Widex A/s

Kristian Tjalfe Klinkby

Peter Magnus Norgaard

Helge Pontoppidan Foeh

Thilo Volker Thiede

Lars Baekgaard Jensen

Jorgen Cederberg

Henning Haugaard Andersen

Peter Magnus Noergaard

Helge Pontoppidan Föh

A hearing aid comprises at least one microphone (M) for converting input sound into an input signal, a subtraction node for subtracting a feedback cancellation signal from the input signal thereby generating a processor input signal, a hearing aid processor (G) for producing a processor output signal by applying an amplification gain to the processor input signal, a receiver (R) for converting the processor output signal into output sound, an adaptive feedback cancellation filter for adaptively deriving the feedback cancellation signal from the processor output signal by applying filter coefficients, calculation means for calculating the autocorrelation of a reference signal, and an adaptation means for adjusting the filter coefficients with an adaptation rate, wherein the adaptation rate is controlled in dependency of the autocorrelation of the reference signal.

Hearing aid, and a method for control of adaptation rate in anti-feedback systems for hearing aids

A signal processing apparatus () for a hearing aid with a controllable directional characteristic is provided which comprises a directional controller () receiving first and second microphone signals () and output an output signal (), a signal analyzer () which detects whether at least one of said first and second microphone signals being undesired signals, and wherein said directional controller minimizes the output signal by adjusting the directional characteristic only if the signal analyzer has detected undesired signals.

Method for controlling the directionality of the sound receiving characteristic of a hearing aid and a signal processing apparatus

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.

Hearing aid and method of estimating dynamic gain limitation in a hearing aid

A hearing aid includes a signal path for receiving at least one audio input signal and an autocorrelation index (ACI) estimator (). The ACI includes a down-sampler for producing a sampling-rate reduced signal of the audio input signal, a sign extractor for extracting a sign signal of the sampling rate reduced signal, a memory and delay for producing and storing delayed versions of the sign signal, a comparator for comparing a subset of the delayed versions of the sign signal with a version of the non-delayed audio input signal, and an averager for averaging the outputs of the comparator to extract delay specific estimates of the audio signal self-resemblance. An autocorrelation estimator obtains an estimated autocorrelation index by determining summarized features from the delay specific estimates of the audio signal self-resemblance. Also disclosed is a method and a computer program for controlling signal processing in a hearing aid.

Hearing aid and method for controlling signal processing in a hearing aid

A hearing aid comprises an input transducer () for deriving an electrical input signal from an acoustic input, a signal processor () for generating an electric output signal, an output transducer () for transforming the electrical output signal into an acoustic output, an adaptive estimation filter () for generating a feedback estimation signal, at least one first adaptive narrow-band filter () for narrow-band-filtering an input signal of the signal processor () at least one second adaptive narrow-band filter () for narrow-band-filtering a reference signal corresponding to an input signal of the adaptive estimation filter (), and an adaptation mechanism () for updating the filter coefficients of the adaptive estimation filter () based on the output signals of the first and second narrow-band filters. The invention further provides a method for reducing acoustic feedback and an electronic circuit.

Hearing aid with adaptive feedback suppression

A hearing aid comprises two microphones, directional processing means for combining the respective audio signals to form a spatial signal, a beamformer for controlling the directional processing means to provide adaptation of the spatial signal, and means for boosting low frequencies of the spatial signal. A feedback estimator generates a feedback compensation signal, which is combined with the boosted spatial signal. By applying feedback compensation only after directional processing and low frequency boosting, the device avoids interference by the feedback estimator with the function of the beamformer. The invention also provides a method of processing signals in a hearing aid.

Hearing aid and a method of processing input signals in a hearing aid

A hearing aid () with multiple microphones comprises a first microphone () for converting sound into a first audio signal, a second microphone () for converting sound into a second audio signal, directional processing means for combining the first and said second audio signal according to a mixing ratio to form a spatial signal, estimating means for estimating a first acoustic feedback signal entering the first microphone and a second acoustic feedback signal entering the second microphone, processing means () for processing said spatial signal by applying a gain not exceeding a resulting maximum gain limit to form a hearing loss compensation signal, wherein the resulting maximum gain limit is derived from the first and second acoustic feedback signals and the mixing ratio, and an output transducer () for converting the hearing loss compensation signal into an acoustic output. The invention further provides a method and a computer program product.

Hearing aid and method of utilizing gain limitation in a hearing aid

A hearing aid () comprises means () for reproducing frequencies above the upper frequency limit of a hearing impaired user. The hearing aid () according to the invention comprises means () for transposing higher bands of frequencies from outside the upper frequency limit of a hearing impaired user down in frequency based on a detected frequency in order to coincide with a lower band of frequencies within the frequency range perceivable by the hearing impaired user. The transposing means () comprise an adaptive notch filter () for detecting a dominant frequency in the lower band of frequencies, adaptation means () controlled by the adaptive notch filter (), an oscillator () controlled by the adaptation means (), and a multiplier () for performing the actual frequency transposition of the signal. The invention further provides a method for processing a signal in a hearing aid.

Hearing aid with enhanced high frequency reproduction and method for processing an audio signal

A hearing aid includes an input transducer for transforming an acoustic input signal into an electrical input signal, a processor for generating an electrical output signal by amplifying the electrical input signal with a processor gain, an output transducer for transforming the electrical output signal into an acoustic output signal, an adaptive feedback suppression filter for generating a feedback cancellation signal, and a model gain estimator generating an upper processor gain limit and for providing a control parameter indicating a possible misadjustment of the model.

Hearing aid with feedback model gain estimation

A hearing aid comprises an input transducer (), a subtraction node for subtracting a feedback cancellation signal from the electrical input signal thereby generating a processor input signal, a signal processor (), an output transducer (), a pair of equalization filters () for selecting from the processor input and output signals a plurality of frequency band signals, a frequency equalization unit for frequency equalization for the selected frequency band signals, and an adaptive feedback estimation filter () for adaptively deriving the feedback cancellation signal from the equalized frequency band signals. The equalization of selected frequency bands of the input signals of the adaptive feedback cancellation filter provides for an improved and in particular a faster adaption of the feedback cancellation. The invention further provides a method of reducing acoustic feedback of a hearing aid, and a hearing aid circuit.

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Varlose, Denmark

Kristian Tjalfe Klinkby