Abstract: Noise canceling transmitter for voice communications comprising a casing having a principal surface opposed to the mouth of the user and three side surfaces facing upwardly, laterally and downwardly when the principal surface is so opposed. Noise canceling openings in the three side surfaces communicate noise to the back of a diaphragm in the transmitter microphone. Openings in the principal surface communicate both noise and the speaker's voice to the front of the diaphragm. The noise acts on both sides of the diaphragm and is thus canceled, while the voice acts only on one side of the diaphragm and vibrates it.

Abstract: This telephone handset hanger is intended particularly for use on a vehicle. It includes a simplified and strengthened spring mechanism for holding the handset in place and an improved switch actuating mechanism.

Abstract: An amplifier for use in an audio communication circuit between a dynamic microphone and an output line. The amplifier produces a signal at the output having characteristics similar to those of a signal from a carbon microphone, i.e., noise is suppressed in the output line when no speech signal is present. The amplifier includes a main channel including two stages coupled through two arms of a T-pad. In the absence of a voice signaal from the microphone, the third arm of the T-pad is effectively grounded through a saturated transistor and thereby holds the main channel in a low gain condition. A signal integrator responds to the output of the first stage and integrates excursions of the voice signal above a predetermined level. As the integrated signal increases, it shifts the transistor gradually away from its saturated condition, thereby gradually increasing the gain of the main channel in response to initiation of a voice signal at the microphone.

Abstract: This transmitter is designed for installation in a telephone handset to replace a standard carbon transmitter, for the purpose of excluding the ambient noise from the telephone lines, so that only the voice of the speaker is transmitted. This transmitter is designed to be installed by a person unskilled in the telephone art. The orientation of this transmitter with respect to the handset structure is critical and is indicated to the person inserting it by markings on the face of the transmitter housing, together with appropriate instructions. This transmitter is of the carbon type, and has improved electrical connections between internal contacts which engage the carbon and external contacts which engage conductors in the handset housing.

Abstract: This headset includes a capsule intended for mounting over either ear of the wearer. The surface of the headset capsule adjacent to the ear is contoured to fit snugly behind either ear. A microphone is mounted on a boom projecting from the front end of the capsule. The boom is tiltable and rotatable so that the position of the microphone may be adjusted relative to the mouth. The rotatability of the boom on the capsule permits adaptation of the headset for wear over either the right or left ear. The boom is curved to keep it out of contact with the face of the wearer. An ear tube extends from the lower end of the capsule at the central plane thereof and is flexible so that it may engage either the right or left ear, depending on the location of the headset. The bottom of the capsule is provided with an ear clip for the purpose of maintaining the position of the capsule and microphone during motion of the head.

Abstract: This microphone has two opposed faces. The sound to be picked up may be directed toward either one of the two opposed faces with equivalent electrical output from the microphone in either case. Since background noise impinges equally on both of the two opposed faces, its effect on the microphone diaphragm is self-canceling, and causes substantially zero output from the transducer.

Abstract: This telephone apparatus includes a headset module and a station module. The headset is of a lightweight type which requires an amplifier for the electrical signal produced by the microphone, in order for the output signal to be compatible with conventional telephone switchboard apparatus. The headset module also includes electrical conductors extending from the microphone and earphone of the headset to a latchable plug forming part of a connector. The station module includes a receptacle for receiving the latchable plug, an amplifier and a connector plug engageable with a conventional receptacle. That connector plug may be part of a rigid assembly including the other parts of the station module, or it may be connected to that assembly by flexible conductors.

Abstract: This headset includes a single earphone and a boom mounted microphone. The headset is mounted on a yoke adapted to fit over a wearer's head with the transducers on either side of the wearer's head. The earphone transducer is in a housing spaced from the wearer's ear and coupled thereto through a flexible tube and an earpiece. A reversible microphone is mounted at the end of a curved conduit whose opposite end is supported on the housing by an electrical connector including an articulated plug assembly which permits rotation and tilting of the conduit with respect to the housing while maintaining electrical connections between the microphone and circuit elements within the housing. The conduit is curved to bring one side or the other of the microphone adjacent to the wearer's mouth when the headset is in place, and the curved conduit is properly positioned by appropriate rotation and tilting of the articulated assembly.

Abstract: This headset includes an earphone and/or a microphone. The headset is mounted on a yoke adapted to fit over a wearer's head with pad means at each end of the yoke for engaging the sides of the wearer's head at areas spaced above the ear. One of the pad means is apertured horizontally to receive a beam which extends in either direction from the pad means, so that that pad means can be placed on the wearer's head with the beam extending forwardly, whether that one pad is on the left or right. A housing is coupled to the forward end of the beam. When the headset includes an earphone, the earphone transducer is in the housing and an ear tube is coupled to the forwardly extending end of the beam and communicates through a hole in the boom with the earphone transducer. The beam is frictionally adjustable longitudinally of an aperture in a casing on the pad means.

Abstract: This headset includes an earphone and/or a microphone. The headset is mounted on a yoke adapted to fit over a wearer's head with pad means at each end of the yoke for engaging the sides of the wearer's head at areas spaced above the ear. One of the pad means is apertured horizontally to receive a beam which extends in either direction from the pad means, so that that pad means can be placed on the wearer's head with the beam extending forwardly, whether that one pad is on the left or right. A housing is coupled to the forward end of the beam. When the headset includes an earphone, the earphone transducer is in the housing and an ear tube is coupled to the forwardly extending end of the beam and communicates through a hole in the beam with the earphone transducer. The beam is frictionally adjustable longitudinally of an aperture in a casing on the pad means.