Abstract: A headset speaker is provided in which a driver is provided in the dome of a speaker earcup and the dome has at least one vent aperture. The vent hole is closed by a movable closure having a corresponding opening therein that permits the size of the opening into the dome to be logarithmically varied between a fully open and fully closed position. A Thuras tube tuned to enhance bass frequencies is provided extending between the driver side and rear of the earcup. An opening to the Thuras tube remains fully closed by the movable closure unless the cup vent aperture is fully closed at which time the Thuras tube is opened.

Abstract: A transducer assembly includes a bi-directional transducer coupled to an ear mold for transmitting and receiving sounds from a remote location. A by-pass channel is provided in the ear mold for ambient sounds which by-pass the transducer.

Abstract: A mounting for a microphone includes a plate with an opening the plate being shaped and arranged so that it holds a microphone secured in said opening with the microphone contacting a person's neck. In this position the microphone can pick up sounds produced by the person through bone conduction.

Abstract: A microphone assembly for mounting in a head gear of a person includes a microphone positioned in intimate contact with the person for receiving vibrations from the vocal cords by bone conduction, a housing for holding the microphone, a mounting ring for mounting the housing to the head gear and a damper element disposed between the microphone and the head gear for damping extraneous sides transmitted through the headgear before they are picked up by the microphone.

Abstract: A headset is provided which includes an inverted cup-shaped housing. The housing contains a rigid membrane which separates the housing into an upper chamber and a lower chamber. An inertial transducer is positioned in the upper chamber secured to the membrane. Electrical leads extend into the transducer through water tight connections. A headband is provided to secure the headset to a listener's ear and a cushion is provided about the open bottom end of the headset housing. Only the transducer itself is water tight. Both the upper and lower chambers of the housing freely permit the passage of water.

Abstract: An inertial transducer is provided comprising a housing containing therein a magnetic circuit including components thereof separated by a spring diaphragm wherein the flexing of the diaphragm causes the components to move toward and away from each other to induce a current in a coil. The spring diaphragm served to separate the housing into two tuned cavities, the frequencies of which differ from each other and from that of the spring diaphragm. The transducer has frequency response peaks at the resonant frequencies of the cavities and spring diaphragm.

Abstract: An improved stylus assembly for a phonograph cartridge is provided. The assembly includes an arm having a jeweled stylus attached to one end thereof. The arm is formed of a hollow aluminum tube which has been anodized so as to form an aluminum oxide skin about the outer surface thereof. The skin extends for no more than one-half the thickness of the arm.

Abstract: An electronic stethoscope for monitoring prosthetic valves for hearts includes a casing to which the center portion of a spring member is mounted. A weighted housing is mounted to the ends of the spring member and contains an opening therethrough in which a magnetic circuit comprising a pole piece, magnet and coil are positioned. The air gap between the pole piece and magnet is varied as the relative distance between the center of the spring and housing vary in response to the operation of a prosthetic heart valve thereby resulting in an induced voltage in the coil which may be amplified and monitored.

Abstract: A miniature sounder having a diaphragm closing one end of a tuned chamber. The other end of the chamber communicates with the interior of a tuned housing. The chamber and housing are both tuned to the desired oscillating frequency of the diaphragm with the chamber resonant frequency comprising substantially three times the desired frequency and twice the housing resonant frequency.

Abstract: A miniature sounder having a diaphragm closing one end of a tuned chamber. The other end of the chamber communicates with the interior of a tuned housing through which an open-ended enclosure extends. The oscillating frequency of the diaphragm. The housing and enclosure are tuned to resonate at the desired frequency.

Abstract: An improved speaker is provided for stereo headsets and the like. The diaphragm for the speaker comprises the dome of an inverted polyester film cup centered within a flurocarbon film diaphragm member. The voice coil for the speaker is wound directly about the periphery of the cup and the adhesive joint between the cup and the diaphragm comprises the sole adhesive joint of a diaphragm.

Abstract: A miniature buzzer for a pocket pager and the like is provided. The buzzer includes a support member in the form of a cylindrical collar having a bore extending therethrough. The bore is stepped with the step defining a knife edge. A pole piece surrounded by a coil and ring magnet extends toward the step. The ring magnet and a central portion of the pole piece define a plane spaced apart from the step. A diaphragm, backed by a magnetic armature seats on the knife edge for attraction/repulsion toward/from the pole piece. The coil is driven by an oscillator extends from the collar. The assembly is contained within a housing the volume of which is also tuned to the oscillator.

Abstract: An inertial-reaction microphone transducer mounting supported on the wearer's head away from the mouth for transmitting speech to the exclusion of ambient. A compliant, radial array of elastomer supporting material presses the transducer gently to the head. The transducer and supporting array may be mounted in a cup covering one ear, or it may be mounted in a capsule having an acoustical labyrinth frequency-selective vent for the neutralization of noise.