Patent classifications
H04R25/453
Feedback control using a correlation measure
A hearing aid is configured to be worn in and/or at an ear of a user, and comprises a) an input transducer for converting an input sound to an electric input signal representing sound, b) an output transducer for converting a processed electric output signal to an output sound, c) a signal processor operationally coupled to the input and output transducers and configured to apply a forward gain to the electric input signal or a signal originating therefrom, wherein the input transducer, the signal processor and the output transducer forming part of a forward path of the hearing aid. The hearing aid further comprises d) a feedback control system for compensating for acoustic or mechanical feedback of an external feedback path from the output transducer to the input transducer, wherein the feedback control system comprises i) a feedback estimation unit for providing a feedback estimate signal of said external feedback path, ii) a combination unit located in the forward path for combining the electric input signal or a signal derived therefrom and the feedback signal detected by said estimation unit, to provide a resulting feedback corrected signal, iii) a correlation detection unit configured to determine a correlation measure between said feedback corrected signal and said output signal, said correlation detection unit further configured to provide a processed version of said correlation measure.
Methods, systems, and devices for adaptively filtering audio signals
Systems, methods, and devices for adaptively filtering audio signals are disclosed. An example system includes a microphone configured to generate a first audio signal in response to receiving a sound, an output transducer configured to provide an output, and a sound processor configured to: (i) filter a first sample of the audio input signal using an adaptive filter to provide a first filtered audio input signal, with the dynamic range of the adaptive filter being limited by an initial value of at least one parameter filter; (ii) process the first filtered audio signal to provide a output audio signal; and (iii) cause the output transducer to provide an output that is based at least in part on the output audio signal. Adaptive signal modeling may be used to update the adaptive filter, with model and the initial value of at least one parameter filter being based on environmental classifier.
MAGNET POSITIONING IN AN EXTERNAL DEVICE
A button sound processor, including an RF coil, such as an inductance coil, and a sound processing apparatus and a magnet, which can be a permanent magnet, wherein the button sound processor has a skin interface side configured to interface with skin of a recipient, and the button sound processor is configured such that the magnet is installable into the button sound processor from the skin interface side.
Noise canceling headphones
The headphones (10) comprise: a transducer (16) (12); an noise-canceling processing chain (30, 40) comprising: a microphone (31, 41); a noise-canceling processing filter (34, 44) which comprises in series: a stabilisation filter (34A, 44A) whose transfer function is substantially equal to the inverse of the transfer function of the processed secondary path, and a noise cancellation filter (34B, 44B) whose transfer function is a noise cancellation transfer function. The secondary path is formed between the transducer (16) and the eardrum, and the transfer function of the processed secondary path is the transfer function of the secondary path combined with the transfer functions of the processing components, excluding the processing filter (34, 44).
Method and apparatus for feedback suppression
A method and apparatus reduce feedback in a hearing aid. The method involves a first transfer function, which includes a feedback path, being estimated for a first section of a signal response. A power of a feedback signal from a second transfer function of the feedback path is estimated for a second section of the signal response, and a parameter of the signal processing device and/or of the feedback suppression unit is adjusted on the basis of the estimated power.
CONFIGURABLE HEARING AID COMPRISING A BEAMFORMER FILTERING UNIT AND A GAIN UNIT
The application relates to a hearing aid comprising a forward path comprising a) a multitude of input units for providing a multitude of electric input signals IN.sub.i, i=1, . . . , M, representative of sound, b) a multi input beam former filtering unit for providing a beam formed signal Y.sub.BF from said multitude of electric input signals, c) a gain unit for applying a hearing aid gain G.sub.HA to said beam formed signal Y.sub.BF, and providing a processed signal, and d) an output unit for providing stimuli perceivable by a user as sound based on said processed signal or a signal derived therefrom. The hearing aid further comprises e) a gain control unit for limiting said hearing aid gain G.sub.HA to a modified full-on gain value G′.sub.FOG. The multi input beam former filtering unit is configured to apply a current frequency dependent directional gain G.sub.DIR,i to each of said multitude of electric input signals IN.sub.i, and the gain control unit is configured to determine the modified full-on gain value G′.sub.FOG in dependence of said current directional gains G.sub.DIR,i, i=1, . . . , M, and a previously determined full-on gain value G.sub.FOG. Thereby an improved hearing aid is provided. The invention may e.g. be used for hearing instruments, headsets, or active ear protection systems.
Method for suppressing interference noise in an acoustic system and acoustic system
A method for suppressing interference noise in an acoustic system with a microphone that generates an input signal and a loudspeaker that generates an acoustic signal which partially feeds back to the microphone. A first intermediate signal is formed along a primary signal path as a function of the input signal, and an output signal is formed via a frequency distortion. The output signal is coupled into a signal feedback path. A second intermediate signal is formed in the signal feedback path via a decorrelation and used as an input value for an adaptive filter. The adaptive filter generates a compensation signal which compensates the input signal. A third intermediate signal is formed from the input signal and/or compensated input signal, which is used as an input value for the adaptive filter. The output signal is fed to the loudspeaker for reproduction.
Detection of feedback path change
Methods and systems for signal processing an audio signal in a hearing device to detect when feedback path change occurs and controlling an adaptive feedback canceler to remove the feedback are provided. The hearing device includes a receiver and a microphone. An exemplary method includes detecting whether a tonal signal is caused by a feedback path change by estimating a product of a subband error signal and a subband output signal generated in response to a subband audio input signal; estimating a fast metric based on the estimated product and estimating a slow metric; and applying or maintaining an adaptation rate to the adaptive feedback canceler of the hearing device, wherein the adaptation rate applied or maintained is selected based upon a value of the difference between the fast and slow metrics compared to a threshold value.
Feedback Reduction For High Frequencies
A digital signal processor processes acoustic sound in a body-worn hearing assist device including separating the microphone signal into frequency bands. Two of the frequency bands, which are preferably adjacent, are considered as a pair. In one of the frequency bands in the pair, the band signal is replicated/split into two subsignals. One of the subsignals is frequency shifted into the other frequency band of the pair. The input signal from the paired frequency band is either significantly attenuated or altogether discarded. The unshifted subsignal is attenuated relative to the frequency-shifted subsignal, which is preferably amplified, before both subsignals are combined as part of the acoustic output. Considering both frequency bands as a pair, the likelihood of feedback is significantly reduced or eliminated.
HEARING DEVICE WITH ADAPTIVE PINNA RESTORATION
A hearing device includes: a pinna restorer for provision of a pinna output based on a first pinna input and a second pinna input, wherein the first pinna input is based on a primary first microphone input signal, and wherein the second pinna input is based on a primary second microphone input signal, the pinna restorer comprising: a first filter for provision of a first mixer input based on the first pinna input, a second filter for provision of a second mixer input based on the second pinna input, a first mixer for provision of a first mixer output based on the first mixer input and the second mixer input, and a pinna controller; and an input mixer for provision of an input mixer output based on the pinna output and a secondary mixer input, wherein the secondary mixer input is based on a secondary microphone input signal.