Abstract: In a device for producing artificial reverberation by means of a one-dimensional waveguide, a one-dimensional waveguide is utilized, which is obtained using digital circuits which contain at least two line sections of different length, each line section consisting of two parallel digital delay arrangements, one for each direction of propagation. At least one three-gate adapter of the digital wave filter type is arranged between two line sections lying side by side, each of two gates of the three-gate adapter being connected with one of the two mutually facing ends of these two line sections, and the dependent gate of the three-gate adapter being terminated with a frequency-dependent absorber of the digital type. By using a digital one-dimensional waveguide with discontinuities and absorbers, it is possible to reverberate a signal diffusely and with a programmable frequency response of the reverberation time without the disadvantage of a reduced sound to noise ratio due to limit cycles.

Abstract: An arrangement for supporting electroacoustic transducers such as a microphone within a housing comprises a housing casing with a transducer within the casing supported by at least one elastic support ring provided between the transducer and the casing. The supporting ring is made of electrically conducting material providing electrical connection means to the housing. The housing itself or a portion thereof provides electrical terminal means for connecting the electrical transducer to an energy source.

Abstract: A mounting for an electroacoustic transducer particularly those having a cardioid directivity characteristic and which has one face with a sound opening and an opposite face comprises a cylindrical housing for the transducer with a first tapered elastic support permeable to sound being provided in the sound path from the sound opening the transducer to one end of the housing and which has a narrow end engaged with the housing and an opposite widened end engaging the transducer from one face side at the rim of the sound opening. A second tapered elastic support permeable to sound has one end engaging the transducer from the opposite face and has an opposite end engaged with the housing.

Abstract: A auxiliary device for adjusting a pickup and pickup arm of a record player is disclosed. The adjusting device has an L-shaped cross section and orienting gratings on the legs thereof for aligning the pickup and pickup arm when the stylus of the pickup is received on a contact point provided on the device.

Abstract: A sound inlet for microphones to inhibit noises caused by sonic pressure changes occurring in shocklike pulses is disclosed which includes, in the area in front of the diaphragm walls which extend the microphone housing and have sound entry channels with openings at its outer surfaces that are closer to the diaphragm plane than those located at its inner surface. A cavity enclosed by the extending walls is closed off at the front of the housing by a cap-shaped or a plug-shaped closure.

Abstract: In a diaphragm arrangement for electroacoustical transducers, in particular for headsets, one or more diaphragms lie in one plane which extends in the immediate proximity of the user's external ear and preferably parallel to the tangential plane of the user's external ear. In order to enable the use of the headset to better discern direction and distance by hearing, the diaphragm is divided into several coherent, preferably stripshaped sections or composed of several, preferably stripshaped part diaphragms which are adjacent or follow each other in that particular direction in which the user's ear is to locate the direction of sound incidence in the use position.

Abstract: A process of forming a sound needle for the scanning of mechanical sound carriers preferably records after the needle has been secured to a holder having a diameter comparable to the maximum diameter of the needle on the surface thereof opposite the needle tip and using a carrier having an opening therethrough, comprises reducing the diameter of the holder until it is a fraction of its original diameter, inserting the holder into the opening of the carrier and applying a securing material between the surface of the needle adjacent to and radially outwardly of the holder and to the carrier in the same area so as to secure the needle to the carrier, and reducing at least the major portion of the holder after the needle is secured to the carrier so as to leave only substantially a needle secured to the carrier.

Abstract: A directional microphone of the interference type comprising a single elongated tube having one or more longitudinal slots or side apertures therein, at least one electroacoustic transducer provided at one end of the tube and an acoustic reflector assembly provided at an opposite free end zone of the tube, by which, preferably, sound waves of the upper audio frequency range are concentrated toward the sound inlet of the interference tube at the opposite free end zone thereof. A directional microphone which is easy to handle and unites the advantages of an interference microphone with that of a reflector microphone is thus obtained.

Abstract: The arrangement for suppressing structure-borne sounds in microphones comprises an electroacoustic transducer which substantially includes a housing part, a diaphragm firmly connected to said housing and receiving the sound, and a corresponding transducer system and in which the electroacoustic conversion of the signal is based on the relative motion between the diaphragm and the transducer system, the natural resonance as well as the logarithmic decrement of said transducer system being at least approximately equal to the natural resonance and the logarithmic decrement of the diaphragm. Microphone types include moving voice coil, electrostatic, and ribbon.

Abstract: An ultrasonic converter having a single side, focused, substantially secondary radiation free directional characteristic, comprises an exponential horn-like directional element and a capacitative transducer with an electret diaphragm. A pre-staged resonator aids in controlling the directional characteristic. The capacitive transducer has an approximately bell-shaped curvature-like diaphragm velocity distribution which tapers off toward the diaphragm edge to improve the focusing which is achieved by employing a non-uniform charge across the surface of the electret diaphragm tapering off toward its edge and a backplate arrangement which supports the diaphragm at a plurality of selected points with a selected dimensioning of singular volumes behind the counter-electrode bores.

Abstract: An earphone comprises a housing including a partition plate with an opening containing a diaphragm. An annular cushion is secured to the periphery of the partition and engages around the wearer's ear to form a coupling space between the diaphragm and the ear. A back covering is connected to the partition defining a soundproof cavity between the partition and the back covering. A partial wall is spaced from the partition on a side opposite the diaphragm to define a first high restoring force cavity. A duct is connected from the restoring force cavity to the outside, and it encloses an air mass which acts as an acoustic mass.

Abstract: The headphone includes a cup-shaped case forming the coupling space and this cup-shaped case, in use, engages the user's head and encloses the user's ear. At least one electroacoustic transducer is included in the cup-shaped case, and the case either is designed as an acoustic frictional resistance or as a supporting structure of such a resistance. The headphone is equipped with acoustic and/or electrical systems compensating the drop at the low frequencies, and there are no reflecting surfaces located close to the external ear of the user. The low frequencies drop may be compensated by passive or blind diaphragms, or the diaphragm of the electroacoustic transducer may be coupled to an air mass. A headset, including two headphones, may be designed for quadraphonic reproduction.

Abstract: The headset comprises a head-encircling band which has a rectangular cross-section, and it includes one or two earpieces which have housings with rectangular slots engaged over and slidable on each band end. In addition, a microphone arm having a microphone at one end and an opposite end with a rotatable ring portion engages through a bore of the ring portion onto the band holding the earpieces or onto a similar band formed on the end of the earpiece housing.

Abstract: A packing receptacle for an article to be packed, in particular a headset, comprises a box and an insert which is removable from the box. The insert comprises a base part having an upstanding end wall at each end with a slot therein for securing the headset to the end walls and for supporting the head set on the base. When the insert is inside of the box, it holds the headset in the box in a manner such that it will be centered in respect to the walls of the box and held away from the walls in a protected position. When the insert is outside of the box, it comprises a stand which supports the headset for display or storage purposes.

Abstract: An electromagnetic or magnetodynamic transducer-sound pickup comprises a phonograph needle which is connected to either a permanent magnet or a soft iron magnetic member and which is mounted for oscillation in front of, or between a plurality of parallel spaced apart pole rods which are provided with energizing coils. The pole rods are connected at one end to a pole plate. Mechanical oscillations of the magnetic system are suppressed in the zone where the pole plate is connected to the pole rods or in the zone where the pole plate is connected to the permanent magnet by an envelope of plastic which is injection molded around the plate and the rods.

Abstract: A headphone earpiece for wearing on a person's ear, comprises an annular pad adapted to engage around the ear and a sound transducer having a transducer diaphragm supported within said pad so as to define a coupling space between the transducer diaphragm and the person's ear. The support means includes a rigid plate between the diaphragm and the pad which has frictional resistances distributed thereover and which may advantageously comprise the material of the plate itself or a plurality of openings or holes having acoustic frictional resistance elements therebehind or positioned in the holes. The rear portion of the support means includes a cap having perforations which covers the back portion of the transducer.

Abstract: An acoustical frictional resistance for electroacoustical transducers, comprises a blank sheet having a first plurality of impressions on its one surface which partially extends into the sheet and having an opposite surface with a second plurality of impressions which extend partially into the opposite surface and meet the first plurality of impressions. The first and second impressions are made so that they partially overlap and define acoustical passages through the sheet at the overlapping areas. The resistances are advantageously made of a thermoplastic material and they may be incorporated in a magnetic system, preferably by molding them integrally with an encapsulation of a magnet and its associated pot and by simultaneously forming passages in which the frictional resistances are placed.

Abstract: The device or arrangement transforms acoustic events, in the form of single-channel audio-frequency signals, into at least two-channel audio information with the monophonic audio-frequency signals being supplied by wireless transmission to a reproducing device, with unequal delays through the two channels, and without the incorporation of a transit-time or delay element in either channel. The device comprises a transmitting device operating on the wireless principle, and including at least one infrared transmitter and at least one ultrasonic transmitter which transmitters are simultaneously modulated with the same monophonic audio-frequency signals, and includes a reproducing device operating on the wireless principle and including at least one infrared receiver and at least one ultrasonic receiver.

Abstract: A sound pickup, for tracking mechanically modulated grooves in a record support by means of a tracing stylus, includes a stylus holder elastically mounted, at its center of motion, in a bearing element of rubber or rubber-like material. A small metal plate is embedded in the bearing element to extend perpendicularly to the longitudinal axis of the stylus holder, and has a central opening therein. The stylus holder passes through the central opening and the diameter of the central opening is slightly larger than the external diameter of the stylus holder in the zone of its passage through the central opening. The thickness of the plate is small relative to such external diameter of the stylus holder, and the stylus holder is connected to the plate only through the bearing element.

Abstract: An arrangement for headphones for converting frequency modulated audio oscillations into amplitude modulated oscillations, and particularly for rendering audible the vibrato of electronic musical instruments, such as electronic organs, includes a housing having an electroacoustic transducer therein with a diaphragm having a smooth frequency response zone which is connected to at least one mechanical transit-time member having a transit time from one end to the other not greater than 20 ms. The transit-time member is advantageously a helical spring which extends axially through the electroacoustic transducer or through a central ferromagnetic core thereof. The portion of the spring within the core is advantageously made of a thicker wire and of a smaller diameter than the remaining core so that it does not contact the walls thereof.