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A brief resume of the nature of telephonic signals is given, showing how the qualities of wave composition which distinguish signals from other electrical waves set the requirements on networks and provide a basis for their design. The principal functions of wave filters, equalizers, telephone transformers, line balancing networks, and artificial lines are outlined. In order that these networks may be used in conjunction with other apparatus in the telephone system they must provide efficient transmission, low distortion, good impedance balance, stoppage of longitudinal currents, stable characteristics with current variations, low external coupling, and low reflection coefficient. In addition to these requirements the network must not cross-talk into associated circuits and must have desirable impedance characteristics in the attenuation range of frequencies as well as throughout the transmission range. An illustration of the use of transmission networks in a typical three-channel carrier telephone system is given describing the functions of the line filter sets, the directional filter sets, band filters, and equalizers. Some of the engineering limitations on the design and construction of networks are discussed.

Principles of Generalized Dissymmetrical Networks. We shall consider first the impedance and propagation characteristics of certain generalized networks, It can be shown that any passive network having one pair of input and one pair of output terminals may, at any frequency, be completely and adequately represented by an equivalent T or π network.1 The impedance and propagation characteristics of any such network may be expressed in terms of its equivalent T or π network. These characteristics are defined by (1) the image impedances, and (2) the transfer constant, the latter including the attenuation constant.2 and the phase constant.2 In the case of a symmetrical network, the image impedances and the transfer constant are, respectively, the iterative impedances (or characteristic impedances) and the propagation constant employed by Campbell, Zobel, and others. The terms involved will be subsequently defined.

Frequency modulation of a sound signal produces some very interesting and sometimes not readily identifiable auditory sensations. Distortion of this type is caused in sound records by the nonuniform speed of the record during the recording or reproducing process.While the physical nature of frequency modulation and some of the physiological effects produced by it are discussed, the paper consists largely of demonstrations including a demonstration of the side‐band nature of flutter, the influence of room acoustics on the perception of flutter, the auditory effects of flutter in single frequency tones, and a demonstration of the auditory effects of frequency modulation in speech and music.

The paper describes the technique and apparatus of sound picture recording and reproduction, with emphasis on their electrical engineering aspects. The various steps in the processes of disk and film recording are outlined as they take place in the Western Electric systems. Microphone placements, sound insulation, monitoring and mixing, and the circuits for amplifying currents and distributing them to recording machines are discussed. This is followed by a description of the disk and film recording machines. The changes which have been required in theater equipment to provide for the reproduction and projection of sound in synchronism with motion pictures are outlined. Some of the laboratory developments and studies out of which recording and reprodutction methods have grown are given brief mention.

(1959). The Implications of Engineering Unionism—Western Electric Experience. Research Management: Vol. 2, No. 3, pp. 149-157.

Shipboard electrical installations present special problems for insulating materials that may not exist in shore installations. As naval vessels necessarily are built to a high degree of compartmentation requiring forced ventilation and also have large capacity power plants installed in relatively small spaces, there is perhaps more insulation per cubic foot of available engine room space than exists in land installations. Many naval vessels are complete cities in themselves. An electric fire in a surface ship is extremely dangerous — an electric fire in a submarine is a hazard. For this reason, all electrical-insulating materials used in naval vessels are screened at present carefully to determine their suitability at elevated temperatures and the effects of noxious gases produced on thermal decomposition of these materials. In order to determine the effects of temperature and operation time upon the production of noxious gases from silicone-insulated rotating equipment under condition of simulated submarine service, the Naval Medical Research Institute set out to find the answer to this problem for the Bureau of Ships.

A preliminary investigation of the ingestion of commercial products containing alcohol among Native Americans in the United States is described. A survey of Indian Health Service Clinic physicians found 1121 persons to be abusing these products. The products most frequently ingested were hair spray and spray disinfectants. The abuse of these products, nicknamed "Montana Gin," has been found in 14 states. Very little is known about the effects of ingestion of these products and further research is needed.

Frequency modulation of a sound signal produces some very interesting and sometimes not readily identifiable auditory sensations. Distortion of this type is caused in sound records by the nonuniform speed of the record during the recording or reproducing process.While the physical nature of frequency modulation and some of the physiological effects produced by it are discussed, the paper consists largely of demonstrations including a demonstration of the side‐band nature of flutter, the influence of room acoustics on the perception of flutter, the auditory effects of flutter in single frequency tones, and a demonstration of the auditory effects of frequency modulation in speech and music.