The recording was carried out with a needle fixed on a membrane with a horn, the recording medium was first a staniole fixed on a rotating cylinder, and then a wax roller. Z. of this type, in which a sound trace, or phonogram, is obtained using a mechanical. impact on the carrier material (cutting, extrusion) is called mechanical.
Initially, deep notation was used (with a groove of variable depth), later (since 1886) transverse notation (with a sinuous groove of constant depth) was also used. Reproduction was carried out using the same device. Creatures. The shortcomings of the phonograph were the low quality and relatives. the brevity of the recording, as well as the impossibility of reproducing the recorded.
The next step is mechanical. Z. was recorded on a disk (E. Berliner, USA, 1888), initially metal, then coated with wax, and finally plastic. This Z. method made it possible to multiply records on a massive scale; discs with records are called gramophone records (gramophone records). For this galvanoplastic by producing metal. a reverse copy of the recording, which was then used as a stamp in the manufacture of records from the corresponding. plastic material when heated.
Since 1925, recording began to be made using the conversion of sound vibrations into electrical ones, which were amplified with the help of electronic devices and only after that turned into a mechanical one. fluctuations of the cutter; this greatly improved the quality of the recordings. Further successes in this area are associated with the improvement of Z. technology, the invention of the so-called. long-playing and stereo. gramophone records (see Gramophone record, Stereophony).
Records were played at first with the help of a gramophone and a gramophone; from the 30s 20th century they were replaced by an electric player (electrophone, radiogram).
Possible mechanical. Z. on film. The equipment for such sound recording was developed in 1927 by A. F. Shorin in the USSR (the “shorinophone”), first for scoring a movie, and then for recording music and speech; 60 sound tracks were placed along the width of the film, which, with a film length of 300 m, made it possible to record for 3-8 hours.
Along with mechanical Magnetic recording finds wide application. Magnetic recording and its reproduction are based on the use of residual magnetism in a ferromagnetic material moving in an alternating magnetic field. With magnetic sound waves, sound vibrations are converted into electrical waves. The latter, after amplification, are fed to the recording head, the poles of which create a concentrated magnetic field on a moving magnetic carrier, forming a residual magnetic track on it, corresponding to the recorded sounds. When such a recording medium passes the sound reproducing head, an alternating electrical current is induced in its winding. voltage converted after amplification into sound vibrations similar to those recorded.
The first experience of magnetic recording dates back to 1888 (O. Smith, USA), but magnetic recording devices suitable for mass production were created only in the middle. 30s 20th century They are called tape recorders. They are recorded on a special a tape coated on one side with a layer of powder from a material capable of being magnetized and retaining magnetic properties (iron oxide, magnesite) or (in portable models) on a thin wire made of a magnetic alloy. A tape recording can be played repeatedly, but it can also be erased.
Magnetic Z. allows you to get recordings of very high quality, incl. and stereophonic, rewrite them, subject them to decomp. transformations, apply the imposition of several different. records (used in works of so-called electronic music), etc. As a rule, recordings for phonograph records are initially made on magnetic tape.
Optical, or photographic, Z., ch. arr. in cinematography. Along the edge of the film optical. This method fixes the sound track, on which sound vibrations are imprinted in the form of density fluctuations (the degree of blackening of the photosensitive layer) or in the form of fluctuations in the width of the transparent part of the track. During playback, a beam of light is passed through the sound track, which falls on a photocell or photoresistance; fluctuations in its illumination are converted into electric. vibrations, and the latter into sound vibrations. At a time when magnetic Z. had not yet come into use, optical. Z. was also used to fix the muses. works on the radio.
A special kind of optical Z. – Z. on film with the use of sound-optical. modulator based on the Kerr effect. Such a Z. was carried out in 1927 in the USSR by P. G. Tager.
References: Furduev V.V., Electroacoustics, M.-L., 1948; Parfentiev A., Physics and film sound recording technique, M., 1948; Shorin A.F., How the screen became a speaker, M., 1949; Okhotnikov V.D., In the world of frozen sounds, M.-L., 1951; Burgov V. A., Fundamentals of sound recording and reproduction, M., 1954; Glukhov V. I. and Kurakin A. T., Technique of sounding the film, M., 1960; Dreyzen I. G., Electroacoustics and sound broadcasting, M., 1961; Panfilov N., Sound in film, M., 1963, 1968; Apollonova L. P. and Shumova N. D., Mechanical sound recording, M.-L., 1964; Volkov-Lannit L. F., The Art of Imprinted Sound, M., 1964; Korolkov V. G., Electrical circuits of tape recorders, M., 1969; Melik-Stepanyan A. M., Sound recording equipment, L., 1972; Meerzon B. Ya., Fundamentals of electroacoustics and magnetic recording of sound, M., 1973. See also lit. under the articles Gramophone, Gramophone record, Tape recorder, Stereophony, Electrophone.
L. S. Termin, 1982.
