ARCHITECTURAL ACOUSTICS IN THE USSR

N. N. Andreev, V. S. Grigoriev, I. G. Leizer,
L. D. Rozenberg, B. D. Tartakovsky

Among the fields of knowledge that arose in our country after the Great October Revolution must be included architectural acoustics as well; before the revolution it practically did not exist.

The few scattered articles on various questions of architectural acoustics that were published in Russia before the revolution are not independent works and are of no interest. The first years after the revolution, accompanied by intervention and burdened by the economic difficulties left to us as a legacy by the tsarist regime, likewise did not favor the development of architectural acoustics in our country; a revival in this field began only in connection with the first five-year plan, which set before the country major tasks of highly varied content, including architectural-acoustic tasks, naturally arising from the requirements of the planned construction of public and service buildings. It is therefore worth looking back at the path we have traveled, assessing the results obtained, and trying to formulate the further lines of development.

It was for this purpose that we compiled the present review, which, we hope, will be useful to the historian of Soviet science, but which we ourselves do not consider definitive; for this we had neither the time nor, perhaps, sufficiently complete materials. We therefore ask readers to send us their comments and additions through the editorial office.

In the course of the work we consulted a number of persons working in this field; to all of them we express our sincere gratitude.

ROOM ACOUSTICS

Interest in room acoustics is not new: it already occupied architects and scholars of antiquity, and since then this interest has grown continuously, especially in connection with the constantly emerging,

sometimes intolerably poor acoustic quality of large rooms. An example of such an acoustically unsatisfactory space is, for instance, Cologne Cathedral (begun in 1248 and completed in the nineteenth century), in which the reverberation lasts about 10 seconds, as a result of which at any considerable distance from the preacher it is impossible to make out almost a single word. Another example of very poor acoustics was the Cathedral of Christ the Saviour, which in prerevolutionary times stood on the site now intended for the Palace of Soviets. Alongside these there were also rooms that were extremely successful acoustically, for example, the former “Noble Assembly,” now the House of Unions.

To single out from the chaos of sound phenomena arising in a room where speech or music is heard those which determine the sound qualities of the room proved not easy. This was achieved only in 1898 by the American professor of physics W. C. Sabine, who clarified the concept of reverberation and established the connection of reverberation with the acoustic qualities of a room and with the parameters that chiefly determine these qualities. However, the significance of Sabine’s work was not appreciated at once; only gradually did it penetrate the circles of architects and scholars, and only in the first decade of the twentieth century did it receive sufficiently broad recognition. Therefore it will be correct to date the beginning of modern architectural acoustics to 1898.

Let us now turn to the development of architectural acoustics in our country. Interest in it in prerevolutionary Russia undoubtedly existed, but, as far as we have been able to establish, only among architects and builders1,2,3,4,5,6,7,9. This is clearly seen from the list of works cited in our (probably incomplete) bibliography. Interest in architectural acoustics among physicists was very slight; we found mention of architectural acoustics only in V. D. Zernov’s survey (1918)10, in the following phrase: “It is known that, when an auditorium or concert hall is being constructed, it is very difficult to foresee in advance what the acoustics of this room will be. If the hall does not prove successful acoustically, then, by regulating the time of reverberation (by placing special resonators in the hall*) or, conversely, curtains that absorb sound, it is evidently possible to correct this deficiency.”

The needs of the reviving country—the construction of radio-broadcasting studios and large rooms for public use—already from 1920 posed before Soviet physics a number of tasks interesting not only in their applied significance but also from the point of view of physics; from this time modern architectural acoustics in our country begins.

The first works on architectural acoustics in the Soviet Union date from 1920–1921. Their initiator and director was

*) Here we encounter an idea later developed in detail by N. Rzhevkin.

S. Ya. Lifshits. The work was conducted at the Physics Institute of Moscow University, at the State Institute of Musical Science, with the participation of students of the architectural faculty of the Higher State Artistic and Technical Workshops (VKhUTEMAS). In the course of this work S. Ya. Lifshits built the first apparatus in Russia for measuring reverberation time, and measurements were made of a number of Moscow theater and concert halls ^{12,15,16}.

In 1923 a synopsis was issued (on a hectograph) for the course in architectural acoustics taught by S. Ya. Lifshits at VKhUTEMAS ^{13}. This was one of the first (and perhaps the first) textbooks in the world on architectural acoustics; despite its imperfections in the interpretation of the physical side of architectural-acoustic phenomena, this and the subsequent books by S. Ya. Lifshits played a significant and useful role in the development of our architectural acoustics.

At approximately the same time (15 September 1922), the Moscow radiotelephone station began operation ^{11}. The room from which the radio broadcast was made was treated with velvet carpets. This was the first Soviet radio studio; its acoustic finishing with material was carried out by I. A. Zeitlenko, who worked essentially empirically.

The subsequent work of S. Ya. Lifshits was directed toward determining the optimum reverberation. Making certain assumptions concerning the psychophysiology of sound perception, Lifshits obtained an analytical dependence between the volume of a room and the optimum reverberation ^{17,18,25}.

The two constants entering into this equation he determined on the basis, on the one hand, of the experimentally established optimum reverberation in small rooms and, on the other hand, of the reverberation time of the Column Hall of the House of Unions in Moscow (considering it perfect in acoustic respect). The formula thus obtained gave fairly good agreement with the results of an experimental survey of a number of halls.

This work was first reported on 15 February 1923 and was one of the early works on this subject. After this there came a lull in architectural acoustics, which continued until 1929–1930. During this interval there appeared only the second edition of S. Ya. Lifshits’s Course of Architectural Acoustics ^{28}.

During the first Stalin Five-Year Plan, intensive construction began of broadcasting stations and sound motion-picture theaters and film studios. A number of popular articles on room acoustics began to appear in the literature. Soviet architectural acoustics began to develop in various branch laboratories. After a series of organizational reorganizations, the center of studio acoustics became the Acoustics Laboratory of the Scientific and Technical Administration of the People’s Commissariat of Posts and Telegraphs (NKPiT) (I. G. Dreizen, S. T. Ter-Osipyan, Yu. M. Sukharevsky).

With the aid of more advanced measuring equipment, a survey of a number of Moscow studios was carried out; moreover, not only the reverberation time was measured, but also its frequency dependence, the shape of the sound-decay curve, and the uniformity of the sound field in the studios.

As a result of a series of experimental works carried out in 1931, Guidelines for the Design and Operation of Radio Studios were issued^60.

In 1930 two works by M. V. Machinsky appeared^42, ^43, devoted to the theory of reverberation, in which he attempted to obtain a reverberation formula by a method that represented something intermediate between the usual statistical theory and an exact wave treatment. However, owing to their complex and cumbersome presentation and to a number of insufficiently justified assumptions, these works did not influence the further development of architectural acoustics, although they contain a number of interesting ideas. The beginning of work on architectural acoustics at the Leningrad Electrotechnical Institute named after V. I. Ulyanov-Lenin (LETI), the Central Radio Laboratory (CRL, Leningrad), the Acoustics Laboratory of the All-Union Electrotechnical Institute (VEI), the State Physico-Technical Institute (GFTI, Leningrad), the Kiev film studio, and several other places also dates to this time.

In all the laboratories mentioned, measuring apparatus was being built, methods of architectural-acoustical measurement were being developed, and experimental surveys were being conducted of existing and newly constructed radio studios, sound cinemas, and sound-film studios.

At the end of 1931, the First All-Union Acoustics Conference was established at the GFTI, where for the first time the majority of persons working in the field of architectural acoustics met^57, ^58, ^59. In addition to reports on current work, several original works in the field of architectural acoustics were presented at the conference. Thus, S. Ya. Lifshits^72 extended his formula for optimal reverberation to the case of radio studios and sound cinemas. L. D. Rozenberg^76 introduced the concept of total reverberation, understanding by this the process of sound decay in two rooms connected to one another by a one-way electroacoustic link. Examples of such rooms may be a film studio—a cinema, a radio studio—a room for listening to radio broadcasts, etc. Formulas were derived showing the nonexponential character of the total reverberation and its dependence on the reverberations of the primary and secondary rooms. The work mentioned, being the first in this field (a similar American work by Hill was published half a year later, in the July issue of the Journal of the Acoustical Society of America for 1932), served as an impetus for a whole series of subsequent studies. Here one should mention the works of M. A. Sapozh-

Kov[^78][^79][^106][^107] (1932–1934), who, independently of Eyring, considered the case of two rooms with acoustic coupling; A. I. Indlin and A. N. Kacherovich[^110][^111] on optimum conditions in sound-film studios and sound cinemas (1935); and, finally, a note by L. D. Rozenberg[^169] on the perception of total reverberation in ordinary and stereophonic transmission.

The next line of work developed in the investigations of Soviet acousticians is the aggregate of important questions concerning the relation between the physical parameters of sound and the character of its perception by the human ear, especially under conditions of single-channel transmission. This includes the works of S. Ya. Lifshits[^89]–[^91], concerning the so-called duration and loudness of a sound impulse. In these works it was shown experimentally that the ear is a ballistic instrument, integrating the intensity of sound within certain limits. Proceeding from these results, S. Ya. Lifshits obtained the frequency dependence of the optimum reverberation, satisfactorily agreeing with experimental observations[^98][^131][^132].

Somewhat later, after the appearance of the works of G. Bekesy, in which it was proved that for a room with a volume of up to \(2000\ \mathrm{m}^3\) the optimum reverberation should not depend on frequency, S. Ya. Lifshits[^163] made an experimental comparison of two rooms, each of \(100\ \mathrm{m}^3\) volume, equipped according to Bekesy and according to Lifshits. Listening tests, carried out by a panel of musician specialists, showed a slight advantage in the choice of the frequency dependence of optimum reverberation according to Lifshits.

The great development of radio broadcasting, the growth in the number of studios, and the diversity in the character of radio transmissions raised a number of questions connected with the proper operation of studios. To study these questions, a research group was created at the Moscow Radio Engineering Center; the work of this group was set forth in the book by A. V. Rabinovich and G. A. Gol'dberg, Radiophony[^113]. A. V. Rabinovich investigated the so-called “distance effect” in radio studios[^104], which consists in the fact that, when the sound source is moved away from or brought closer to the microphone in a radio studio, the listener receives an impression different from that obtained in direct listening. G. A. Gol'dberg[^218] studied “effective reverberation” in radio studios, which is one of the principal causes of the distance effect. He oscillographed the curves of decay of sound energy in radio studios at various distances between the sound source and the microphone, and showed that under such conditions the sound-decay curve consists of two parts: a jump caused by the cessation of the arrival of direct sounds, and an exponential decrease caused by the reverberation of the studio. As the distance between the sound source and the microphone increases, the magnitude of the jump decreases, and the general course of the curve approaches the classical case.

In the work of I. G. Dreizen^158, the change in the ratio of the energies of direct and reverberant sounds necessary for a listener (through a microphone) to perceive a change in timbre was investigated. This quantity proved to be equal to 6 db for speech and singing.

The following interesting works in this direction were carried out by G. A. Goldberg and S. T. Ter-Osipyants in the Central Laboratory of Gramplasttrest, organized in 1934 and subsequently transformed into the Central Laboratory of the House of Sound Recording, and then into the All-Union Scientific Research Institute of Sound Recording (VNIIZ). These institutions were created and brought to a high level by I. E. Goron. A brilliant organizer and a major engineer with great knowledge and experience in practical acoustics, he played, and continues to play, a major role in the development of sound recording in our country; many very successful solutions of architectural-acoustical problems that arose during the construction of the House of Sound Recording belong to him.

The works of Goldberg and Ter-Osipyants concerned the perception of reverberation. In the first part of the experiments^120, the perception of exponentially decaying sound impulses was studied. The results of comparing impulses with different initial loudness levels showed that the perception of the rate of decay (i.e., reverberation) does not depend on the initial level and that the threshold for distinguishing reverberation is proportional to the reverberation itself. These results do not confirm the hypothesis of S. Ya. Lifshits, advanced by him to explain the dependence of optimal reverberation on the object.

In the second part of the experiments^156, G. A. Goldberg and S. T. Ter-Osipyants compared by ear two reverberation processes—an ordinary one and one with a jump, produced as a result of switching off the source of direct sound rays. By comparison the observer established the reverberation (without a jump) that gave the same auditory impression as the process with a jump. It turned out that neither the rate of decay, nor the same integral effect of the decaying impulse, nor the same duration of sounding are criteria by which the ear establishes the similarity of the two processes. From a large number of trials it was possible to establish that two processes decaying in different ways sound identical if they pass through the same level at a time 0.1–0.3 sec after the beginning of decay. This proposition is valid in the case where the magnitude of the jump does not exceed 17 db. Otherwise, the process with a jump cannot be made similar (by ear) to the normal decay process.

In the third part^183, decaying processes of different frequencies were compared. In this connection, the independence of the perception of reverberation from frequency was established, which refutes the hypothesis of S. Ya. Lifshits and MacNair, advanced by them to explain the dependence of the optimum reverberation on frequency.

Finally, the perceptibility of an impulse against the background of the main decay curve of sound of the same frequency was tested.

It must be regretted that these works have still not been published and therefore are known only to a comparatively small circle of acousticians.

In rooms in which sound is reproduced electrically, the character of the sound is affected not only by the properties of the room but also by the properties of the sound source, in particular its directivity. Therefore, naturally, the question arose of criteria for evaluating the acoustic properties of sound-reinforced rooms. V. V. Furduev^172,173 proposed as such a criterion the so-called “acoustic ratio,” which is the ratio of the energy density formed by the totality of all reflected waves to the density of sound energy in the direct wave. However, subsequent experiment did not confirm this proposition. A. V. Rabinovich^243 and Yu. M. Sukharevskii^305 proposed using for this purpose a refined “acoustic ratio,” or reverberation-interference factor, which is the ratio of all “harmful” reflections to the useful ones. In this case the useful reflections are considered to be those that arrive at the listener’s ear with a delay of no more than 60 m/sec (including the direct sound), while everything that arrives with a greater delay is harmful.

Experimental studies have in general confirmed the existence of a correspondence between this quantity and speech intelligibility, although the question cannot yet be considered definitively resolved.

A. V. Rabinovich^197 studied the question of the perceptibility of an echo and its influence on speech intelligibility. He experimentally determined the conditions for the perceptibility of an echo in the open air, i.e., in the absence of any other reflections besides the one under investigation, and the percentage change in articulation arising in the presence of an echo.

Another line of work, developed by Soviet acousticians, belonged to the field of purely physical processes connected with sound fields in enclosed rooms. The earliest should be considered the article by the well-known Russian art historian V. V. Stasov^1 on “voice vessels,” i.e., vessels that were built into the walls of churches, forming small spaces connected with the main volume of the room.

In our time this question was studied by S. N. Rzhevkin^139,141,196,243 and I. Verkhovskaya^119.

The earliest is the work of I. N. Verkhovskaya, carried out by her (as follows from the editor’s preface to the collection) in 1932–1933 under the direction of the late P. N. Belikov. In the work itself there are indications that P. N. Belikov himself had dealt with this question as early as 1926.

In this work, apparently for the first time, it was not only stated but also experimentally proved that resonators (in particular, the voice vessels used in Russian churches of the 11th–17th centuries) can

as increasing the reverberation of rooms, so also decreasing it, and that in most cases resonators were used precisely for reducing reverberation, i.e., as sound-absorbing constructions.

I. N. Verkhovskaya also gives rather interesting information of a historical-archaeological nature. The point is that resonators in churches were used only during the period from the 11th to the 17th centuries. I. N. Verkhovskaya believes that before the 11th century, when churches were built of wood and were small in size, reverberation in them was slight, and there was no need to use special devices for its reduction. This became necessary only when large stone churches appeared.

Beginning with the 17th century, when rich church furnishings appeared, the amount of sound absorption increased, and the need for resonators again disappeared.

S. N. Rzhevkin was the first to examine the sound process in the case of a large volume connected with several small volumes, and showed that the presence of such resonators adjoining the main volume by no means always leads to an increase in the reverberation time, as had previously been supposed. In a whole series of cases, instead of storing sound energy and then returning it to the room, resonators may draw off a certain amount of energy without giving it back, and thus reduce the reverberation time. S. N. Rzhevkin developed these ideas in the form of so-called resonance absorbers; his works in this direction, very interesting and of great practical significance, are presented by him in the survey he himself compiled^402, which is why we have found it possible to dwell on them here only briefly.

Next one should note the works of G. A. Chigrinsky, who unfortunately perished during the blockade of Leningrad. Being an architect and, consequently, not possessing the methods usual for a physicist, he nevertheless succeeded in producing a number of original works on the ray treatment of questions of reverberation. By a method first proposed by Picker and Kosten, consisting in unfolding all successive reflections of a sound ray into a straight line (G. A. Chigrinsky^265 came to this method independently), he considered the “pictures of reflections,” as he aptly called them, in rectangular rooms with allowance for the nonuniform distribution of absorption. The results he obtained made it possible to study quantitatively the influence of the ratios of absorption sizes, the influence of the placement of absorbing materials, and the influence of openings in the walls of a room on reverberation. However, the most interesting result was the possibility of quantitatively calculating the reverberation of non-closed spaces.

In his following works^266, ^267 he extended his results to the case of nonrectangular polyhedra that nevertheless fill space.

In his works, Chigrinsky, like all our and foreign researchers before him, proceeded from the assumption that at the point of reception one must sum the energy of sounds arriving as a result of reflection from different directions. In other words, he neglected the phenomena of interference. Apparently, M. V. Machinsky was the first to draw attention to the conditional character of such an assumption in his works mentioned above, but experimental confirmation of this assumption was given by L. D. Rozenberg^371, who investigated the interference field of sources arranged in the form of a rectilinear regular chain. Measuring the distribution of sound pressure at a certain distance from the chain, L. D. Rozenberg showed that in the case of coherent radiation by the elements of the chain, for example with a monochromatic sound, there is indeed obtained a sharply expressed stable interference field, the peaks and troughs in which may differ by 25–30 db. In the case, however, of the radiation of incoherent noise or music, the interference field is practically absent, and the strength of the sound at different points of the field deviates from the mean value by 0.5–1.0 db, which gives the right to perform an energy summation of sound waves arriving from different directions.

In his subsequent works L. D. Rozenberg^368, ^369, ^370 considered fields formed by so-called distributed systems of radiators, understanding by the latter such systems in which the sound field at any point of the space being sounded is created by the sum of sounds arriving from a large number of radiators of the given system. The results he obtained, first, made it possible to approach rationally the design of such distributed systems, and, second, using the method of fictitious sources and replacing the sound process in an enclosed room by an infinite field of fictitious sources, L. D. Rozenberg succeeded in solving a number of problems of architectural acoustics that had not been solved earlier. From the formulas he obtained, the well-known expressions of Millington, Eyring, etc., follow as particular cases. In particular^405, he obtained the following simple rule for the most rational (from the standpoint of obtaining the greatest effect) placement of sound-absorbing material in an enclosed room: the sum of the sound absorptions along each of the three principal directions of a rectangular room must be a constant quantity.

However, the use of the method of fictitious sources is justified only in the case of completely reflecting surfaces, i.e., in practically the least interesting cases. With absorbing surfaces, generally speaking, the field of reflected sounds cannot be represented as originating from a fictitious source. In their fundamental review of architectural acoustics, the American physicists F. Morse and R. Bolt, advocating the wave theory of room acoustics developed by them, even refused to consider all

works based on the method of fictitious sources. But L. M. Brekhovskikh^409,410 showed the groundlessness of such an opinion and gave exact criteria for the magnitude of the error obtained when using the method of fictitious sources. The results he obtained show that in the overwhelming majority of real rooms the application of the method of fictitious sources leads to errors lying within the limits of ordinary engineering calculations, while all derivations and final results are obtained in a form incomparably simpler than when the exact formulas of wave theory are applied.

Several more theoretical works in the same field should also be noted, among which two works by B. P. Konstantinov^227,228 stand out. In them there is considered an effect, previously not taken into account by anyone, of sound absorption by a wall that is solid from the acoustical point of view, caused by thermal conductivity. B. P. Konstantinov, proceeding from Kirchhoff’s theory, shows that, although small, this effect may play a role, for example, in the attenuation of sound in reverberation chambers; along the way the unsatisfactory nature of one of Strutt’s calculations is shown.

Finally, let us note that the earliest work giving a wave theory of the attenuation of sound in a room with absorbing walls is the work of I. G. Dreizen^122.

SOUND ABSORPTION

Naturally, with the general revival of work on architectural acoustics, the question of providing the USSR with sound-absorbing and sound-insulating materials and structures became one of the foremost issues. It is also appropriate here to emphasize that the development of this branch in the USSR was marked by a circumstance characteristic of the science of our country: along with the practical side, the theoretical side of the question also developed, and contact between them was never interrupted. In this field this was determined, in addition to the general tendencies of Soviet science, far removed both from crude empiricism and from scholastic theories, also by the active work of the Acoustical Commission of the Academy of Sciences of the USSR and of acoustical conferences.

The main work developed here in three directions: porous sound-absorbing materials, layered sound-absorbing constructions, and resonant sound-absorbing systems.

A porous sound-absorbing material, the correct interpretation of whose properties had already been given by Rayleigh, absorbs the energy of the sound wave incident upon it as a result of friction in its pores; the vibrations of the solid skeleton itself are not taken into account.

The work on creating Soviet porous sound-absorbing materials was begun in connection with the design of the Moscow Radio House, on the initiative of engineer I. A. Zeitlenok (who died in 1933) in 1932.

In Rosstromproekt, through the efforts of P. V. Lapshin, the material “arborite” (a type of cardboard) was developed. Several studios were treated with trial batches of it. However, owing to its flammability, this material did not come into widespread use. After some time this group of works was transferred to the Central Laboratory of the Gramplasttrest. The principal task of the acoustical department of this laboratory at that time consisted in solving problems that had arisen in connection with the design of the House of Sound Recording. Here (G. A. Gol’dberg, S. T. Ter-Osipyants) laboratory installations were created for investigating sound-absorbing materials.

During the construction of the House of Sound Recording (completed in 1938), a whole series of various domestic materials was used[^171][^199][^200][^201]. Therefore the studios and control rooms of the House of Sound Recording constitute a living museum of domestic sound-absorbing materials.

In 1933–1934 S. P. Alekseev[^206], with the participation of E. V. Kostyrko, developed in the laboratory of the Architectural Institute several successful specimens of sound-absorbing materials, among which granulated plaster (AGP) was used for finishing the Red Army Theater in Moscow.

At this time (1934) similar work began to develop on a considerable scale at the Central Scientific Research Institute of Industrial Structures (TsNIPS). Here V. A. Andrievsky and V. M. Khodarkevich developed a good acoustical plaster; a trial batch of it was manufactured. Sound-absorbing boards were also developed: organite (based on wood raw material) in various external finishes, fibroacoustite (based on wool), and xylolite (based on wood sawdust). Further, one must note the work of N. V. Zasursky[^222], who developed a technology for manufacturing a number of sound-absorbing materials. The TsNIPS laboratory, however, did not confine itself solely to developing the technological process, but carried out the necessary acoustical measurements and dealt with sound-insulating materials with the same seriousness. This work is reflected in the book Acoustical Materials and Their Application, compiled by engineer A. K. Timofeev; unfortunately, the authors who carried out these works are not indicated in it[^269]. In 1938 this laboratory was transferred to the construction of the Palace of Soviets (SDS), whose needs for the development of particularly high-quality sound-absorbing and sound-insulating materials had by that time become quite urgent. In the subsequent years interesting attempts were made to obtain sound-absorbing and sound-insulating materials with an artistic appearance and high sanitary-construction qualities; thus artistic painting on porous plaster, patterned coverings, etc., were successfully tested; noncombustible sound-absorbing boards (foam chamotte[^234][^291], ceramic materials[^212][^234]) of good external appearance were also obtained.

All this work was based on systematic measurements of the sound-absorption coefficient as a function of frequency; corresponding measuring installations were created. [M. S. Antsyferov, K. A. Vital’ (killed in the war), G. D. Malyuzhenets.] We shall speak below about the theoretical interpretation of the process of sound absorption by a porous material.

Finally, let us note the careful work of D. S. Novakhovskaya (State Scientific-Research Institute of the Brick Industry, NKPSM) on the creation of pumice concrete, carried out jointly with the SDS[^211],[^295]; she developed the technological process and studied the sound absorption of pumice concrete; a trial batch of 450 m² was also manufactured and used experimentally.

In parallel with the technological and production developments, and in close contact with them, theoretical works also developed on the sound absorption of both materials and structures. A large part of these works was published in Nos. 2 and 3 of the Proceedings of the Acoustical Commission of the Academy of Sciences of the USSR, which, alongside the Acoustics Bureau of the SDS and the acoustical laboratory of the Physical Institute of the Academy of Sciences of the USSR (FIAN), played a leading role in the study of questions of sound absorption. Since acquaintance with these works is facilitated by the availability of the above-mentioned collections, we shall set out this question without going into detail.

The equations for the propagation of a sound wave in a porous material with a rigid frame proceed from the assumption that the loss of energy is concentrated in the process of viscous friction; hence the known equations of motion, differing from the usual equations of acoustics by the presence of terms proportional to velocity (Darcy’s equations). One may introduce into them a peculiar sound potential and extend them to the case of anisotropy, which is of practical interest (N. N. Andreev[^209a]). However, the question of thermal sound absorption in a porous material remained unexamined; the question of calculating sound absorption by the surface of a material attracted considerable attention from Soviet scientists. The primitive method, accepted in foreign literature, of describing a sound-absorbing material by means of impedance was subjected to just criticism. It was shown that a more exact calculation (practically more complicated) sometimes leads to sharply different results at large angles of incidence (N. N. Andreev and E. E. Lysenko[^209a]). At the present time we also know the conditions of applicability of the primitive method, formulated in the elegant work of L. M. Brekhovskikh[^409],[^410]. Incidentally, let us note that this work also considered another important question—the limit of applicability of geometrical acoustics in problems of architectural acoustics. It must be noted that these fundamental questions have still remained unexamined anywhere outside the USSR.

Let us also note here one more work of a fundamental character—on the influence of the size of a sound-absorbing specimen on the effective

coefficient of sound absorption (A. V. Rimsky-Korsakov and K. V. Struve[^246]). In view of the mathematical difficulties the question was not fully resolved; however, it was shown that the effective absorption coefficient of specimens smaller in size than a half-wave is considerably higher than in the case of an infinitely large specimen—and this has no small practical significance both for the correct interpretation of measurements and for the use of sound-absorbing material in practice.

Since it turns out that, when a sound-absorbing material with small pores is used, it is not possible to obtain large absorption coefficients, while the presence of large pores makes the material unacceptable from the sanitary and construction points of view, here, as has been done abroad as well, a transition began to perforated materials, the use of niches, and so on. All these questions in the USSR became especially urgent in connection with the need for highly absorbing materials for the CDS and with the difficult task of very great sound absorption that had to be achieved in the Large Hall of the Palace of Soviets; we shall speak especially about the latter problem below. This includes the work of N. N. Andreev and E. E. Lysenko, in which the increase of sound absorption of a porous material due to the presence in it of cylindrical pits[^210] is considered, and two works on the sound absorption of niches by V. A. Tsikunov[^264] and M. A. Sapozhkov[^249]. But the works of G. D. Malyuzhinets[^165],[^166],[^192],[^193],[^230],[^231],[^233] should be particularly noted. In these works he first of all investigated the sound conductivity of a rigid sound-absorbing screen, using a fairly rigorous method of calculation proceeding from the wave equation without friction, and also took account of the influence of friction. Here it should be noted, incidentally, that later an entirely rigorous solution of a similar problem (for the case of a circular opening in the partition of a circular concentric tube) was given by Academician V. A. Fock[^361]. Further, G. D. Malyuzhinets considered the case, important for practice, of covering a porous sound-absorbing material with a rigid perforated screen, both lying directly on the sound absorber and with an air layer between them; finally, he also considered the case of co-oscillation of the rigid screen, due to its finite inertia. It may be said without exaggeration that all these works give a very complete—and more complete than the foreign works—picture of the acoustic properties of perforation. It should be added that the experimental study of the properties of perforation was not neglected either; it was carried out mainly in the CDS laboratory under the direction of G. S. Malyuzhinets by Yu. P. Krasheninnikov and others.

A special question arose in connection with the need to obtain almost complete absorption of sound waves on the ceiling of the Large Hall of the Palace of Soviets. Ordinary sound-absorbing materials cannot be used here because of the practical impossibility of increasing their sound-

absorption to the required dimensions, even if one disregards the necessity of an artistically acceptable exterior appearance. A search was conducted for the principle of a “high-quality sound absorber,” and a lively discussion took place (S. Ya. Lifshits, S. N. Rzhevkin, and many others). However, the solution proposed by G. D. Malyuzhinets was recognized as the best. He proceeded from the principle of a multilayer sound absorber, developed in America by Bedell and consisting of a series of sound-absorbing curtains separated by air gaps. But Bedell’s sound absorber had been constructed purely empirically, and it remained unclear how large the limiting sound absorption was that could be obtained by this method while maintaining dimensions reasonable from a constructional point of view. G. D. Malyuzhinets gave an elegant theory of such an absorber and also developed methods for calculating it, which made it possible to find the optimal parameters; it proved possible to obtain almost complete sound absorption even at fairly low frequencies.

The agreement of the theory with the experiment, which was carried out in the SDS laboratory by the method of Tuma’s tube, was quite complete. But it was not possible to proceed to testing a piece of the ceiling of the Grand Hall—to determine how much the mounts actually needed would affect the calculated sound absorption—because of the outbreak of the Patriotic War.

The third direction in the development of sound-absorbing materials of both medium and high efficiency was determined by the work of S. N. Rzhevkin and his collaborators. A survey by S. N. Rzhevkin, published in this same journal^420, is devoted to this question.

SOUND REINFORCEMENT

Before the advent of radio broadcasting, architectural acoustics considered only the conditions for the perception of the sound of natural sound sources in rooms of the usual type or in special rooms—auditoriums.

The requirements of radio broadcasting radically changed the situation. Despite the fact that, in the radio-broadcasting chain, performance takes place in a studio, while reproduction takes place in an arbitrary room, nevertheless the radio-broadcasting path should in principle be considered as a sound-reinforcement path. The radio-broadcasting path, considered as a whole, is identical in its functional purpose with the “recording—sound reproduction” path, for example in gramophone recording.

This new element—the perception of sound by electroacoustic devices, then amplification and reproduction by means of electroacoustic devices—entered somewhat later both into the practice of using lecture rooms and, finally, into stage practice. It may be said that sound-reinforcement technology revolu-

ARCHITECTURAL ACOUSTICS IN THE USSR

...“architectural acoustics,” and at the present time it is hardly conceivable to design a large auditorium or theater without taking into account the use of sound-reinforcement systems. Moreover, sound-reinforcement technology now possesses means for correcting the acoustic defects of a room, which open up entirely new prospects for architectural acoustics.

At the first stage in the development of Russian architectural acoustics, the greatest interest was aroused by those aspects of acoustic phenomena in an enclosed space that determine the perception of speech and music under direct perception of the sound, i.e., when the listener is in the same room as the lecturer or performer. Thus, the architectural acoustics of ordinary small lecture-type rooms and the architectural acoustics of theater spaces were studied. In doing so, the work was based on the concepts put forward at the end of the last century by Sabine. In Soviet times this period is associated mainly with the works of S. Ya. Lifshits ¹²,¹³,¹⁵,¹⁶, dating from 1922–1926.

The process by which sound-reinforcement technology penetrated acoustic practice affected the development of Soviet architectural acoustics to a considerably greater degree than it affected the development of architectural acoustics abroad. From the very beginning, Soviet architectural-acoustic research was closely connected with the requirements of radio broadcasting and subsequently with the requirements of sound reinforcement. In the works of Soviet authors, the ideas of integrated design of the architectural-acoustic properties of rooms in which sound is perceived and reproduced, and of the corresponding elements of the sound-reinforcement system, were pursued most clearly and actively.

The impetus for the development of sound-reinforcement technology was provided not only by radio broadcasting, but also by sound cinema. For broadcasting studios, filming ateliers, and sound motion-picture theaters there were not and could not be those classical prototypes that existed in the field of designing lecture halls and theaters. In a number of cases it was necessary to adapt premises that were known to be poorly suited, and to obtain satisfactory acoustic data. All this required a theoretical analysis of the architectural-acoustic properties of rooms in relation to the properties of electroacoustic systems. As a result, the passive, cognitive method of architectural-acoustic investigation of rooms was gradually replaced by an active method of creating rooms with the required acoustics.

Here one may indicate three lines of development. The first—the “studio” line—deals with natural sound in a specially designed room (studio, atelier) when electroacoustic sound receivers are used, while subjective perception takes place in other, heterogeneous rooms possessing arbitrary acoustic qualities. This case occurs in radio broadcasting. The second, typical of sound cinema, envisages...

...involves the reception of sound from natural sources in a specially equipped room (studio, atelier) and the reproduction of sound likewise in a specialized room—the auditorium of a movie theater. Here we already have elements of stereophony, since it is necessary that the sound image be localized by the spectator in the same way as the visual one. Finally, the third provides for the presence, in a specialized room (auditorium, lecture hall), of natural sound sources (speaker, musical instruments, singers or actors), and alongside these a system of electroacoustic sound receivers and loudspeakers ensuring the required loudness level over the entire area of the audience seating. In the simplest cases—in amplifying the speech of a speaker—the requirements for sound quality and for stereophony may be lowered, but in the most highly developed variant a high degree of accuracy of reproduction is required, together with the attainment of the fullest possible stereophonic effect. The case of gramophone recording is close to that of radio broadcasting, since the recording is carried out in a studio, while reproduction is usually effected by a broadcast receiver or a mechanical gramophone in a room not specially adapted for the purpose.

It is quite natural that the demands of practice compelled various organizations engaged in radio broadcasting, sound recording, or sound reproduction to solve problems of architectural acoustics as applied to studio premises and subsequently to mass auditoria of the sound-motion-picture type. Therefore the centers of practical and, in part, theoretical work in the field of architectural acoustics connected with the artificial perception and reproduction of sound material became broadcasting organizations, research and educational institutes of the motion-picture industry system, film studios, and organizations of the gramophone industry. The relatively high sound powers, many times exceeding the ordinary power levels used earlier for musical accompaniment of motion pictures, and especially the requirements of speech intelligibility, led from the very beginning to the adoption of new initial points of view in designing the auditorium of a movie theater. The inadequacy of reverberation time as a qualitative criterion for evaluating the acoustics of a room became apparent at once, but at first considerations of geometrical acoustics, taking into account the directivity of loudspeakers, were chiefly invoked.

In the first period of the development of Soviet radio broadcasting—approximately from 1922 onward—a number of works, both survey and original, were published, dealing mainly with the equipment of broadcasting studios and the conditions of their operation ^{11,14,21,26,27}. At the same time a considerable part of the works was devoted to considering the studio as a room treated with sound-absorbing materials, i.e., it treated the question from the standpoint of architectural acoustics proper. Gradually more and more attention began to be paid to the radio studio as an element

of a broadcasting chain, i.e., as a room in which the perception of the sound of natural sound sources is carried out with the aid of electroacoustic sound receivers (microphones). Naturally, at the first stage the question is posed of the “operation of the microphone” in the radio studio, but in the end the conception of the studio as an element of the electroacoustic sound-amplification chain becomes generally accepted. The center of research work in this period is the Scientific Research Institute of Communications of the Scientific and Technical Administration of the NKPiT. Research work on the equipment and operation of studios is also being carried out by the technical personnel of a number of the Union’s main radio stations. To 1931 belong the publication of a number of significant works in the collections of the NTU NKPiT \(^{50,60,61,63}\). Here mention should be made of the work of I. G. Dreizen \(^{50}\), where, on the basis of experimental material, it is shown that averaged acoustic parameters are insufficient for assessing the quality of a studio, since the final result depends essentially on the placement of the performers and, in particular, on the placement of the microphone. To this same period belong the investigations of Yu. M. Sukharevsky \(^{61,62}\), concerning the work of performing ensembles in radio studios. Among the substantial works summarizing the existing experience are also the books by I. G. Dreizen, Electroacoustics in Broadcasting \(^{87}\), Radiophony by A. V. Rabinovich and A. G. Goldberg \(^{86}\), and Broadcasting Studios and Microphones by A. V. Rabinovich and Yu. M. Sukharevsky \(^{222}\). In the last work, considerable attention is devoted to the assessment of “optimal reverberation” as a criterion of studio quality, and to the assessment of microphones of various types from the point of view of the final quality of sound.

The circumstance that, in a typical broadcasting chain, reproduction of sound is carried out in a room with indeterminate, random acoustic data imposes a certain imprint on works devoted to the acoustics of broadcasting studios. The studio is regarded more or less as an isolated object, and qualitative assessments always suffer from a certain a priori character. The situation is substantially different in the recording and reproduction of sound in sound cinematography. Here we have, in essence, a single chain, which includes two architecturally and acoustically treated rooms and which must be subject to unified quality standards. This circumstance, clearly realized already at the very beginning of work in the field of sound cinema in the USSR, led to the further fruitful development of the conception of a combined assessment of the architectural-acoustic properties of the initial and final rooms of the chain (i.e., the studio and the auditorium) and of the electroacoustic system connecting them. The question of the total reverberation in the recording and reproduction of sound was considered by L. D. Rozenberg already in 1932 \(^{76}\). In this work, for the first time, the question was clearly posed of the inapplicability of the usual architectural-acoustic qualitative

criteria (standard reverberation, optimal reverberation) for assessing the quality of rooms associated with the recording–reproduction chain.

In connection with the development of sound cinema in the USSR, around 1929 new centers of scientific research work arose in the field of room acoustics and the acoustics of sound amplification. Research work was conducted both in scientific research institutions engaged in the development of sound-recording and sound-reproduction systems (the All-Union Electrotechnical Institute, the Scientific Research Cinema and Photo Institute, and others), and in educational institutes of the cinema-industry system, and, finally, in the laboratories of the leading film studios.

Some of the published works (chiefly the works of A. I. Indlin and A. G. Kacherovich[^110],[^126]) are based on the same conception that was developed in the above-mentioned work of L. D. Rozenberg, i.e., they consider the question of the necessary total power of acoustic radiators in a motion-picture theater auditorium and of the optimal ratios between the reverberation times in the studio and in the auditorium. An essentially new conception was introduced in 1937 by V. V. Furduyev in the works “Method of Acoustic Design of Auditoria Equipped with Loudspeaker Devices” and “Method of Acoustic Design of Sound Motion-Picture Theaters”[^172],[^173]. Here the principal qualitative criterion adopted is the ratio of the level of direct sound to the level of diffuse sound, and a connection is established between the form of the room (in the part occupied by the audience seats) and the shape of the directional characteristic of the loudspeaker devices. This work marks the beginning of a gradual departure from “reverberation” estimates of the quality of a room equipped with a sound-reproducing or sound-amplifying installation.

The acoustic design of the main auditoria of the Palace of Soviets (the Great Hall, with a seating capacity of 20,000, and the Small Hall, with a seating capacity of 5,000) was a powerful stimulus to an in-depth elaboration—both theoretical and experimental—of questions of sound amplification in large auditoria. From 1938 onward, the acoustics sector of the Construction of the Palace of Soviets became one of the centers of work in the theory of sound amplification in connection with architectural acoustics. Until that time, sound amplification had been considered chiefly as an auxiliary means for correcting the vocal qualities of a speaker and, in certain cases, for correcting defects of an auditorium. In designing the main auditoria of the Palace of Soviets, Soviet acoustics for the first time encountered the acoustic design of rooms in which sound-amplification systems played a decisive role.

The state of the question of sound amplification in the Great Hall of the Palace of Soviets as of 1939 is elucidated in A. V. Rimsky-Korsakov’s work “A Critical Survey of Methods of Sound Amplification in Very Large Rooms”[^245]. A great theoretical, experimental, and pro-

The design material obtained by the acoustics sector of the Construction of the Palace of Soviets and by the acoustics laboratory of the CDS in the period from 1937 to 1941, unfortunately, still remains unpublished, or, if published, only in part. This compels us to dwell somewhat more fully on the examination of the work of the Construction of the Palace of Soviets in the field of sound reinforcement.

The Small Hall of the Palace of Soviets, despite its unusual dimensions, is essentially an auditorium of the ordinary type, i.e., it has a stage opening, a more or less pronounced stage box and forestage, and so on. Therefore the sound-reinforcement installation of the Small Hall could be a frontal three-channel stereophonic sound-reinforcement system. By contrast, the Large Hall—with its circular form, high dome, and round stage platform—is wholly unusual both in form and in dimensions, which makes it impossible to apply here any trivial solution for a sound-reinforcement system. The dual purpose of the Large Hall—as an auditorium for meetings, which presupposes a symmetry close to frontal (when the speaker is located in the sector of the presidium), and as a theater auditorium with circular symmetry—made it necessary to duplicate the sound-reinforcement systems. The additional requirement of the “invisibility” of the loudspeaker devices, i.e., the complete architectural masking of the loudspeakers and their merging with the interior of the hall, made the task still more difficult.

The two main concepts chosen by the acoustics sector of the CDS in designing the sound-reinforcement systems are briefly described in the above-cited work of A. V. Rimsky-Korsakov. The first envisages the use of concentrated group sound sources, located at a considerable height (at the level of the last rows of the amphitheater) above the round stage platform, in order to create a five-channel stereophonic system with circular symmetry. Speech reinforcement was to be carried out with the aid of concentrated (also group) sound sources located frontally in the area of the presidium. The second concept envisaged, while abandoning stereophony, the use of small-sized loudspeakers distributed over the entire area occupied by the spectators’ seats. Such a sound-reinforcement system, according to the accepted terminology, is defined as a “distributed” sound-reinforcement system. The first concept was further developed by V. S. Grigoriev; the second, proposed by N. N. Andreev, was developed by L. D. Rosenberg and B. D. Tartakovsky347,357,36,371,374.

Each of these solutions gives rise to its own difficulties. The basic question here is the correct localization of the sound image—in the first case, with the actual sound sources placed high up (since the natural sources are of no significance for the greater part of the audience), and in the second case, with the sound of the loudspeakers “spread out” over the area of the spectators’ seats—

... Tests conducted by V. F. Natarov235, 236, 293 showed the possibility of correct and stable localization of the sound source for displacements in the frontal plane and a significantly lower accuracy for displacements in depth; the question of the divergence threshold for displacements in the sagittal plane was left open in these works. In experiments with a distributed system, the divergence threshold was determined by the test method when demonstrating a sound motion picture (L. D. Rozenberg and B. D. Tartakovsky348, 360, 374); the experiments showed sufficient stability of the “fusion” of the visual image with the sound. In this connection, of course, one must take into account the large scale of the image on the screen, which facilitates “fusion” and increases the divergence threshold. However, the question of the localization of sound sources from the standpoint of sound-reinforcement technique still cannot be regarded as finally resolved.

The properties of distributed systems of sound sources have been investigated both theoretically and experimentally. The results of these investigations are reflected in a number of works by L. D. Rozenberg and B. D. Tartakovsky mentioned above. Theoretical calculations, based on the assumption of incoherence of the radiation of the individual sources, agree well with the experimental results obtained with speech and musical sound material371. Sufficient uniformity of the sound field can be obtained even with a relatively sparse arrangement of sources. The necessary density of loudspeaker placement is determined mainly by the requirement that the overall sound be continuous, i.e., that the sound of distant sources be perceived as “pseudoreverberation” and not as a repeated echo. The use of a distributed system of sound sources makes it possible to obtain good intelligibility with relatively small sound absorption in the room, and also reduces the danger of feedback with the speaker’s microphone. A negative property of the system is the above-mentioned pseudoreverberation, which, however, under the conditions of the Grand Hall of the Palace of Soviets, which has no natural reverberation, may also prove to be a positive factor.

The investigations carried out, however, do not yet provide a basis for a final choice of a distributed sound-reinforcement system for the Grand Hall of the Palace of Soviets, since, owing to the low directivity of small-sized radiators, such a system is characterized by the radiation of a large amount of energy upward. This creates the danger of a disturbing echo from the dome of the hall. Therefore the experiments and calculations performed require further refinement; further investigation is also required of the stereophonic properties of a distributed system with circular symmetry of the auditorium.

It is obvious that, in a room of somewhat unusual shape and large dimensions, the directivity of the radiators included in the sound-reinforcement installation cannot be chosen arbitrarily. The requirements formulated by V. V. Furduyev for the directiv...

tions (see above) refer to rooms of the type of an ordinary auditorium. Yu. M. Sukharevsky^256, 257, 307 showed that satisfactory ratios are obtained in this case when using horn loudspeakers possessing an approximately ellipsoidal spatial directivity characteristic. In doing so, however, the conditions for the simultaneous operation in one room of a group of loudspeakers and microphones were not taken into account, i.e., the results applied rather to the case of sound reproduction and not to that of sound reinforcement. Even with the usual configuration of an auditorium and with frontal stereophony, the problem of sound reinforcement is considerably more difficult than the problem of sound reproduction. In the Grand Hall of the Palace of Soviets the solution of the problem could be found only with the joint design of the auditorium and of the directional properties of the radiators of the stereophonic system. The work of the acoustics sector of the CDS, carried out toward finding methods for creating radiators with directivity characteristics corresponding to the configuration of the Grand Hall (S. A. Makov), although directly related to the architectural-acoustical problem of designing the Grand Hall, still lies rather in the field of electroacoustics, and we cannot dwell on it here in detail.

In connection with the problems of designing the Palace of Soviets there is a series of studies devoted to the operating conditions, in an enclosed room, of the complete sound-reinforcement path. Any sound-reinforcement system provides for the simultaneous presence in the auditorium of sound receivers and sound radiators connected by a common amplifying system. With stereophonic sound reinforcement several such systems operate in the auditorium (in the Grand Hall of the Palace of Soviets, according to the design, five sound-reinforcement systems). Even with the ordinary frontal version of a sound-reinforcement system, when the radiator can be brought forward relative to the front of the arrangement of the sound receivers located in the stage box, and, consequently, when the sound receivers are in the zone of weakened radiation of the loudspeakers, limitations on the degree of sound reinforcement arise owing to acoustic feedback between the loudspeaker and the sound receiver. With stereophonic sound reinforcement these couplings may be not only direct (along one path), but also cross-couplings. An especially difficult problem is the case of stereophony with central symmetry, where the considerable attenuation of the radiation of the system of loudspeakers located above the circular stage platform in the downward direction presents significant difficulties. Here the problem can be solved only by designing special directional sound receivers with reduced sensitivity in the upper hemisphere. We see that a definite architectural-acoustical problem entails a corresponding electroacoustical problem. The theoretical and experimental investigations of Yu. M. Sukharevsky and G. A. Goldberg^306,303,310,325a,325b,92 po-

showed that the question of acoustic feedback between a loudspeaker and a microphone belonging to one and the same sound-amplification system operating in an enclosed room can be reduced to consideration of acoustic feedback between a distributed system of loudspeakers and a microphone located in the field of this system in unbounded space. This concept made it possible to find the limiting possibilities of sound amplification in an enclosed room, though still in an idealized treatment. The same question was considered by I. G. Dreizen and is treated in detail in his course on electroacoustics ^279.

The exceptional dimensions and shape of the Great Hall of the Palace of Soviets brought to the fore two further fundamental questions in sound-amplification technology—the question of artificial reverberation and that of masking echoes. Although even before that time methods for creating artificial reverberation (chiefly by means of the so-called “echo chamber” ^204) had been discussed in the literature, they were considered only from the standpoint of using artificial reverberation as an auxiliary sound effect in radio broadcasting and in motion-picture sound recording. In the Great Hall of the Palace of Soviets, with a sound-amplification system using concentrated group sources, normal reverberation is absent, which makes it necessary to reproduce reverberation artificially. With a sound-amplification system consisting of distributed sources, there is present, as was indicated above, a pseudo-reverberation which, however, is not fully similar to the natural reverberation familiar to the listener and must likewise be supplemented by artificial reverberation. Works devoted to this problem considered reverberators with acoustic feedback and with recording on a carrier. These works, carried out immediately before the Second World War, have still not been published.

Artificial reverberation can also serve as a means of combating discrete reflections (echoes) in large rooms. Experimental works by S. T. Ter-Osipyants and G. A. Goldberg ^260,183 were devoted to this question; the question of the perceptibility of echoes in speech perception was investigated by A. V. Rabinovich ^297 using a test method.

It remains for us to consider only the question of stereophonic sound reproduction and stereophonic sound amplification, in order to complete the survey of works devoted to sound reproduction and sound amplification in connection with architectural acoustics. Studies on stereophonic localization and on stereophonic sound-reproducing and sound-amplifying systems carried out in the system of Construction of the Palace of Soviets were mentioned above. However, stereophony naturally was also of interest in the field of sound recording and reproduction. Here, first of all, the experimental works of I. E. Goron must be noted. Stereophonic experiments with two- and three-channel high-class sound-amplification systems

accuracy of reproduction were carried out by I. E. Goron in 1936 in the Hall of Columns of the House of Unions in Moscow. These works received their further development in the development of a system of three-channel stereophonic recording of sound on a magnetic medium. Already after the Patriotic War (1947), the apparatus developed by I. E. Goron made it possible to carry out a number of stereophonic experiments that demonstrated the operational suitability of the method. In the field of sound cinematography, stereophonic experiments were carried out by M. Z. Vysotskii and V. N. Konoplev180, 181, but only with two-channel sound recording.

We shall not touch upon more specialized questions of sound-amplification technique, for example, questions of compression and expansion of the dynamic range. Despite the fact that the requirements for the dynamic characteristics of the sound-amplification path are most closely connected with the architectural-acoustical properties of the room, consideration of this line of research would lead us too far away from strictly architectural-acoustical questions.

The brief survey given shows that the main line of development of Soviet technical acoustics in this field is developing more and more in the direction of creating methods that make it possible to speak not only of architectural acoustics, but already of architectural electroacoustics. This is especially reflected in the works devoted to an object that is extremely difficult acoustically—the Palace of Soviets. A broad program of test and quantitative experiments, for which the acoustic testing ground of the PDS327 was created, was to provide the qualitative criteria necessary for designing complex sound-amplification systems. This work was interrupted by the war, which diverted the main forces of Soviet acousticians to the solution of other problems.

SOUND INSULATION

As is known, questions of sound insulation and noise reduction in buildings received sufficient scientific and technical treatment only from the beginning of the thirties of our century. Works that had appeared earlier in this field were of a casual character, and their results were unclear and contradictory. The situation was the same with our domestic literature on sound insulation.

In 1931 there appeared the survey work of S. T. Ter-Osipyan63, in which, for the first time in a modern treatment, the questions of sound insulation of buildings were posed, a summary was given of the results of investigations available by that time, and paths were indicated for further scientific and technical research. To 1933 belongs the survey article by M. Ya. Shponkin on the sound insulation of cinemas92, and in the same year there appeared the first original Soviet work by I. G. Rusakov94 on the measurement of sound insulation. In this work are presented the results of measure-

measurements carried out by the author at the Leningrad Electrophysical Institute of the insulation of doors at different degrees of tightness of their closing, as well as of the insulation of special soundproof booths.

For the further development of Soviet research and scientific-technical work in the field of sound insulation and noise reduction, an important role was played by the construction of sound studios and the construction of the Palace of Soviets. In designing the Palace of Soviets, a number of complex problems of its sound insulation arose. The Acoustics Department, with its acoustic laboratory, organized under the Construction Administration of the Palace of Soviets, worked through, among other questions of acoustics, the available scientific-technical material on sound insulation and carried out its own extensive research work in this field. As a result, a methodology was created for designing the sound insulation of the Palace of Soviets, which was of great importance for the development of sound insulation in the USSR. In an article by I. G. Leizer^335^, a brief survey is given of questions of sound insulation in the Palace of Soviets and of the structural solutions adopted in the design.

Turning to a review of the individual problems of sound insulation and noise reduction in buildings that were developed in the USSR, we shall begin with the sound insulation of walls and floors. For developing the measurement methodology, great importance was attached to the study carried out by V. S. Grigor'ev in the acoustic laboratory of the Construction Administration of the Palace of Soviets on the averaging of readings in chambers for measuring sound insulation^328^. In this work, through numerous careful measurements, the characteristics of the sound field in chambers under different methods of excitation (pure tone, warbling tone, noise generator) were clarified, and various methods of averaging readings were investigated. As a result of this study, the possibility was obtained of sufficiently accurate and reliable measurements of the sound insulation of walls and floors. Using this methodology, V. M. Rudnik, in the same laboratory, carried out measurements of the insulation against airborne sound (and, for floors, also against impact sound) of special sound-insulating floors and walls adopted for the Palace of Soviets. The measurements showed the high sound insulation of these structures, which included floating floors and walls among their elements^300,349,350^. L. A. Yakovlev performed measurements of the sound insulation of floors and walls in existing buildings^314,364^.

For measuring the sound vibrations of building structures, the acoustic laboratory of the Construction Administration of the Palace of Soviets, under the direction of M. S. Antsyferov, developed and built electrodynamic vibrometers having a sufficiently uniform frequency response over a wide range of audio frequencies. With the aid of these vibrometers, M. S. Antsyferov, G. A. Surin, and R. E. Gassko investigated the indirect paths of sound transmission in chambers for measuring sound insulation in existing buildings, the sound vibrations caused by the metro in nearby buildings and on the foundations of the Palace of Soviets, and a number of other ques—

of owls ^213,253,254,255,274,303,304,322,324,353. These measurements made it possible to clarify the relation between the noise level in rooms and the vibrations of the enclosing structures. L. A. Yakovlev investigated the propagation of noise through the frame of buildings under impact excitation of floors ^367, as well as the propagation of airborne noise through several rooms interconnected by open apertures ^314.

The question of the influence of the sound absorption of a room on the reduction of the noise level in it was considered in the work of L. D. Rozenberg ^299. By decomposing the sound strength at any point of the room into that produced by the direct sound and the diffuse density of sound energy resulting from random reflections, one can determine the magnitude of the attenuation of noise owing to the presence of sound absorption, since the latter affects only the second component of the sound strength.

In all cases it is meaningful to increase the sound-absorption coefficient to a value of 0.3—0.4, which gives an attenuation of 10—15 db, and only in rare cases is it meaningful to bring the absorption coefficient up to a value of 0.5—0.7.

Measurements of the noise of urban transport, which are of great importance for the sound insulation of buildings, were carried out on the streets of Moscow by S. P. Alekseev. A book by K. N. Shabishev ^268 is devoted to this same question.

Measurements of the noise of the Moscow metro were carried out by S. P. Alekseev ^149. V. S. Kazanskii, working on the investigation of machine noise, conducted a study of the noise of the escalators of the Moscow metro ^281. The Acoustic Laboratory of the Construction of the Palace of Soviets carried out investigations of the noise caused by the metro in nearby buildings ^274,315. These measurements, together with the above-mentioned measurements of vibrations in the same buildings, were performed in order to obtain the data needed in designing the Palace of Soviets, to which the metro station and tunnels adjoin.

The noise of fans, which are the principal and a very powerful source of noise in ventilation installations, is the subject of works carried out at TsAGI by E. Ya. Yudin ^379,91. These works present the results of an experimental investigation, performed by the author, of the noise of fans of various types, and propose “noise characteristics” that make it possible to determine the noise level produced by a given fan under various conditions of its operation.

The Acoustic Laboratory of the Construction of the Palace of Soviets carried out measurements of the noise of ventilation installations in a number of buildings in Moscow ^319,320,321,365,366. These detailed and painstaking measurements provided extensive material on the noise level of fans of various types, its spectral composition, the propagation of noise through air ducts, the noise penetrating into the rooms served by the installations, the effectiveness of various types of silencers, and so on.

A. I. Belov performed a series of studies on the attenuation of ventilation noise. A theoretical investigation of the attenuation of sou—

... in ducts with absorbing walls ^177,178 enabled him to propose a simple formula for calculating such attenuation, which found wide application in the USSR in design practice. A. I. Belov, together with N. D. Fainshtein, also carried out, on commission from the Construction Administration of the Palace of Soviets, experimental work on the study of sound attenuation in air ducts with absorbing walls and with silencers of various types ^214, which provided valuable material for design.

The acoustics laboratory of the Construction Administration of the Palace of Soviets measured the noise of other sanitary-engineering installations as well—for example, centrifugal pumps, garbage grinders, and the like ^3,6,317. The same laboratory carried out measurements of vibrations and noise caused by elevators in buildings ^253,3,8.

A theoretical treatment of the problem, important for the vibration and sound insulation of buildings, of isolating machine installations and apparatus by means of elastic pads was given in the work of I. G. Leizer ^382. This work gives a method for calculating the natural frequencies and free and forced vibrations of the system for any arrangement of the elastic pads, and also gives an estimate of the vibration- and sound-insulating effect thereby achieved (regarding the machine on pads as a system with six degrees of freedom).

Studies of the dynamic moduli of elasticity of materials used for vibration and sound insulation, in the range of sonic and infrasonic frequencies, were carried out by the acoustics laboratory of the Construction Administration of the Palace of Soviets ^275,381.

In conclusion it should be noted that a number of buildings have been constructed in the USSR in which rooms with high sound insulation have been provided. These include, for example, the studio of the Moscow Television Center ^296, the studios of the Moscow House of Sound Recording, the sound-measuring chambers of the acoustics laboratory of the Physics Institute of the Academy of Sciences of the USSR, and others.

MEASUREMENTS

In our country, the need for architectural-acoustical measurements initially arose chiefly in connection with the development of radio broadcasting, during the construction of studios. Therefore the level of measuring technology was sufficiently high. In measurements, amplifying apparatus and electroacoustic transmitters and sound receivers were always used, although at the beginning a subjective-comparative method of reading was usually employed.

The first indications of methods for measuring reverberation are contained in the book by S. Ya. Lifshits ^13,28. Here we have not only a summary of the measurement methods previously used by other authors, but also those improvements (amounting to the use of electroacoustic sound receivers in the subjective method of reading) that were introduced by S. Ya. Lifshits himself.

However, more profound studies appeared when specialized acoustic laboratories began to be created. The creation of reverberation chambers with as long a reverberation time as possible, and their use for studying sound-absorbing materials and structures, as well as anechoic chambers making it possible to imitate the conditions of open space, required the development of new methodological procedures for architectural-acoustic measurements.

In the work of G. A. Goldberg^217, a summary is given of the methods used for measuring reverberation, and a comparative assessment of the accuracy of these methods is also presented. It is interesting to note that the use of electroacoustic radiators, possessing a considerably greater acoustic power than the radiators used in purely acoustic methods of measurement, and undoubtedly much greater than the power of the human voice, made it necessary to introduce refinements into the very definition of the concept of reverberation. G. A. Goldberg investigated the influence of the distance of the measuring microphone from the loudspeaker when measuring reverberation and introduced the concept of “effective reverberation,” excluding the jump in level after the source is switched off that is caused by the cessation of the action of direct sound on the sound receiver.

A systematic analysis of the methods of architectural-acoustic measurements in reverberant and anechoic rooms was given by A. A. Kharkevich^262. He also gives a prospective list of tasks still awaiting solution, despite the progress achieved in this field.

A characteristic feature of the developing Soviet methodology of architectural-acoustic measurements is the striving toward automation of measurement processes. Thus, the work of Z. I. Mityagina^103 is devoted to a description of an automatic reverberometer, developed by the acoustic sector of LETI, which directly records the curve of decay of the sound level in the room under investigation. The advantages of direct recording of the reverberation curve are demonstrated in this work with complete clarity.

In the work of M. A. Sapozhkov^77,79, a review is given of the work of TsRL and LETI in the field of architectural acoustics and, in particular, in the field of methods of architectural-acoustic measurements. A comparative study was carried out of three methods for measuring reverberation—the subjective method, the relay method, and the method of direct recording of the reverberation curve on an oscillograph. As was to be expected, the third method proved to be the best. Measurements carried out in actual rooms showed the inadequacy of the concept of reverberation (including optimal reverberation) for a true characterization of the acoustic data of a room. A. A. Kharkevich^262a gave a systematic analysis of automatic methods used in acoustic and, in particular, in architectural-acoustic measurements.

The second field of architectural-acoustic measurements should be considered to be measurements of sound absorption by the reverberation method and

measurement of sound and vibration insulation. The reverberation method of measuring sound absorption is reduced to measuring the reverberation time in a reverberant chamber, with and without a sample of the material under investigation present in it. Such measurements, using one or another type of reverberometer and most often using oscillographic recording of the sound process, were carried out in a number of laboratories. In particular, mention may be made of the measurements carried out by I. G. Dreizen in the studios of the NKS and elsewhere.

Let us now note how work on architectural acoustics was organized in the USSR, dwelling only on the principal centers of work. There were four of them: the House of Sound Recording, the acoustics sector of the SDS, the acoustics laboratory of FIAN, and the Acoustics Commission of the Academy of Sciences of the USSR. The House of Sound Recording has already been discussed above. The central problem that stimulated the development of full-scale architectural acoustics in the USSR was the acoustics of the Palace of Soviets. For its sake, in 1937 an acoustics sector was created, headed by L. D. Rozenberg; attached to the sector was an acoustic testing ground built by V. S. Grigor'ev—probably the only one in the world and highly advanced in automation and convenience of measurement work. The new building of the acoustics laboratory of FIAN—still not fully completed because of the war, with respect to the finishing of rooms for architectural-acoustic measurements—was designed by S. N. Rzhevkin and I. G. Leizer chiefly for solving the same problems of the Palace of Soviets. All these organizations worked jointly, and their coordinating center was the Acoustics Commission of the Academy of Sciences of the USSR, headed by N. N. Andreev.

BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS

The bibliography lists works relating to the following divisions of acoustics:

a) Spatial acoustics. Reverberation. Geometrical acoustics. Wave theory of acoustic processes in rooms. Sound-absorbing materials and structures.

b) Sound insulation. Sound-insulating structures and materials. Vibration insulation.

c) Sound reinforcement. Methods of sound reinforcement. Directional radiators.

d) Measurements in the field of architectural acoustics. Studies of the perception of sound in rooms.

In compiling the bibliography, in addition to works printed in Russian and in other languages of the peoples of the USSR, use was made of archival materials of the Construction Administration of the Palace of Soviets and of the Scientific Research Institute of Sound Recording. In addition, several popular articles are included which were of some interest in the 1930s, at the beginning of the extensive construction of radio studios and cinemas. Works carried out in Russia but published abroad are also included.

For ease of use, the bibliography is arranged by years.

1861

1. Stasov V. V., Resonators in ancient Novgorod and Pskov churches. Proceedings of the Imperial Archaeological Society, St. Petersburg, 3 (1861).

1873

1. (No author.) Elimination of resonance with the aid of stretched wires. Zodchii (1873).

1890

1. (No author.) Acoustics. Encyclopedic Dictionary, 1, 318, St. Petersburg, Brockhaus and Efron (1890).

1896

1. (No author.) Acoustics. Technical Encyclopedia, 1, 93, St. Petersburg, “Prosveshchenie” (1896).

1900

1. (No author.) On the acoustics of buildings. Zodchii, 3, 81 (1900).

1905

1. Ewald V., Sonority in auditoria. Zodchii, Nos. 50, 51 (1905).

1913

1. Lukomsky G. K., Ancient theaters and traditions in the history of the evolution of the theater building. Author’s edition (1913).

2. Kryson Yu. D., Sound. Encyclopedic Dictionary, 21, 10, St. Petersburg, A. and I. Granat & Co. (1913).

1916

1. Belyaev S. V., Problems of room acoustics. Architectural-Artistic Weekly, Nos. 13–15 (1916). Also appeared as a separate edition, Petrograd, 1916.

1918

1. Zernov V. D., Advances in acoustics over the last 15 years. UFN, 1, 121 (1918).

1922

1. The first Soviet radio studio (Moscow broadcasting station). Telegraphy and Telephony without Wires, No. 16, 684 (1922).

1923

1. Lifshits S. Ya., Acoustics of auditoria. Architecture, Nos. 1–2 (1923).

2. Lifshits S. Ya., A course of lectures on architectural acoustics. Published by the Architectural Institute (1923) (hectograph).

1924

1. Vinogradov K. N., The Brussels broadcasting station. Telegraphy and Telephony without Wires, No. 22, p. 23 (1924).

2. Lifshits S. Ya., Optimum reverberation. ZhRFKhO, physical section, 56, 360 (1924).

1925

1. Lifshits S. Ya., Review of works on architectural acoustics. ZhRFKhO, physical section, 57, 105 (1925).

1. Lifshits S. Ya., Optimum reverberation. Proceedings of the State Institute of Musical Culture, issue 1 (1925).
2. S. Lifshitz, Optimum reverberation for an auditorium. Phys. Rev., 3, 391 (1925).

1926

1. Andreev N. N., Architectural acoustics. BSE, 2, 97 (1926).
2. S. Beljajew, Akustik grösser Räume. Deutsche Bauzeitung, Berlin (1926).
3. Vostryakov V., Radio in England (tape recorder and studios). Radio Amateur, No. 3, 7, p. 140 (1926).
4. Kovalenkov V. I., Method of artificially producing acoustic resonance in rooms, application No. 334 (20 III 1922). Telegraphy and Telephony without Wires, No. 7, p. 234 (1926).
5. Leont’ev K. A., Experimental study of sound diffraction. ZhRFKhO, Physical Section, 58, 211 (1926).
6. Lifshits S. Ya., International standards in architectural acoustics. Report at the Congress of Physicists (1926).
7. S. Lifshitz, M an intensity of sound in an auditorium and optimum reverberation. Phys. Rev., 27, 618 (1926).

1927

1. Baev I. A. and Ridel’ Yu. O., Measurement of the quality of speech transmission by the articulation method. Scientific-Technical Collection of NKPiT, No. 1, Moscow (1927).
2. Delacroix V. E., Materials on radio broadcasting abroad (studios). Telegraphy and Telephony without Wires, No. 8, 680 (1927).
3. Lifshits S. Ya., Course in architectural acoustics. 2nd ed., Moscow, MVTU (1927).
4. El’tsin I., Acoustics. Technical Encyclopedia, 1, p. 424 (1927).

1928

1. Govve and Vudke, Acoustic insulation in residential premises. Construction Industry, No. 6, p. 497 (1928).
2. Subbotin K. P., On booths for telephone call offices. Life and Technology of Communications, No. 1 (1928).

1929

1. Anatol’ev V. I., Problems of acoustics. Acoustic calculation of concert halls, theaters, and lecture auditoria. Odessa (1929).
2. Belov A. I., Acoustic measurements with sound pulses. Telegraphy and Telephony without Wires, No. 57, 572 (1929).
3. Zernov V. D. and Bryantsev P. D., On the question of the sound conductivity of building materials. Proceedings of MIIT, 10, 265 (1929).
4. Krasovskii F. Z., Telephone booths designed by engineer Krasovskii. Life and Technology of Communications, No. 1, p. 13 (1929).

1930

1. Grekov I., Concert halls and halls for sound cinema. Construction Industry, No. 6–7, p. 538 (1930).
2. Enisherlov, Measurement of noise (on the question of acoustics in construction). Construction Industry, No. 6–7, p. 537 (1930).
3. Zeitlenok I. A., Radio studios. Communications Technology, No. 6, p. 16; No. 7–8, p. 13 (1930).

1. Lebedev V. M. Acoustics and electroacoustics in radio broadcasting. Tekhnika svyazi, No. 6, p. 56 (1930).

2. Lifshits S. Ya. Optimum reverberation for sound cinemas. Report at the Congress of Physicists in Odessa (1930).

3. S. Litshitz, Vorlesung über Bauakustik. Verl. K. Wittwer, Stuttgart (1930).

4. Machinsky M. V. On the theory of reverberation of a room having the shape of a parallelepiped. ZhRFKhO, Physical Section, 62, 59 (1930).

5. Machinsky M. V. On the effect of interference on the process of attenuation. ZhRFKhO, Physical Section, 62, 91 (1930).

6. Otsen, Some methods of combating noise in ventilation installations. Stroit. promyshlennost’, No. 6–7, p. 541 (1930).

7. Pasternak S. S. The problem of sound in construction. Sound insulation of parts of buildings and machines. Stroit. promyshlennost’, No. 67, p. 537 (1930).

8. Rabinovich A. V. How to improve audibility in club premises. Moscow, GIZ (1930).

1931

1. Alyoshin V. E. and Khrushchev A. A. Equipment of a broadcasting center. Studio equipment. Radiofront, No. 7–8, p. 459 (1931).

2. (No author.) Berlin radio center. Radiofront, No. 6, p. 371 (1931).

3. All-Union Conference on Questions of Sound Cinema and Radio. Moscow, 1931. Technical Department, No. 4–5, p. 37 (1931).

4. Dreizen I. G. Acoustics of radio studios and methods of studio measurements. Proceedings of the NTU NKPiT, IV, 4 (1931).

5. Dreizen I. G. Work of the electroacoustics laboratory of the NTU. Tekhnika svyazi, No. 1, p. 57 (1931).

6. Dreizen I. G. Universal reverberometer. Proceedings of the NTU NKPiT, 4, 71 (1931).

7. Elkin P. I. Radio-broadcasting equipment of the Radio Corporation (studio-transmitter). Tekhnika svyazi, No. 1, p. 70 (1931).

8. Zeitlenok I. A. A modern broadcasting center. Tekhnika svyazi, No. 1, p. 81 (1931).

9. Lifshits S. Ya. Sound permeability in buildings. (Survey.) Sots. rekonstruktsiya i nauka, No. 2–3, p. 197 (1931).

10. Lifshits S. Ya. Acoustics of buildings and their insulation from noise and shaking. Moscow–Leningrad, GNTI (1931).

11. First All-Union Acoustical Conference, September 27–30, 1931. Review of the work and resolutions. Vestn. el.-tekhn., No. 11–12, p. 477 (1931). (Reports on architectural acoustics: Sapozhkov M. A., Rozenberg L. D., Lifshits S. Ya., Dreizen I. G., Mayer E.)

12. Rusakov I. G. First All-Union Acoustical Conference, September 27–30, 1931. ZhTF, 1, 732 (1931).

13. Rzhevkin S. N. First All-Union Acoustical Conference. Sots. rekonstruktsiya i nauka, No. 2–3, p. 263 (1931).

14. Guidelines for the arrangement and operation of radio studios. Proceedings of the NTU NKPiT, IV, 78 (1931).

15. Sukharevsky Yu. M. On the question of the use of musical ensembles in a radio studio. Proceedings of the NTU NKPiT, IV, 57 (1931).

16. Sukharevsky Yu. M. A musical ensemble in a radio studio. Radiofront, No. 21–22, p. 1273 (1931).

17. Ter-Osipyants S. T. On sound insulation of radio studios. Proceedings of the NTU NKPiT, IV, 37 (1931).

18. Khlamov V. Protection of the new Berlin Radio House from noise. Radiofront, No. 6, p. 372 (1931).

1932

1. Alekseev S. P., Measurements in radio studios at low-frequency units. Tekhnika svyazi, No. 6, p. 15 (1932).

2. Alekseev S. P. and Ter-Osipyants S. T., Equipment and operation of small studios. Tekhnika svyazi, No. 6, p. 11 (1932).

3. Belov A. I., What acoustic laboratories of the Soviet Union are engaged in. ZhTF, 2, 62 (1932).

4. Zeitlenok I. A., Design of radio studios. Tekhnika svyazi, No. 11, p. 40; No. 12, p. 40 (1932).

5. Zeitlenok I. A., Basic principles of designing a radio palace. Radiofront, No. 10, p. 19 (1932).

6. Kaloshin G. K., Equipment of broadcasting centers. Tekhnika svyazi, No. 12, p. 27 (1932).

7. Lifshits S. Ya., Acoustics of the Palace of Soviets. Sots. rekonstruktsiya i nauka, No. 6, p. 206 (1932).

8. Lifshits S. Ya., Reverberation optimum. ZhTF, 2, 136 (1932).

9. S. Lifshitz, Acoustics of Large Auditorium. JASA, 4, 112 (1932).

10. Best dimensions for studios. (No author.) Radiofront, No. 2, p. 73 (1932).

11. Pokrasov A., Radiofication of the Northern Station. Radiofront, No. 20, p. 56 (1932).

12. Rozenberg L. D., Summary reverberation in sound recording and reproduction. ZhTF, 2, 139 (1932).

13. Sapozhkov M. A., Brief report on the work of the Acoustic Department of TsRL and the Acoustic Laboratory of LETI on room acoustics. ZhTF, 2, 143 (1932).

14. Sapozhkov M. A., Remarks on room acoustics. ZhTF, 2, 395 (1932).

15. Sapozhkov M. A., Investigation of the acoustic properties of rooms. Vestnik LETI, No. 1 (1932).

16. Fedunovich V. S., On the question of noises for radio studios. Tekhnika svyazi, No. 3, p. 77 (1932).

17. Evert A., Arrangement of loudspeakers. Radiofront, No. 10, p. 33 (1932).

1933

1. Alekseev S. P., Questions of radio chronicle. Tekhnika svyazi, No. 5, 25 (1933).

2. Alekseev S. P. and Ignatov L. G., Methods of radiofication of industrial premises. Tekhnika svyazi, No. 7, p. 18 (1933).

3. Andreev N. N., Architectural acoustics. Technical Encyclopedia, 22, 183 (1933).

4. Belyaev S. V., Room acoustics. Moscow, Gosstroiizdat (1933).

5. Gol'dberg T. A. and Rabinovich V. A., Radiophony. Moscow, Radiolizdat (1933).

6. Dreizen I. G., Electroacoustics in broadcasting. Moscow, Svyaz’tekhizdat (1933).

7. Lifshits S. Ya., Acoustics of large auditoria. ZhTF, 3, 1062 (1933).

8. Lifshits S. Ya., Two integral laws of perception. Loudness and duration of a sound impulse. ZhTF, 3, 1057 (1933).

9. S. Lifshitz, Zwei Integralgesetze des Hörens. Zeits. f. Phys., 83, 123 (1933).

10. S. Lifshitz, Two Integral Laws of Sound Perception. Relating Loudness and Apparent Duration of Sound Impulses. JASA, 5, 31 (1933).

11. Moshoshkin M. Ya., Installation of an atelier at sound-film factories. Kino-foto-promyshlennost’, No. 2, p. 3 (1933).

1. Rzhevkin S. N., Methods of noise research. In the book The Problem of Studying Noises. Collection of articles edited by S. N. Rzhevkin. Moscow—Leningrad (1933).
2. Rusakov I. G., On the measurement of sound insulation. ZhTF, 3, 388 (1933).
3. Sapozhkov M. A., Remarks on the theory of oscillations of one-dimensional space. ZhTF, 4, 1109 (1934).
4. Sapozhkov M. A., A method and apparatus for studying the acoustic properties of rooms. Kino-foto-promyshlennost’, No. 2, p. 74 (1933).

1934

1. Dreyzen I. G., On the question of calculating sound pressure in the radiation field of an ensemble. ZhTF, 4, 649 (1934).
2. Lifshits S. Ya., Length of sound and the musical optimum of reverberation. ZhTF, 4, 1740 (1934).
3. Lifshits S. Ya., Has architectural acoustics reached an impasse? Arkhitektura SSSR, No. 10, p. 70 (1934).
4. Lifshits S. Ya., The problem of the acoustics of the Palace of Soviets. Arkhitektura SSSR, No. 5, p. 74 (1934).
5. Lyudvig G. D., New developments in the acoustics of public buildings. Arkhitektura SSSR, No. 1, p. 61 (1934).
6. Lyudvig G. D., Building acoustics under the blows of Comrade Lifshits. Arkhitektura SSSR, No. 10, p. 72 (1934).
7. Mityagina Z. I., An automatic reverberograph and its application to the study of various questions in room acoustics. ZhTF, 4, 1575 (1934).
8. Rabinovich A. B., The distance effect in radio studios. ZhTF, 4, 1134 (1934).
9. Rozenberg L. D., Fundamentals of Technical Acoustics. Kharkov (1934). (In Ukrainian.)
10. Sapozhkov M. A., On the question of coupled rooms. ZhTF, 4, 822 (1934).
11. Sapozhkov M. A., On the question of determining optimal reverberation in coupled rooms. ZhTF, 4, 1588 (1934).

1935

1. All-Union Acoustical Conference (2nd, Moscow, 1935). Abstracts of reports. Moscow—Leningrad, Publishing House of the Academy of Sciences of the USSR (1935).
2. Gol’dberg G. A. and Ter-Osipyants S. T., Measurements of reverberation in Moscow halls (the Hall of the House of Scientists and the October Hall of the House of Unions). Report of the State Union Sound-Recording Laboratory (GSЛZ), 1—99—35 (1935). (Unpublished.)
3. Indlin A. I. and Kacherovich A. N., On optimal conditions in sound motion-picture theaters. ZhTF, 5, 928 (1935).
4. Indlin A. I. and Kacherovich A. N., Remarks on the acoustic conditions of synchronized film shooting in an atelier. ZhTF, 5, 939 (1935).
5. Indlin A. I. and Kacherovich A. N., On electrical power in sound motion-picture theaters. ZhTF, 5, 1298 (1935).
6. Rabinovich A. V. and Gol’dberg G. A., Radio Broadcasting. Moscow, Svyaz’izdat (1935), 2nd ed.
7. Rzhevkin S. N., Investigation of articulation and intelligibility of speech in the Moscow Planetarium. ZhTF, 5, 1303 (1935).
8. Rozenberg L. D., Room acoustics. Radio, Nos. 5, 6, 7, 8 (1935). (In Ukrainian.)
9. Sapozhkov M. A., On determining optimal absorption in coupled rooms. Scientific-technical collection of the Electrical Engineering Institute of Communications, No. 15, p. 38 (1935).

1936

1. Andreev N. N., On the sliding of sound along absorbing boundaries. Izv. Acad. Sci. USSR, phys. series, 5, 625 (1936).

2. Noise-proof aircraft cabins. Science and Technology, No. 14, p. 17 (1936).

3. Verkhovskaya I. N., Resonators and their role in room acoustics. Proceedings of the Scientific Research Music Institute of the Moscow State Conservatory. Acoustical Collection, issue 1, p. 46 (1936).

4. Goldberg G. A. and Ter-Osip’yants S. T., Perception of reverberation. Reports of GSLZ, 1—83 (1936). (Unpublished.)

5. Gol’dovskii E. M. and Knorring E., On noise inside an aircraft cabin. Civil Aviation, No. 1, p. 45 (1936).

6. Dreizen I. G., Distribution of sound-absorbing material in a radio studio. ZhTF, 6, 2131 (1936).

7. J. Dreisen, The orientation of the natural acoustics vibrations in room with concentrated absorbents and of anomalous shapes. Techn. Phys. of USSR, 3, 1 (1936).

8. Ipatov L. G., Measurements of absorption coefficients on a corner installation. ZhTF, 6, 2151 (1936).

9. Kazanskii V. S., Modern technology for combating noise. ZhTF, 6, 2200 (1936).

10. Kacherovich A. N. and Indlin A. I., A method for the acoustic calculation of sound cinemas. Moscow, Roskinoizdat (1936).

11. Kel’berer V. P., Myasnikov L. L. and Stotsenko M. P., A simplified method for determining the sound-insulation coefficient of materials. ZhTF, 6, 2145 (1936).

12. Leizer I. G., Acoustic analysis of the drawings of the Music Hall of Rockefeller Center in New York. Reports of SDS No. SP-215 (1936). (Unpublished.)

13. Leizer I. G., Diffraction of sound waves at the colonnade of the Great Hall of DS. Reports of SDS No. SP-231 (1936). (Unpublished.)

14. Lifshits S. Ya., All-Union Acoustical Conference, December 1–5, 1935. Survey of reports. Socialist Reconstruction and Science (1936).

15. Lifshits S. Ya., Optimal frequency characteristic of sound-absorbing material. ZhTF, 6, 2127 (1936).

16. S. Lifshitz, Apparent Duration of Sound Perception and Musical Optimum Reverberation. JASA, 7, 213 (1936).

17. Malyuzhinets G. D., Sound absorption of a porous layer with a perforated covering, located at a distance from a rigid wall. Report at the meeting of the Acoustical Commission of the Academy of Sciences of the USSR of December 13, 1936. (Unpublished.)

18. Malyuzhinets G. D., Calculation of the sound conductivity of perforated screens through an attached mass. Report at the meeting of the Acoustical Section of the Association of Physicists of NKTP, October 2, 1936.

19. Nevyazhskii G. L., The harmfulness of noise in the light of new investigations. ZhTF, 6, 2195 (1936).

20. Ostroumov G. A., Electroacoustics. Moscow, 1936.

21. Rabinovich A. V., Fundamentals of Acoustics. Moscow, Kinofotoizdat (1936).

22. Rzhevkin S. N., Second All-Union Acoustical Conference. UFN, 16, 267 (1936).

23. Rzhevkin S. N., On resonant sound absorption. ZhTF, 6, 2103 (1936).

24. Rzhevkin S. N., On the results of the work of the Second All-Union Acoustical Conference. Bulletin of the Academy of Sciences of the USSR, No. 1 (1936).

25. Rzhevkin S. N., Resonance absorption of sound. Techn. Phys. of USSR, 3, 1 (1936).

1. Rozenberg L. D., Second All-Union Acoustical Conference. Sov. kino, No. 1, p. 50 (1936).

2. Simonov I. D., Localization of sound in enclosed spaces. Proceedings of the Research Music Institute of the Moscow State Conservatory, Acoustical Collection, issue 1, p. 37 (1936).

3. Simonov I. D., Installation for measuring reverberation. Proceedings of the Research Music Institute of the Moscow State Conservatory. Acoustical Collection, issue 1, p. 41 (1936).

4. Furduyev V. V., Architectural acoustics. Physical Dictionary, 1, 190 (1936).

5. Shafranov A. S., On acoustical plugs. ZhTF, 6, 2188 (1936).

6. Shneider Yu. I., Measurements of certain sound-absorbing materials by the reverberation method. ZhTF, 6, 2147 (1936).

7. Shtrasberg E. E., Isolation of buildings from noise and vibration. Bulletin of Science and Technology, No. 7, p. 21 (1936).

1937

1. Alekseev S. P., Noise of metro ventilation shafts and the struggle against it. ZhTF, 7, 242 (1937).

2. Antsyferov M. S., Calculation of the absorption coefficient of a material pierced with tubes with absorbing walls. Reports of the SDS (1937).

3. Antsyferov M. S., Calculation of the frequency spectrum of a system of mushroom-shaped cylindrical resonators. Proceedings of the Research Institute of Cinema and Photography (NIKFI) 6, 138 (1937).

4. Antsyferov M. S., Resonance sound absorption. Proceedings of NIKFI, 6, 154 (1937).

5. Antsyferov M. S. and Mikheeva N. K., Installation for the reverberometric determination of sound-absorption coefficients. Proceedings of NIKFI, 6, 164 (1937).

6. Belov A. I., Application of the theory of quadrupoles in architectural acoustics. ZhTF, 7, 2041 (1937).

7. Ginzburg A. M., The arrangement of concert shells in gardens. ZhTF, 7, 163 (1937).

8. Gol’dberg G. A. and Ter-Osipyants S. T., Perception of reverberation. Reports of the GSIZ, 1–100 (1937).

9. D. S., Regarding Yatskevich’s article “Stereophonic transmission over a single channel.” Tekhnika svyazi, No. 1 (1939).

10. Dreyzen I. G., On the acoustical effect of distance and the perception of timbre in radio transmission. ZhTF, 7, 861 (1937).

11. Kacherovich A. N., Investigations of constructions for the acoustical treatment of sound motion-picture studios. Reports of the Research Section of the Leningrad Institute of Motion-Picture Engineers (LIKI) (1937). (Unpublished.)

12. Kacherovich A. N., Synopsis of lectures on architectural acoustics. Leningrad Institute of Motion-Picture Engineers (1937). (Lithographed.)

13. Krechmer S. I. and Rzhevkin S. N., Investigation of wave processes by the model method with the use of ultrasonic waves. UFN, 18, 1 (1937).

14. Lifshits S. Ya., Course in architectural acoustics. 3rd ed., Moscow—Leningrad, ONTI (1937).

15. Lifshits S. Ya., Experimental investigations of the frequency optimum of reverberation. DAN SSSR, 15, 317 (1937).

16. Mikheeva N. K., Measurement of the absorption coefficient of materials used for damping motion-picture studios. Proceedings of NIKFI, 6, 173 (1937).

17. Malyuzhinets G. D., Influence of a perforated screen on the sound absorption of a material. Reports of the SDS, TR 20010 (1937). (Unpublished.)

1. Malyuzhinets G. D., Sound conductivity of a screen with a large number of small openings using sound-absorbing materials. Reports of GSLZ (1937). (Unpublished.)

2. Malyuzhinets G. D., Rzhevkin S. N. and Ter-Osipyants S. T., Theoretical considerations on installations for obtaining a strong sound-absorbing dome, Part 1. Reports of SDS, TR 20016 (1937). (Unpublished.)

3. Myasnikov L. L., Acoustic measurements. L.—M., ONTI (1937).

4. Rosenberg L. D., Some considerations on total reverberation. ZhTF, 7, 2167 (1937).

5. Skrebkov S. S., The theory of the thermoelement in connection with the measurement of reverberation. ZhTF, 7, 1268 (1937).

6. Ter-Osipyants S. T., Development of sound-absorbing structures for Studio “S”. Reports of GSLZ, 1—81 (1937). (Unpublished.)

7. Furduyev V. V., A method of acoustic design of auditoria equipped with loudspeaker devices. DAN SSSR, 15, 313 (1937).

8. Furduyev V. V., On methods of acoustic design of sound cinemas. Kino-foto-khimpromyshlennost, No. 7, 31 (1937).

9. Yatsevich V., Stereoscopic transmission over one channel. Tekhnika svyazi, No. 1, p. 38 (1937).

1938

1. Alekseev S. P., Absorbent for lining the tubing of the Moscow Metro second stage. ZhTF, 8, 906 (1938).

2. Alekseev S. P., Sound insulation in the construction of industrial, residential, and public buildings. M.—L., ONTI (1938).

3. Belov A. I., Sound attenuation in pipes with absorbing walls. ZhTF, 8, 752 (1938).

4. Belov A. I., On the acoustic calculation of ventilation installations. ZhTF, 8, 64 (1938).

5. Boiko L. A., Natural oscillations of long waves in a straight circular cylinder with a partition. Scientific Notes of Moscow State University, vol. XXIV, book 2, p. 28 (1938).

6. Vysotsky M. Z. and Konoplev V. N., Spatial reproduction of sound in widescreen and sound cinema. ZhTF, 8, 399 (1938).

7. Vysotsky M. Z. and Konoplev V. N., Spatial reproduction of sound in widescreen and sound cinema. News of the Electrical Low-Current Industry (IEST), No. 2, 40 (1938).

8. Galenkov. Noise control in the Bodo apparatus rooms. Tekhnika svyazi, No. 5, p. 54 (1938).

9. Gol’dberg G. A. and Ter-Osipyants S. T., Perception of reverberation. Reports of GSLZ, 1—84 (1938). (Unpublished.)

10. Goron I. E., Studios of the National Broadcasting Company in New York. Elektrosvyaz, No. 1 (1938).

11. Grigoryev V. S., Gorbachëv N. V. and Molchanov A. I., Problems of motion-picture installation in large auditoria. Kino-foto-promyshlennost (1938).

12. Dreizen I. G., Course in electroacoustics. Part 1, Svyazradioizdat (1938).

13. Indlin A. I., Acoustics. M., Goskinoizdat (1938).

187a. Indlin A. I., On the question of acoustic conditions in a film studio during synchronous filming. Kino-foto-promyshlennost, No. 6 (1938), p. 18.

1. Kacherovich A. N., On optimal conditions in the studio for sound recording. Proceedings of LIKI (1938).

2. Kozyrev. On the possibility of studying, on models, the acoustic properties of the Large and Small Halls of the Palace of Soviets. Reports of SDS TR 20013 (1938). (Unpublished.)

1. Krechmer S. I. and Rzhevkin S. N., Application of ultrasonic waves to the study of wave processes on models. Proceedings of the Physics Institute named after P. N. Lebedev, 1, issue 4, 48 (1938).

2. Lifshits S. Ya., Reverberation. Physical Dictionary, 4, 606 (1938).

3. Malozhinets G. D., Theory of sound absorption and the effect of elastic fastening of a material on sound absorption. Reports of the SDS, TR 20011 (1938). (Unpublished.)

4. Malozhinets G. D., Sound conductivity of a screen with a large number of small openings using sound-absorbing materials. Dissertation, Moscow State University (1938).

5. Makov S. A. and Burin R. Ya., Choice of a method for calculating acoustic power for sound reinforcement of enclosed spaces. Reports of the SDS, TR 12810 (1938). (Unpublished.)

6. Nevyazhsky L. I. and Suponin K. I., New methodology and apparatus for measuring industrial noise. ZhTF, 8, 243 (1938).

7. Rzhevkin S. N., On the possibility of obtaining large coefficients of sound absorption by means of resonator systems. DAN SSSR, 18, 25 (1938).

8. Sapozhkov M. A., Influence of the room on the efficiency of loudspeakers. Elektrosvyaz’, No. 5, 80 (1938).

9. Sokolov I. T., Reverberometer. Physical Dictionary, 4, 607 (1938).

10. Ter-Osipyants S. T., Sound-absorbing construction for studio “C.” Reports of GSIZ, 1—86 (1938). (Unpublished.)

11. Ter-Osipyants S. T., Measurement of the sound absorption of samples of fiberboard panels in resonant cells. Reports of GSIZ, 1—93 (1938). (Unpublished.)

12. Ter-Osipyants S. T., Development of absorbing constructions for studio “A.” Reports of GSIZ, 1—91 (1938). (Unpublished.)

13. Tetelbaum S. I. and Vysotsky V. F., Increasing the directivity coefficient of a loudspeaker in noisy auditoria. IZEST, 1, 17 (1938).

14. Furduev V. V., On the reception of reverberant sound by directional microphones. Kino-foto-promyshlennost’, No. 5, p. 24 (1938).

15. Shneider Yu. I. and Granovsky A. M., Broadcasting from a damped room using an echo chamber. Tekhnika svyazi, No. 4, p. 13 (1938).

16. Shneider Yu. I., Combating noise in ventilation ducts of industrial and public structures. ZhTF, 8, 1671 (1938).

1939

1. Alekseev S. P., Sound-absorbing materials developed at the Moscow Architectural Institute. Proceedings of the Acoustical Commission of the Academy of Sciences of the USSR, 3, p. 65, Moscow–Leningrad (1939).

2. Alekseev S. P. and Shneider Yu. I., Combating urban and factory noise. (For architects and civil engineers.) Moscow, Gosstroiizdat (1939).

3. Alekseev S. P. and Shneider Yu. I., Noise in ventilation installations and combating it. Published by Promstroiproekt, issue 16 (1939).

4. Andreev N. N., On porous sound-absorbing materials. Proceedings of the Acoustical Commission of the Academy of Sciences of the USSR, 3, p. 9 (1939).

209a. Andreev N. N. and Lysenko E. E., Sound absorption of a porous material in view of the porosity and the air gap. Proceedings of the Acoustical Commission of the Academy of Sciences of the USSR, 2, 7 (1939).

1. Andreev N. N. and Lysenko E. E., On sound absorption of perforated materials. Proceedings of the Acoustical Commission, 2, 17 (1939).

1. Andrievskii V. A., Acoustic pumice. Review of research work for 1938. Reports of the CDS, TR 20049 (1939). (Unpublished.)

2. Andrievskii V. A., Ceramic acoustic materials. Review of research work for 1938–1939. Reports of the CDS, TR 20050 (1939). (Unpublished.)

3. Ancyferov M. S., Measurement of vibrations of the ballast of the track of the Moscow Metro. Reports of the CDS, RDT 20613 (1939). (Unpublished.)

4. Belov A. I. and Fainshtein N. D., Experimental study of sound attenuation in ventilation ducts. ZhTF, 9, 1499 (1939).

5. Goldberg G. A., Measurements of sound-absorbing materials. Proceedings of the Acoustic Commission of the Academy of Sciences of the USSR, 3, 33 (1939).

6. Goldberg G. A., On the question of the dependence of the sound-absorption coefficient on the dimensions of the specimen. Proceedings of the Acoustic Commission of the Academy of Sciences of the USSR, 3, 37 (1939).

7. Goldberg G. A., Modern methods of measuring reverberation. Proceedings of the Acoustic Commission of the Academy of Sciences of the USSR, 1, 43 (1939).

8. Goldberg G. A., On effective reverberation. Abstract of a report at the construction section of the Moscow Radio House. Proceedings of the Acoustic Commission of the Academy of Sciences of the USSR, 3 (1939).

9. Goldberg G. A. and Ter-Osipian S. T., Correction of the acoustics of Studio “B” of the House of Sound Recording. Reports of GSLZ, 1–81 (1939). (Unpublished.)

10. Grossman V., The House of Sound Recording in Moscow. Architecture of the USSR, No. 10, p. 24 (1939).

11. Egorov Yu. N., Sound-absorbing chamber of the All-Union Scientific Research Institute of Metrology. Proceedings of the Acoustic Commission, 3, 43 (1939).

12. Zasurskii N. V., Technology for the production of sound-absorbing building materials. (From the work of the Laboratory of Insulating Materials of the Central Scientific Research Institute of Industrial Structures.) Proceedings of the Acoustic Commission, 3, 55 (1939).

13. Kacherovich A. N., Acoustics. (A textbook for the correspondence division of the All-Union courses for cinema mechanics.) Goskinoizdat (1939).

14. Kozyrev V. V., Investigation of the acoustic properties of the Great Hall by the light-beam method on a model. Reports of the CDS, TR 20025 (1939). (Unpublished.)

15. Kozyrev V. V., On methods of working with models in the study of sound propagation by the light-beam method. Reports of the CDS, TR 20030 (1939). (Unpublished.)

16. Kostsov A. M., Effective value of reverberation. ZhTF, 9, 919 (1939).

17. Konstantinov B. P., On the absorption of sound waves upon reflection from a hard boundary. ZhTF, 9, 226 (1939).

18. Konstantinov B. P., On the attenuation of sound in a room with hard walls and on the diffuse absorption coefficient. ZhTF, 9, 424 (1939).

19. Makov S. A., Method for calculating the sound reinforcement of rooms of elongated shape. Reports of the CDS, TR 20324 (1939). (Unpublished.)

20. Malyuzhinets G. D., Sound absorber for the Great Hall of the Palace of Soviets. Report at the session of the Physical-Mathematical Department of the Academy of Sciences of the USSR (1939).

21. Malyuzhinets G. D., Sound absorption of a porous material with allowance for longitudinal porosity and an air interlayer. Reports of the CDS, TR 20002 (1939). (Unpublished.)

22. Malyuzhinets G. D., On the possibility of using a perforated sheet for lining the dome of the Great Hall of the Palace of Soviets. Reports of the CDS, TR 20002 (1939). (Unpublished.)

23. Malyuzhinets G. D., Formulation of the problem of finding the optimal distribution of friction in a sound-absorbing layer for the case of nor-

ARCHITECTURAL ACOUSTICS IN THE USSR

...of normal incidence of a sound wave. TsDS Reports, TR 20043 (1939). (Unpublished.)

1. Melnikov F. I., Gas-ceramic acoustic materials. TsDS Reports, TR 2005 (1939). (Unpublished.)

2. Natarov B. F., Investigation of the influence of different parts of the frequency spectrum on localization of a sound source and on the threshold of divergence in a room. TsDS Reports, TR 20318 (1939). (Unpublished.)

235a. Natarov B. F., Investigation of the dependence of the sound image on different loudness levels of two operating loudspeakers. TsDS Reports. (Unpublished.)

1. Natarov B. F., Localization of a sound source in rooms. TsDS Reports, TR 20316 (1939). (Unpublished.)

236a. Natarov B. F., Investigation of the thresholds and angles of divergence of sound and visual images. TsDS Reports. (Unpublished.)

1. Nesterov V. S., Investigation of single- and double-layer resonant sound absorbers by the tube method. TsDS Reports, TR 20042 (1939). (Unpublished.)

2. Nesterov V. S., Absorption of sound by double resonant systems. ZhTF, 9, 1727 (1939).

3. Novikov A. F. and Rimsky-Korsakov A. V., Sound-absorbing chamber of the Research Institute of the Music Industry. Proceedings of the Acoustic Commission of the Academy of Sciences of the USSR, 3, 49. In the book Acoustic Measurements, Moscow—Leningrad (1939).

4. Pustovoitenko I. P., Calculation of the sound-absorption coefficient of a material pierced by pipes with absorbing walls. Proceedings of the Acoustic Commission of the Academy of Sciences of the USSR, 2, 25 (1939).

5. Rabinovich A. V., Equipment and operation of studios. Moscow, Svyazradioizdat (1939).

6. Rabinovich A. V. and Sukharevsky Yu. M., Broadcasting studios and microphones. Moscow, Svyazradioizdat (1939).

7. Rzhevkin S. N., Absorption of sound by acoustic resonators. Proceedings of the Acoustic Commission of the Academy of Sciences of the USSR, 3, 133 (1939).

8. Rzhevkin S. N., Theory and design of the simplest resonant sound-absorbing systems. DAN SSSR, 22, 568 (1939).

9. Rimsky-Korsakov A. V., A critical review of methods of reinforcing sound in very large rooms. Proceedings of the Acoustic Commission of the Academy of Sciences of the USSR, 2, 79 (1939).

10. Rimsky-Korsakov A. V. and Struve K. V., On the reflection of sound waves from a surface whose dimensions are comparable with the wavelength. Proceedings of the Acoustic Commission of the Academy of Sciences of the USSR, 2, 69 (1939).

11. Rosenberg L. D., Acoustics of the Great Hall of the Palace of Soviets. Architecture of the USSR, No. 4, p. 53 (1939).

12. Rosenberg L. D. and Tartakovsky B. D., Acoustics in the Palace of Soviets. Construction Industry, No. 11—12, p. 42 (1939).

13. Sapozhkov M. A., Efficiency of sound absorption by niches of various shapes. Proceedings of the Acoustic Commission of the Academy of Sciences of the USSR, 2, 49 (1939).

14. Sedov L. I., Determination of the added mass of an oblique grating consisting of rectangles. TsDS Reports, TR 20037a (set forth in the book: Plane Motions of an Ideal Fluid, Moscow (1940)).

15. Sedov L. I., Added mass of a grating consisting of rectangles. TsDS Reports, TR 20022 (1939). (Unpublished.)

16. Simonov D. I., Method for calculating the echo from a cylindrical wall. TsDS Reports, TR 20047 (1939). (Unpublished.)

17. Surin G. A., Vibrations in residential buildings and their comparison with noise. TsDS Reports, TR 20619 (1939). (Unpublished.)

18. Surin G. A., Vibrations of the foundations of the Palace of Soviets from passing metro trains. TsDS Reports, TR 20617 (1939). (Unpublished.)

1. Surin G. A., An apparatus for determining the elastic properties of sound-insulating gaskets. Reports of the CDS, TR 20616 (1939). (Unpublished.)

2. Sukharevskii Yu. M., Methods for calculating the sound field of a horn loudspeaker. Izv. OTN AN, 7, 73 (1939).

3. Sukharevskii Yu. M., On the density of sound energy in a room with a directional radiator. DAN SSSR, 25, 16 (1939).

4. Ter-Osipyants S. T., Investigation of a monoresonant absorber by the tube method. Reports of GSEZ (1—90 (1939). (Unpublished.)

5. Ter-Osipyants S. T., Determination of the sound-absorbing action of sound-absorbing structures in a room. Reports of the CDS, TR 20046 (1939). (Unpublished.)

6. Ter-Osipyants S. T. and Gol’dberg G. A., Masking of the echo of a pulse by decaying sound. Reports of the CDS, TR 20045 (1939). (Unpublished.)

7. Timofeev A. K., A handbook of applied acoustics for the builder. Moscow, Gosstroiizdat (1939).

8. Kharkevich A. A., Acoustic measurements in enclosed rooms. Proceedings of the Acoustical Commission of the Academy of Sciences of the USSR, 1, 65 (1939).

262a. Kharkevich A. A., Automation of acoustic measurements. Proceedings of the Acoustical Commission of the Academy of Sciences of the USSR, 1, 27 (1939).

1. Khodarkevich V. I., Acoustic plaster. Reports of the CDS, TR 20067 (1939). (Unpublished.)

2. Tsikunov V., On oscillations inside a niche whose open surface is excited in a prescribed manner. Proceedings of the Acoustical Commission of the Academy of Sciences of the USSR, 3, 37 (1939).

3. Chigrinskii G. A., The pattern of reflections and elements of the acoustics of prismatic polyhedra, ZhTF, 9, 2120 (1939).

4. Chigrinskii G. A., The pattern of reflections and reverberation of non-closed spaces. ZhTF, 9, 1484 (1939).

5. Chigrinskii G. A., The pattern of reflections and its application in architectural acoustics. DAN SSSR, 23, 631 (1939).

6. Shabshev K. N., Problems of urban noise and the struggle against it. L. (1939).

1940

1. Acoustic materials and their application. Works of the Laboratory of Building Acoustics and Insulating Materials. Compiled by A. K. Timofeev, Moscow, Gosstroiizdat (1940).

2. Andreeva-Galanina E. Ts., Vibrations, their hygienic significance and measures for combating them. Leningrad, Publishing House of the Institute of Occupational Hygiene and Occupational Diseases (1940).

3. Antsiferov M. S., Acoustics of auditoriums, Physics in School, No. 3 (1940).

4. Vital’ K. A., On the oblique incidence of sound on a resonant absorber. ZhTF, 10, 980 (1940).

5. Vital’ K. A., Application of Cremer’s theory and porous materials of the pumice type. Reports of the CDS, RDP-4—33 (1940). (Unpublished.)

6. Gassko R. E., Vibrations and noise in houses above a subway line. Reports of the CDS, RDP-4—31 (1940). (Unpublished.)

7. Gassko R. E. and Sadikov Yu. N., A machine for measuring the impedances of sound-insulating gaskets. Reports of the CDS, RDP-6—4—27 (1940). (Unpublished.)

8. Grigoryants N., Oscillations, waves and acoustics. Moscow, Military Air Engineering Lenin Academy of the Workers’ and Peasants’ Red Army named after Zhukovsky (1940).

9. Gurevich M. I., Added mass of an element of a double lattice made of flat plates. Reports of the CDS, part 1, RDP-84—1; part 2, RDP-82—2 (1940). (Unpublished.)

1. Davydova F. L., Acoustic materials for layered sound-absorbing structures. Reports of the CDS, LDP-1—3 (1940). (Unpublished.)

2. Dreyzen I. G., Course in electroacoustics. Part II, Sound reinforcement. M., Svyazradioizdat (1940).

3. Drozdov P. F., Stereophonic uniformity of the field of distributed radiators. Reports of the CDS, RDP-4—61 (1940). (Unpublished.)

4. Kazansky V. S., Principal causes of noise in the escalators of the Moscow Metro. ZhTF, 10, 1251 (1940).

5. Kacherovich A. N., Study of the acoustics of ateliers and synchronous pavilions (of the Lenfilm studios). L., Tekhfilm, Report (1940). (Unpublished.)

6. Kelberg V. P. and Ladyzhensky R. M., The struggle against noise in ventilation installations. M.—L., State Publishing House of Construction Literature (1940).

7. Klimova A. Ya., Calculation of sound-absorption curves of single-layer structures. Reports of the CDS, RDP-4—39 (1940). (Unpublished.)

8. Krasheninnikov Yu. P., Sound-absorbing properties of fabrics. Reports of the CDS, RDP-4—23 (1940). (Unpublished.)

9. Krasheninnikov Yu. P., Description of a slit installation for measuring the impedance of sound-absorbing materials. Reports of the CDS, TR 20044 (1940). (Unpublished.)

10. Lenoblinto of the silicate industry. Physical methods for determining the character of porosity as an indicator of the acoustic quality of ceramic materials. Reports of the CDS, TR 20063 (1940). (Unpublished.)

11. Makarov A. V., Electrooptical method for measuring the sound conductivity of screens. Reports of the CDS, RDP-4—12 (1940). (Unpublished.)

12. Malyuzhinets G. D., On the influence of the weight of a perforated screen on its sound conductivity. Reports of the CDS, RDP-4—53 (1940). (Unpublished.)

13. Maslova V. P., Experimental investigation of the acoustic characteristics of sound-absorbing materials. Reports of the CDS, RDP-4—49 (1940). (Unpublished.)

14. Melnikov F. I., Report on the topic: Acoustic gas ceramics, Part I. Reports of the CDS, RDP-1—2 (1940). (Unpublished.)

15. Moscow Institute of Communications Engineers. Executant Goldberg G. A., Investigation of reverberation systems for DS. (Investigation of reverberations and masking of echo by reverberation.) Reports of the CDS, TR 20322 and RDP-31—2 (1940). (Unpublished.)

16. Natarov B. F., On the question of the placement of loudspeakers in motion-picture theaters. Kino-foto-khimpromyshlennost, No. 3, p. 14 (1940).

17. Nesterov V. S., Absorption of sound by a three-layer resonant system. ZhTF, 10, 617 (1940).

18. Novakhovskaya D. S., Sound-absorbing material—pemosolite. Prom. stroymaterialov, No. 10—11, p. 38 (1940).

19. Rabinovich A. V., Acoustics of the Moscow Television Center. Elektrosvyaz, No. 4, p. 62 (1940).

20. Rabinovich A. V., On the noticeability of echo and its influence on the intelligibility of speech. ZhTF, 10, 605 (1940).

21. Rabinovich A. V., Open-type telephone booths. Report of the CDS, RDP-4—15 (1940). (Unpublished.)

22. Rosenberg L. D., On the influence of the mean sound-absorption coefficient on the level of sound intensity. ZhTF, 10, 1634 (1940).

23. Rudnik V. M., Measurements of the sound insulation of walls made of ceramic blocks. Reports of the CDS, RDP-4—41 (1940). (Unpublished.)

24. Svirsky I. V., Mathematical investigation of the optimal distribution of friction in a sound-absorbing layer. Reports of the CDS, TR 20061 (1940). (Unpublished.)

25. Smolikov Ya. N., Vibrations of industrial buildings and measures for reducing them. Vestn. inzh. i tekhn., No. 1, p. 36 (1940).

1. Surin G. A., Vibrations of the foundations of the Palace of Soviets and the role of sound insulation. Reports of the SDS, RDP-4—34 (1940). (Unpublished.)

2. Surin G. A., Measurement of vibration velocities (vibrators and a calibration plate for them). Reports of the SDS, TR 20618 (1940). (Unpublished.)

3. Sukharevsky Yu. M., The influence of acoustic conditions in a room on the intelligibility of reproduction. Chapter from a dissertation. MEI (1940).

4. Sukharevsky Yu. M., On the theory of acoustic feedback in sound-amplifying systems. DAN SSSR, 26 (1940).

5. Sukharevsky Yu. M., On the density of sound energy in a room with a directional radiator. DAN SSSR, 25, 1 (1940).

6. Sukharevsky Yu. M., On the ultimate possible amplification of sound in a closed room. DAN SSSR, 26, 839 (1940).

7. Sukharevsky Yu. M., On the use of delayed feedback to obtain artificial reverberation. Reports of the SDS, TR 20058 (1940). (Unpublished.)

8. Sukharevsky Yu. M., Experimental study of acoustic feedback in a closed room. DAN SSSR, 26, 646 (1940).

9. Chugunov S. S., Description of a high-frequency installation for measuring sound conductivity and sound absorption. Reports of the SDS, TR 20055 (1940). (Unpublished.)

10. Shvarts B. P., Design of the auditorium of a sound cinema. Kino-foto-khimpromyshlennost, No. 4, p. 18 (1940).

11. Shneider Yu. I., Acoustic equipment of standard studios. Elektrosvyaz, No. 4, p. 25 (1940).

12. Yakovlev L. A., Measurements of the transmission of crowd noise in the foyer premises of the Vakhtangov Theater. Reports of the SDS, RDP-4—5 (1940). (Unpublished.)

13. Yakovlev L. A., Measurements of subway noise in the buildings of the Pushkin Museum of Fine Arts and the Lenin Library. Reports of the SDS, TR 20621 (1940). (Unpublished.)

14. Yakovlev L. A., Measurements of the noise of a garbage crusher. Reports of the SDS, RDP-64—7 (1940). (Unpublished.)

15. Yakovlev L. A., Measurements of the noise of a centrifugal pump in the DS houses. Reports of the SDS, RDP-4—3 (1940). (Unpublished.)

16. Yakovlev L. A., Measurements of the noise of an “Otis” elevator in the NKT building. Reports of the SDS, TR 20620 (1940). (Unpublished.)

17. Yakovlev L. A., Measurements of the noise of ventilation installations of high capacity and sound insulation of silencers. Reports of the SDS, TR 20508 (1940). (Unpublished.)

18. Yakovlev L. A., Measurements of ventilation noise in the House of Sound Recording. Reports of the SDS, RDP-4—38 and TR 20615 (1940). (Unpublished.)

19. Yakovlev L. A., Measurements of ventilation noise in the Bolshoi Theater. Reports of the SDS, RDP-4—13 (1940). (Unpublished.)

1941

1. Antsyferov M. S., Measurements of vibrations from an elevator in the NKT building. Reports of the SDS, RDP-4—50 (1941). (Unpublished.)

2. Vital K. A., Oblique incidence of sound on a double resonant system. ZhTF, 11, 1029 (1941).

3. Gassko R. E., Vibrations and noise in houses above the metro route. Reports of the SDS, RDP-4—31 (1940). (Unpublished.)

4. Goldberg G. A., On the design of sound-amplification systems in a small hall. Inf. tekhn. Byull. SDS, No. 5—6, M. (1941).

5. Goldberg G. A., Acoustic feedback in concentrated systems. Reports of the SDS, RDP-3—6 (1940).

325б. Goldberg G. A., Investigation of acoustic feedbacks. Reports of the CDS, RDP-4—58 (1940). (Unpublished.)

1. Goldberg G. A. and Tartakovsky B. D., Design of the sound amplification of the cupola of the Great Hall of the Palace of Soviets. Inform. Tekhn. Byull. CDS, No. 5—6, M. (1941).

2. Grigor’ev V. S., Sound-measuring testing ground of the construction of the Palace of Soviets. Inform. Tekhn. Byull. CDS, No. 5—6, M. (1941).

3. Grigor’ev V. S., On methods of averaging readings in the measurement of sound insulation by Meyer’s method. Reports of the CDS, RDP-4—9, (1941). (Unpublished.)

4. Igumnov V. I., Method for calculating the perceived acoustic ratio in corridor-type premises. Reports of the CDS, RDP-2—3 (1940). (Unpublished.)

5. Kacherovich A. N., On acoustic conditions in a sound cinema. Kino-foto-khimpromyshlennost’, No. 3, 18 (1941).

6. Kel’berg V. P., Handbook on thermal and sound insulation. Issue: Sound insulation and sound absorption. Published by Lenoblknigo of the refrigeration industry, L. (1941).

7. Krasheninnikov Yu. P., On the question of the use of asbestos fabrics in layered sound-absorbing structures. Report of the CDS, RDP-4—6 (1940). (Unpublished.)

8. Krasheninnikov Yu. P., A simplified method for calculating layered sound-absorbing structures. Reports of the CDS, RDP-4—37 (1940). (Unpublished.)

9. Krasheninnikov Yu. P., Experimental investigation of trial structures of a layered sound absorber. Reports of the CDS, RDP-4—26 (1940). (Unpublished.)

10. Leinzer I. G., Sound insulation in the Palace of Soviets. Inform. Tekhn. Byull. CDS, No. 5—6, M. (1941).

11. Malyuzhinets G. D., Nomogram for calculating mechanical impedances. Reports of the CDS, RDP-4—202 (1941). (Unpublished.)

12. Malyuzhinets G. D., Application of the impedance-hodograph method for the graphical calculation of layered sound-absorbing structures. Reports of the CDS, RDP-456 (1941). (Unpublished.)

13. Malyuzhinets G. D., Layered sound-absorbing structures. Inform. Tekhn. Byull. CDS, No. 5—6, M. (1941).

14. Malyuzhinets G. D., Energy calculation of layered sound-absorbing structures. Reports of the CDS, RDP-4—54 (1940). (Unpublished.)

15. Makov S. A., Requirements for the characteristics of the directivity of microphones for stereophonic sound transmission. Reports of the CDS, RDP-3—1 (1941). (Unpublished.)

16. Nesterov V. S., Sound absorption by multilayer resonant systems. DAN SSSR, 31, 237 (1941).

17. Nesterov V. S., Experimental investigation of the conductivity of round apertures of a tube set normally to the end face. DAN SSSR, 31, 879 (1941).

18. Rabinovich A. V., A new method for calculating the acoustic ratio. Reports of the CDS, RDP-2—2 (1940). (Unpublished.)

19. Rezvyakova Z. N., A fast-acting sound-level recorder. Obshchee mashinostroenie, No. 5, 27 (1941).

20. Rozhkin S. N. and Ter-Osipyan Ts. T., Investigation of the resistance of frictional layers for sound-absorbing systems. ZhTF, 11, 149 (1941).

21. Rosenberg L. D., Certain propositions and problems solved and to be solved in the field of acoustics of the Palace of Soviets. Inform. Tekhn. Byull. CDS, No. 5—6, M. (1941).

22. Rosenberg L. D. and Tartakovsky B. D., Application of distributed radiator systems for purposes of sound reinforcement. DAN SSSR, 31, 883 (1941).

1. Rozenberg L. D. and Tartakovskii B. D., Application of distributed radiator systems for sound reinforcement and sound reproduction. Inf. tekhn. byull. SDS, No. 5–6, M. (1941).

2. Rudnik V. M., Measurement of the sound insulation of a complex wall (with an additionally elastically fastened wall). Reports of SDS, RDP-4—203 (1941). (Unpublished.)

3. Rudnik V. M., Measurements of the sound insulation of floors of two types (with a floating floor). Reports of SDS, RDP-4—29 (1941). (Unpublished.)

4. Slavin I. I., Damping of vibrations of machines. Reports of the All-Union Scientific-Research Institute for Labor Protection of the All-Union Central Council of Trade Unions, L. (1941). (Unpublished.)

5. Slavin I. I., On the placement and selection of the power of loudspeakers for sound reinforcement of industrial premises of power stations. Reports of the All-Union Scientific-Research Institute for Labor Protection of the All-Union Central Council of Trade Unions, L. (1941). (Unpublished.)

6. Surin G. A., Measurements of the bypass paths of sound in the frame building of the B. Hall named after Lenin. Reports of SDS (1941). (Unpublished.)

7. Surin G. A., Determination of the dynamic range of measurement of sound insulation in chambers. Reports of SDS, RDP-4—55 (1941). (Unpublished.)

8. Sukharevskii Yu. M., An attempt at an objective study of the acoustics of the Tchaikovsky Hall in Moscow. Reports of the Acoustics Laboratory, USSR Academy of Sciences Physical Institute (1941). (Unpublished.)

9. Sukharevskii Yu. M. et al., Experimental study of the acoustics of the conference hall of the People’s Commissariat of the Navy. Reports of SDS, RDP-4—28 (1941). (Unpublished.)

10. Tartakovskii B. D., The field of reflected sound waves in the large hall of the DS with distributed loudspeakers. Reports of SDS, RDP-3—3 (1941). (Unpublished.)

11. Tartakovskii B. D., On the diffraction of sound reflected from the framework of the dome of the Large Hall. Reports of SDS (1941). (Unpublished.)

12. Tartakovskii B. D., Reflection of sound from curvilinear surfaces (study of the double reflection of sound from the dome of the B. Hall). Reports of SDS, RDT-2—2 (1941). (Unpublished.)

13. Tartakovskii B. D., Experimental study of systems of distributed sound sources (SDS lecture hall). Reports of SDS, RDP-4—16 (1941). (Unpublished.)

14. Fock V. A., Theoretical study of the conductance of a circular opening in a partition placed across a tube. DAN SSSR, 31, 875 (1941).

15. Khodarkevich V. I., Technical report on the subject: Acoustic plaster, part 1. Reports of SDS, RDP-1—2 (1941). (Unpublished.)

16. Shapiro B. K., On the calculation of cells of an acoustic filter, whose individual elements are not small in comparison with the wavelength. ZhTF, 11, 466 (1941).

17. Yakovlev L. A., Measurements of the sound insulation of a floating floor in a residential building. Reports of SDS, RDP-4—41 (1941). (Unpublished.)

18. Yakovlev L. A., Measurements of ventilation noise in the Stanislavsky Theater. Reports of SDS, RDP-4—4 (1941). (Unpublished.)

19. Yakovlev L. A., Measurements of ventilation noise in the building of the Tchaikovsky Hall. Reports of SDS (1941). (Unpublished.)

20. Yakovlev L. A., Measurements of noise transmission through the framework of the building of the Council of People’s Commissars of the USSR. Reports of SDS (1941). (Unpublished.)

1942

1. Rozenberg L. D., Method for calculating sound fields formed by distributed systems of radiators. ZhTF, 12, 102 (1942).

2. Rozenberg L. D., Method for calculating sound fields formed by distributed systems of radiators operating in enclosed rooms. ZhTF, 12, 220 (1942).

1943

1. Rozenberg L. D., Nonuniformity of the field produced by an infinite chain of incoherent radiators. ZhTF, 12, 573 (1942).

2. Rozenberg L. D., On the character of the sound field obtained in the reproduction of music by a distributed system of radiators. ZhTF, 12, 211 (1942).

3. Gurevich M. I., Sound conductivity of a dense lattice. Dissertation, Mechanical Institute of Moscow State University (1943).

4. Nesterov V. S., Resonant sound-absorbing systems. Dissertation, FIAN USSR (1943).

5. Rozenberg L. D. and Tartakovsky B. D., Application of distributed systems of radiators for the sound accompaniment of film projection. DAN USSR, 41, 5 (1943).

1944

1. Antsiferov M. S. and Ivanov K. M., Measurements of floor vibrations in the hall of the House of Soviets caused by the metro. Report of the SDS (1944). (Unpublished.)

2. Goron I. E., Radio broadcasting. Moscow, Svyazizdat (1944).

3. Nepomnyashchy E. A., Investigation of the noise of axial fans. ZhTF, 14, 108 (1944).

4. Standards for sound insulation of residential buildings from internal noises (draft). Academy of Architecture of the USSR, Moscow (1944).

5. Yudin E. Ya., On fan noise. TsAGI collection “Industrial Aerodynamics,” Moscow (1944).

1945

1. Andreev N. N., Contemporary acoustics. Bulletin of the Academy of Sciences of the USSR, No. 1–2, p. 46 (1945).

2. Iorch Yu. I., Measurement of the elastic properties of short rods made of vibration-insulating materials. Moscow Order of Lenin State University named after M. V. Lomonosov. Scientific Notes, issue 77, Physics, book 3, p. 240 (1945).

3. Leizer L. G., Vibrations of machines and instruments installed on elastic pads, and the isolating effect of such installations. Dissertation, MEI (1945).

4. Malozhinets G. D., Sound absorption by a layered structure at low frequencies. Reports of the SDS (1945). (Unpublished.)

5. Malozhinets G. D., On the question of different definitions of the concept of sound insulation in a diffuse sound field. Reports of the Acoustic Laboratory of FIAN (1945). (Unpublished.)

6. Malozhinets G. D. and Tartakovsky B. D., Single-layer sound-absorbing structures. Reports of the SDS (1945). (Unpublished.)

7. Rimsky-Korsakov A. V., Survey of works on sound reinforcement in world literature for the period 1940–1945. Reports of the SDS (1945). (Unpublished.)

8. Tartakovsky B. D., Acoustic calculation of the dome of the Large Hall. Reports of the SDS, ZP-11–28 (1945). (Unpublished.)

9. Tartakovsky B. D., The influence of coffered ceilings on the acoustics of the Large Hall of the DS. Reports of the SDS, ZP-46 (1945). (Unpublished.)

10. Tartakovsky B. D., Principles of the acoustic design of the main interiors of the Palace of Soviets. Reports of the SDS, ZP-11 (1945). (Unpublished.)

11. Furduev V. V., Acoustics of sound film projection. (Manual for cinema mechanics), Moscow, Goskinoizdat (1945).

12. Yudin E. Ya., A brief guide to the acoustic calculation of ventilation installations. Moscow, Stroyizdat Narkomstroy (1945).

1946

1. Gol’dberg G. A., On the asymptotic law of decay of regenerative reverberation. Reports of the SDS (1946). (Unpublished.)

2. Iorish Yu. I., Determination of the dynamic modulus of elasticity of vibroisolating materials. Reports of the SDS (1946). (Unpublished.)

3. Karnovskii M. I., A device for observing sound processes on water models. Collection of papers of the Kiev Institute of Cinema Engineers, 1 (1946).

4. Karnovskii M. I. and Tverskaya M. B., Numerical value of a certain integral. Collection of papers of the Kiev Institute of Cinema Engineers, 1 (1946).

5. Kucher E. R., Method for calculating the diffraction of sound waves by a ring belt. Reports of the SDS (1946). (Unpublished.)

6. Kucher E. R., Determination of the magnitude of diffraction reflection from a dihedral angle. Reports of the SDS (1946). (Unpublished.)

7. Malyuzhinets G. D., Calculation of wide-band layered sound absorbers. Reports of the SDS (1946). (Unpublished.)

8. Malyuzhinets G. D. and Ageeva N. S., The influence of the elasticity of sheets on the absorption of single-layer sound-absorbing structures. Reports of the SDS (1946). (Unpublished.)

9. Malyuzhinets G. D., Experimental investigation of layered structures on mock-ups of MPEI studios. Reports of the SDS (1946). (Unpublished.)

10. Malyuzhinets S. D., Tabulated functions of three parameters applicable in calculations of sound absorbers. Reports of the SDS (1946). (Unpublished.)

11. Rzhevkin S. N., A review of work on resonant sound absorbers. UFN, 30, 40 (1946).

12. Rzhevkin S. N., A resonant sound absorber with a compliant wall. ZhTF, 16, 381 (1946).

13. Rimskii-Korsakov A. V., A review of work on sound reinforcement according to the report materials of the SDS. Reports of the SDS (1946). (Unpublished.)

14. Rozenberg L. D., On the placement of sound-absorbing material in an enclosed room. DAN SSSR, 51, 599 (1946).

15. Tartakovskii B. D., Acoustic calculation of the dome of the Great Hall. Reports of the SDS (1946). (Unpublished.)

1947

1. Alekseev S. P., The struggle against urban noise. Journal of Municipal Economy of Moscow, No. 7 (1947).

2. Al’tshuler M. S., On the stability of a vibrometer on an exciting surface. ZhTF, 17, 1441 (1947).

3. Brekhovskikh L. M., On the limits of applicability of certain approximate methods used in acoustics. DAN SSSR, 18, 587 (1947).

4. Brekhovskikh L. M., Limits of applicability of certain approximate methods used in architectural acoustics. (Concerning the article by Morse and Bolt “Sound Waves in Rooms.”) UFN, 32, 464 (1947).

5. Karnovskii M. I. and Lazarevich V. M., A reverberometer with direct readout. Reports of the Kiev Institute of Cinema Engineers (1947). (Unpublished.)

6. Malyuzhinets G. D., Some additions to the calculations of sound absorbers for the Great Hall of the Palace of Soviets. Reports of the SDS (1947). (Unpublished.)

1. Rzhevkin S. N. and Nesterov V. S., Resonant sound absorbers for building practice. Proceedings of the VNIITO of Radio Engineering and Electrical Communications named after Popov. Electroacoustics Section, 4 (1947).

2. Rzhevkin S. N. and Furduyev V. V., On the development of work on electroacoustics in the USSR. Radiotekhnika, No. 8 (1947).

3. Rosenberg L. D., List of principal literature on architectural acoustics in Russian. UFN, 32, 476 (1947).

1948

1. Alekseev S. P., Acoustics of rooms. Section “Sound insulation.” Handbook of Architecture. Publishing House of the Academy of Architecture of the USSR (1948).

2. Alekseev S. P. (ed. by Andreev N. N.), Noise. Publishing House of the Academy of Sciences of the USSR (1948).

3. Alekseev S. P., Zharinov V. L. and Vorobyev S. I., Sound insulation in construction. Gostroizdat (1948). (In press.)

4. Kacherovich A. N., Sound-absorbing material for synchronous pavilions. Proceedings of NIKFI (1948). (Unpublished.)

5. Rzhevkin S. N., Achievements of Soviet acoustics. UFN, 34, 1 (1948).

6. Furduyev V. V., Electroacoustics. Chs. XII–XVI. Gostekhizdat, Moscow (1948).