Feedback Suppression Patents (Class 381/83)
  • Patent number: 10199030
    Abstract: A method and system for a noise cancellation comprises an amplifier in communication with the three or more speakers disposed in an area. A system controller produces a driver signal for each of the speakers in response to a signal from at least one microphone detecting sound in the area and communicates the driver signals to the amplifier. The amplifier drives each speaker with the driver signal produced for that speaker. In response to the driver signals, the speakers emit sound that combined produces a substantially uniform sound pressure field for a particular zone within the area. The substantially uniform sound pressure field produced by the speakers has a magnitude and phase adapted to attenuate a noise field in the area corresponding to the sound detected by the at least one microphone.
    Type: Grant
    Filed: March 22, 2017
    Date of Patent: February 5, 2019
    Assignee: Bose Corporation
    Inventors: Wade P. Torres, David Easterbrook, Paul T. Bender, David J. Warkentin, Steven H. Isabelle, Ryan C. Struzik
  • Patent number: 10178486
    Abstract: In embodiments of this invention howling sounds are removed without disturbing speech and music. Microphone signals are converted to the frequency domain where howling frequencies are detected and estimated using howling to noise ratios. A notch filter adaptively designed for the howling frequency is applied to remove the howling.
    Type: Grant
    Filed: June 19, 2014
    Date of Patent: January 8, 2019
    Assignee: Creative Technology Ltd
    Inventors: River Yuan, Steve Verity, Ian Minett, Robert Ridder
  • Patent number: 10101962
    Abstract: Commands for modifying audio playback, such as to mute and unmute or pause and play audio, may be input to a mobile device by a user through interacting with the speaker in the device. The user input may be facilitated by monitoring a characteristic of the speaker and identifying signatures in the changing characteristics of the speaker that correspond with predetermined user activities. For example, a resonance frequency of the speaker may be monitored for a change resulting from a user placing a hand to cover the speaker output. When the resonance frequency change is detected, the audio playback may be muted. The speaker may continue to be monitored for a change indicating removal of the user's hand, and then audio playback may be unmuted.
    Type: Grant
    Filed: June 28, 2016
    Date of Patent: October 16, 2018
    Assignee: Cirrus Logic, Inc.
    Inventors: Jie Su, Rong Hu
  • Patent number: 10070219
    Abstract: An acoustic feedback detection method and device. According to the method, whether acoustic feedback occurs is determined based on a frequency characteristic of an acoustic feedback signal. Specifically, a judgment value is determined using a power peak value and an average peak value, and it is determined whether acoustic feedback occurs in a signal based on a magnitude of the judgment value and a duration of the power peak value. In this case, whether acoustic feedback occurs can be determined based on the frequency characteristic of the signal.
    Type: Grant
    Filed: December 24, 2014
    Date of Patent: September 4, 2018
    Assignee: Hytera Communications Corporation Limited
    Inventor: Ni Huang
  • Patent number: 9916841
    Abstract: The invention includes a method, apparatus, and computer program to selectively suppress wind noise while preserving narrow-band signals in acoustic data. Sound from one or several microphones is digitized into binary data. A time-frequency transform is applied to the data to produce a series of spectra. The spectra are analyzed to detect the presence of wind noise and narrow band signals. Wind noise is selectively suppressed while preserving the narrow band signals. The narrow band signal is interpolated through the times and frequencies when it is masked by the wind noise. A time series is then synthesized from the signal spectral estimate that can be listened to. This invention overcomes prior art limitations that require more than one microphone and an independent measurement of wind speed. Its application results in good-quality speech from data severely degraded by wind noise.
    Type: Grant
    Filed: June 9, 2016
    Date of Patent: March 13, 2018
    Assignee: 2236008 Ontario Inc.
    Inventors: Phillip Alan Hetherington, Xueman Li, Pierre Zakarauskas
  • Patent number: 9794695
    Abstract: A method for detecting whistling in an audio system includes determining an average frequency of an input signal of the audio system, sampling the input signal in consecutive blocks of at least one sample, wherein the average frequency is determined blockwise, and determining whether feedback related whistling is present in the input signal of the audio system by evaluating a stability of the average frequency, wherein the evaluation of the stability of the average frequency comprises: determining a difference of two values of the determined average frequency for two blocks, and comparing the determined difference to a first threshold value.
    Type: Grant
    Filed: February 19, 2013
    Date of Patent: October 17, 2017
    Assignee: GN HEARING A/S
    Inventor: Naim Sheikh
  • Patent number: 9654861
    Abstract: Personal audio systems and methods are disclosed. A personal audio system includes a class table storing processing parameters respectively associated with a plurality of annoyance noise classes, a controller, and a processor. The controller identifies an annoyance noise class of an annoyance noise included in an ambient audio stream and retrieves, from the class table, one or more processing parameters associated with the identified annoyance noise class. The processor to processes the ambient audio stream according to the one or more retrieved processing parameters class to provide a personal audio stream. The processor includes a pitch tracker to identify a fundamental frequency of the annoyance noise and a filter bank including a band reject filter tuned to the fundamental frequency.
    Type: Grant
    Filed: November 13, 2015
    Date of Patent: May 16, 2017
    Assignee: Doppler Labs, Inc.
    Inventors: Gints Klimanis, Anthony Parks, Jeff Baker
  • Patent number: 9559733
    Abstract: A communication system includes a carrier generator configured to generate a first carrier signal and a demodulator configured to demodulate a modulated signal responsive to the first carrier signal. The demodulator includes a filter and a bandwidth adjusting circuit. The filter is configured to filter a first signal. The first signal is a product of the first carrier signal and the modulated signal. The filter has a first cutoff frequency and a bandwidth. The bandwidth of the filter is controlled by a set of control signals. The bandwidth adjusting circuit is configured to adjust the bandwidth of the filter based on a frequency of the filtered first signal and a frequency of the first signal, or a phase of the filtered first signal and a phase of the first signal. The bandwidth adjusting circuit is configured to generate the set of control signals.
    Type: Grant
    Filed: October 30, 2015
    Date of Patent: January 31, 2017
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Feng Wei Kuo, William Wu Shen, Chewn-Pu Jou, Huan-Neng Chen, Lan-Chou Cho
  • Patent number: 9397630
    Abstract: An audio signal attenuation system and method for detecting an audio emergency warning signal (or alarm) in a vehicle in which an audio signal is being played. Embodiments of the system and method make it easier for a police, fire, or other emergency alarm or siren to be heard in a loud or noisy listening environment when audio signal is being reproduced. This is achieved using selective frequency attenuation, which identifies a frequency of the alarm and then selectively attenuates the alarm frequency in the audio signal. Moreover, direction data that includes information about from which direction the alarm is coming can be used to selectively attenuate the alarm frequency in certain channels (or speakers) of the audio signal. In some embodiments, audio cues are used to alert the listener to the alarm signal and are adjusted based on alarm distance from the vehicle, speed, and the type of alarm.
    Type: Grant
    Filed: April 8, 2013
    Date of Patent: July 19, 2016
    Assignee: DTS, INC.
    Inventors: Liang (Vincent) Wang, Christopher Yap, Shankar Rathoud, Cedric Tio
  • Patent number: 9373340
    Abstract: The invention includes a method, apparatus, and computer program to selectively suppress wind noise while preserving narrow-band signals in acoustic data. Sound from one or several microphones is digitized into binary data. A time-frequency transform is applied to the data to produce a series of spectra. The spectra are analyzed to detect the presence of wind noise and narrow band signals. Wind noise is selectively suppressed while preserving the narrow band signals. The narrow band signal is interpolated through the times and frequencies when it is masked by the wind noise. A time series is then synthesized from the signal spectral estimate that can be listened to. This invention overcomes prior art limitations that require more than one microphone and an independent measurement of wind speed. Its application results in good-quality speech from data severely degraded by wind noise.
    Type: Grant
    Filed: January 25, 2011
    Date of Patent: June 21, 2016
    Assignee: 2236008 Ontario, Inc.
    Inventors: Phil Hetherington, Xueman Li, Pierre Zakarauskas
  • Patent number: 9338562
    Abstract: A listening device includes an input transducer, an output transducer, a signal processor, and a feedback cancellation system for estimating acoustic feedback. The feedback cancellation system includes an adaptive FBC filter arranged in parallel to the forward path, an adaptive whitening filter, and a howl detection unit that performs howl detection based on an output of the adaptive whitening filter. The adaptive FBC filter includes a variable FBC filter part and an FBC update algorithm part for updating the variable FBC filter part, the FBC update algorithm part receiving first and second FBC algorithm input signals influenced by the electrical input and the electrical output signals. Further, the feedback cancellation system receives an electrical update signal essentially consisting of the direct part of the electrical input signal and coefficients of the adaptive whitening filter are based on the electrical update signal.
    Type: Grant
    Filed: June 25, 2014
    Date of Patent: May 10, 2016
    Assignee: OTICON A/S
    Inventors: Thomas Bo Elmedyb, Johan Hellgren
  • Patent number: 9271069
    Abstract: An audio conference system has a plurality of specially designed microphone housings into each of which a directional microphone is positioned. Each microphone housing is positioned entirely within the body of the audio conferencing system, the microphone housings are strategically positioned at each one of four corners of the audio conference system body in order to provide maximum exposure of a microphone to its operating environment, and the interior structure of the microphone housing is designing to reflect unwanted energy harmlessly away from the microphone. Each directional microphone is positioned in the microphone housing such that the most sensitive node in its polar response pattern is oriented normal (at right angles) to a line radiating outward from the center of the system.
    Type: Grant
    Filed: July 7, 2014
    Date of Patent: February 23, 2016
    Assignee: RevoLabs, Inc
    Inventors: Klaus Hartung, Scot T. Armstrong
  • Patent number: 9137612
    Abstract: A hearing aid comprises a microphone configured to receive an acoustic input signal and convert the signal into an electric input signal, an audiological signal processing unit coupled to the microphone and configured to process the electric input signal to a processed signal, an amplifier coupled to the audiological signal processing unit and configured to amplify the processed signal to an amplified signal, and a receiver coupled to the amplifier and configured to transform the amplified signal into an acoustic output signal. The hearing aid further comprises a howl detector coupled to the signal processing unit and configured to detect the presence of a feedback howl originating from the hearing aid an analyzer coupled to the howl detector and configured to determine a value indicative of whether the feedback howl detected is potentially audible to a person neighboring the user of the hearing aid.
    Type: Grant
    Filed: June 20, 2013
    Date of Patent: September 15, 2015
    Assignee: OTICON A/S
    Inventor: Graham Naylor
  • Patent number: 9042575
    Abstract: A method, device and computer program product for processing audio signals, the method including determining beamformer filter coefficients to be applied to the audio signals; applying the beamformer filter coefficients to the audio signals; outputting the filtered audio signals from an audio output comprising a plurality of speakers coupled with the device; and receiving at a microphone coupled with the device, the filtered audio signals output from the audio output. The filter coefficients are determined such that the filtered audio signals are suppressed when received at the microphone.
    Type: Grant
    Filed: December 30, 2011
    Date of Patent: May 26, 2015
    Assignee: Skype
    Inventor: Karsten Vandborg Sorensen
  • Patent number: 8953818
    Abstract: A listening device for processing an input sound to an output sound, includes an input transducer for converting an input sound to an electric input signal, an output transducer for converting a processed electric output signal to an output sound, a forward path being defined between the input transducer and the output transducer and including a signal processing unit for processing an input signal in a number of frequency bands and an SBS unit for performing spectral band substitution from one frequency band to another and providing an SBS-processed output signal, and an LG-estimator unit for estimating loop gain in each frequency band thereby identifying plus-bands having an estimated loop gain according to a plus-criterion and minus-bands having an estimated loop gain according to a minus-criterion.
    Type: Grant
    Filed: February 6, 2009
    Date of Patent: February 10, 2015
    Assignee: Oticon A/S
    Inventors: Thomas Bo Elmedyb, Jesper Jensen
  • Patent number: 8948407
    Abstract: A personal audio device, such as a wireless telephone, includes noise canceling circuit that adaptively generates an anti-noise signal from a reference microphone signal and injects the anti-noise signal into the speaker or other transducer output to cause cancellation of ambient audio sounds. An error microphone may also be provided proximate the speaker to measure the output of the transducer in order to control the adaptation of the anti-noise signal and to estimate an electro-acoustical path from the noise canceling circuit through the transducer. A processing circuit that performs the adaptive noise canceling (ANC) function also either adjusts the frequency response of the anti-noise signal with respect to the reference microphone signal, and/or by adjusting the response of the adaptive filter independent of the adaptation provided by the reference microphone signal.
    Type: Grant
    Filed: December 21, 2011
    Date of Patent: February 3, 2015
    Assignee: Cirrus Logic, Inc.
    Inventors: Jeffrey Alderson, Nitin Kwatra, Gautham Devendra Kamath, Ali Abdollahzadeh Milani, John L. Melanson
  • Patent number: 8917885
    Abstract: A pseudo noise superimposing unit superimposes a pseudo noise (M-sequence) to an audio signal picked up by a microphone and outputs the superimposed signal to an amplifying system. An calculating unit calculates a correlation value between the audio signal picked up by the microphone and the pseudo noise. The calculating unit estimates a gain of a closed loop based on the correlation value. A gain control unit suppresses a gain of the audio signal based on the estimated gain of the closed loop.
    Type: Grant
    Filed: September 24, 2009
    Date of Patent: December 23, 2014
    Assignee: Yamaha Corporation
    Inventors: Shinya Sakurada, Takuro Sone, Takaya Kakizaki, Sachiya Sasaki, Kosuke Saito
  • Patent number: 8913752
    Abstract: An audio signal measurement method for a speaker and an electronic apparatus having the speaker are provided. The electronic apparatus further has a processing circuit and a power amplifier. The processing circuit is coupled to the speaker and configured to execute a time domain to frequency domain transform according to a voltage value of an audio signal and a current value of current feedback from the speaker so as to obtain a frequency response curve. The power amplifier is coupled to the speaker and configured to drive the speaker according the voltage value of the audio signal. The processing circuit is capable of determining whether the frequency response curve is located within a predetermined area such that the processing circuit generates a signal when the frequency response curve is located out of the predetermined area. Thereby, the electronic apparatus may measure its transducer distortion and acoustic box leakage.
    Type: Grant
    Filed: March 22, 2012
    Date of Patent: December 16, 2014
    Assignee: HTC Corporation
    Inventors: Hann-Shi Tong, Yu-Sheng Lee, Yu-Chieh Lai, Lei Chen, Chun-Ren Hu, Wei-Syuan Lin
  • Patent number: 8891786
    Abstract: Systems, methods, and other embodiments associated with selective notch filtering for howling suppression are described. According to one embodiment, an apparatus includes a howling detector that detects howling by performing a time domain analysis of speech signals to identify a speech signal that may be exhibiting howling and performing frequency domain analysis to confirm that the speech signal is exhibiting howling. The apparatus also includes a suppression selector configured to select a suppression technique, a signal processor configured to process the speech signal according to a selected suppression technique. The apparatus outputs, without suppression-related processing, speech signals that are not identified based on the time domain analysis.
    Type: Grant
    Filed: April 6, 2011
    Date of Patent: November 18, 2014
    Assignee: Marvell International Ltd.
    Inventor: Xin Wang
  • Patent number: 8873764
    Abstract: An acoustic echo suppression unit according to an embodiment of the present invention includes and input interface for extracting a downmix signal from an input signal, the input signal including the downmix signal and parametric side information, wherein the downmix and the parametric side information together represent a multichannel signal, a calculator for calculating filter coefficients for an adaptive filter, wherein the calculator is adapted to determine the filter coefficients based on the downmix signal and a microphone signal or a signal derived from the microphone signal, and an adaptive filter adapted to filter the microphone signal or the signal derived from the microphone signal based on the filter coefficients to suppress an echo caused by the multichannel signal in the microphone signal.
    Type: Grant
    Filed: October 13, 2011
    Date of Patent: October 28, 2014
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Fabian Kuech, Markus Kallinger, Markus Schmidt, Meray Zourub, Marco Diatschuk, Oliver Moser
  • Patent number: 8842862
    Abstract: The adjustment of a hearing device with regard to a current feedback path is to be designed in a more user-friendly manner. For this purpose, provision is made for hearing aid equipment, in particular a hearing device or a non-programmable device such as a headset, including a measuring device for measuring a feedback path and an operating facility for operating the hearing aid equipment by the wearer. The operating facility allows a measurement cycle to be activated to determine at least one characteristic of the feedback path. The hearing aid wearer can thus make adjustments themselves in terms of the feedback path and therefore does not have to rely on an acoustician.
    Type: Grant
    Filed: February 22, 2006
    Date of Patent: September 23, 2014
    Assignee: Siemens Audiologische Technik GmbH
    Inventor: Tom Weidner
  • Patent number: 8804979
    Abstract: A method and an audio processing system determine a system parameter, e.g. step size, in an adaptive algorithm, e.g. an adaptive feedback cancellation algorithm so as to provide an alternative scheme for feedback estimation in a multi-microphone audio processing system. A feedback part of the system's open loop transfer function is estimated and separated in a transient part and a steady state part, which can be used to control the adaptation rate of the adaptive feedback cancellation algorithm by adjusting the system parameter, e.g. step size parameter, of the algorithm when desired system properties, such as a steady state value or a convergence rate of the feedback, are given/desired. The method can be used for different adaptation algorithms such as LMS, NLMS, RLS, etc. in hearing aids, headsets, handsfree telephone systems, teleconferencing systems, public address systems, etc.
    Type: Grant
    Filed: October 6, 2011
    Date of Patent: August 12, 2014
    Assignee: Oticon A/S
    Inventors: Thomas Bo Elmedyb, Jesper Jensen, Meng Guo
  • Patent number: 8804977
    Abstract: An echo suppression system and method, and a computer-readable storage medium that is configured with instructions that when executed carry out echo suppression. Each of the system and the method includes the elements of a linear echo suppressor having a reference signal path, with a nonlinearity introduced in the reference signal path to introduce energy in spectral bands. Unlike an echo canceller, the echo suppression system and method are relatively robust to errors in the introduced nonlinearity.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: August 12, 2014
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Timothy J. Neal, Glenn N. Dickins
  • Patent number: 8731207
    Abstract: An embodiment of an apparatus for computing control information for a suppression filter for filtering a second audio signal to suppress an echo based on a first audio signal includes a computer having a value determiner for determining at least one energy-related value for a band-pass signal of at least two temporally successive data blocks of at least one signal of a group of signals. The computer further includes a mean value determiner for determining at least one mean value of the at least one determined energy-related value for the band-pass signal. The computer further includes a modifier for modifying the at least one energy-related value for the band-pass signal on the basis of the determined mean value for the band-pass signal. The computer further includes a control information computer for computing the control information for the suppression filter on the basis of the at least one modified energy-related value.
    Type: Grant
    Filed: January 12, 2009
    Date of Patent: May 20, 2014
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der Angewandten Forschung e.V.
    Inventors: Fabian Kuech, Markus Kallinger, Christof Faller, Alexis Favrot
  • Patent number: 8724823
    Abstract: An input signal is processed through noise suppression (NS) and echo control (EC) via a multipath model that reduces noise pumping effects while maintaining EC performance. A copy of a “noisy” input signal is sent to an EC component before the noisy signal is sent to a NS component, which processes the signal first, when there is a consistent noise level for estimation. The copy of the pre-processing noisy signal is sent to the EC component along with a “clean” or “noise-suppressed” signal output from the NS component. The EC component analyzes the noisy signal as if the EC was the first component in the signal chain to determine what actions to take. The EC component then applies these actions to the clean signal received from the NS component.
    Type: Grant
    Filed: May 20, 2011
    Date of Patent: May 13, 2014
    Assignee: Google Inc.
    Inventors: Andrew John MacDonald, Jan Skoglund, Björn Volcker
  • Patent number: 8675883
    Abstract: A new acoustic echo suppressor and method for acoustic echo suppression is described herein. Exemplary embodiments of the acoustic echo suppressor use one linear regression model for each subband. The linear regression model for each subband may operate on the squared magnitude of the input samples as well as corresponding cross-products. In this way, accurate and robust estimates of the echo signal in each subband can be obtained, thereby providing good echo reduction while keeping the signal distortion low.
    Type: Grant
    Filed: January 18, 2011
    Date of Patent: March 18, 2014
    Assignee: Cisco Technology, Inc.
    Inventor: Oystein Birkenes
  • Patent number: 8660281
    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.
    Type: Grant
    Filed: February 3, 2010
    Date of Patent: February 25, 2014
    Assignee: University of Ottawa
    Inventors: Martin Bouchard, Homayoun Kamkar Parsi
  • Patent number: 8630426
    Abstract: A method for reducing howling in a communication system containing collocated mobile devices is presented. In a transmitter, an audio signal is received at a microphone. Acoustic feedback is removed from the audio signal and the resulting signal is encoded and transmitted either using direct or trunked mode operation to a receiver. The encoded signal is decoded at the transmitter, in addition to at the receiver, and fed back to an echo canceller with sufficient delay to account for substantially the entirety of a loop delay from encoding of the audio signal to reception of the acoustic feedback at the microphone to enable removal of the acoustic feedback. An estimate of the acoustic feedback is used to initially remove the acoustic feedback, the error being fed back to the processor to adaptively change the signal being subtracted from the audio signal to better reduce the acoustic feedback.
    Type: Grant
    Filed: November 6, 2009
    Date of Patent: January 14, 2014
    Assignee: Motorola Solutions, Inc.
    Inventor: Peter William Hilding Svendsen
  • Patent number: 8594340
    Abstract: Where information is to be conveyed as acoustic waves, embodiments of the present invention provide a transmitter capable of causing acoustic waves that convey information to be not easily perceived by the human ear. A transmitter, being an apparatus that converts various types of encoded information into acoustic wave(s) in the audible spectrum and carries out transmission thereof, comprises microphone(s) that cause ambient sound(s) from location(s) at which acoustic wave(s) is/are transmitted to be input as ambient sound signal(s); peak frequency detector(s) that detect, within ambient sound signal(s), peak frequency or frequencies of major constituent(s) of ambient sound(s); carrier wave generator(s) that generate carrier waves at a plurality of frequencies that are natural number multiples of peak frequency or frequencies and that can be used to mask ambient sound(s); and modulator(s) that modulate a plurality of carrier waves with baseband signal(s).
    Type: Grant
    Filed: September 15, 2012
    Date of Patent: November 26, 2013
    Assignee: Field System, Inc.
    Inventors: Tomio Takara, Hiroshi Suzuki, Takashige Tsukuma, Yoshimaru Maruno, Ichiro Okuyama
  • Patent number: 8588430
    Abstract: It is described a method for controlling an adaptation of a behavior of an audio device (100) to a current acoustic environmental condition. The method comprises (a) monitoring an audio output signal (x(t), x?(t)) being provided to an acoustic output device (110) of the audio device (100) for outputting an acoustic output signal, (b) measuring an audio input signal (z(t)) being provided by an acoustic input device (120) of the audio device (100), wherein the audio input signal (z(t)) is indicative for a feedback portion of the acoustic output signal and for the current acoustic environmental condition, (c) determining a relation between the audio output signal (x?(t)) and the audio input signal (z(t)) and (d) adapting the behavior of the audio device (100) based on the determined relation.
    Type: Grant
    Filed: February 9, 2010
    Date of Patent: November 19, 2013
    Assignee: NXP B.V.
    Inventors: Wouter Joos Tirry, Peterjan Schreurs, Ralf Funken
  • Patent number: 8509450
    Abstract: A method of enhancing an audio signal includes the steps of: a) receiving a primary audio input signal, b) receiving a detected audio signal which comprises: A) an echo component derived from play-out of the primary audio input signal and B) a noise component, and c) estimating from the primary audio input signal and the detected audio signal: 1) a set of frequency-specific lower bound gains, such that each frequency-specific lower bound gain, when applied to a respective frequency of the primary audio input signal, would cause the noise component to just mask the echo component at that respective frequency and 2) a set of frequency-specific upper bound gains, such that each frequency-specific upper bound gain, when applied to a respective frequency of the primary audio input signal, would cause the echo component to just mask the noise component at that respective frequency; d) estimating a set of frequency-specific gains in such a way that each frequency-specific gain falls between the respective frequency-
    Type: Grant
    Filed: August 23, 2010
    Date of Patent: August 13, 2013
    Assignee: Cambridge Silicon Radio Limited
    Inventor: Xuejing Sun
  • Patent number: 8477956
    Abstract: A howling suppression device that can reduce quality deterioration of processed sound includes: a delay unit delaying the input signal to output the delayed input signal as a reference signal; a signal separation unit including an adaptive filter extracting a periodic signal component from the reference signal by adaptively updating a filter coefficient; a howling detection unit detecting an occurrence of howling using at least a signal of the periodic signal component output from the adaptive filter; and a howling suppression unit. The howling suppression unit includes: a suppression filter obtaining the updated filter coefficient from the adaptive filter with timing when the howling detection unit detects the occurrence of the howling, to extract the periodic signal component from the reference signal based on the filter coefficient; and a subtractor subtracting the periodic signal component from the input signal so as to output a signal obtained by the subtraction.
    Type: Grant
    Filed: January 26, 2010
    Date of Patent: July 2, 2013
    Assignee: Panasonic Corporation
    Inventor: Takefumi Ura
  • Patent number: 8477952
    Abstract: The invention concerns in a first aspect an audio system comprising a microphone, audio signal processing means, an output transducer and means for detecting a possible feedback tone and the corresponding frequency of the feedback tone in the audio system between the output transducer and the microphone. According to the invention means for counteracting feedback are provided. Further, means are provided for changing the phase of the audio signal at a given frequency. In a further aspect, a binaural hearing aid system comprising first and second hearing instruments according to the first aspect, each hearing instrument comprising transceiver circuitry allowing an exchange of signals between the two hearing instruments, and wherein the binaural hearing aid system is adapted to provide that a phase change introduced in the first audio signal by a controller of the first hearing instrument is or can be introduced in the second audio signal of the second hearing instrument via said transceiver circuitry.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: July 2, 2013
    Assignee: Oticon A/S
    Inventors: Thomas Bo Elmedyb, Johan Hellgren
  • Patent number: 8477976
    Abstract: A method for detecting whistling in an audio system includes determining an average frequency of an input signal of the audio system, sampling the input signal in consecutive blocks of at least one sample, wherein the average frequency is determined blockwise, and determining whether feedback related whistling is present in the input signal of the audio system by evaluating a stability of the average frequency, wherein the evaluation of the stability of the average frequency comprises: determining a difference of two values of the determined average frequency for two blocks, and comparing the determined difference to a first threshold value.
    Type: Grant
    Filed: December 29, 2010
    Date of Patent: July 2, 2013
    Assignee: GN ReSound A/S
    Inventor: Naim Sheikh
  • Patent number: 8462958
    Abstract: A preferred embodiment of an apparatus for computing filter coefficients for an adaptive filter for filtering a microphone signal so as to suppress an echo due to a loudspeaker signal includes an extractor for extracting a stationary component signal or a non-stationary component signal from the loudspeaker signal or from a signal derived from the loudspeaker signal, and a computer for computing the filter coefficients for the adaptive filter on the basis of the extracted stationary component signal or the extracted non-stationary component signal.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: June 11, 2013
    Assignee: Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.
    Inventors: Fabian Kuech, Markus Kallinger, Christof Faller, Alexis Favrot
  • Patent number: 8428274
    Abstract: An acoustic-feedback detection apparatus includes: a first level detecting section configured to detect a signal level of sound signals obtained from a position in a sound-signal system in which a microphone and speaker are connected; a first extracting section configured to extract, from the sound signals of which the signal level is detected, signals in a band having a bandwidth predetermined for each of at least one predetermined center frequency; a second level detecting section configured to detect a signal level of the signals in each band, the signals being extracted by the first extracting section; and a determining section configured to determine whether or not acoustic feedback is occurring, on the basis of a threshold determined according to the signal level detected by the first level detecting section and a waveform of each signal level detected by the second level detecting section.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: April 23, 2013
    Assignee: Sony Corporation
    Inventors: Goro Shiraishi, Kohei Asada
  • Patent number: 8406430
    Abstract: An apparatus may include a noise estimation unit configured to determine a noise spectrum associated with a noise signal, and generate a filter based on the determined noise spectrum. The apparatus may also include a noise synthesis unit configured to generate a colored noise using the filter generated by the noise estimation unit. The apparatus may be incorporated in an echo canceller.
    Type: Grant
    Filed: November 19, 2009
    Date of Patent: March 26, 2013
    Assignee: Infineon Technologies AG
    Inventors: Christophe Beaugeant, Philippe Degry
  • Patent number: 8385557
    Abstract: A multichannel acoustic echo reduction system is described herein. The system includes an acoustic echo canceller (AEC) component having a fixed filter for each respective combination of loudspeaker and microphone signals and having an adaptive filter for each microphone signal. For each microphone signal, the AEC component modifies the microphone signal to reduce contributions from the outputs of the loudspeakers based at least in part on the respective adaptive filter associated with the microphone signal and the set of fixed filters associated with the respective microphone signal.
    Type: Grant
    Filed: June 19, 2008
    Date of Patent: February 26, 2013
    Assignee: Microsoft Corporation
    Inventors: Ivan Jelev Tashev, Alejandro Acero, Nilesh Madhu
  • Patent number: 8379870
    Abstract: A method and device for transforming ambient audio are provided. Example embodiments may include monitoring ambient audio proximate to a sound processing device located in an environment. The device may receive a selection from a user interface. The selection may comprise one of a number of available first selections, each available first selection identifying one of multiple transformation modes. The device may access memory to obtain transformation audio and process the transformation audio, based on the ambient audio and the selection. The device may also use the transformation audio to provide modified output audio for propagation into the environment.
    Type: Grant
    Filed: October 3, 2008
    Date of Patent: February 19, 2013
    Assignee: Adaptive Sound Technologies, Inc.
    Inventors: Sam J. Nicolino, Jr., Ira Chayut, Stephen R. Pollock
  • Patent number: 8358797
    Abstract: A method of changing at least two parameter settings of a device includes detecting an abnormal change in an external feedback path and an input signal generated by an abnormal pressure wave, and activating a pressure wave detection switch and an abnormal feedback path detection switch for changing the at least one parameter setting in the device. A device includes a digital signal processor configured to implement a detection algorithm to detect an abnormal change in an external feedback path, an adaptive internal feedback cancellation system for continually monitoring and responsively adapting to changes occurring in an external feedback path, a pattern recognition algorithm for detecting input signals generated when an abnormal pressure wave is generated, at least two parameter settings for adjusting the characteristics of the device, and an abnormal feedback path detection switch for switching the device to a next available parameter setting.
    Type: Grant
    Filed: August 12, 2009
    Date of Patent: January 22, 2013
    Assignee: Intricon Corporation
    Inventor: Robert J. Fretz
  • Patent number: 8340317
    Abstract: An audio processing system is provided for controlling the acoustics of a loudspeaker-room system. The loudspeaker-room system having a listening room and loudspeakers located in said listening room, and transfer functions with linear and non-linear components. The audio processing system comprises a compensator with a transfer function for obtaining at least two compensated signals from the input signals. The transfer functions of the compensator may include linear and non-linear components and are inverse to the transfer functions of the loudspeaker-room system to the extent that a desired overall transfer function is established.
    Type: Grant
    Filed: May 6, 2004
    Date of Patent: December 25, 2012
    Assignee: Harman Becker Automotive Systems GmbH
    Inventors: Gerhard Pfaffinger, Markus Christoph
  • Patent number: 8325938
    Abstract: A handsfree call apparatus includes: a speaker held in the vicinity of a user's ear by a holding unit with a speaker unit thereof not being attached to a baffle board so as to mix sounds emitted from the front and back of a diaphragm thereof; a microphone, which is provided to a region where sounds emitted from the front and back of the diaphragm of the speaker are mixed and canceled out, configured to collect the call voice of the user; an output unit configured to output a call voice signal of the user from the microphone to transmit this to a call partner; and an input unit configured to receive a call voice signal from the call partner to supply this to the speaker.
    Type: Grant
    Filed: August 7, 2009
    Date of Patent: December 4, 2012
    Assignee: Sony Corporation
    Inventor: Teppei Yokota
  • Patent number: 8320574
    Abstract: Various embodiments of the present invention are directed to methods and systems that reduce acoustic echoes in audio signals in accordance with changing conditions at first and second locations that are linked together in a communication system. In particular, one embodiment of the present invention relates to a method for determining an approximate impulse-response vector for canceling an acoustic echo resulting from an audio signal transmitted from the first location to the second location. This method includes forming a trust region within a search space based on computing a recursive specification vector defining the trust region. The method also includes computing a recursive shadow-impulse-response vector that lies substantially within the trust region, and computing the approximate impulse-response vector based on the recursive shadow-impulse-response vector and the recursive specification vector.
    Type: Grant
    Filed: April 12, 2007
    Date of Patent: November 27, 2012
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Majid Fozunbal
  • Patent number: 8315408
    Abstract: An electronic audio device with a digital audio output channel in which an amplifier output voltage is gradually ramped up and down to avoid causing a popping sound when the device is turned on and off. This is accomplished without employing any additional hardware, by incrementally changing a digital input word applied to a digital audio source, such as a DSP, so as to gradually change the amplifier output voltage between a minimum, such as zero volts, and a DC working voltage. On powering up, the amplifier is only turned on after the digital word is applied, but while it still results in a minimum amplifier output, and on powering down the amplifier is turned off after it's output has been ramped down, but before removing the digital input word. Sources and output channels can also be switched over by powering down, and then powering up, following the same method.
    Type: Grant
    Filed: July 9, 2009
    Date of Patent: November 20, 2012
    Assignee: Agere Systems LLC
    Inventors: Rupinder Judge, Tie Liu, Robert Peruzzi, Richard Verney
  • Patent number: 8311590
    Abstract: An electronic device comprises a microphone, a transceiver circuit, a loudspeaker, a sense element and a processing circuit. The microphone is configured to receive a first audio signal. The transceiver circuit is configured to communicate the first audio signal to a remote device and to receive a second audio signal from the remote device. The loudspeaker is configured to provide an audible signal based on the second audio signal. The sense element is configured to sense the audible signal provided by the loudspeaker. The sense element may be positioned at a distance from the loudspeaker different than a distance between the microphone and the loudspeaker. The processing circuit is configured to process at least one of the first audio signal and the second audio signal based on a sensed signal from the sense element.
    Type: Grant
    Filed: December 5, 2006
    Date of Patent: November 13, 2012
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Ronald J. Horowitz
  • Patent number: 8306234
    Abstract: Improving the acoustical communication between interlocutors in at least two positions in a room includes generating electrical signals representative of acoustical signals present at the respective interlocutor positions, amplifying each of the electrical signals and converting the amplified electrical signals into acoustical signals. A time delay is applied to the electrical signals such that the acoustical signal arriving first at one of the interlocutor positions originates from the direction of the other interlocutor position.
    Type: Grant
    Filed: May 24, 2007
    Date of Patent: November 6, 2012
    Assignee: Harman Becker Automotive Systems GmbH
    Inventors: Markus Christoph, Tim Haulick, Gerhard Schmidt
  • Patent number: 8265295
    Abstract: A system and method for analyzing a signal to monitor the dynamics of its magnitude and frequency characteristics over time. An electronic circuit for identifying feedback in an audio signal, formed in accordance with embodiments of the invention may comprise a feedback control block operable to determine a candidate frequency having potential feedback such that the feedback control block is further operable to perform an iterative analysis of the magnitude of the audio signal at the candidate frequency to determine the growth characteristics of the signal. The electronic circuit may further include a test filter block operable to deploy a test filter at a candidate frequency and a permanent filter block operable to deploy a permanent filter at the candidate frequency if the feedback control block determines that the growth characteristics of the signal at the candidate frequency comprises feedback characteristics after the test filter has been deployed.
    Type: Grant
    Filed: February 8, 2006
    Date of Patent: September 11, 2012
    Assignee: Rane Corporation
    Inventor: Dana Troxel
  • Patent number: 8265313
    Abstract: A method and a hearing device for cancelling or preventing feedback are disclosed. The hearing device comprises a microphone (1), a transfer function (2) and a receiver (3), wherein the transfer function (2) defines relation between an input signal (12) of the hearing device and an output signal (13, 13?) of the hearing device. The method according to the present invention comprises the steps of estimating an external transfer function (21) of an external feedback path (11) defined by sound traveling from the receiver (3) to the microphone (1), estimating the input signal (12?) having no feedback components of the external feedback path (11) using an auxiliary signal (15), which does not comprise feedback components of the external feedback path (11), and using the estimated input signal (14) for estimating the external transfer function (21) of the external feedback path (11).
    Type: Grant
    Filed: May 22, 2007
    Date of Patent: September 11, 2012
    Assignee: Phonak AG
    Inventor: Sascha Korl
  • Patent number: 8265289
    Abstract: A method and system for clear signal capture comprehend several individual aspects that address specific problems in improved ways. In addition, the method and system also comprehend a hands-free implementation that is a practical solution to a very complex problem. Individual aspects comprehended related to echo and noise reduction, and divergence control.
    Type: Grant
    Filed: August 21, 2008
    Date of Patent: September 11, 2012
    Assignee: Clarity Technologies, Inc.
    Inventors: Rogerio G. Alves, Kuan-Chieh Yen
  • Patent number: 8243953
    Abstract: A system and method for analyzing a signal to identify one or more candidate frequencies that may have a potential feedback problem. An electronic circuit for identifying feedback in an audio signal, formed in accordance with embodiments of the invention, may comprise a feedback control block operable to: 1) determine a magnitude of a first dominant spectral component in a wide-band span of frequencies of a signal, 2) determine a magnitude of a second dominant spectral component in a mid-band span of frequencies of the signal, and 3) determine a magnitude of a third dominant spectral component in a narrow-band span of frequencies of the signal. The feedback control block may then further analyze the magnitude and frequency of the first, second, and third dominant spectral components to determine the presence of feedback characteristics in the signal.
    Type: Grant
    Filed: February 8, 2006
    Date of Patent: August 14, 2012
    Assignee: Rane Corporation
    Inventor: Dana Troxel