Abstract: A directional microphone system is disclosed, which comprises circuitry for low pass filtering a first order signal, and circuitry for high pass filtering a second order signal. The system further comprises circuitry for summing the low pass filtered first order signal and the high pass filtered second order signal. A method of determining whether a plurality of microphones have sufficiently matched frequency response characteristics to be used in a multi-order directional microphone array is also disclosed. For a microphone array having at least three microphones, wherein one of the microphones is disposed between the other of the microphones, a method of determining the arrangement of the microphones in the array is also disclosed.

Abstract: A system for programming hearing aids utilizing a multi-electrode programming strip. The strip is removably attached to a connector and inserted into the aid through a narrow slot in the faceplate; the slot is bounded by the faceplate and by one of the edges of the battery door. When the door is closed, the strip (and the electrodes thereon) is urged against corresponding terminals located inside the aid.

Abstract: A receiver for converting electrical energy to acoustical energy, and a method of manufacturing the receiver, are disclosed. The receiver comprises an armature having a peripheral edge, a magnet stack and a weld joint for attaching the armature to the magnet stack at the peripheral edge of said armature. The method comprises providing an armature having a peripheral edge, providing a magnet stack adjacent said armature, and welding said armature to the magnet stack at the peripheral edge of said armature.

Abstract: A headset including a housing, a resilient, convex headband fixed to the housing, an earphone fixed to the housing and displaceable relative to one end of the headband and a microphone fixed to a swivel arm that is on the housing. The headband has two spaced hinge joints arranged such that interconnected portions of the headband are pivotable towards one another from a position of use into a closed position in which the portions face one another. A retainer locks the headband in the closed position.

Abstract: The present invention relates to a hearing aid receiver (10) having a coil (12) with a tunnel (14) therethrough, a magnetic structure (16) having a central magnetic gap (18), an armature (20), and a fluid (30, 32) with a viscosity greater than air to provide shock protection to the receiver (10). The tunnel (14) and the magnetic gap (18) collectively form an armature aperture (28). The armature (20) extends through the armature aperture (28). The fluid (30, 32) lies within the armature aperture (28).

Abstract: A potentiometer is disclosed that provides a user with tactile feel while making adjustments. The potentiometer includes a housing having a central bore with a rotor extending therein. A knob having a protrusion is operably connected to the rotor along with a wiper. A detent member having a lobe attachment segment and a fixed segment is operably connected to the housing. The lobe is deflected by the knob protrusion while the ring is compressed by forcing the lobe attachment segment towards said fixed segment. Furthermore, attached to the housing is a base plate carrying a resistive strip engaged by the wiper.

Abstract: A programmable electrical switch having a housing and a plurality of single-switch-position conducting leads which are positioned in two substantially aligned rows is disclosed. Each of the leads has a proximal end that is disposed within the housing and a distal end that extends outwardly from the housing. The leads are disposed in the housing so that they are electrically independent of one another. The switch may also have a conducting bridge electrically interconnecting the leads in each of the rows. The switch also includes a moveable conductive contact that is positioned between a pair of opposing leads to electrically bridge a gap between the opposing leads.

Abstract: A miniature transducer such as for an in-the-canal hearing aid, is disclosed. The transducer comprises a housing formed of a top cup joined to a bottom cup and defines an interior and an exterior. The bottom cup includes a base surface and a plurality of interconnected walls. The transducer further comprises a motor including a coil, a stack and an armature disposed substantially within the bottom cup. The housing includes an opening and a portion of the stack extends outwardly through the opening. Because the stack extends outwardly through the opening, the overall thickness of the transducer is reduced.

Abstract: Multiple embodiments of a solid state condenser transducer, and methods of manufacture, are disclosed. The transducer comprises a semi-conductor substrate forming a frame and having an opening, a thin-film cantilever structure forming a diaphragm extending over a portion of the opening, the structure having a proximal portion and a distal portion. The proximal portion is attached to the frame, and the distal portion extends over a portion of the frame. A variable gap capacitor having a movable plate and a fixed plate is provided, wherein the movable plate is disposed on the distal portion of the structure and the fixed plate is disposed on the frame adjacent the movable plate.

Abstract: An impedance matching, reducing, or buffering circuit for permitting smooth signal flow from a first transmission medium to a second transmission medium. The circuit provides a first node adapted for coupling to the first transmission medium and for receiving a signal from the first transmission medium. The circuit further provides a buried channel transistor, that is coupled to the first node and that is biased by additional circuit devices, for transforming the impedance imposed on the signal. The use of the buried mode transistor reduces noise on the surface of the transistor while at the same time keeps other performance standards high. The circuit additionally provides a second node that is coupled to the buried channel transistor and that is adapted for coupling to the second transmission medium for conveying the signal to the second transmission medium.

Abstract: A housing for shielding a transducer of the type mounted on a silicon die attached to a flexible circuit. The housing provides a jacket which protects the silicon die from physical damage. The jacket, in cooperation with the top and bottom cups, further provides a shield for the silicon die from light and electromagnetic interferences. An acoustic port located on the top portion of the jacket furnishes the means by which acoustic energy enters the jacket to contact the transducer. A back cavity, formed between the bottom cup and the silicon die, serves as the acoustic pressure reference which allows the microphone to function properly.

Abstract: A unidirectional microphone assembly for receiving sound within a range of sound frequencies is disclosed. The microphone assembly comprises a housing formed of a sound absorbing material. The housing has an outer surface, and a bore extending inwardly along a bore axis from the outer surface to form a chamber within the housing. The microphone assembly further comprises a directional microphone having an axis of maximum reception. The microphone is disposed within the chamber and positioned with its axis of maximum reception directed outwardly substantially along the bore axis.

Abstract: A buffer circuit, such as for use with a low voltage hearing aid, is disclosed. The hearing aid comprises a microphone, a receiver and an amplifier. The amplifier is disposed between the microphone and the receiver. The buffer circuit has a MOS device including a well terminal and a gate terminal equipotentially coupled together to reduce the effective threshold voltage of the MOS device, thereby reducing the gate-to-source voltage of the MOS device. This permits a greater linear output signal range for the amplifier.

Abstract: An electret assembly for a microphone is disclosed. The microphone is adapted for use with a hearing aid. The electret assembly comprises a motor ring having first and second opposing peripheral surfaces and an aperture extending therebetween. The motor ring includes four generally co-planer ledges recessed below the first opposing surface and defining a rectangle. A charged plate is disposed on the ledges. The charged plate is substantially flush with the first opposing surface. A flexible diaphragm is secured to the second opposing surface and extending across the aperture. A bead of epoxy secures the charged plate to the motor ring.

Abstract: A solid state miniature condenser and condenser microphone of good sensitivity is disclosed. The microphone comprises a fixed perforated backplate that constitutes a fixed electrode in a parallel plate condenser, a diaphragm sensitive to incident sound pressure waves that constitutes a moveable plate in the parallel plate condenser, keepers to position the diaphragm in relationship to the backplate without applying appreciable tension to the diaphragm, and FET circuitry which provides an output proportional to the change in capacitance of the condenser when the diaphragm moves in relationship to the backplate.

Abstract: An impedance matching, reducing, or buffering circuit for permitting smooth signal flow from a first transmission medium to a second transmission medium. The circuit provides a first node adapted for coupling to the first transmission medium and for receiving a signal from the first transmission medium. The circuit further provides a buried channel transistor, that is coupled to the first node and that is biased by additional circuit devices, for transforming the impedance imposed on the signal. The use of the buried mode transistor reduces noise on the surface of the transistor while at the same time keeps other performance standards high. The circuit additionally provides a second node that is coupled to the buried channel transistor and that is adapted for coupling to the second transmission medium for conveying the signal to the second transmission medium.