Abstract: An input signal representing speech is preamplified, filtered, and fed foward in parallel to Automatic Gain Control (AGC) circuitry and to a gain controllable amplifier. The AGC detects the peak absolute value of the input signal, charing a capacitor in accordance with such detections. The capacitor is discharged at a faster rate (variable down to 1 msec) when a greater charge value is stored but at a slower rate (variable up to 4 seconds) when a lower charge value is stored. The gain controllable amplifier is controlled for gain inversely to the charge value stored on the capacitor. The AGC captures greater than 60 dB of allowable input signal range, compressing such input signal into a (controllable) limited amplitude dynamic range.

Abstract: A power efficient hearing aid uses a programmable biasing technique to set the quiescent operating points of amplifiers used by the hearing aid to avoid excessive power usage by the hearing aid. The hearing aid also includes power supply circuitry which develops +1.25 volts and -1.25 volts relative to ground from a single +1.25 volt source. The hearing aid also conserves power by selectively disabling low frequency signal processing channels in the presence of relatively large amplitude ambient noise.

Abstract: The present invention concerns an electronic device for processing a sound signal, said device being of the type comprising: means for receiving said sound signal and for transforming it into an electric signal, means for processing said electric signal, and means for restoring a modified sound signal from said processed electric signal. According to the invention, the device includes means (8) for selecting at least one band of frequencies of said signal, said means being disposed between said means (1) receiving the sound signal and said processing means (10) of the corresponding electric signal. In particular, the invention is applicable to hearing aids.

Abstract: An audio system for automotive vehicles with a plurality of speakers disposed inside the passenger compartment room of the automotive vehicle which includes a front speaker disposed at the front end of passenger compartment room and a rear speaker disposed at the rear end of passenger compartment room, front fader unit which is connected to the front speaker and is capable of transmitting mainly low frequency sounds by fading high frequency sounds, rear fader unit which is connected to the rear speaker and is capable of fading both high and low frequency sounds, and control unit for actuating said front fader unit and rear fader unit so as to control the balance of the front and rear speakers.

Abstract: A midrange loudspeaker driver of the cone diaphragm and magnetic coil type having a reflection free zone immediately behind the diaphragm and within the driver to significantly reduce internal reflections of the diaphragm's rear waves resulting in improved clarity and transparency of sound.

Abstract: An electrical component combination having a receiver and an amplifier. The receiver has three pins extending from its front surface. The amplifier has six pads on its rear surface. The pins are bonded to three of the pads providing electrical and mechanical connection between the receiver and amplifier. The other pads may provide frequency control, power control and gain trim. The combination is placed within a hearing aid housing. The housing may be an in the ear type. The combination provides electrical and mechanical access to the components. The components may be receivers, amplifiers, pre-amplifiers, filters, microphones or other such components.

Abstract: In a hearing aid with a microphone, an amplifier and a receiver supplying amplified sound to the user, a second signal path is provided comprising a second, feedback-suppressing microphone, placed at a location to receive feedback-causing sound from the receiver. The output of second provided microphone is suitably attenuated and delayed by an amount .DELTA.t corresponding to the effective acoustical distance a+b between the second microphone and the main microphone and supplied to a difference amplifier in opposition to the signal from the main microphone. Thus, the component of the signal from the main microphone likely to cause positive feedback or "howling" is substantially cancelled out. In another embodiment, the feedback-suppressing signal path is an acoustical path comprising a tube leading to a rear cavity in a microphone of the directional or differential type.

Abstract: A multi-channel electronic visual aid device which is able to signal to the user whether sound is coming from the left or right, front or back, or both. For the plurality of channels, which may operate in pairs, the sound is picked up by a respective microphone and amplified and rectified into a DC voltage. The DC voltage is next fed to an analog to digital converter and then to a digital encoder. The binary code from the encoder is coupled into a logic circuit where the binary code is decoded to provide a plurality of output levels which are used to drive an indicator which, in turn, provides a visual indication of the sound level received. The binary codes for each pair of channels are also fed into a digital comparator.

Abstract: In a folding type telephone apparatus of folding type comprising a first housing and a second housing rotatably connected by a hinge, electric components and printed circuit boards of respective housings are connected by an electrical connecting member of a tape shaped flexible printed circuit which is wound at least two times around a shaft of the hinge. Using the wound electrical connecting member maintains a reliable electrical connection between the housings even after the telephone apparatus has been used for a long time.

Abstract: A speaker system has an acoustic diaphragm and an image projection screen provided on a surface of the diaphragm integrally therewith so as to enable the user to enjoy both realistic image on the screen and powerful sound reproduced through the diaphragm. The rear surface of the diaphragm is closed at a peripheral portion thereof while the central portion of the rear surface of the diaphragm is opened to the exterior, so that the speaker system can provide a high level of reproduced sound pressure in low-pitched region, while the thickness of the speaker is reduced remarkably. The diaphgram can be driven by a plurality of driving units so that the speaker system can operate only with an ordinary stereophonic amplifier.

Abstract: An electronic filter for an electroacoustic system. The system has a microphone for generating an electrical output from external sounds and an electrically driven transducer for emitting sound. Some of the sound emitted by the transducer returns to the microphone means to add a feedback contribution to its electical output. The electronic filter includes a first circuit for electronic processing of the electrical output of the microphone to produce a filtered signal. An adaptive filter, interconnected with the first circuit, performs electronic processing of the filtered signal to produce an adaptive output to the first circuit to substantially offset the feedback contribution in the electrical output of the microphone, and the adaptive filter includes means for adapting only in response to polarities of signals supplied to and from the first circuit.

Abstract: A moving coil loudspeaker including a bobbin, a cone secured to the bobbin by cement, a spider secured to the bobbin by the cement, a voice coil including a first electrical wire that is wrapped around the bobbin and has ends supported by the bobbin, and flexible second and third electrical wires for making electrical connection of the first electrical wire to external circuitry, the second and third wires being connected to the ends of the first wire by connections that are anchored on the bobbin by the cement securing the spider and the cone to the bobbin.

Abstract: The present invention comprises an apparatus and method for inserting into, orienting within, and withdrawing from an ear a hearing aid, earphone, transducer, microprocessor, radio, sensor, or other mechanical or electronic device. The apparatus includes a housing attached to and containing the device. The housing has slots in which a handle, which is secured inside the housing, can slide. A magnet placed proximate the handle causes the handle to slide out, away from the housing, making it easy to grasp. The device can thus be inserted in, oriented within, or withdrawn from the ear by use of the handle. In its rest position, the handle lies flush against the housing making it almost visually imperceptible.

Abstract: A whole-surface driven speaker includes first and second support plates having sound-passing perforations and groups of magnets mounted on the plates. The plates are substantially parallel to each other. A diaphragm is disposed in between the plates. A plurality of conductor strips are mounted on the surface of the diaphragm. The strips are connected to receive pulse-code modulated signals. The strips respectively correspond to a plurality of binary bits of the signals of different bit significance. Each strip has a predetermined width and a predetermined number of windings and carries a predetermined current magnitude such that electromechanical forces on the diaphragm caused by the bit signals flowing through the strips are proportional to the respective bit significance of the strips.

Abstract: A whole surface driven speaker includes a diaphragm of an insulating plastic sheet carrying a conductor coil pattern. A foamed mica plate is bonded to the diaphragm. Two groups of permanent magnets are arranged on both sides of the diaphragm and oppose each other with pole faces of the same polarity across the diaphragm but with poles faces of opposite polarity adjoining each other on each side of the diaphragm.

Abstract: In order to prevent howling in a hearing aid (10) having a microphone (1), an amplifier (3) and a receiver (4) the hearing aid is provided with a second microphone (2) which is only sensitive to sound near to it. The microphones (1, 2) are connected to the amplifier (3) in anti-phase relative to each other.

Abstract: A hearing aid faceplate assembly includes a faceplate having a volume control/switch receiving aperture. A volume control/switch integrated circuit assembly is mounted within the aperture. The volume control/switch integrated circuit assembly includes a module substrate, an amplifier mounted to the substrate and a volume control mounted to the substrate and electrically coupled to the amplifier.

Abstract: A hearing aid has a microphone, an amplifier and a receiver and at least one frequency-defining element in series with a switch connected to the amplifier. For telephone listening, the switch is closed and the frequency-defining element lowers the high frequencies in the incoming signal from the telephone receiver so that a comfortable tone results for the hearing-impaired person using the telephone. The frequency-defining element may be a part of a frequency-dependent voltage divider, a part of a frequency-dependent negative feedback circuit, or a component in a resonant circuit.

Abstract: An accessory communication device for telephone sets includes: a wearer's harness member made of a flexible material for being manipulated to be worn around a user's neck; a pair of earphone arrangements each having a flexible cord and a connector provided thereto detachably held at the opposing sides of the wearer's harness member for being comfortably positioned in a user's ears; and a transmitting fixture having electric circuits and connecting members respectively disposed therein for making electrical connections with the earphone arrangements and a telephone set so as to effect communication transmitting and receiving operations therewith.

Abstract: An elastic or shock-absorbing support member for a microphone. The support member includes a single hose member shaped in the form of an elastic loop. In comparison to its other dimensions, the elastic loop has a very thin wall and an inner diameter which is approximately twice the width of the loop. The loop connects a clamping piece supporting the microphone or the microphone housing to a connecting piece of a tripod.