Abstract: Feedback detection, adaptive notch filtering, and gain adjustment are combined for managing feedback. Feedback detection includes detection of short term and long term spectral peaks and assessing their magnitude, shape, rate of growth, and power concentration ratio. A plurality of notch filters are available and are allocated according to the spectral magnitude of the feedback detected. Wide band gain adjustment supplements the notch filters.

Abstract: An earpiece includes an open tip in the shape of a dome, with apertures in the dome and a protrusion at the top of the dome for displacing ear wax, wherein the dome merges with the protrusion along a continuous curve. The dome is supported from a central body by non-linear ribs that normally have high compliance but exhibit low compliance at a limit of extension or compression. The tip can include more than one dome on the central body. If there is more than one dome, the apertures in the domes are not aligned with each other.

Abstract: A remote control unit includes an RF transceiver that complies with a Bluetooth® standard and an RF transmitter that does not comply with the Bluetooth® standard, whereby the remote control unit serves as a wireless gateway between Bluetooth® compliant devices and the hearing aid. The hearing aid can further include a transmitter and the remote control unit can further include a receiver, neither of which comply with the Bluetooth® standard. The transmitters operate in the ISM band at low power, minimizing power dissipation within a hearing aid.

Abstract: A hearing aid includes at least one capacitive switch for controlling or communicating with the hearing aid by touch. The capacitive switch is an electrode on the inside of the housing coupled to a touch detector. Touching the outside of the hearing aid adjacent the electrode produces a switching operation. The hearing aid includes a programmed microprocessor coupled to the touch detector. The microprocessor is programmed to effect predetermined functions in response to particular touch patterns.

Abstract: A maintenance station includes means for disinfecting, drying, recharging, and communicating with one or more hearing aids using light. In a preferred embodiment of the invention, a fluorescent lamp is primarily for disinfecting a hearing aid, an incandescent lamp is primarily for recharging a hearing aid, and a light emitting diode is primarily for communicating with a hearing aid. All power dissipated within the station aids in drying the hearing aids within.

Abstract: A hearing aid includes a case and a photovoltaic cell located in the case near a translucent portion of the case. A detector circuit includes a voltage comparator for monitoring the voltage from the photocell and indicating variations in voltage. The variations are analyzed to detect data for operating the hearing aid.

Abstract: A hearing aid includes a case, a photovoltaic cell located within the case, and a light gathering member optically coupled to the photovoltaic cell. The photovoltaic cell is preferably a multi-junction cell and the light gathering member gathers light at the wavelengths preferentially absorbed by the multi-junction cell.

Abstract: A hearing aid having a rechargeable battery and a charger for charging the battery includes a first microphone and a first speaker in the hearing aid and a second microphone and a second speaker in the charger for acoustically transferring data between the hearing aid and the charger. The hearing aid can detect the charge state of a battery and send a signal to the charger indicative of the charge state. The charger also includes a chamber for receiving at least a portion of the hearing aid.

Abstract: A hearing aid includes a secondary battery and means for identifying the kind of battery for charging. After the battery is identified, an appropriate algorithm for charging the battery is selected and used for charging the battery. Primary batteries are not charged. The hearing aid also includes a voltage reduction circuit for supplying a constant voltage to circuitry within the hearing aid. The battery preferably has an energy density greater than 500 watt-hours per liter.

Abstract: A hearing aid includes an antenna and is powered by one or more signals received by the antenna. At least some of the power for operating the hearing aid is derived from a received signal. Power not used for operation is used for charging a battery, if any, in the hearing aid. The signal can be modulated for one-way communication or there is two-way communication if the hearing aid includes a transmitter coupled to the same antenna or a second antenna.

Abstract: A hearing aid includes a speaker in a tip that is located in an ear canal. The tip includes a coupling, a retainer that mechanically engages the coupling, and a sleeve axially surrounding the retainer. The retainer attenuates lower frequencies than are attenuated by the sleeve. The sleeve is preferably a foam rubber and the retainer is preferably a composite material. A flange on the retainer reflects sound back into the sleeve for additional attenuation. It has been discovered that operation is improved if the outside diameter of the sleeve and the outside diameter of the retainer are in the ratio of approximately 1.75:1.

Abstract: A battery charger for a hearing aid includes a housing that defines at least one socket for receiving any one of a plurality of adapters. Each adapter closely fits and at least partially contains one hearing aid to hold the hearing aid in place during charging. The hearing aid includes a plurality of electrical contacts in a pattern and the adapter defines a plurality of apertures in the same pattern. Resilient contacts in the charger extend through the apertures in the adapter to contact the hearing aid.

Abstract: Noise reduction circuitry in a hearing aid includes a programmable filter coupled to a microphone coupled to the ear canal. The filter is programmed in a feedback loop in which the coefficients of the filter are set in accordance with a signal from the microphone. The filter is programmed for a transfer function that is substantially the inverse of the spectrum of the sound detected by the microphone to provide a relatively quiet chamber in the ear canal.

Abstract: A hearing aid having a plurality of frequency bands is calibrated by evaluating the response of the hearing aid in each band and programming the hearing aid to produce a specific sound pressure level in each band, thereby providing a calibrated instrument that can be used for both evaluation and compensation of hearing loss. The sound pressure levels are preferably the same for each band. The evaluation step is preferably performed at the center frequency of each band.

Abstract: A hearing aid is identified by storing a first binary code in the hearing aid as a first identification code, storing a second binary code in the hearing aid as a default code, and replacing the default code with a second identification code if a second hearing aid is used by the person using the first hearing aid. The identification code includes a bit indicating for which ear the hearing aid is intended. If two hearing aids are used, the identification code of the first hearing aid is substituted for the default code in the second hearing aid and vice-versa, thereby pairing the first hearing aid with the second hearing aid and indicating that there are two hearing aids needed, even if one hearing aid should become lost or inoperative.

Abstract: Data is transferred to and from a hearing aid by transmitting an audible carrier having a frequency greater than 5 kilohertz, modulating the carrier with data, and detecting the modulated carrier in the hearing aid with a narrow band filter. The frequency is in a region where impairment occurs and there are many other sounds, thereby masking the communication, yet not interfering with it.

Abstract: A hearing aid is identified by storing a binary code in the hearing aid, receiving a transmitted code, reading out a subset of bits from the stored binary code, and comparing the transmitted code with the subset for identification. The reading step preferably reads the lowest order nibble, byte, or word of the binary code. In accordance with another aspect of the invention, a charger for the hearing aid, a controller for the hearing aid, and a programmer for the hearing aid store the identification codes for two way communication among the devices.

Abstract: Hearing loss is evaluated and compensated by applying a hearing aid having substantially uniform frequency response across several bands of the audible spectrum, evaluating hearing loss in each band using the hearing aid, programming the hearing aid to compensate for the loss in each band, and using the hearing aid to compensate for hearing loss. The evaluation is preferably preceded by substantially canceling noise in the ear canal using the electronics in the hearing aid. In accordance with another aspect of the invention, the evaluation is not performed if a hearing aid is not recognized by a hand held programmer but the user has the option of programming a hearing aid with existing data. The evaluation optionally includes providing background noise in the ear not being evaluated to reduce the chance of cross-coupling during the evaluation.

Abstract: A hearing aid having a rechargeable battery and a charger for charging the battery include means for transferring data means for transferring data unidirectionally or bidirectionally between the hearing aid and the charger using either a magnetic field, light, or sound. The hearing aid includes means for detecting the charge state of a battery and for sending a signal to the charger indicative of the charge state. For acoustic coupling, the charger includes a microphone and a speaker and also includes a chamber for receiving at least a portion of the hearing aid.