Abstract: A method of fabricating an ear canal impression which includes the steps of (a) placing a covering on the tympanic membrane of a hearing-impaired person, (b) marking the junction between the bony and cartilaginous portions of the auditory canal, (c) introducing an ear canal impression material into the auditory canal, (d) and allowing the ear canal impression material to harden to form the ear canal impression whereby the ear canal impression includes an indentation on its surface corresponding to said marking is provided. The ear canal impression is then employed to fabricate an ear canal mold for a completely-in-canal hearing aid device. In this fashion, the hearing aid when placed in the auditory ear canal is assured to fit and rest snugly on the bony canal. This prevents the device from shifting away from the tympanic membrane and, therefore, reduces the opportunity for positive feedback and discomfort for the individual.

Abstract: A thin diaphragm for contacting an individual's tympanic membrane is sufficiently stiff and flexible to vibrate in response to audio frequencies so as to augment or over-ride the displacement of the individual's tympanic membrane in order to increase the acoustic efficiency of the tympanic membrane at all frequencies but particularly above 1000 Hz so as to improve mild hearing loss.

Abstract: A method for forming a standardized faceplate for an individually adapted in-the-ear hearing aid shell which matches the physical characteristics of the hearing aid user's ear, and for fabricating an individually-adapted in-the-ear hearing aid shell made of radiation-reactive material and a battery compartment therein.

Abstract: An integrated circuit chip set design for a wireless hearing aid communication system including a battery operated transceiver unit worn in the vicinity of the ear of the user and a compact battery operated transmitter/receiver unit worn by or in close range of the user. The basis of the integrated circuit chip set design is to optimize circuit size, speed, power, and manufacturability for a personal use wireless audio communication system using the reflective transmission technology. Power and speed consideration of the circuits are designed to accommodate wireless audio RF reflective transmissions for a close range to the user. The transceiver and the receiver of the system are designed to switch between certain transmission states in order to facilitate rapid switching between a first mode in which the transmitter is transmitting to the receiver and a second mode in which the transceiver is transmitting to the receiver.

Abstract: A method for fabricating an individually adapted in-the-ear hearing aid shell with a battery compartment cast into the shell such that the door of the battery compartment is flush or slightly recessed in the portion of the shell that contacts the user's ear cavity.

Abstract: Topologies for Class AB amplifiers which have reduced quiescent power consumption are disclosed. An exemplary amplifier according to the present invention comprises two transconductance amplifying cells, each having an output transistor. Each output transistor is biased such that it conducts a small quiescent current which is preferably sufficient in magnitude to reduce amplifier distortion. The class AB amplifiers are well suited for low power supply voltage applications, such as hearing aids.

Abstract: An improved audio compressor of the type which is used in a hearing aid and having a programmable compression ratio is disclosed. In the preferred embodiment, the compressor includes a variable gain limiter which provides variable gain amplification of the input signal and as a further function of a programmable control signal. A feedforward circuit is disposed in parallel to the variable gain limiter and provides a fixed gain signal. The output of the limiter and the feedforward circuit are combined at a summing node, which serves as an output. The gain curve of the compressor defines a sigmoid function having a pivot midway between the upper and lower break points.

Abstract: An inconspicuous hearing system is described that uses a coil to electromagnetically couple with, and therefore drive, a permanent magnet attached to the tympanic membrane or ossicular chain. This hearing system enables hearing impaired individuals, as well as persons with normal hearing, to selectively receive sound signals in a wide variety of hearing environments while avoiding socially or aesthetically unacceptable stigmas associated with visible wires, headphones, earpieces, etc.

Abstract: An improved audio compressor of the type which is useful in a hearing aid and having a programmable compression ratio is disclosed. In the preferred embodiment, the compressor is used in a hearing aid device of the type which comprises a bandsplit filter to divide an input audio signal into a plurality of frequency bands. Associated with each frequency band is a limiter means which provides variable gain amplification of the input signal as a function of the amplitude of the input signal and as a further function of a programmable control signal. A feedforward means is disposed in parallel to the limiter means, said feedforward means providing a fixed gain signal. The output of the limiter means and the feedforward means are combined at a summing node which forms the input to a variable gain amplifier. Associated control circuitry allows the limiter gain to be programmed to meet the needs of an individual user. The compressor has a variable compression ratio in the form of a sigmoid function.

Abstract: The present invention comprises a hearing system apparatus and method for electromagnetically communicating signals to a magnetic transducer. The apparatus includes a signalling circuit for producing a pulse-width modulated current signal. An antenna means is coupled to the signalling circuit for producing a variable electromagnetic field whose energy intensity is modulated by the output of the signalling circuit. In addition, an energy storage circuit is coupled to the antenna for storing a substantial portion of the energy stored in the magnetic field produced by the antenna when the magnetic field collapses between cycles of the current signal. Also, an energy recycling circuit is coupled to the storage circuit and the antenna for recovering the energy stored in the storage circuit for use in the next electromagnetic field cycle.

Abstract: A contact transducer assembly for an electromagnetically driven hearing device such as a hearing aid or other audio signal reproducing device worn by a user is described. The contact transducer assembly includes a transducer which is attached to a biocompatible support. This assembly is supported on the tympanic membrane of the wearer by surface adhesion, such that it can be readily inserted and removed in a manner similar to that of a conventional contact lens worn on the eye.

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 method and apparatus for discriminating the data signal of a transmitter means. Binary encoded data is transmitted between a transmitter means and a receiver means in an amplitude modulated signal varying about a threshold level. A means and method are included for determining the number of threshold crossings of the carrier during each of a number of discrete successive time intervals. A further method and means characterizes those of said time intervals wherein the number of threshold crossings equals or exceeds a first predetermined number as a mark, and those of said time intervals wherein the number of threshold crossings does not exceed said predetermined number as a null. The number of successive marks not separated by a predetermined number of nulls is then counted by a further aspect of the method and means.

Abstract: A programmable low voltage compressor circuit suitable for use with hearing aids is described. The compressor has a continuously variable compression ratio wherein the gain of the compressor may be programmably controlled over a wide range and the compressor may be powered from a power source as low as 1.1 volt. The compressor employs a variolosser wherein the gain is controlled by the ratio of the currents flowing out of first and second control terminals. A control circuit coupled to the variolosser controls the magnitude of the currents flowing out of the two control terminals. The control circuit includes a peak detector which generates a signal related to the peak positive envelope of the signal input to the compressor. A voltage to current converter is coupled to the peak detector for increasing the magnitude of the current flowing out of one of the control terminals of the variolosser as the voltage output of the peak detector increases.

Abstract: A programmable low voltage multi-band compression system suitable for use with hearing aids is described. Received audio signals are processed by a band split filter which separates the received audio signal into a plurality of frequency bands. A plurality of compressors coupled to the band split filter compresses each of the respective frequency bands. The output of the compressor are then summed to generate a composite audio signal. The compression ratio of each of the compressors is set, in response to a set of control signals, to a preselected independent value. The average gain of each of the compressors is set to a preselected level independently of the other compressors. In addition, the compression ratio of each compressor may vary with input signal level. Another set of control signals is employed for setting the gain of the compressor to provide a volume control function.

Abstract: An improved variable gain circuit is described having an input for an audio signal and an output for an audio signal. An operational amplifier having inverting and non-inverting inputs and an output has its input connected to the audio input. The first differential cell having inverting and non-inverting inputs, output, and a first control current terminal, has one input connected to the output of the operational amplifier and the other input connected to a reference potential. The output of the first differential cell is connected to one of the inputs of the operational amplifier in negative feedback relation and a source of controlling current is connected to the control current terminal. The second differential cell is also provided having inverting and non-inverting inputs, an output, and a second control current terminal. One input of the second differential cell is connected to the output of the operational amplifier and the other of the inputs is connected to the source of reference potential.

Abstract: A method and apparatus are described for treating hearing impairment in a human. The external auditory canal is substantially enlarged surgically in region proximate the ear drum. An electronic hearing aid is placed in this region. The hearing aid has a external housing molded to conform with the shape of the surgically enlarged region.

Abstract: An improved variable gain circuit is described having an input for an audio signal and an output for an audio signal. An operational amplifier having inverting and non-inverting inputs and an output has its input connected to the audio input. The first differential cell having inverting and non-inverting inputs, output, and a first control current terminal, has one input connected to the output of the operational amplifier and the other input connected to a reference potential. The output of the first differential cell is connected to one of the inputs of the operational amplifier in negative feedback relation and a source of controlling current is connected to the control current terminal. The second differential cell is also provided having inverting and non-inverting inputs, an output, and a second control current terminal. One input of the second differential cell is connected to the output of the operational amplifier and the other of the inputs is connected to the source of reference potential.