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: The headphone preferably comprises a toroidal seal ring which rests against or surrounds the user's ear and is constituted of a soft, yielding, and preferably elastic material. The seal ring, with the headphone positioned on the head of a user, forms a coupling space between an active diaphragm, actuated by an electroacoustic transducer, and the auditory canal of the user's ear. This coupling space is substantially sealed from the exterior of the headphone, and is formed with at least one opening and preferably several openings each receiving a respective passive oscillatory diaphragm having a definite self-resonance. Each passive diaphragm is associated with a sound path leading therefrom to the open air, to the back side of the active transducer diaphragm, or to acoustically effective cavities. Respective acoustic frictional resistances are associated with each passive diaphragm. The arrangement of the passive diaphragms relative to the active transducer diaphragm may take various forms.

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.

Abstract: The headphone comprises a low frequency transducer system and a high frequency transducer system, with the low frequency transducer system including an electrodynamic transducer. The high frequency transducer system includes an electrostatic transducer, and a supply transformer for the high frequency transducer system is mounted in the housing of the headphone. The two transducer systems are mounted coaxially of each other, with the high frequency transducer system being outwardly of the low frequency transducer system. The high frequency system may have a disc form or may have an annular form and, in the latter case, the inner diameter of the high frequency system corresponds to the outer diameter of the low frequency system which is received in a circular recess of the high frequency system.