Adaptive Filter Topology Patents (Class 381/71.11)
  • Patent number: 9495952
    Abstract: An electronic device for controlling noise is described. The electronic device includes a force sensor for detecting a force on the electronic device. The electronic device also includes noise control circuitry for generating a noise control signal based on a noise signal and the force. Another electronic device for controlling noise is also described. The electronic device includes a speaker that outputs a runtime ultrasound signal, an error microphone that receives a runtime ultrasound channel signal and noise control circuitry coupled to the speaker and to the error microphone. The noise control circuitry determines at least one calibration parameter and determines a runtime channel response based on the runtime ultrasound channel signal. The noise control circuitry also determines a runtime placement based on the runtime channel response and the at least one calibration parameter and determines at least one runtime active noise control parameter based on the runtime placement.
    Type: Grant
    Filed: August 7, 2012
    Date of Patent: November 15, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Hyun Jin Park, Brian Lee Momeyer, Jeremy Patrick Toman, Kwokleung Chan, Hui-ya Liao Nelson, Louis Dominic Oliveira
  • Patent number: 9494088
    Abstract: A variety of methods, devices and filters are described that are suitable for averaging measured power train operating parameters over a period that varies as a function of an engine cylinder firing characteristic such as a current operational firing fraction or firing sequence. The averaged measured operating parameter may be used in a variety of different engine control related functions, calculations and/or operations. The described techniques and devices are particularly well suited for use during skip fire operation of an engine.
    Type: Grant
    Filed: May 5, 2015
    Date of Patent: November 15, 2016
    Assignee: Tula Technology, Inc.
    Inventors: Louis J. Serrano, Mohammad R. Pirjaberi, Charles H. Loucks
  • Patent number: 9489937
    Abstract: Systems and methods for simultaneously capturing live audio and video feeds and reducing motor/rotor noise associated with the video feed for a multirotor unmanned aerial vehicle (UAV). Noise reduction occurs in real time or near real time as one or more frequencies associated with a motor, rotor, or attitude of the UAV are recognized, subtracted and/or dithered from the audio feed, resulting in one or more correction signals. The one or more correction signals may be dynamically summed in order to generate a corrected audio feed for transmission.
    Type: Grant
    Filed: March 9, 2015
    Date of Patent: November 8, 2016
    Assignee: Trace Live Network Inc.
    Inventors: Paul Beard, Cameron Chell, Jamie Clarke, Craig McDermott, Erika Racicot, Paul Readwin
  • Patent number: 9485035
    Abstract: The technology described in this document can be embodied in a computer-implemented method that includes receiving, at one or more processing devices, a plurality of values representing a set of coefficients of an adaptive filter over a period of time, and identifying, by the one or more processing devices based on the plurality of values, a phase error associated with a transfer function of the adaptive filter. The method also includes adjusting, based on the identified phase error, a phase associated with the transfer function of the adaptive filter such that coefficients calculated using the adjusted transfer o function reduce the phase error. The method further includes determining a set of coefficients for the adaptive filter based on the adjusted transfer function, and programming the adaptive filter with the determined set of coefficients to enable operation of the adaptive filter.
    Type: Grant
    Filed: December 9, 2015
    Date of Patent: November 1, 2016
    Assignee: Bose Corporation
    Inventor: Emery M. Ku
  • Patent number: 9467770
    Abstract: There is provided a headphone or headset comprising at least one housing, at least one microphone for detecting interference sound, at least one active noise compensation unit for implementing active noise compensation based on the interference sound detected by the at least one microphone and for the output of a compensation signal. The headphone or the headset has at least one electroacoustic reproduction transducer for output of the compensation signal from the noise compensation unit and a circumaural cushion having a recess for receiving a spectacles side arm. The active noise compensation unit is adapted in noise compensation to take account of the effect of the recess in the ear cushion.
    Type: Grant
    Filed: August 5, 2014
    Date of Patent: October 11, 2016
    Assignee: Sennheiser electronic GmbH & Co. KG
    Inventors: Christian Grone, Stefan Marten, Oliver Pabst
  • Patent number: 9462994
    Abstract: A bioacoustic sensor assembly is described including a transducer generating an acoustic signal and an actuator configured to deform a portion of the transducer to increase a signal-to-noise ratio of the acoustic signal. The disclosure also provides methods and systems for reducing the impact of noise vibrations at the transducer.
    Type: Grant
    Filed: May 9, 2013
    Date of Patent: October 11, 2016
    Inventors: Daniel J. Rogers, Justin Tungjunyatham, Christopher J. Roed
  • Patent number: 9451370
    Abstract: A method for operating a hearing device worn by a hearing device user. The method includes picking up an audio signal (a) by an input transducer of the hearing device. The audio signal (a) includes a source signal (s) of a sound source (SS) and a disturbing signal (d) of a disturbing source (DS). The method also includes receiving a transmission signal (d_AIS) via an interface unit of the hearing device. The transmission signal (d_AIS) includes the disturbing signal (d) or at least characteristic features of the disturbing signal (d). The method also includes at least partially eliminating the disturbing signal (d) from the audio signal (a) by using the disturbing signal (d) transmitted by the transmission signal (d_AIS) or by using the characteristic features of the disturbing signal (d) transmitted by the transmission signal (d_AIS) for obtaining an adjusted audio signal (a*), and processing the adjusted audio signal (a*).
    Type: Grant
    Filed: March 12, 2012
    Date of Patent: September 20, 2016
    Assignee: SONOVA AG
    Inventors: Ivo Hasler, Micha Knaus
  • Patent number: 9439012
    Abstract: A method and an apparatus for audio testing are provided. The method is adapted to an electronic device with a first and second audio receive devices and a first and second audio send devices. The method includes following steps. A first and second audio testing signals are sent to the first and second audio receive devices of the electronic device. The electronic device has a first loop forming by connecting the first audio receive device and the first audio send device electrically, and has a second loop forming by connecting the second audio receive device and the second audio send device electrically. The first and second audio send devices send a first and second response signals respectively. The first and second response signals are received and analyzed to test functions of the first and second audio receive devices and the first and second audio send devices.
    Type: Grant
    Filed: June 4, 2014
    Date of Patent: September 6, 2016
    Assignee: Wistron Corporation
    Inventors: Ying-Chieh Hsu, Shaw-Renn Hwang
  • Patent number: 9406290
    Abstract: A mobile device vibrational sound system includes a processing circuit configured to activate a selectively vibratable element based on a triggering event, and control operation of a speaker to provide a mitigation sound configured to at least partially cancel a vibrational sound resulting from activation of the vibratable element.
    Type: Grant
    Filed: April 24, 2014
    Date of Patent: August 2, 2016
    Assignee: Elwha LLC
    Inventors: Alistair K. Chan, Roderick A. Hyde
  • Patent number: 9406293
    Abstract: A device and method to detect desired audio includes a ratio calculator. The ratio calculator calculates a ratio between a primary acoustic signal, and a reference acoustic signal. The primary acoustic signal contains desired audio and undesired audio and the reference acoustic signal contains mostly undesired audio, substantially void of undesired audio. A long-term mean value calculator is coupled to the ratio calculator. The long-term mean value calculator maintains an average of the ratio. A comparator is coupled to the ratio calculator and the long-term value calculator. The comparator compares the ratio with the average. Desired audio is detected when the ratio is greater than the average by a threshold amount.
    Type: Grant
    Filed: February 18, 2014
    Date of Patent: August 2, 2016
    Assignee: KOPIN CORPORATION
    Inventor: Dashen Fan
  • Patent number: 9384727
    Abstract: The present invention refers to an active sound reduction system and method for attenuation of sound emitted by a primary sound source, especially for attenuation of snoring sounds emitted by a human being. This system comprises a primary sound source, at least one speaker as a secondary sound source for producing an attenuating sound to be superposed with the sound emitted by said primary sound source, a reference microphone for receiving sound from said primary sound source, and at least one error microphone being allocated to each speaker to form a speaker/microphone pair. The at least one error microphone is provided as a directional microphone pointing at its allocated speaker to receive residual sound resulting from the superposition of the sounds from the primary sound source and the corresponding speaker. The error microphone and speaker of at least one speaker/microphone pair and the primary sound source are arranged substantially collinear.
    Type: Grant
    Filed: July 30, 2010
    Date of Patent: July 5, 2016
    Assignee: KONINKLIJKE PHILIPS N.V.
    Inventors: Paul Sebastian Booij, Adriaan Johan Van Leest, Ronaldus Maria Aarts
  • Patent number: 9368099
    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: March 28, 2014
    Date of Patent: June 14, 2016
    Assignee: CIRRUS LOGIC, INC.
    Inventors: Jeffrey Alderson, Nitin Kwatra, Gautham Devendra Kamath, Ali Abdollahzadeh Milani, John L. Melanson
  • Patent number: 9330652
    Abstract: In one aspect, multiple adaptive W filters and associated adaptive filter controllers are provided that use multiple reference microphone signals to produce multiple, “component” anti-noise signals. These are gain weighted and summed to produce a single anti-noise signal, which drives an earpiece speaker. The weighting changes based on computed measures of the coherence between content in each reference signal and content in an error signal. Other embodiments are also described and claimed.
    Type: Grant
    Filed: September 24, 2013
    Date of Patent: May 3, 2016
    Assignee: Apple Inc.
    Inventors: Thomas M. Jensen, Vladan Bajic, Andrew P. Bright
  • Patent number: 9318095
    Abstract: The disclosed active vibration noise control device is suitable for use in cancelling out vibration noise by outputting control noise from a plurality of speakers. When a vibration noise frequency is in a dip bandwidth, the active vibration noise control device alters the step size parameters used to update the filter coefficient at at least one filter coefficient update means from among a plurality of filter coefficient update means. Thus, the filter coefficient update speed can be retarded in unstable dip bandwidths, enabling loss in silencing effect which occurs during dip characteristics to be appropriately reduced.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: April 19, 2016
    Assignee: PIONEER CORPORATION
    Inventors: Kensaku Obata, Yoshiki Ohta, Yoshitomo Imanishi, Akihiro Iseki
  • Patent number: 9307336
    Abstract: An audio output circuit applied in an electronic device includes a filter capacitor and a transistor. A base of the transistor is connected to an audio processing unit, an emitter of the transistor is connected to a voltage port, a processor and an earphone detecting unit of the electronic device is electrically connected to a collector of the transistor. The filter capacitor is connected between the base of the transistor and the ground. The filter capacitor filters the audio signals generated by the audio processing unit, to ensure that and the transistor is always turned on.
    Type: Grant
    Filed: July 29, 2014
    Date of Patent: April 5, 2016
    Assignee: ScienBiziP Consulting(Shenzhen) Co., Ltd.
    Inventors: Ya-Guo Wang, Chun-Ching Chen
  • Patent number: 9294837
    Abstract: A vehicular active vibrational noise control apparatus includes an amplitude limiter for limiting the amplitude of a canceling signal based on a signal level of an audio signal, and a vehicle speed detector for detecting the vehicle speed of a vehicle, which incorporates therein the vehicular active vibrational noise control apparatus. The amplitude limiter changes an amplitude limitation rule, which represents a relationship of a limiting value for the amplitude of the canceling signal to the signal level, depending on the vehicle speed, and limits the amplitude of the canceling signal based on the limiting value determined according to the amplitude limitation rule.
    Type: Grant
    Filed: March 20, 2014
    Date of Patent: March 22, 2016
    Assignee: Honda Motor Co., Ltd.
    Inventors: Kosuke Sakamoto, Toshio Inoue, Satoru Kikuchi, Takanori Yamamoto
  • Patent number: 9286907
    Abstract: According to various embodiments of the invention, a new and effective keyboard click noise reduction scheme is presented. The keyboard click noise reduction scheme may have various processing units including: Dynamic Signal Modeler, Smart Model Selector, Adaptive Filtering Module, Keyboard/Impulse Noise and Voice Activity Detectors, and a Post-Processing Unit. By adaptively changing the coefficients of the proposed adaptive filter through minimizing the output energy, the scheme can provide the target signal/voice with nearly zero keyboard click noise. The scheme could be used in real-time to minimize keyboard click noise or any kind of unwanted noise, especially noise having transient impulse characteristics.
    Type: Grant
    Filed: November 21, 2012
    Date of Patent: March 15, 2016
    Assignee: Creative Technology Ltd
    Inventors: Jun Yang, Klaas Carlo Vogelsang, Ian Kenneth Minett, Robert Jan Ridder, Steven Burritt Verity
  • Patent number: 9275625
    Abstract: Apparatus and methods for audio noise attenuation are disclosed. An audio signal analyzer can determine whether an input audio signal received from a microphone device includes a noise signal having identifiable content. If there is a noise signal having identifiable content, a content source is accessed to obtain a copy of the noise signal. An audio canceller can generate a processed audio signal, having an attenuated noise signal, based on comparing the copy of the noise signal to the input audio signal. Additionally or alternatively, data may be communicated on a communication channel to a separate media device to receive at least a portion of the copy of the noise signal from the separate media device, or to receive content-identification data corresponding to the content source.
    Type: Grant
    Filed: March 6, 2013
    Date of Patent: March 1, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Lae-Hoon Kim, Asif Iqbal Mohammad, Erik Visser, Jongwon Shin
  • Patent number: 9269343
    Abstract: An audio processing device comprises a feedback estimation system for estimating feedback from an output transducer to an input transducer, the feedback estimation system comprising an adaptive filter comprising a variable filter part for filtering an input signal according to variable filter coefficients and an algorithm part comprising an adaptive algorithm for dynamically updating filter coefficients, a control unit for controlling the de-correlation unit and the adaptive algorithm, and a correlation detection unit for determining a) the auto-correlation of a signal of the forward path and providing an AC-value and/or b) the cross-correlation between two different signals of the forward path and providing an XC-value.
    Type: Grant
    Filed: November 26, 2013
    Date of Patent: February 23, 2016
    Assignee: OTICON A/S
    Inventors: Steen Michael Munk, Anders Meng
  • Patent number: 9240819
    Abstract: The technology described in this document can be embodied in a computer-implemented method that includes receiving, at one or more processing devices, a plurality of values representing a set of coefficients of an adaptive filter over a period of time, and identifying, by the one or more processing devices based on the plurality of values, a phase error associated with a transfer function of the adaptive filter. The method also includes adjusting, based on the identified phase error, a phase associated with the transfer function of the adaptive filter such that coefficients calculated using the adjusted transfer function reduce the phase error. The method further includes determining a set of coefficients for the adaptive filter based on the adjusted transfer function, and programming the adaptive filter with the determined set of coefficients to enable operation of the adaptive filter.
    Type: Grant
    Filed: October 2, 2014
    Date of Patent: January 19, 2016
    Assignee: Bose Corporation
    Inventor: Emery M. Ku
  • Patent number: 9208769
    Abstract: An adaptive noise-cancelling headphone including an earcup housing having a driver for outputting sound to a user positioned therein. The headphone further including an active noise control assembly. The active noise control assembly may include an ambient microphone capable of detecting an ambient noise outside of the housing and an error microphone capable of detecting an earcup noise inside of the housing. Based on the detected noise, active noise cancellation within the headphone is either enabled or disabled. The headphone may further include a passive noise control assembly. The passive noise control assembly may include an acoustic valve associated with an acoustic vent formed within the earcup housing. The acoustic valve is capable of being modified between an open configuration to decrease sound attenuation and a closed configuration to increase sound attenuation in response to the detected ambient noise so as to improve an acoustic performance of the earcup.
    Type: Grant
    Filed: December 18, 2012
    Date of Patent: December 8, 2015
    Assignee: Apple Inc.
    Inventor: Yacine Azmi
  • Patent number: 9198588
    Abstract: One apparatus includes a notch filter that has a state observer unit and a parameter adaptation unit. The state observer unit is configured to receive a sampled noisy electrical signal and a sampled filtered electrical signal, the state observer unit having an estimated noise signal output, the estimated noise signal output carrying an estimated noise signal to be subtracted from the sampled noisy electrical signal, resulting in the filtered electrical signal. The parameter adaptation unit is configured to receive the estimated noise signal and an error signal from the state observer unit. The parameter adaptation unit is also configured to determine, based on the estimated noise signal and the error signal, an updated estimated noise frequency, thereby causing the state observer unit to generate an updated estimated noise signal to be provided on the estimated noise signal output.
    Type: Grant
    Filed: October 31, 2012
    Date of Patent: December 1, 2015
    Assignee: Welch Allyn, Inc.
    Inventors: Yaolong Lou, Yong Sern Gwee, Peter Glocker
  • Patent number: 9185499
    Abstract: A hearing aid includes: at least one microphone for provision of at least one microphone audio signal in response to sound received at the at least one microphone; a signal separation unit configured to provide an estimate of a target signal and an estimate of a masker signal based on the at least one microphone audio signal; a frequency modifying unit configured to modify a frequency content of at least one of the estimate of the target signal and the estimate of the masker signal, to thereby output the estimated target signal and the estimated masker signal substantially in different frequency bands; and a receiver for conversion of a combination of the estimate of the target signal and the estimate of the masker signal output by the frequency modifying unit into an acoustic signal for transmission towards an eardrum of a user of the hearing aid.
    Type: Grant
    Filed: July 12, 2012
    Date of Patent: November 10, 2015
    Assignee: GN RESOUND A/S
    Inventors: Karl-Fredrik J. Gran, Andrew B. Dittberner
  • Patent number: 9177542
    Abstract: A system, device and method that is configured to operate an active noise reduction system for a motor vehicle, where there is an adaptive feed-forward noise reduction system input sine wave at a frequency to be cancelled, and where the adaptive feed-forward noise reduction system includes an adaptive filter that outputs noise reduction signals that are used to drive one or more transducers with their outputs directed to reduce engine noise, and further includes an input transducer with an output signal that is a source of a control signal for the adaptive filter. The output signal of the input transducer is filtered before it reaches the adaptive filter so as to reduce the level of the output signal of the input transducer at one or more frequencies that are close to the frequency of the input sine wave.
    Type: Grant
    Filed: March 29, 2013
    Date of Patent: November 3, 2015
    Assignee: Bose Corporation
    Inventor: Davis Y. Pan
  • Patent number: 9142207
    Abstract: A personal audio device, such as a wireless telephone, includes an adaptive noise canceling (ANC) 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 is also provided proximate the speaker to measure the ambient sounds and transducer output near the transducer, thus providing an indication of the effectiveness of the noise canceling. A processing circuit uses the reference and/or error microphone, optionally along with a microphone provided for capturing near-end speech, to determine whether the ANC circuit is incorrectly adapting or may incorrectly adapt to the instant acoustic environment and/or whether the anti-noise signal may be incorrect and/or disruptive and then take action in the processing circuit to prevent or remedy such conditions.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: September 22, 2015
    Assignee: CIRRUS LOGIC, INC.
    Inventors: Jon D. Hendrix, Ali Abdollahzadeh Milani, Nitin Kwatra, Dayong Zhou, Yang Lu, Jeffrey Alderson
  • Patent number: 9084049
    Abstract: Frequency-domain techniques are used for adaptive equalization that is responsive to spectral magnitude characteristics but not sensitive to phase characteristics of system response. Signal correlation may be used to improve adaptation accuracy when significant levels of ambient sounds are present. A preferred filter implementation uses convolution-based block transforms and cross-fade windows.
    Type: Grant
    Filed: September 13, 2011
    Date of Patent: July 14, 2015
    Assignee: Dolby Laboratories Licensing Corporation
    Inventors: Louis D. Fielder, David S. McGrath
  • Patent number: 9076427
    Abstract: A personal audio device, such as a wireless telephone, generates an anti-noise signal from a microphone signal and injects the anti-noise signal into the speaker or other transducer output to cause cancellation of ambient audio sounds. The microphone measures the ambient environment, but also contains a component due to the transducer acoustic output. An adaptive filter is used to estimate the electro-acoustical path from the noise-canceling circuit through the transducer to the at least one microphone so that source audio can be removed from the microphone signal. A determination of the relative amount of the ambient sounds present in the microphone signal versus the amount of the transducer output of the source audio present in the microphone signal is made to determine whether to update the adaptive response.
    Type: Grant
    Filed: March 7, 2013
    Date of Patent: July 7, 2015
    Assignee: Cirrus Logic, Inc.
    Inventors: Jeffrey Alderson, Jon D. Hendrix, Yang Lu
  • Patent number: 9048772
    Abstract: A method for operating an electric motor is provided, wherein a motor actuating signal is generated and transmitted to the motor. In order to reduce the noise generated by operating the motor, a suitable additional signal is generated and overlaid on the motor actuating signal when the motor actuating signal is transmitted to the motor.
    Type: Grant
    Filed: December 2, 2010
    Date of Patent: June 2, 2015
    Assignee: CONTI TEMIC MICROELECTRONIC GMBH
    Inventors: Erwin Keβler, Wolfgang Schulter
  • Patent number: 9042569
    Abstract: An active noise control device detects composite vibration of a vibration transmitting route to which both vibration of a rotating body caused by generation or transmission of drive force of a vehicle and vibration of a wheel generated by contact between the wheel and a road surface are transmitted. A first reference signal for defining a reference waveform of a canceling sound for canceling vibration noise in a vehicle interior is generated based on the composite vibration. The component of the canceling sound for canceling vibration noise of the rotating body is removed from the first reference signal to generate a second reference signal for defining a reference waveform of the canceling sound for canceling vibration noise of the wheel. The canceling sound is outputted based on the second reference signal.
    Type: Grant
    Filed: June 4, 2009
    Date of Patent: May 26, 2015
    Assignee: Honda Motor Co., Ltd.
    Inventors: Kosuke Sakamoto, Toshio Inoue
  • Publication number: 20150117658
    Abstract: By using the adaptive filter, the reference input signal is processed so as to identify a pseudo-signal of a particular signal to be deleted. The pseudo-signal is subtracted from the mixture containing a target signal inputted from a microphone, the particular signal to be deleted, and a noise so as to obtain an error signal. A stationary noise is estimated to obtain a stationary noise estimated value. A non-stationary noise is estimated to obtain a non-stationary noise estimated value. The stationary noise estimated value is mixed with the non-stationary estimated value to obtain a mixed noise estimated value. An update amount is calculated according to a correlation value between the error signal and the reference input signal, and the mixed noise estimated value. According to the update amount, a coefficient of the adaptive filter is updated.
    Type: Application
    Filed: December 31, 2014
    Publication date: April 30, 2015
    Applicant: NEC CORPORATION
    Inventor: Akihiko SUGIYAMA
  • Patent number: 9020159
    Abstract: A noise control device includes the following structural elements. A signal memory records both of a noise signal supplied from a noise microphone and an error signal supplied from an error microphone. A filter coefficient calculator calculates a fixed filter coefficient of a control filter by using data recorded in the signal memory. A filter coefficient renewing section renews, at a given timing, a filter coefficient set at a fixed filter in a control filter to a filter coefficient read out from the filter coefficient calculator.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: April 28, 2015
    Assignee: Panasonic Intellectual Property Management Co., Ltd.
    Inventors: Keiji Mori, Hiroyuki Kano, Tsuyoshi Maeda, Yoshifumi Asao
  • Patent number: 9020158
    Abstract: An active noise control system generates an anti-noise signal to drive a speaker to produce sound waves to destructively interfere with an undesired sound in a quiet zone. The anti-noise signal is generated with an adaptive filter having filter coefficients. The coefficients of the adaptive filter may be adjusted based on a first filter adjustment from a first listening region, and a second filter adjustment from a second listening region. A first weighting factor may be applied to the first filter adjustment, and a second weighting factor may be applied to the second filter adjustment. The first and second weighting factors may dictate the location and size of the quiet zone as being outside or partially within at least one of the first listening region and the second listening region.
    Type: Grant
    Filed: April 8, 2009
    Date of Patent: April 28, 2015
    Assignee: Harman International Industries, Incorporated
    Inventors: Duane Wertz, Vasant Shridhar
  • Patent number: 9020171
    Abstract: A method for controlling adaptation of a feedback suppression filter in a hearing aid comprises the step of suspending the adaptation of the feedback suppression filter when the level of a hearing aid reference signal is below a predetermined threshold. The invention further provides a hearing aid with a feedback suppression filter and with means for suspending adaptation of the feedback suppression filter.
    Type: Grant
    Filed: March 26, 2012
    Date of Patent: April 28, 2015
    Assignee: Widex A/S
    Inventors: Helge Pontoppidan Foeh, Peter Magnus Norgaard, Thilo Volker Thiede
  • Patent number: 9014387
    Abstract: A personal audio device including earspeakers, includes an adaptive noise canceling (ANC) circuit that adaptively generates an anti-noise signal for each earspeaker from at least one microphone signal that measures the ambient audio, and the anti-noise signals are combined with source audio to provide outputs for the earspeakers. The anti-noise signals cause cancellation of ambient audio sounds at the respective earspeakers. A processing circuit uses the microphone signal(s) to generate the anti-noise signals, which can be generated by adaptive filters. The processing circuit controls adaptation of the adaptive filters such that when an event requiring action on the adaptation of one of the adaptive filters is detected, action is taken on the other one of the adaptive filters. Another feature of the ANC system uses microphone signals provided at both of the earspeakers to perform processing on a voice microphone signal that receives speech of the user.
    Type: Grant
    Filed: March 12, 2013
    Date of Patent: April 21, 2015
    Assignee: Cirrus Logic, Inc.
    Inventors: Jon D. Hendrix, Jeffrey Alderson
  • Publication number: 20150104032
    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 estimate an electro-acoustical path from the noise canceling circuit through the transducer. A processing circuit uses the reference and/or error microphone, optionally along with a microphone provided for capturing near-end speech, to determine whether one of the reference or error microphones is obstructed by comparing their received signal content and takes action to avoid generation of erroneous anti-noise.
    Type: Application
    Filed: December 22, 2014
    Publication date: April 16, 2015
    Inventors: Nitin Kwatra, Jeffrey Alderson, Jon D. Hendrix
  • Patent number: 9008329
    Abstract: Provided are methods and systems for noise suppression within multiple time-frequency points of spectral representations. A multi-feature cluster tracker is used to track signal and noise sources and to predict signal versus noise dominance at each time-frequency point. Multiple features, such as binaural and monaural features, may be used for these purposes. A Gaussian mixture model (GMM) is developed and, in some embodiments, dynamically updated for distinguishing signal from noise and performing mask-based noise reduction. Each frequency band may use a different GMM or share a GMM with other frequency bands. A GMM may be combined from two models, with one trained to model time-frequency points in which the target dominates and another trained to model time-frequency points in which the noise dominates. Dynamic updates of a GMM may be performed using an expectation-maximization algorithm in an unsupervised fashion.
    Type: Grant
    Filed: June 8, 2012
    Date of Patent: April 14, 2015
    Assignee: Audience, Inc.
    Inventors: Michael Mandel, Carlos Avendano
  • Patent number: 9002027
    Abstract: A space-time adaptive beamformer for reducing noise in a vehicle that includes two or more microphones. A first weighting network is used for adjusting the signal characteristics of at least one output of the microphones while at least one delay network is also used for delaying the output in time of at least one output of the microphones. A second weighting network then adjusts the signal characteristics of the output of each of the delay networks and at sum adder works to combine the output of the first weighting network and the second weighting network. Finally, an output of the sum adder is combined with an artificial noise free reference signal to provide a low distortion noise reduced output. By generating a desired signal that acts as an artificial noise free signal reference, adequate noise reduction to be obtained without the distortion created due to processing non-linearity.
    Type: Grant
    Filed: June 27, 2011
    Date of Patent: April 7, 2015
    Assignee: Gentex Corporation
    Inventors: Robert R. Turnbull, Michael A. Bryson
  • Publication number: 20150078572
    Abstract: A processing circuit may include: (i) an adaptive filter having a response that generates an anti-noise signal from a reference microphone signal, wherein the response is shaped in conformity with the reference microphone signal and a playback corrected error, and wherein the playback corrected error is based on a difference between an error microphone signal and a secondary path estimate; (ii) a secondary path estimate filter configured to model an electro-acoustic path of a source audio signal and having a response that generates a secondary path estimate from the source audio signal; (iii) a secondary coefficient control block that shapes the response of the secondary path estimate filter in conformity with the source audio signal and the playback corrected error by adapting the response of the secondary path estimate filter to minimize the playback corrected error; and (iv) a noise injection portion for injecting a noise signal into the source audio signal, wherein the noise signal is shaped based on the
    Type: Application
    Filed: September 13, 2013
    Publication date: March 19, 2015
    Applicant: Cirrus Logic, Inc.
    Inventor: Ali Abdollahzadeh Milani
  • Patent number: 8983058
    Abstract: The present invention relates to an echo canceller (300) for estimating a model of an echo signal and a method thereof. The echo canceller comprises at least an adaptive main filter (301) for modeling the echo signal and an adaptive shadow filter (302) for modeling the echo signal. The adaptive main filter is an adaptive filter for which the adaptation speed is proportional to a system noise estimate and the adaptation speed of the shadow filter (302) is faster than the adaptation speed of the adaptive main filter (301). The echo canceller (300) comprises a processor (303) for determining whether the adaptive shadow filter models the echo signal better than the adaptive main filter and an updater (304) for updating the system noise estimate of the adaptive main filter (301) if the adaptive shadow filter models (302) the echo signal better than the adaptive main filter (301).
    Type: Grant
    Filed: April 22, 2010
    Date of Patent: March 17, 2015
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Anders Eriksson, Per Ahgren
  • Publication number: 20150071454
    Abstract: A hearing aid includes: a microphone; a hearing aid processing unit configured to provide a gain to a first signal based on an output signal from the microphone to generate a second signal; a receiver configured to convert the second signal into sound; an adaptive filter configured to adaptively estimate a transfer function corresponding to a pathway from an input side of the receiver to an output side of the microphone; and a feedback removal unit configured to subtract a third signal generated based on the transfer function from the output signal of the microphone to obtain a signal and output the signal as the first signal; and a control unit configured to control the gain setting unit and an adaptive speed of the adaptive filter.
    Type: Application
    Filed: September 4, 2014
    Publication date: March 12, 2015
    Applicant: RION Co., Ltd.
    Inventors: Masahiro SUNOHARA, Kazuteru NISHIYAMA
  • Publication number: 20150071453
    Abstract: An anti-noise signal is produced in accordance with an active noise cancellation process (ANC), at an input of a speaker so as to control how much background noise a user can hear. Strength of the anti-noise signal is adjusted gradually, rather than abruptly, in proportion to decreasing or increasing sound pressure level (SPL) of the background noise, during inactivation or activation of the ANC process. Other embodiments are also described and claimed.
    Type: Application
    Filed: June 13, 2014
    Publication date: March 12, 2015
    Inventors: Bruce C. Po, Vladan Bajic
  • Patent number: 8965757
    Abstract: Multi-channel noise suppression systems and methods are described that omit the traditional delay-and-sum fixed beamformer in devices that include a primary speech microphone and at least one noise reference microphone with the desired speech being in the near-field of the device. The multi-channel noise suppression systems and methods use a blocking matrix (BM) to remove desired speech in the input speech signal received by the noise reference microphone to get a “cleaner” background noise component. Then, an adaptive noise canceler (ANC) is used to remove the background noise in the input speech signal received by the primary speech microphone based on the “cleaner” background noise component to achieve noise suppression. The filters implemented by the BM and ANC are derived using closed-form solutions that require calculation of time-varying statistics of complex frequency domain signals in the noise suppression system.
    Type: Grant
    Filed: November 14, 2011
    Date of Patent: February 24, 2015
    Assignee: Broadcom Corporation
    Inventors: Jes Thyssen, Huaiyu Zeng, Juin-Hwey Chen, Nelson Sollenberger, Xianxian Zhang
  • Patent number: 8958571
    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 estimate an electro-acoustical path from the noise canceling circuit through the transducer. A processing circuit uses the reference and/or error microphone, optionally along with a microphone provided for capturing near-end speech, to determine whether one of the reference or error microphones is obstructed by comparing their received signal content and takes action to avoid generation of erroneous anti-noise.
    Type: Grant
    Filed: September 30, 2011
    Date of Patent: February 17, 2015
    Assignee: Cirrus Logic, Inc.
    Inventors: Nitin Kwatra, Jeffrey Alderson, Jon D. Hendrix
  • Patent number: 8953813
    Abstract: A digital active noise cancellation circuit device (330) includes an oversampled, sigma-delta, A/D converter (204), a digital decimation filter (208), a digital intermediate filter (308), a digital interpolation filter (232), and a sigma-delta, D/A converter (252).
    Type: Grant
    Filed: December 21, 2010
    Date of Patent: February 10, 2015
    Assignee: Dialog Semiconductor GmbH
    Inventor: Sebastian Loeda
  • Patent number: 8953776
    Abstract: By using the adaptive filter, the reference input signal is processed so as to identify a pseudo-signal of a particular signal to be deleted. The pseudo-signal is subtracted from the mixture containing a target signal inputted from a microphone, the particular signal to be deleted, and a noise so as to obtain an error signal. A stationary noise is estimated to obtain a stationary noise estimated value. A non-stationary noise is estimated to obtain a non-stationary noise estimated value. The stationary noise estimated value is mixed with the non-stationary estimated value to obtain a mixed noise estimated value. An update amount is calculated according to a correlation value between the error signal and the reference input signal, and the mixed noise estimated value. According to the update amount, a coefficient of the adaptive filter is updated.
    Type: Grant
    Filed: August 19, 2008
    Date of Patent: February 10, 2015
    Assignee: NEC Corporation
    Inventor: Akihiko Sugiyama
  • 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: 8949120
    Abstract: Systems and methods for controlling adaptivity of noise cancellation are presented. One or more audio signals are received by one or more corresponding microphones. The one or more signals may be decomposed into frequency sub-bands. Noise cancellation consistent with identified adaptation constraints is performed on the one or more audio signals. The one or more audio signals may then be reconstructed from the frequency sub-bands and outputted via an output device.
    Type: Grant
    Filed: April 13, 2009
    Date of Patent: February 3, 2015
    Assignee: Audience, Inc.
    Inventors: Mark Every, Ludger Solbach, Carlo Murgia, Ye Jiang
  • Patent number: 8948410
    Abstract: A noise canceling system comprises a microphone generating a captured signal and a sound transducer radiating a sound canceling audio signal in the audio environment. A feedback path from the microphone to the sound transducer includes a non-adaptive canceling filter and a variable gain and receives the captured signal and generates a drive signal for the sound transducer. A gain detector determines a secondary path gain for at least part of a secondary path of a feedback loop. The secondary path may include the microphone, the sound transducer, and the acoustic path therebetween but does not include the non-adaptive canceling filter or the variable gain. A gain controller adjusts the in of the variable gain in response to the secondary path gain. The system use simple gain estimation and control to efficiently compensate for variations in the secondary path to provide improved stability and noise canceling performance.
    Type: Grant
    Filed: December 11, 2009
    Date of Patent: February 3, 2015
    Assignee: Koninklijke Philips N.V.
    Inventor: Adriaan Johan Van Leest
  • Patent number: 8942976
    Abstract: The present invention provides a noise reduction control method using a microphone array and a noise reduction control device using a microphone array wherein the method comprises the steps of: S1: collecting, by the microphone array, acoustic signals; S2: estimating incidence angles of all acoustic signals of the microphone array; S3: conducting a statistics on signal components according to incidence angles; S4: determining a parameter ? from a ratio of noise components according to the statistical result and using the parameter ? as a control parameter for controlling an adaptive filter. With the present invention, space position information of the sound is obtained directly with the microphone array to control update of the adaptive filter more accurately, so as to eliminate noise, enhance SNR and protect speech quality well at the same time.
    Type: Grant
    Filed: December 15, 2010
    Date of Patent: January 27, 2015
    Assignee: Goertek Inc.
    Inventors: Bo Li, Shasha Lou, Song Li
  • Patent number: 8934620
    Abstract: Methods and devices for improved echo cancellation in high noise environments, such as in-car speakerphones and the like, are provided that improve cancellation convergence in a high noise environment and in the presence of double talk. A new update method enables a robust echo canceller to update with reduced concern for the canceller being in a receive state or a double talk state. If a signal generated by a local talker is substantially the same as high noise, in terms of corruption of the echo canceller, the echo canceller converges in a robust manner even with continuous high noise at the input.
    Type: Grant
    Filed: March 30, 2012
    Date of Patent: January 13, 2015
    Assignee: Cogent Signals, Inc.
    Inventor: David Lee Rowley