Abstract: A compact electro-acoustic transducer assembly is provided having a housing formed with an acoustic output socket extending longitudinally of the housing and at least one electro-acoustic transducer mounted on the housing in registration with the acoustic output socket. The housing is provided with an aperture for transmission of sound waves from the acoustic output of the transducer to the socket. Conductive leads are deposited on the surface of the housing for providing electrical connection between the transducer and a circuit board supporting the housing. The electrical input terminals to the transducer are surface mounted thereon for engagement against the conductive leads deposited on the housing. The transducer may be formed with a thin plate-like permanent magnet formed of a rare earth cobalt material and supported in a flux-retaining member.

Abstract: A control panel is provided incorporating a plurality of controls and an arrangement for the rapid mounting and demounting thereof in an aperture of a support. The mounting and demounting arrangement permits the retention of the panel with one side of the opening retained in a slot in a corresponding side of the panel and the other side of the opening being retained between a projection and a displaceable dog on the opposite side of said panel. Said dog is mounted on a bolt threaded in said panel for displacement between a first position in which the dog engages the wall of the opening and a second position wherein the dog is displaced both away from the wall of the opening in the axial direction of the bolt and pivoted by the bolt out of registration of the wall to permit release of the panel. The controls may include diaphragm-type push-button switches, slide switches and rotatable multi-position switches.

Abstract: An acoustic headset having a pair of elongated channel structures for carrying sound tubes which are provided with ear pieces situated adjacent upper end regions of the channel structures. These channel structures have distant from their upper end regions, respectively, lower end regions interconnected with each other by way of a connecting structure which forms a continuous, elongated, one-piece body with the pair of channel structures. The connecting structure interconnects the pair of channel structures for movement toward and away from each other while a releasable holding structure is connected with the pair of channel structures for releasably holding them at a selected distance from each other, so that in this way it is possible for the ear pieces to be accommodated to the distance between the ears of a given individual.

Abstract: An apparatus for transmitting the wearer's voice is mounted inside a breathing mask and includes a microphone and a protective sheath substantially encasing the microphone. The protective sheath includes a thin, pliable wall which is kept in contact with the sensing diaphragm of the microphone so that, when the wearer speaks and sets the sheath wall into vibration, the vibration is directly communicated to the microphone diaphragm. In one illustrative embodiment, the sheath is formed as an integral, continuous pocket in the mask body which extends inside the mask and has an opening out of the mask.