Abstract: Improved approaches of designing and fitting hearing aids to make hearing aids more accessible to people with hearing loss are disclosed. The hearing aids can be capable of being fitted by users themselves or by other non-hearing specialists. In one embodiment a hearing aid can be self-calibrating. In another embodiment, hearing aids can be fitted, i.e., configured, for individuals with hearing loss using a simplified procedure that hearing aid users or non-hearing specialists can easily follow.

Abstract: Method and apparatus for environment detection and adaptation in hearing assistance devices. Performance of feature extraction and environment detection to perform adaptation to hearing assistance device operation for a number of hearing assistance environments. The system detecting various noise sources independent of speech. The system determining adaptive actions to take place based on predicted sound class. The system providing individually customizable response to inputs from different sound classes. In various embodiments, the system employing a Bayesian classifier to perform sound classifications using a priori probability data and training data for predetermined sound classes. Additional method and apparatus can be found in the specification and as provided by the attached claims and their equivalents.

Abstract: A method of noise reduction of low-level input signals in a hearing aid involves applying compression to the input signal using a first compression ratio if a detected measure of amplitude modulation in the input signal is below a selected modulation level, and using a second compression ratio if the measure of amplitude modulation is above the selected modulation level. This reduces the volume of low-level steady-state noise while increasing the volume of modulated signals, e.g. speech. A hearing aid having a noise reduction system (10) has means for determining a level of amplitude modulation from a noise level and an absolute average level of an input signal, and comprises a dynamic compressor having a first compression ratio and a second compression ratio. The means for determining the level of amplitude modulation is configured to control the dynamic compressor in such a way that, below a predetermined input level, unmodulated sounds are amplified less than unmodulated sounds.

Abstract: A sound processing apparatus, a sound processing method and a hearing aid efficiently emphasize the sound of an utterer regardless of the distance between microphones. The sound processing apparatus outputs a first directivity signal in which the main axis of directivity is formed in the direction of the utterer and outputs a second directivity signal in which the dead zone of directivity is formed in the direction of the utterer. The sound processing apparatus calculates the level of the first directivity signal and the level of the second directivity signal, and determines the distance to the utterer based on the level of the first directivity signal and the level of the second directivity signal. The sound processing apparatus derives a gain to be given to the first directivity signal according to the result of the determination and controls the level of the first directivity signal by using the gain.

Abstract: A hearing apparatus and a method thereof for processing a noise included in an input signal are provided. The method of processing noise involves: pairing a hearing apparatus with an electronic appliance; extracting noise characteristic information of the paired electronic appliance; and processing noise from the electronic appliance included in an input signal based on the noise characteristic information.

Abstract: A hearing device includes: a microphone for converting audio into an audio signal; a preprocessing unit for analog processing of the audio signal and having an input and an output, wherein the input is connected to an output of the microphone; an A/D converter for converting the processed analog audio signal into a digital audio signal, the A/D converter having an input and an output, wherein the input of the A/D converter is connected to the output of the preprocessing unit; and a processing unit for digital processing of an output from the A/D converter, wherein the processing unit is connected to the preprocessing unit, and is configured to apply a first transfer function to the audio signal in a first mode of operation, or a second transfer function with a cutoff frequency to the audio signal in a second mode of operation, depending on a control signal.

Abstract: The user's personal intention is conveyed to a hearing aid using a method that does not place heavy physical and psychological loads. A hearing aid to be worn by a user for auditory compensation comprises: at least one microphone which converts a sound to an input signal; a hearing-aid signal processing unit configured to generate an output signal from the input signal; a receiver which outputs, as a sound, the output signal generated by the hearing-aid signal processing unit; and a hearing-aid processing control unit configured to generate control information for controlling signal processing, based on a non-audible sound which is made by the user and is hard to hear from outside, wherein, when the hearing-aid processing control unit generates the control information, the hearing-aid signal processing unit is configured to generate the output signal according to the generated control information.

Abstract: A fitting device for fitting a hearing device to compensate for a hearing loss of a user is disclosed, the hearing device comprising a receiver and a microphone, wherein a feedback path exists between the receiver and the microphone, wherein the hearing device further comprises an adaptive feedback canceller configured to reduce feedback, the adaptive feedback canceller comprising a fixed filter corresponding to an invariant portion of the feedback path, and an adaptive filter corresponding to a variant portion of the feedback path, the fitting device comprising a processor configured to determine the invariant portion of the feedback path, wherein the processor is configured to provide the fixed filter with information relating to the invariant portion of the feedback path independently of the user using the hearing device.

Abstract: Disclosed herein is a system for binaural noise reduction for hearing assistance devices using information generated at a first hearing assistance device and information received from a second hearing assistance device. In various embodiments, the present subject matter provides a gain measurement for noise reduction using information from a second hearing assistance device that is transferred at a lower bit rate or bandwidth by the use of coding for further quantization of the information to reduce the amount of information needed to make a gain calculation at the first hearing assistance device. The present subject matter can be used for hearing aids with wireless or wired connections.

Abstract: Disclosed herein, among other things, are methods and apparatus for improved noise reduction for hearing assistance devices. In various embodiments, a hearing assistance device includes a microphone and a processor configured to receive signals from the microphone. The processor is configured to perform noise reduction which adjusts maximum gain reduction as a function of signal-to-noise ratio (SNR), and which reduces the strength of its maximum gain reduction for intermediate signal-to-noise ratio levels to reduce speech distortion. In various embodiments, the hearing assistance device includes a memory configured to log noise reduction data for user environments. Also provided are methods to further adjust the noise reduction based on the logged information.

Abstract: A method for operating a hearing device and a hearing device are provided. Electrical acoustic signals are generated by the hearing device from a recorded ambient sound, the electrical signals being weighted according to their degree of matching with a predefinable acoustic signal class and being mixed together to form an output sound signal. The weight of the acoustic signal is greater or lesser, the greater the extent of the degree of matching.

Abstract: This disclosure relates to measurement of maximum stable gain of a hearing assistance device, including but not limited to hearing aids, as a function of frequency. In various approaches an adaptive filter with a variable step size is used to determine maximum stable gain as a function of frequency. In various approaches, the determination is done in process steps performed by the hearing assistance device. In various approaches, the determination is done in process steps performed by the hearing assistance device and by a host computer.

Abstract: A noise suppressor selects, for individual frequency components, maximums by comparing a plurality of noise suppressed spectra 105 and 106 a plurality of noise suppressing units 4 and 5 output, thereby obtaining an output spectrum 107 having the frequency components selected as its components. A first noise suppressing unit 4 generates a noise suppressed spectrum 105 by multiplying an input spectrum 102 by amplitude suppression gains, and makes the amplitude suppression gains greater than most of the amplitude suppression gains in a noise signal intervals of a second noise suppressing unit 5.

Abstract: A hearing device has a signal-processing apparatus for processing an input signal into an output signal, and a feedback-canceller apparatus for reducing feedback artifacts on the basis of the input signal and the output signal. The feedback-canceller apparatus has an adaptive, first filter, for establishing a set of filter coefficients for a predefined feedback situation. The feedback-canceller apparatus is configured to store the set of filter coefficients. It has at least one second filter, which can be operated directly parallel to the first filter on the basis of the stored set of filter coefficients. The adaptive, first filter can be continuously adapted to a current feedback situation, and the feedback-canceller apparatus is configured such that in the current feedback situation it automatically selects either the first or the second filter. As a result, it generally only requires a simple switchover, but not a complete adaptation.

Abstract: An input signal is provided with a low microphone noise in a hearing apparatus. The microphone noise in the input signal of the hearing apparatus is reduced, by the input signal being filtered by a Wiener filter, if a noise power determined at the input signal is smaller than a predetermined limit value. The Wiener filter is however deactivated, if the noise power is greater than the limit value or equal to the limit value.

Abstract: This document provides a hearing assistance device for playing processed sound inside a wearer's ear canal, the hearing assistance device comprising a first housing, signal processing electronics disposed at least partially within the first housing, a first microphone connected to the first housing, the first microphone adapted for reception of sound, a second microphone configured to receive sound from inside the wearer's ear canal when the hearing assistance device is worn and in use and microphone mixing electronics in communication with the signal processing electronics and in communication with the first microphone and the second microphone, the microphone mixing electronics adapted to combine low frequency information from the first microphone and high frequency information from the second microphone to produce a composite audio signal.

Abstract: A method estimates noise power spectral density (PSD) in an input sound signal to generate an output for noise reduction of the input sound signal. The method includes storing frames of a digitized version of the input signal, each frame having a predefined number N2 of samples corresponding to a frame length in time of L2=N2/sampling frequency. It further includes performing a time to frequency transformation, deriving a periodogram comprising an energy content |Y|2 from the corresponding spectrum Y, applying a gain function G(k,m)=f(?s2(km),?w2l (k,m?1), |Y(k,m)|2), to estimate a noise energy level |?|2 in each frequency sample, where ?s2 is the speech PSD and ?w2 the noise PSD. It further includes dividing spectra into a number of sub-bands, and providing a first estimate |{circumflex over (N)}|2 of the noise PSD level in a sub-band and a second, improved estimate |{circumflex over (N)}|2 of the noise PSD level in a subband by applying a bias compensation factor B to the first estimate.

Abstract: The present application discloses methods, systems, and hearing prostheses for reducing wind noise and/or thermal noise in an audio signal transmitted to the user of a hearing prosthesis. A method in accordance with the present disclosure includes utilizing delay-sum beamforming to improve the signal-to-noise ratio in an audio signal that contains wind noise and/or thermal noise. In the presence of at least one of wind noise and thermal noise, amplitudes and phases of at least two input signals are matched. The two signals are then added together, resulting in an average improvement in the signal-to-noise ratio of the signal transmitted to the user of about 3 dB.

Abstract: A novel system prevents surrounding sound to enter through a hearing apparatus, for instance through a ventilation opening, and reach an eardrum of the wearer in the form of interference sound. Contrary to auditory accessories designed especially to protect against noise, it is not possible for many hearing apparatus to compensate for such an interference sound by means of active noise cancellation. The hearing apparatuses do not have the special components needed. No compensation sound signal can therefore form with a correct phase. In accordance with the invention, a compensation sound is only generated for a relatively narrow spectral band. This spectral band is determined as a function of a hearing ability of the wearer of the hearing apparatus and/or as a function of a spectral distribution of the energy of the interference sound or a sound producing the interference sound. The improvement is particularly suited to compensating for an interference sound in a hearing device.

Abstract: A hearing device includes: a microphone for converting audio into an audio signal; a preprocessing unit for analog processing of the audio signal and having an input and an output, wherein the input is connected to an output of the microphone; an A/D converter for converting the processed analog audio signal into a digital audio signal, the A/D converter having an input and an output, wherein the input of the A/D converter is connected to the output of the preprocessing unit; and a processing unit for digital processing of an output from the A/D converter, wherein the processing unit is connected to the preprocessing unit, and is configured to apply a first transfer function to the audio signal in a first mode of operation, or a second transfer function with a cutoff frequency to the audio signal in a second mode of operation, depending on a control signal.

Abstract: A portable audio device has a voice coil audio signal processor in which a desired audio content signal is combined with an anti-noise signal produced by an active noise cancellation block. A voice coil amplifier receives a volume setting and is coupled to an output of the voice coil audio signal processor. A speaker is coupled to an output of the voice coil amplifier. In addition, a telecoil audio signal processor also receives the desired audio content, and feeds a telecoil amplifier that receives a telecoil coupling strength setting, followed by a telecoil. Other embodiments are also described and claimed.

Abstract: A hearing assistance device includes two transducers which react to a characteristic of an acoustic wave to capture data representative of the characteristic. The device is arranged so that each transducers is located adjacent a respective ear of a person wearing the device. A signal processor processes the data to provide relatively more emphasis of data representing a first sound source the person is facing over data representing a second sound source the person is not facing. At least one speaker utilizes the data to reproduce sounds to the person. An active noise reduction system provides a signal to the speaker for reducing an amount of ambient acoustic noise in the vicinity of the person that is heard by the person.

Abstract: A method and apparatus for providing uplink signal-to-noise ratio (SNR) estimation in a wireless communication system. A first signal is received over a first channel and a second signal is received over a second channel, where the second signal is received at a higher signal power level than said first signal. A signal-to-noise ratio (SNR) of the second signal is measured, and the SNR of the first signal is determined based at least in part upon the measured SNR of the second signal.

Abstract: A howling suppression device includes: a subtractor which generates an error signal; an adaptive filter which applies filtering to the error signal; and a coefficient update control unit which controls an update rate of a filter coefficient and includes: a convergence analysis unit which determines whether or not a condition that the degree of convergence of filter characteristics is higher than a criterion value is satisfied; a change amount analysis unit which determines whether or not a condition that the degree of convergence has turned out to be higher is satisfied; and an update rate control unit which sets the update rate to a first rate when both the conditions are satisfied and to a second rate when at least one of the conditions is not satisfied. The adaptive filter updates the filter coefficient at the update rate.

Abstract: Provided is an external noise shielding apparatus and method for use in a hearing aid device. The external noise shielding apparatus and method periodically monitors and shields external noise introduced into the hearing aid device to thus enable a user to discernibly hear a voice signal even in the external noise environment.

Abstract: A hearing aid (62, 72, 82, 92, 102, 112) adapted for alleviating tinnitus of a user (75), comprises an audio input means (83), a signal processing unit (88, 98, 108, 118) and an output transducer (80). The hearing aid further comprises a band stop filter (87) arranged to match a tinnitus of the user and switching means (86, 116) and switch control means (84, 114) for controlling the switching of said band stop filter (87) into and out of the signal path between the audio input means (83) and the output transducer (80), in response to a predefined trigger event. The invention further provides a method of adjusting a hearing aid.

Abstract: A method comprises processing M subband communication signals and N target-cancelled signals in each subband with a set of beamformer coefficients to obtain an inverse target-cancelled covariance matrix of order N in each band; using a target absence signal to obtain an initial estimate of the noise power in a beamformer output signal averaged over recent frames with target absence in each subband; multiplying the initial noise estimate with a noise correction factor to obtain a refined estimate of the power of the beamformer output noise signal component in each subband; processing the refined estimate with the magnitude of the beamformer output to obtain a postfilter gain value in each subband; processing the beamformer output signal with the postfilter gain value to obtain a postfilter output signal in each subband; and processing the postfilter output subband signals to obtain an enhanced beamformed output signal.

Abstract: A method for a multi microphone noise reduction in a complex noisy environment is proposed. A left and a right noise power spectral density for a left and a right noise input frame is estimated for computing a diffuse noise gain. A target speech power spectral density is extracted from the noise input frame. A directional noise gain is calculated from the target speech power spectral density and the noise power spectral density. The noisy input frame is filtered by Kalman filtering method. A Kalman based gain is generated from the Kalman filtered noisy frame and the noise power spectral density. A spectral enhancement gain is computed by combining the diffuse noise gain, the directional noise gain, and the Kalman based gain. The method reduces different combinations of diverse background noise and increases speech intelligibility, while guaranteeing to preserve the interaural cues of the target speech and directional background noises.

Abstract: A call other than a conversion partner call and various sounds are detected by input audio signals from plural microphones without deteriorating a voice recognition precision. A hearing aid apparatus according to the present invention corrects a frequency characteristic of the call voice other than the conversation partner voice based on an arrival direction of the call voice other than the conversation partner voice, which is estimated based on the audio signal converted by the plural microphones, checks a call word standard pattern representing features of a phoneme and a syllabic sound based on other voice data picked up by using the microphones having one characteristic against a call voice other than the conversation partner voice in which the frequency characteristic is corrected by the frequency characteristic correction processing unit to determine whether the call voice is a call word, and forms a directivity in the direction other than the arrival direction of the voice of the conversation partner.

Abstract: A system and method for use in filtering of an acoustic signal are provided for producing an output signal of attenuated amount of diffuse sound in accordance with predetermined parameters of desired output directional response and required attenuation of diffuse sound. The system includes a filtration module and a filter generation module including a directional analysis module and filter construction module.

Abstract: A method for processing the signals from two or more microphones in a listening device, and a listening device for conducting the method which has a casing holding the microphones, a signal processing unit which provides an output signal corresponding to the microphone signals and suited to the user's hearing, and a receiver unit for delivering the output signal to the user whereby the signals from the microphones are analyzed in order to detect when the casing of the listening device is being touched, whereby further the signal processing of the signal processing unit changes whenever touching of the casing is detected.

Abstract: A hearing aid has improved immunity to RF electromagnetic interference produced from wireless communications devices. A microphone receives audio signals from the environment. Audio circuitry is connected to the microphone and amplifies the audio signals. A speaker is connected to the audio circuitry and directs the audio signals into an ear canal of the user of the hearing aid. The audio connection lines connect the microphone and audio circuitry and the speaker and audio circuitry. A filter is connected into each of the audio connection lines and operative for reducing the RF coupling from a wireless communications device.

Abstract: Described herein are an apparatus and method for displaying the signal processing effects of a hearing upon speech. Such visual speech mapping may include displaying text corresponding to words spoken to a patient wearing a hearing aid as derived from an input signal derived from the hearing aid. The text is displayed with indicia representing the effects of the signal processing function performed by the hearing aid upon individual letters or groups of letters.

Abstract: An encoding method and apparatus and a decoding method and apparatus are provided. The decoding method includes skipping extension information included in an input bitstream, extracting a three-dimensional (3D) down-mix signal and spatial information from the input bitstream, removing 3D effects from the 3D down-mix signal by performing a 3D rendering operation on the 3D down-mix signal, and generating a multi-channel signal using a down-mix signal obtained by the removal and the spatial information. Accordingly, it is possible to efficiently encode multi-channel signals with 3D effects and to adaptively restore and reproduce audio signals with optimum sound quality according to the characteristics of an audio reproduction environment.

Abstract: Disclosed is a method of reducing feedback in a hearing aid adapted to be worn by a user, the method comprising the step of: receiving an audio input signal in an input transducer in the hearing aid; wherein the method further comprises the steps of: transforming the input signal into the frequency domain; dividing the audio signal into a plurality of frequency bands; determining a threshold frequency over which a plurality of upper frequency bands lies; multiplying each of the plurality of upper frequency bands by a random phase, thereby obtaining a plurality of phase randomized upper frequency bands; synthesizing the plurality of phase randomized upper frequency bands and the lower frequency bands to an output signal; transforming the output signal into the time-domain; and transmitting the output signal to an output transducer of the hearing aid.

Abstract: A system is provided for training and improvement of noise reduction in hearing assistance devices. In various embodiments the system includes a hearing assistance device having a microphone configured to detect sound. A memory is configured to store background noise detected by the microphone and configured to store a previous recording of speech. A processor includes a training module coupled to the memory and configured to perform training on a binary classifier using programmable feature extraction applied to a sum of the speech and the noise. The processor is configured to process the sound using an output of the binary classifier.

Abstract: In order to enable better estimation of dynamic interference noise, a device and a method for estimating interference noise provide a value for the power density of a total signal, containing a wanted signal and the interference noise to be estimated, in a current time window. The value of the total signal is compared with an estimated value, multiplied with an amplification factor, of interference noise from a time window prior to the current time window and the smaller of the two values from the comparison is used as a preliminary estimated value for the interference noise in the current time window. A codebook estimated value for the interference noise in the current time window is also provided. Finally, the larger of the preliminary estimated value and the codebook estimated value is used as the estimated value for the interference noise in the current time window.

Abstract: A multiband dynamics compressor implements a solution for minimizing unwanted changes to the long-term frequency response. The solution essentially proposes undoing the multiband compression in a controlled manner using much slower smoothing times. In this regard, the compensation provided acts more like an equalizer than a compressor. What is applied is a very slowly time-varying, frequency-dependent post-gain (make-up gain) that attempts to restore the smoothed long-term level of each compressor band.

Abstract: A device for in-ear sound generation comprises a sound determining unit adapted to determine a first sound signal, a sound collecting unit exposed to the ear canal and adapted to collect a second sound signal, a sound correction determining unit adapted to determine a third sound signal, and a loudspeaker exposed to an ear canal and adapted to emit the third sound signal The third sound signal includes the first sound signal and a correction component, the correction component essentially corresponding to a weighted and phase-inverted signal. The phase-inverted signal is obtained by phase inversion from a difference signal essentially corresponding to a difference between the second sound signal and the first sound signal.

Abstract: Adaptive notch filters can be used to estimate offending frequencies caused by feedback within a hearing aid system. The offending frequencies can be suppressed by filtering. Offending frequencies can be identified based on variability of the adaptive notch filter parameters.

Abstract: Hearing assist devices and devices and services that are capable of providing external operational support thereto are described. In accordance with various embodiments, the performance of one or more functions by a hearing assist device is assisted or improved in some manner by utilizing resources of an external device and/or service to which the hearing assist device may be communicatively connected. Such performance assistance or improvement may be achieved, for example and without limitation, by utilizing power resources, processing resources, storage resources, sensor resources, and/or user interface resources of an external device or service to which the hearing assist device may be communicatively connected.

Abstract: A hearing assist device is associated with an ear of a user. Health characteristics of the user are measured by sensors of the hearing assist device. The measured health characteristics may be analyzed in the hearing assist device, or transmitted from the hearing assist device for remote analysis. Based on the analysis, alerts, instructions, and other information may be displayed to the user in the form of text or graphics, or may be played by the hearing assist device in the form of sound/voice. Medical personnel may be alerted when problems with the user are detected by the hearing assist device. The user may provide verbal commands to the hearing assist device. The hearing assist device may be configured to filter sounds, and may be configured for a personal hearing frequency response of the user. The hearing assist device may be configured for speech recognition to recognize commands.

Abstract: The determination of a suitable step size for controlling the adaptation of a filter of an acoustic feedback compensator especially for hearing aids is to be improved. A step size controller is therefore provided in which an input signal is analyzed in at least two frequency bands. In doing so, any steep signal edges in the individual frequency bands are detected. The adaptation step size of an adaptive filter is then controlled depending on the number of frequency bands in which steep signal edges are detected, wherein the magnitude of the signal edges can be included in the decision.

Abstract: A noise reduction is provided for a hearing apparatus, with which both stationary and also non-stationary interference noises can be attenuated in an input signal. An output signal is in this way to convey a quite sound impression. A signal processing is provided, which effects a noise reduction on the basis of two different methods. Provision is made on the one hand for a noise reduction for stationary interference noises and on the other hand for a noise reduction for spatially oriented interference noises. A selection facility selects between the two noise reductions.

Abstract: A hearing aid includes an ambient microphone configured to receive and convert environmental sound into an electronic input signal, a hearing loss processor configured to compensate the electronic input signal in accordance with a hearing loss of a user of the hearing aid, and to generate an electronic output signal, a receiver, an ear canal microphone configured for converting ear canal sound pressure including subsonic energy into an ear canal signal, an occlusion suppressor connected for reception and processing of the ear canal signal, and for transmitting an occlusion suppression signal, a signal combiner configured for combining the occlusion suppression signal and the electronic output signal to form a combined signal, and for transmitting the combined signal to the receiver, and a subsonic filter for filtering subsonic energy, wherein the receiver is configured to receive the combined signal, and convert the combined signal into an acoustic output signal.

Abstract: An apparatus and method for active cancellation of interference at a hearing assistive devices are presented. The apparatus includes an interference cancellation circuit for cancelling an interference component of a composite signal, and an activator circuit for enabling interference cancellation circuit. The interference cancellation circuit generates an estimated replica of the interference from an interference profile, inverts the replica to form a cancellation waveform, then adds the cancellation waveform to the composite signal to cancel the interference component. An interference profile can be provided by performing a training sequence on a composite signal to detect a repetitive signal and building a profile using its parameters, retrieving a profile stored in memory, or using an antenna to capture an RF signal.

Abstract: There is presented a hearing aid that comprises an input transducer for transforming an acoustic input signal into an electrical input signal, a compressor for generating an electrical output signal from the electrical input signal, an output transducer for transforming the electrical output signal into an acoustic output signal, an autocorrelation estimator for calculating an autocorrelation estimate of the electrical input signal, and an acoustic loop gain estimator for determining a dynamic gain limit from the autocorrelation estimate and an instantaneous gain level of the signal processor. The invention further provides a method of adjusting signal path gain in a hearing aid, and a system for providing increased stability in a hearing aid.

Abstract: In a digital hearing aid device (1) frequency modification is employed above a lower spectral bound and in accordance with a compression factor. The frequency modification is dynamically adjusted in dependence on a sound environment analysis (10) or an end-user input (30), by modifying the frequency modification parameters such as a lower spectral bound and a compression factor. The adjustment can be based on an interpolation between predefined parameters. In certain sound environments, such as loud noise, own-voice and telephone conversations, frequency modification is reduced or switched off. The proposed solutions have the advantage that the occurrence of disturbing noise and of distortions of harmonic relationships at the end-user's ear is reduced and signal processing resources as well as battery resources are saved.

Abstract: A method for processing signals including an input, an output and a signal processor, comprising detecting a first periodic signal received at an input, adjusting frequency or phase of the first periodic signal in response to detecting the first periodic signal, comparing an amplitude of the first periodic signal before adjusting the frequency or phase to the amplitude after adjusting the frequency or phase to produce a first amplitude change and determining whether the first periodic signal is an acoustic feedback signal based on the first amplitude change. Apparatus including signal processing electronics to receive an input signal from a microphone and programmed to provide phase or frequency changes to signals in a processing channel and to detect periodic feedback signals based on the changes of signals in the processing channel, and a speaker. Variations include feedback reduction or cancellation systems and phase or frequency adjustment systems.

Abstract: Feedback whistle in hearing devices is intended to be able to be suppressed without loss of output of the useful signal. To this end, it is provided to establish or predetermine a frequency range which is susceptible to feedback. From an input signal which has a spectral component in the frequency range susceptible to feedback, a predeterminable component is substituted with a synthetic signal. Mixing-in a synthetic signal is also possibly used to widen the spectrum of an input signal, which is limited.