Residual Echo Cancellation Patents (Class 379/406.05)
  • Patent number: 10523808
    Abstract: Enabling and disabling the updating of an adaptive filter for echo cancellation of a communication device is discussed. In some embodiments, an echo canceler in a communication device may include an adaptive filter enabled to update responsive to a determination that a first condition is satisfied that there is no double talk detected on the communication device, and a determination that a second condition is satisfied based, at least in part, on a performance characteristic. The adaptive filter may be disabled from updating responsive to at least one of the first condition and the second condition not being satisfied. Described is disabling the adaptive filter from updating responsive to detecting a performance characteristic of the adaptive filter to fail to meet a condition indicating that the adaptive filter is diverging. The condition may be independent of whether double-talk is determined to be present on the communication device.
    Type: Grant
    Filed: October 21, 2016
    Date of Patent: December 31, 2019
    Assignee: Sorenson IP Holdings, LLC
    Inventor: Mark Adams
  • Patent number: 10334113
    Abstract: A gain control system for dynamically tuning an echo canceller, the echo canceller being configured to estimate an echo of a far-end signal and subtract that echo estimate from a microphone signal to output an echo cancelled signal, the gain control system comprising a monitoring unit configured to estimate an energy associated with an impulse response of an adaptive filter configured to generate the echo estimate from the far-end signal and a gain tuner configured to adjust an attenuation of at least one of the microphone signal and the far-end signal in dependence on the estimated energy.
    Type: Grant
    Filed: June 8, 2017
    Date of Patent: June 25, 2019
    Assignee: Imagination Technologies Limited
    Inventors: Senthil Kumar Mani, Gandhi Namani, Srinivas Akella, Sai Ravi Teja Pulugurtha
  • Patent number: 10181329
    Abstract: An audio processing device includes a first microphone configured to receive a first signal a second microphone configured to receive a second signal, a noise reduction gain determination circuit configured to determine a noise reduction gain based on the first signal and the second signal, a noise reduction circuit configured to attenuate the first signal based on the determined noise reduction gain, and an output circuit configured to output the attenuated signal.
    Type: Grant
    Filed: September 5, 2014
    Date of Patent: January 15, 2019
    Assignee: Intel IP Corporation
    Inventors: Ludovick Lepauloux, Fabrice Plante, Christophe Beaugeant
  • Patent number: 9838074
    Abstract: Embodiments of the present invention provide a crosstalk suppression method and apparatus. By obtaining a first electrical signal indicating a data bit stream of a first optical signal output by a laser diode (LD) in an optical transceiver module and a transmission parameter of a photodiode (PD), adjusting the first electrical signal based on the transmission parameter of the PD to obtain a third electrical signal indicating an electrical signal transformed by the PD from the first optical signal transmitted by the LD, and subtracting the third electrical signal from a second electrical signal output by the PD in the optical transceiver module, an electrical signal generated by the optical signal transmitted by the LD and reflected or refracted to the PD is removed from the electrical signal output by the PD, thereby suppressing crosstalk and improving the sensitivity of the optical transceiver module.
    Type: Grant
    Filed: June 17, 2015
    Date of Patent: December 5, 2017
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Xiaoping Zhou, Yinghua Dong
  • Patent number: 9768829
    Abstract: A method for processing audio signals is provided comprising outputting an audio signal; receiving the output audio signal via a first receiving path as a first received audio signal; receiving the output audio signal via a second receiving path as a second received audio signal; determining an echo suppression gain based on the first received audio signal and the second received audio signal; and filtering echo suppression of the audio signal based on the first received audio signal and the echo suppression gain.
    Type: Grant
    Filed: November 14, 2012
    Date of Patent: September 19, 2017
    Assignee: INTEL DEUTSCHLAND GMBH
    Inventors: Christelle Yemdji, Nicholas Evans, Christophe Beaugeant, Ludovick Lepauloux
  • Patent number: 9307318
    Abstract: In one form, an audio processor circuit includes a first digital signal processing circuit, a second digital signal processing circuit, and an interleaver. The first digital signal processing circuit has an input for receiving a far-end audio signal, and an output. The second digital signal processing circuit has an input for receiving a digital near-end audio signal, and an output. The interleaver has a first input coupled to the output of the first digital signal processing circuit, a second input coupled to the output of the second digital signal processing circuit, and an output for alternatively providing signals received from the first and second inputs to the output.
    Type: Grant
    Filed: March 7, 2013
    Date of Patent: April 5, 2016
    Assignee: SILICON LABORATORIES INC.
    Inventors: David O. Anderton, Kevin Hung, Dana Taipale
  • Patent number: 9269370
    Abstract: According to a preferred aspect of the instant invention, there is provided a system and method that allows the user to attenuate ambient noise in speech recordings in the audio part of a video recording. The user does not need to define particular sections or samples or individual parameters. The system is automatically analyzing the input signal and in a plurality of individual steps detects the ambient noise, determines an adaptive filter, implements the filter and therewith attenuates the ambient noise accordingly.
    Type: Grant
    Filed: December 12, 2014
    Date of Patent: February 23, 2016
    Assignee: MAGIX AG
    Inventors: Tilman Herberger, Titus Tost, Georg Flemming
  • Patent number: 9203527
    Abstract: A system and method for sharing a designated audio signal may reproduce the designated audio signal via transducer into an acoustic space. The designated audio signal may be a recorded audio signal, an encoded audio signal, a streamed audio signal and an audio signal component of a multi-media content item. An input audio signal may be received representing a sound field in the acoustic space. One or more microphones may receive the input audio signal. A component contributed by the reproduced designated audio signal may be suppressed in the input audio signal. An echo suppressor may suppress the recaptured designated audio signal. The designated audio signal may be mixed with the suppressed input audio signal to generate an uplink audio signal. The designated audio signal mixed with the suppressed input audio signal may not include artifacts caused by the transducer, the microphone and the acoustic space.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: December 1, 2015
    Assignee: 2236008 Ontario Inc.
    Inventors: Leona Arlene Neufeld, Phillip Alan Hetherington
  • Patent number: 9123321
    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 to the speaker to provide an error signal indicative of the effectiveness of the noise cancellation. A secondary path estimating adaptive filter is used to estimate the electro-acoustical path from the noise canceling circuit through the transducer so that source audio can be removed from the error signal. Adaptation of adaptive filters is sequenced so that update of their coefficients does not cause instability or error in the update. A level of the source audio with respect to the ambient audio can be determined to determine whether the system may generate erroneous anti-noise and/or become unstable.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: September 1, 2015
    Assignee: Cirrus Logic, Inc.
    Inventors: Jeffrey Alderson, Jon D. Hendrix, Dayong Zhou, Antonio John Miller, Chin Yong, Gautham Devendra Kamath
  • Patent number: 9100466
    Abstract: A method for processing an audio signal is described comprising receiving a first audio signal via a first receiving path comprising a first microphone; receiving a second audio signal via a second receiving path comprising a second microphone; and performing echo suppression of the first audio signal based on the first audio signal and the second audio signal.
    Type: Grant
    Filed: May 13, 2013
    Date of Patent: August 4, 2015
    Assignee: INTEL IP CORPORATION
    Inventors: Christelle Yemdji, Ludovick Lepauloux, Christophe Beaugeant, Nicholas Evans
  • Patent number: 9042567
    Abstract: An acoustic echo cancellation (AEC) system includes a remote device, for capturing a remote captured sound, a server coupled to the remote device, and a local device coupled to the server. The server transmits the remote captured sound from the remote device to the local device. The local device receives, stores and plays the remote captured sound as a local playback sound. An echo is generated from reflection of the local playback sound. The local device captures the echo and a local sound into a local captured sound, and transmits both the remote captured sound and the local captured sound to the server. The server performs AEC on the local captured sound by using the remote captured sound from the local device and transmits the AEC processed local captured sound to the remote device.
    Type: Grant
    Filed: March 17, 2013
    Date of Patent: May 26, 2015
    Assignee: QUANTA COMPUTER INC.
    Inventors: Kuo-Chun Huang, Kai-Ju Cheng, Rong-Quen Chen, Shih-Hsiang Lo
  • Patent number: 9036814
    Abstract: Method, user device and computer program product for suppressing echo. An audio signal is output from a speaker. A microphone receives an audio signal, wherein the received audio signal includes an echo resulting from the outputted audio signal. A Finite Impulse Response filter estimate ?(n) is dynamically adapted in the time domain based on the outputted audio signal and the received audio signal to model an echo path h(n) related to the echo in the received audio signal. The filter estimate ?(n) is used in an estimate of the echo power in the received audio signal, and the estimated echo power is used to apply echo suppression to the received audio signal, thereby suppressing the echo in the received audio signal.
    Type: Grant
    Filed: May 7, 2013
    Date of Patent: May 19, 2015
    Assignee: MICROSOFT TECHNOLOGY LICENSING, LLC
    Inventor: Karsten Vandborg Sorensen
  • Patent number: 9020144
    Abstract: An audio-based system may perform noise and echo suppression by initially processing an audio signal that is subject to acoustic echo or echo resulting from other system characteristics. The audio signal is processed in the time domain using an adaptive echo-cancellation filter. The audio is then further processed in the frequency domain to simultaneously reduce background noise and residual echo.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: April 28, 2015
    Assignee: Rawles LLC
    Inventor: Jun Yang
  • Patent number: 9008302
    Abstract: A new audio echo cancellation (AEC) approach is disclosed. To facilitate echo cancellation, the method adjusts for errors (called drift) in sampling rates for both capturing audio and playing audio. This ensures that the AEC module receives both the signals at precisely the same sampling frequency. Furthermore, the far-end signal and near-end mixed signal are time aligned to ensure that the alignment is suitable for application of AEC techniques. An additional enhancement to reduce errors utilizes a concept of native frequency. A by-product of drift compensation allows for excellent buffer control for capture/playback and buffer overflow/underflow errors from drift errors are eliminated.
    Type: Grant
    Filed: October 10, 2011
    Date of Patent: April 14, 2015
    Assignee: Optical Fusion, Inc.
    Inventors: Mukund N. Thapa, Vinoda Kumar Somashekhara, Mariya Krishnasamy, Vinay V. Kabadi
  • Publication number: 20150086006
    Abstract: In an echo suppressor, a frequency bin component detector compares a far-end signal amplitude spectrum with a threshold value for each frequency bin to determine whether or not each frequency bin includes a frequency component. A frequency bin echo path characteristic estimator uses the far-end signal amplitude spectrum in the frequency bins determined to have a frequency component by the frequency bin component detector and the near-end input signal amplitude spectrum of corresponding frequency bins to estimate the echo path characteristics of the frequency bins. An estimated echo signal calculation-and-echo suppressor section calculates estimated echo signals based on the echo path characteristic in each frequency bin and the far-end signal amplitude spectrum to suppress the estimated echo signals from the near-end input signal amplitude spectrum.
    Type: Application
    Filed: July 18, 2014
    Publication date: March 26, 2015
    Applicant: OKI ELECTRIC INDUSTRY CO., LTD.
    Inventor: Naoya KAWABATA
  • Patent number: 8972255
    Abstract: Embodiments of methods and devices for classifying background noise contained in an audio signal are disclosed. In one embodiment, the device includes a module for extracting from the audio signal a background noise signal, termed the noise signal. Also included is a second that calculates a first parameter, termed the temporal indicator. The temporal indicator relates to the temporal evolution of the noise signal. The second module also calculates a second parameter, termed the frequency indicator. The frequency indicator relates to the frequency spectrum of the noise signal. Finally, the device includes a third module that classifies the background noise by selecting, as a function of the calculated values of the temporal indicator and of the frequency indicator, a class of background noise from among a predefined set of classes of background noise.
    Type: Grant
    Filed: March 22, 2010
    Date of Patent: March 3, 2015
    Assignee: France Telecom
    Inventors: Adrien Leman, Julien Faure
  • Patent number: 8942370
    Abstract: A communications device is presented for providing bi-directional audio communications between a near-end user and a far-end user via a bidirectional communications channel. The communications device includes an adaptive echo canceller receiving a near-end audio signal and a far-end audio signal and providing an echo-canceled near-end audio signal for transmission to the far-end user via the communications channel. The adaptive echo canceller includes a first bank of analysis filters for filtering the near-end audio signal, a second bank of analysis filters for filtering the far-end audio signal, and a bank of synthesis filters for filtering sub-band echo-canceled signals generated within the adaptive echo canceller. The first and second filter banks have a frequency response optimized to reduce echo residual gain.
    Type: Grant
    Filed: March 5, 2012
    Date of Patent: January 27, 2015
    Assignee: Microsoft Corporation
    Inventors: Qin Li, Wei-ge Chen, Chao He
  • 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
  • Publication number: 20140355751
    Abstract: Systems and methods are provided for echo reduction. For example, first audio data associated with a current time unit is obtained, the first audio data being generated by an audio-acquisition device of a receiver based on at least information associated with a first audio signal acquired by the audio-acquisition device and a second audio signal output from an audio-playback device of the receiver, the second audio signal being output from the audio-playback device of the receiver based on at least information associated with second audio data transmitted previously by a sender before the current time unit; third audio data transmitted by the sender during a second time unit preceding the current time unit is obtained; and fourth audio data is obtained by performing echo reduction on the first audio data based on at least information associated with the third audio data.
    Type: Application
    Filed: February 20, 2014
    Publication date: December 4, 2014
    Applicant: Tencent Technology (Shenzhen) Company Limited
    Inventors: Xingping Long, Hong Liu, Muyong Cao
  • Patent number: 8873740
    Abstract: The present invention provides for echo cancellation circuitry and variable rate encoding circuitry to cooperate with one another to effectively provide comfort noise in an effective and efficient manner. The echo cancellation circuitry will use far-end signals to generate estimated echo signals, which correspond to the actual echo signals appearing in near-end signals. The estimated echo signals are essentially subtracted from the near-end signals in an effort to remove the actual echo signals from the near-end signals. The echo cancellation circuitry will monitor any residual echo signals in the resulting processed near-end signals and provide residual echo control signals that are indicative of whether the residual echo signals should be replaced with comfort noise. The residual echo control signals are used at least in part by the variable rate encoding circuitry to determine the encoding rate to use for encoding different portions of the processed near-end signals.
    Type: Grant
    Filed: October 24, 2012
    Date of Patent: October 28, 2014
    Assignee: Apple Inc.
    Inventors: Peter Yue, Rafi Rabipour
  • Patent number: 8861713
    Abstract: Echo cancellation is provided in a telephone device by calculating a metric value indicative of a similarity between a representation of an incoming signal from a far end talker and a representation of an outgoing signal from a near end talker. A threshold value is derived based on the metric value. A portion of the outgoing signal is removed by using the threshold value to determine an amount to remove from the outgoing signal with continuous, real-time updating of the threshold value.
    Type: Grant
    Filed: March 17, 2013
    Date of Patent: October 14, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Jianzhong Xu, Bogdan Kosanovic
  • Patent number: 8855329
    Abstract: An active noise control (ANC) system may be implemented to both sides of a fan, such that both directions of the noise emitting are treated to reduce the overall noise. The impact on airflow is minimal, and the technique is very effective in a broad range of low frequencies. Passive sound-absorbing materials may be included for attenuation of high frequencies. The resulting quiet fan produces a low level of noise compared to any other device based on fan, which produces the same capacity of airflow. The quiet fan may be incorporated in any mechanical system which requires airflow induction such as: computers, air conditioners, machines, and more.
    Type: Grant
    Filed: January 20, 2008
    Date of Patent: October 7, 2014
    Assignee: Silentium Ltd.
    Inventors: Alon Slapak, Tzvika Fridman, Ofira Rubin
  • Patent number: 8824667
    Abstract: In one embodiment, an acoustic echo control (AEC) module receives an outgoing signal and an incoming signal, which, at various times, contains acoustic echo corresponding to the outgoing signal. The AEC module has a delay estimation block that estimates, in the time domain, the echo delay using an adaptive filtering technique. This delay estimation is used to align samples of the incoming signal having acoustic echo with the corresponding samples of the outgoing signal from which the acoustic echo originated. The AEC module determines whether or not samples of the incoming signal contain acoustic echo based on the aligned outgoing signal, and the determinations are applied to a hangover counter. The AEC module then suppresses acoustic echo in the incoming signal and adds comfort noise to the incoming signal. The amount of echo suppression performed is gradually increased or decreased based on comparisons of the counter to a hangover threshold.
    Type: Grant
    Filed: August 31, 2011
    Date of Patent: September 2, 2014
    Assignee: LSI Corporation
    Inventors: Ivan Leonidovich Mazurenko, Dmitry Nikolaevich Babin, Denis Vassilevich Parfenov, Alexander Alexandrovich Petyushko, Alexander Markovic
  • Patent number: 8792649
    Abstract: An adaptive filter unit outputs a send-mid signal obtained by eliminating echo from a send-in signal, and a power comparing unit calculates a power ratio between received signal power and send-mid signal power. When a receiver ST detecting unit detects a single talk state at a receiving side, an acoustic coupling amount estimating unit estimates and updates the estimated amount of acoustic coupling from the power ratio. A residual echo power estimating unit estimates estimated residual echo power from the received signal power and the estimated amount of acoustic coupling, and a signal-to-echo ratio estimating unit estimates a ratio between the send-mid signal power and the estimated residual echo power. An amplitude suppression coefficient determining unit determines the amplitude suppression coefficient corresponding to the ratio, and an amplitude suppression unit amplitude suppresses the send-mid signal.
    Type: Grant
    Filed: September 24, 2008
    Date of Patent: July 29, 2014
    Assignee: Mitsubishi Electric Corporation
    Inventor: Atsuyoshi Yano
  • Patent number: 8774399
    Abstract: A telecommunication system including a speakerphone provides a coupled signal path, including a microphone, configured to sense an incoming audio signal and an echo signal and generate a coupled signal. The echo signal includes non-linear distortion generated by a speaker of the speakerphone. An echo signal path, including an amplifier, is configured to sense the echo signal and generate an echo reference signal. The echo reference signal includes the non-linear distortion. An acoustic echo canceller is configured to receive the coupled signal from the coupled signal path, to receive the echo reference signal from the echo signal path, and to cancel out the non-linear distortion included in the coupled signal based on the non-linear distortion included in the echo reference signal.
    Type: Grant
    Filed: December 27, 2011
    Date of Patent: July 8, 2014
    Assignee: Broadcom Corporation
    Inventors: Prakash C. Khanduri, Bosen Zhao
  • Patent number: 8767951
    Abstract: A talk deciding system includes a receiving portion which receives far-end side decision information indicating a talking state on a far-end side, an inputting portion which inputs an emitted signal from the far-end side, a speaker which emits the emitted signal being input into the inputting portion, a microphone which picks up a voice on a near-end side and outputs a picked-up signal, and a deciding portion which preliminarily decides a talking state on the near-end side based on the picked-up signal being output from the microphone and the emitted signal being input into the speaker, and generates near-end side decision information indicating a talking state on the near-end side. The deciding portion decides the talking state on the near-end side based on the far-end side decision information being received at the receiving portion and the near-end side decision information.
    Type: Grant
    Filed: August 22, 2007
    Date of Patent: July 1, 2014
    Assignee: Yamaha Corporation
    Inventors: Satoshi Sekine, Hiraku Okumura
  • Patent number: 8750491
    Abstract: Architecture that mitigates echo in voice communications using echo detection and adaptive management of attenuation by a non-linear processor (NLP). Suppression values provided by the NLP are determined based on echo detection and retained on a case-by-case basis to automatically increase or decrease the attenuation as needed. Feedback is incorporated that where the controls for the NLP attenuation is given by the amount of echo that remains, and this in turn affects the amount of echo that remains.
    Type: Grant
    Filed: March 24, 2009
    Date of Patent: June 10, 2014
    Assignee: Microsoft Corporation
    Inventors: Vinod Prakash, Chao He
  • Patent number: 8724798
    Abstract: A method and apparatus for canceling an echo in audio communication is disclosed. The method comprises receiving an audio signal from a network and subsequently detecting a mixture audio signal comprising a target audio signal and an echo audio signal, the echo signal corresponding to the received audio signal. The method then comprises estimating the target audio signal by determining magnitude spectrograms for the mixture and received audio signals respectively, estimating a magnitude spectrogram of the target audio signal dependent on those of the mixture and received audio signal, and generating an output audio signal that estimates the target audio signal, the output audio signal being dependent on the estimated magnitude spectrogram.
    Type: Grant
    Filed: November 20, 2009
    Date of Patent: May 13, 2014
    Assignee: Adobe Systems Incorporated
    Inventors: Paris Smaragdis, Gautham J. Mysore
  • Patent number: 8705760
    Abstract: The active noise control device includes: a signal obtaining section that obtains an electric signal relating to the predetermined sound; a control section that adjusts an amplitude and a phase of the electric signal obtained by the signal obtaining section; a vibrating section having a diaphragm and a vibrator, the vibrator vibrating in accordance with an output from the control section. Because a sound radiated from the diaphragm toward the first region is substantially in opposite phase to that toward the second region, the control section controls the vibrator so that the diaphragm generates a sound that attenuates the predetermined sound in the first region, and causes the predetermined sound to have a desired frequency characteristic in the second region.
    Type: Grant
    Filed: March 17, 2010
    Date of Patent: April 22, 2014
    Assignee: Panasonic Corporation
    Inventor: Ko Mizuno
  • 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: 8638836
    Abstract: A transceiver mitigates signal leakage into a receive path from a transmit path. A subtraction circuit determines a difference between a receive signal and a compensation signal to produce a compensated receive signal prior to demodulation by a demodulator. An equalizer both amplitude adjusts and phase adjusts orthogonal baseband transmit signals based on the difference from the subtraction circuit to produce the compensation signal. A digital tuning circuit determines at least one amplitude adjust coefficient to be used by the equalizer. The equalizer can have a polarity switch or a variable attenuator or a variable delay.
    Type: Grant
    Filed: August 31, 2009
    Date of Patent: January 28, 2014
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Pallab Midya, Rakers L Patrick, William J Roeckner
  • Patent number: 8620232
    Abstract: The present document discloses a method and system for improving echo cancellation in the presence of non-linear distortions. A circuit attenuates a transmit signal in one or more spectral bands based on a receive signal. The distorted echo comprised within the transmit signal results from distortions incurred by the receive signal when being rendered by an electronic device. The circuit compares energy values of the receive signal in multiple spectral bands with multiple corresponding spectral band dependent distortion thresholds and determines that for a first spectral band from multiple spectral bands. A first energy value from multiple energy values exceeding a first distortion threshold from multiple distortion thresholds attenuates the transmit signal in one or more spectral bands at higher frequencies than the first spectral band with corresponding spectral band dependent attenuation factors.
    Type: Grant
    Filed: October 17, 2012
    Date of Patent: December 31, 2013
    Assignee: Dialog Semiconductor B.V.
    Inventor: Michiel Andre Helsloot
  • Patent number: 8605891
    Abstract: A system and method for provide a stable gain from an adaptive gain control device in a signal path. An echo canceller is also located in the signal path, and is used to provide performance information regarding losses in the signal. This performance information is fed to the automatic gain control device via a connection. The automatic gain control device thereafter uses the performance information to determine a maximum gain that might be provided based upon losses cause by echo conditions. The gain however is limited in order to provide for a stable system. The performance information includes a loss rate that includes a combination of the echo return loss and the echo return loss enhancement.
    Type: Grant
    Filed: June 21, 2011
    Date of Patent: December 10, 2013
    Assignee: Broadcom Corporation
    Inventor: Wilfrid LeBlanc
  • Patent number: 8600037
    Abstract: Echo cancellation is handled using a pattern classification technique. During a training phase, the communications device is trained to learn patterns of signal inputs that correspond to certain communication modes. After numerous different patterns have been classified by mode, the classified patterns are used during real-time use of the communications device in order to determine, dynamically, the mode in which the communications device is currently operating. The communications device may then apply, to the microphone-produced signal, a suppression action.
    Type: Grant
    Filed: June 1, 2012
    Date of Patent: December 3, 2013
    Assignee: Apple Inc.
    Inventor: Arvindh Krishnaswany
  • Patent number: 8582754
    Abstract: During playing of a streamed audio while engaging in a voice communication session, a communication device may be operable to generate a background audio during an echo cancellation operation for the voice communication session, using known information associated with the streamed audio. The streamed audio may comprise audio content that is received from one or more external sources and/or locally generated within the communication device. The known information associated with the streamed audio may comprise an echo replica corresponding to an echo associated with the streamed audio and/or a modified version of the streamed audio. In instances when a residual echo suppression is operational during the echo cancellation operation, the communication device may be operable to suppress a residual echo based on a signal level of the echo replica corresponding to the echo associated with the streamed audio and/or a signal level of the modified version of the streamed audio.
    Type: Grant
    Filed: March 21, 2011
    Date of Patent: November 12, 2013
    Assignee: Broadcom Corporation
    Inventors: Franck Beaucoup, Wilfrid LeBlanc, Aleksander Radisavljevic
  • Patent number: 8526599
    Abstract: An input/output apparatus includes a speaker, a microphone, an adaptive filter circuit and a control circuit. The speaker is configured to output audio based on a voice-receiving signal. The microphone is configured to produce a voice-transmitting signal based on gathered audio. The adaptive filter circuit is configured to produce a residual signal based on a pseudo echo signal and a amplified voice-transmitting signal. The pseudo echo signal is produced from the voice-receiving signal and a transfer coefficient which expresses audio transfer properties between the speaker and the microphone. The amplified voice-transmitting signal is produced by causing a microphone amplification circuit to amplify the voice-transmitting signal. The control circuit is configured to stop output of the residual signal from the adaptive filter circuit during at least one of the speaker and the microphone is muted.
    Type: Grant
    Filed: September 18, 2012
    Date of Patent: September 3, 2013
    Assignee: Panasonic Corporation
    Inventor: Ryoji Suzuki
  • Patent number: 8498423
    Abstract: A method is provided which is suitable to cope with non-linear echo paths during acoustic echo cancellation in speakerphones. Non-linear paths occur particularly in hands-free operation of, e.g., a mobile phone, due to driving the amplifier and loudspeaker in the non-linear range. The idea is to combine the commonly known one microphone approach of linear acoustic echo cancellation using an adaptive filter and a post-processor together with a multiple microphone approach using beam forming which separately removes the non-linear part of the echo.
    Type: Grant
    Filed: June 16, 2008
    Date of Patent: July 30, 2013
    Assignee: Koninklijke Philips N.V.
    Inventors: Rainer Thaden, Cornelis Pieter Janse, David Antoine Christian Marie Roovers
  • Patent number: 8494178
    Abstract: Methods and techniques to implement a digital signal processor for avoidance of audio feedback are disclosed, in particular, audio signal processing systems that reduce the requirement for physical segregation of sound acquisition and diffusion zones. In a more general aspect, the components and techniques described herein provide a for a sound space and sound processing equipment such that sound travelling electronically in a loop through the sound processing equipment that is output into a physical sound diffusion zone, received at the input to the sound processing equipment, and then re-amplified, etc. is attenuated over that loop by frequency modification. The frequency modification is such that, at least for some signals, on each pass through the loop, the sound processing equipment will attenuate or amplify individual sub-bands of the frequency spectrum of the audio signal that is received at the input of the sound processing equipment.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: July 23, 2013
    Assignee: Pixar
    Inventors: Loren Carpenter, Lanny Smoot, Alex Stahl
  • Patent number: 8488776
    Abstract: The coefficient generating section receives a first signal which is the output signal of the microphone of a signal generated by subtracting the output signal of a linear echo canceller from the output signal of the microphone and a second signal which is the output signal of the linear echo canceller. The coefficient generating section detects the minimum value of the variation with time of the ratio of the amplitude of the first signal to that of the second signal and outputs the value of constant times the detected minimum value as a crosstalk coefficient indicating the degree of crosstalk of the echo. The converting section corrects the first signal according to the crosstalk coefficient and the second signal to generate a near-end signal which is the resultant signal of when the echo is removed from the first signal and outputs the near-end signal to an output terminal.
    Type: Grant
    Filed: October 16, 2008
    Date of Patent: July 16, 2013
    Assignee: NEC Corporation
    Inventor: Osamu Hoshuyama
  • 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: 8473286
    Abstract: A noise feedback coding (NFC) system and method that utilizes a simple and relatively inexpensive general structural configuration, but achieves improved flexibility with respect to controlling the shape of coding noise. The NFC system and method utilizes an all-zero noise feedback filter that is configured to approximate the response of a pole-zero noise feedback filter.
    Type: Grant
    Filed: February 24, 2005
    Date of Patent: June 25, 2013
    Assignee: Broadcom Corporation
    Inventor: Jes Thyssen
  • Patent number: 8462962
    Abstract: A sound processor includes a conversion unit converts a reference sound signal corresponding to a base of sound to be output and an observation sound signal based on each of sound signals output by a plurality of sound receiving units into frequency components, an echo suppression unit estimates echo derived from sound based on a converted reference sound signal and suppressing the estimated echo in a converted observation sound signal, a noise suppression unit estimates noise based on an arrival direction of sound and suppressing the estimated noise in the converted observation sound signal and an integrating process unit suppresses, with respect to each frequency component, echo and noise in the converted sound signal based on a observation sound signal obtained after echo suppression and a observation sound signal obtained after noise suppression.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: June 11, 2013
    Assignee: Fujitsu Limited
    Inventors: Taisuke Itou, Naoshi Matsuo
  • Patent number: 8433061
    Abstract: Far-end audio signal data generated by a far-end device during voice cross-talk between the far-end device and a near-end device is received via a network. Energy levels of frequency components of the received far-end audio signal data are determined. Near-end audio signal data produced by a microphone array is received, the near-end audio signal data including components contributed by a loudspeaker playing at least some of the far-end audio signal data. Which frequency components of the near-end audio signal data to use to compute likely near-end sound source directions is controlled dynamically, where the controlling is based on the determined energy levels of the frequency components of the received far-end audio signal data.
    Type: Grant
    Filed: December 10, 2007
    Date of Patent: April 30, 2013
    Assignee: Microsoft Corporation
    Inventor: Ross Cutler
  • Patent number: 8433074
    Abstract: Converter 100 uses either the output signal of a sound pickup device or the signal obtained by subtracting the output signal of an echo canceller from the output signal of the sound pickup device as a first signal, uses an estimated crosstalk value indicative of an estimated value of the amount of crosstalk of an echo leaking into the first signal to correct the first signal, and limits the corrected first signal not to be smaller than estimated near-end noise.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: April 30, 2013
    Assignee: NEC Corporation
    Inventor: Osamu Hoshuyama
  • Patent number: 8416946
    Abstract: A regression-based residual echo suppression (RES) system and process for suppressing the portion of the microphone signal corresponding to a playback of a speaker audio signal that was not suppressed by an acoustic echo canceller (AEC). In general, a prescribed regression technique is used between a prescribed spectral attribute of multiple past and present, fixed-length, periods (e.g., frames) of the speaker signal and the same spectral attribute of a current period (e.g., frame) of the echo residual in the output of the AEC. This automatically takes into consideration the correlation between the time periods of the speaker signal. The parameters of the regression can be easily tracked using adaptive methods. Multiple applications of RES can be used to produce better results and this system and process can be applied to stereo-RES as well.
    Type: Grant
    Filed: September 24, 2010
    Date of Patent: April 9, 2013
    Assignee: Microsoft Corporation
    Inventors: Amit Chhetri, Arungunram Surendran, Jack Stokes, John Platt
  • Patent number: 8411871
    Abstract: Implementations related to echo cancellation are depicted and described herein.
    Type: Grant
    Filed: August 22, 2007
    Date of Patent: April 2, 2013
    Assignee: Lantiq Deutschland GmbH
    Inventors: David Schwingshackl, Joerg Hauptmann, Gerhard Paoli, Dietmar Straeussnigg
  • 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: 8391471
    Abstract: An echo suppressing apparatus operable with a sound output device for outputting sound based on a reference signal and a sound processing device for processing an observed signal based on a received sound, the echo suppressing apparatus includes: an echo removal section for removing an echo component of the observed signal which is presumed on the basis of both the observed signal and the reference signal; a ratio calculation section for calculating a power ratio of the observed signal to the reference signal; a correction amount calculation section for calculating, based on the power ratio, a correction amount for the observed signal after removal; a correction section for correcting, based on the calculated correction amount, the observed signal after removal, so as to suppress a residual echo remaining in the observed signal after removal; and an output section for outputting the corrected observed signal to the sound processing device.
    Type: Grant
    Filed: February 22, 2010
    Date of Patent: March 5, 2013
    Assignee: Fujitsu Limited
    Inventor: Taisuke Itou
  • 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: RE47820
    Abstract: An apparatus for providing a current loudspeaker-enclosure-microphone system description of a loudspeaker-enclosure-microphone system is provided. The apparatus has a first transformation unit for generating a plurality of wave-domain loudspeaker audio signals. Moreover, the apparatus has a second transformation unit for generating a plurality of wave-domain microphone audio signals. Furthermore, the apparatus has a system description generator for generating the current loudspeaker-enclosure-microphone system description based on the plurality of wave-domain loudspeaker audio signals, based on the plurality of wave-domain microphone audio signals, and based on a plurality of coupling values, wherein the system description generator is configured to determine each coupling value assigned to a wave-domain pair of a plurality of wave-domain pairs by determining a relation indicator indicating a relation between a loudspeaker-signal-transformation value and a microphone-signal-transformation value.
    Type: Grant
    Filed: April 25, 2018
    Date of Patent: January 14, 2020
    Assignee: FRAUNHOFER-GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
    Inventors: Martin Schneider, Walter Kellermann