Tonal Noise Or Particular Frequency Or Band Patents (Class 381/71.14)
  • Patent number: 8379872
    Abstract: A talk-through system for hearing protectors such as headphones, helmets, earplugs and the like, in which separate left and right microphones are controlled by separate left and right switches. The microphones allow ambient sound to be heard by the wearer of the hearing protector, and normally the wearer hears audio from both microphones in the appropriate ears. Pushing a switch causes the audio from the ear on which the switch is mounted to be enhanced and, preferably, switched to both ears. Various arrangements of control logic are provided such that activation of a switch can cause changes in audio processing.
    Type: Grant
    Filed: May 24, 2010
    Date of Patent: February 19, 2013
    Assignee: Red Tail Hawk Corporation
    Inventor: John W. Parkins
  • Patent number: 8345888
    Abstract: In an ANR circuit of a personal ANR device, a digital filter is structured to introduce one or more zeros to add gain to introduce positive phase in the provision of feedback-based ANR, wherein the gain follows a frequency-dependent “ski-slope” gain curve with little gain added at lower audible frequencies, with increasing gain that increases with frequency added at higher audible frequencies, and with the increasing gain flattening at frequencies above audible frequencies.
    Type: Grant
    Filed: March 30, 2010
    Date of Patent: January 1, 2013
    Assignee: Bose Corporation
    Inventors: Ricardo F. Carreras, Daniel M. Gauger, Jr., Steven H. Isabelle
  • Patent number: 8340963
    Abstract: An echo suppressing system includes: a sound output device for outputting sound based on a sound signal, including a passing section for allowing passage of a component of a different frequency band, and a plurality of sound output sections, each of which outputs sound based on each of the plurality of sound signals passed through the passing section; a summer for summing the plurality of sound signals to generate a reference sound signal; a sound input device for converting input sound into a sound signal; and an echo suppressor for suppressing echo based on the sound output by the sound output device, including an input section to which a sound signal is input from the sound input device as an observation sound signal, and a correction section for correcting the observation sound signal so as to suppress echo included in the observation sound signal.
    Type: Grant
    Filed: April 8, 2010
    Date of Patent: December 25, 2012
    Assignee: Fujitsu Limited
    Inventors: Naoshi Matsuo, Taisuke Itou
  • Patent number: 8331578
    Abstract: An apparatus, method and computer program, the apparatus including a loudspeaker configured to convert an electrical input signal into an acoustic output signal; a connecting portion configured to interchangeably connect to either a first adapter or a second adapter where the first adapter is configured to fit in a user's ear canal and the second adapter is configured to fit to a user's concha; and a regulator for regulating sound pressure level created by the acoustic output signal at an ear drum of the user in dependence on whether the first adapter or the second adapter is connected to the connecting portion.
    Type: Grant
    Filed: June 17, 2009
    Date of Patent: December 11, 2012
    Assignee: Nokia Corporation
    Inventors: Tommi Antero Raussi, Jari Toropainen, Antti Pekka Kelloniemi
  • Patent number: 8315404
    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 targeted space. The speaker is also driven to produce sound waves representative of a desired audio signal. Sound waves are detected in the target space and a representative signal is generated. The representative signal is combined with an audio compensation signal to remove a signal component representative of the sound waves based on the desired audio signal and generate an error signal. The active noise control adjusts the anti-noise signal based on the error signal. The active noise control system converts the sample rates of an input signal representative of the undesired sound, the desired audio signal, and the error signal. The active noise control system converts the sample rate of the anti-noise signal.
    Type: Grant
    Filed: March 12, 2012
    Date of Patent: November 20, 2012
    Assignee: Harman International Industries, Incorporated
    Inventors: Vasant Shridhar, Duane Wertz
  • Patent number: 8300842
    Abstract: A noise enhancement system for an automobile utilizes a single input of engine speed to derive a control signal used to drive a speaker. The speaker generates sounds that enhance or replicate the desired sounds from the engine. The output from the speaker is crafted dependent on the vehicle operating conditions. Instead of multiple transducers and inputs the noise enhancement system of this invention utilizes the single input of engine RPM engine speed. By utilizing only engine speed, the noise enhancement system is cost effective and significantly less complex.
    Type: Grant
    Filed: May 3, 2005
    Date of Patent: October 30, 2012
    Assignee: Mahle International GmbH
    Inventor: Manish Vaishya
  • Patent number: 8270626
    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 targeted space. The speaker is also driven to produce sound waves representative of a desired audio signal. Sound waves are detected in the target space and a representative signal is generated. The representative signal is combined with an audio compensation signal to remove a signal component representative of the sound waves based on the desired audio signal and generate an error signal. The active noise control adjusts the anti-noise signal based on the error signal. The active noise control system converts the sample rates of an input signal representative of the undesired sound, the desired audio signal, and the error signal. The active noise control system converts the sample rate of the anti-noise signal.
    Type: Grant
    Filed: March 13, 2012
    Date of Patent: September 18, 2012
    Assignee: Harman International Industries, Incorporated
    Inventors: Vasant Shridhar, Duane Wertz
  • Patent number: 8265292
    Abstract: The subject matter of this specification can be embodied in, among other things, a computer-implemented method for removing noise from audio that includes building a sound model that represents noises which result from activations of input controls of a computer device. The method further includes receiving an audio signal produced from a microphone substantially near the computer device. The method further includes identifying, without using the microphone, an activation of at least one input control from among the input controls. The method further includes associating a portion of the audio signal as corresponding to the identified activation. The method further includes applying, from the audio model, a representation of a noise for the identified activation to the associated portion of the audio signal so as to cancel at least part of the noise from the audio signal.
    Type: Grant
    Filed: September 30, 2011
    Date of Patent: September 11, 2012
    Assignee: Google Inc.
    Inventor: Jerrold Leichter
  • Patent number: 8254595
    Abstract: An apparatus configured as a compandor to achieve a defined dynamic range for an output signal in response to an input signal. In particular, the apparatus comprises a first circuit adapted to generate a first signal from the input signal, wherein the first signal includes a first dynamic range (e.g., a first sensitivity and first compression point); and a second circuit adapted to generate a second signal from the input signal, wherein the second signal includes a second dynamic range (e.g., a second sensitivity and second compression point) that is different from the first dynamic range of the first signal. The apparatus may further include a third circuit adapted to generate an output signal related to a sum of the first and second signals. By adjusting the first and second dynamic ranges, an overall dynamic range for the output signal of the companding apparatus may be achieved.
    Type: Grant
    Filed: March 25, 2008
    Date of Patent: August 28, 2012
    Assignee: QUALCOMM Incorporated
    Inventor: Russell John Fagg
  • Patent number: 8233633
    Abstract: A noise control device includes a signal processor that detects a noise outputted from a noise source, and generates a control signal based on the noise and a control acoustic system that generates a control sound for canceling the noise, based on the control signal outputted from the signal processor. The noise control device also includes an output correction section that corrects the control signal outputted from the signal processor, in a frequency band for which a noise control process time ?, which is a time period from when the noise is outputted from the noise source to pass through the signal processor and the control acoustic system to when the control sound reaches the control point, is larger than a noise transfer time T, which is a time period from when the noise is outputted from the noise source to when the noise reaches the control point via the noise transfer system (?>T).
    Type: Grant
    Filed: November 12, 2009
    Date of Patent: July 31, 2012
    Assignee: Panasonic Corporation
    Inventor: Hiroyuki Kano
  • Patent number: 8229130
    Abstract: A conversation shielding system comprises sensors that detect the location of a confidential conversation and the presence and location of a potential eavesdropper, audio output devices that produce masking sounds to shield the conversation from the eavesdropper, and a controller that automatically controls the operation of the output devices in response to data from the sensors. An optional portable controller may manually engage the system. A method for shielding conversation comprises identifying a conversation to be shielded, detecting a potential eavesdropper, automatically determining masking sound types, locations and volume that will shield the conversation, directing emission of masking sounds from at least one audio output device in order to shield the conversation, including adjusting the masking sound type, location, and volume in response to movement of the conversation or the eavesdropper, and continuing to shield the conversation until it ends or the eavesdropper is no longer detected.
    Type: Grant
    Filed: September 10, 2008
    Date of Patent: July 24, 2012
    Assignee: Massachusetts Institute of Technology
    Inventors: Joseph A. Paradiso, Yasuhiro Ono
  • Patent number: 8215446
    Abstract: A region of air is manipulated to reflect, absorb, or redirect sound energy to prevent the sound energy from reaching a listener separated from the sound source by the region of air. The region of air may be manipulated by directing ultrasonic sound waves with a sound pressure level of at least 140 decibels at the region of air.
    Type: Grant
    Filed: June 25, 2010
    Date of Patent: July 10, 2012
    Inventor: F. Joseph Pompei
  • Patent number: 8208623
    Abstract: In an echo processing method and device which can detect an accurate echo section without effects of a far end signal, an echo delay, and a reduction of an echo cancellation amount, a signal of a specified frequency band is generated in conformity with a near end signal, and the signal of the specified frequency band is added to the near end signal to form a transmitting signal. Receiving signals are separated into the signal of the specified frequency band and a signal of a band other than the specified frequency band. An echo section is detected based on the signal of the specified frequency band separated. An echo component in the signal of the band other than the specified frequency band is removed and a level of the echo component is detected based on the near end signal in the echo section.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: June 26, 2012
    Assignee: Fujitsu Limited
    Inventors: Takeshi Otani, Masanao Suzuki, Yasuji Ota
  • Patent number: 8208651
    Abstract: A noise reduction system for actively blocking a noise source for a means of transport. The noise reduction system comprises at least one counter sound source and at least one intensity sensor. The at least one counter sound source and the at least one intensity sensor are arranged in a measuring region. In the measuring region, measuring of the noise intensity of the noise source and measuring of the counter sound intensity of the counter sound source are by the intensity sensor. Based on the measured noise intensity and the counter sound intensity, the counter sound source is controllable such that the sound energy input of the noise source can be globally reduced by the counter sound source.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: June 26, 2012
    Assignee: Airbus Operations GmbH
    Inventors: Sten Boehme, Delf Sachau, Thomas Kletschkowski, Harald Breitbach, Kai Simanowski
  • Patent number: 8193941
    Abstract: Health-sensing and health-action devices and systems are generally described. The health-sensing device may include one or more of a sensor, a filter, and a transmitter. The sensor may be configured to sense one or more factors relating to an indicator of a health related condition or occurrence such as snoring and may include one or more microphone devices, accelerometers, and/or MEMs devices. The filter may be configured to evaluate a signal from the sensor and determine if the indicator has been detected. The transmitter may be arranged for initiating a transmission based on a signal from the filter. The health-action device may be configured for responding to an indicator of a health related condition or occurrence of a user and may include one or more of a receiver, a processor, and a responder. The health-action device may stimulate the user or may cancel the snoring sound.
    Type: Grant
    Filed: May 6, 2009
    Date of Patent: June 5, 2012
    Assignee: Empire Technology Development LLC
    Inventors: Andrew Wolfe, Thomas Martin Conte
  • Patent number: 8189765
    Abstract: A multichannel echo canceller according to the present invention includes an echo cancellation section which receives loudspeaker input signals sp1, sp2 including a second acoustic signal to be respectively inputted to a plurality of loudspeakers 10, 20 provided in a first location and detection signals m1, m2 detected by a plurality of microphones 11, 21 provided in the first location; separates a first acoustic signal and a second acoustic signal, which are included in the detection signals m1, m2, by performing signal processing based on an independent component analysis; cancels as an echo the second acoustic signal, which is included in the detection signals m1, m2, by outputting only the separated first acoustic signal to a plurality of loudspeakers 30, 40 provided in a second location.
    Type: Grant
    Filed: July 6, 2007
    Date of Patent: May 29, 2012
    Assignee: Panasonic Corporation
    Inventors: Tsuyoki Nishikawa, Takeo Kanamori, Koichiro Mizushima
  • Patent number: 8189800
    Abstract: An active silencer includes: a speaker generating control sound which interferes with noise; a microphone detecting noise remaining after the interference as a remaining noise signal; a sound quality evaluation unit evaluating the sound quality of the remaining noise and output a result of the sound quality evaluation; an actuation signal determination unit determining, according to the result of the sound quality evaluation, the detection timing of the frequency component of the remaining noise signal to be used when the control sound is generated for a plurality of bands of the remaining noise, corresponding to the plurality of bands of a reference signal corresponding to the noise; and a control signal generation unit generating and output a control signal for generation of the control sound depending on a plurality of bands of the determined remaining noise signal and a plurality of bands of the reference signal corresponding to the noise.
    Type: Grant
    Filed: March 15, 2010
    Date of Patent: May 29, 2012
    Assignee: Fujitsu Limited
    Inventors: Taro Togawa, Takeshi Otani, Kaori Endo, Yasuji Ota
  • Patent number: 8184819
    Abstract: A system and method facilitating signal enhancement utilizing an adaptive filter is provided. The invention includes an adaptive filter that filters an input based upon a plurality of adaptive coefficients, the adaptive filter modifying at least one of the adaptive coefficients based on a feedback output. The invention further includes a feedback component that provides the feedback output based, at least in part, upon a non-linear function of the acoustic reverberation reduced output. The invention further provides a noise statistics component that stores noise statistics associated with a noise portion of an input signal and a signal+noise statistics component that stores signal+noise statistics associated with a signal and noise portion of the input signal.
    Type: Grant
    Filed: December 29, 2005
    Date of Patent: May 22, 2012
    Assignee: Microsoft Corporation
    Inventors: Henrique S. Malvar, Dinei A. Florencio, Bradford W. Gillespie
  • Patent number: 8170229
    Abstract: Apparatus and Method for canceling or reducing voice sounds produced during a conversation by the user of a cellular telephone or other communication device such that other persons close to the user cannot hear the users voice and is not disturbed by the conversation.
    Type: Grant
    Filed: November 4, 2008
    Date of Patent: May 1, 2012
    Inventor: James Carl Kesterson
  • Patent number: 8140327
    Abstract: The systems and methods described herein may filter and eliminate noise from natural language utterances to improve accuracy associated with speech recognition and parsing capabilities. In particular, the systems and methods described herein may use a microphone array to provide directional signal capture, noise elimination, and cross-talk reduction associated with an input speech signal. Furthermore, a filter arranged between the microphone array and a speech coder may use band shaping, notch filtering, and adaptive echo cancellation to optimize a signal-to-noise ratio associated with the speech signal. The speech signal may then be sent to the speech coder, which may use adaptive lossy audio compression to optimize bandwidth requirements associated with transmitting the speech signal to a main unit that provides the speech recognition, parsing, and other natural language processing capabilities.
    Type: Grant
    Filed: April 22, 2010
    Date of Patent: March 20, 2012
    Assignee: VoiceBox Technologies, Inc.
    Inventors: Robert A. Kennewick, David Locke, Michael R. Kennewick, Sr., Michael R. Kennewick, Jr., Richard Kennewick, Tom Freeman
  • Patent number: 8135140
    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 targeted space. The speaker is also driven to produce sound waves representative of a desired audio signal. Sound waves are detected in the target space and a representative signal is generated. The representative signal is combined with an audio compensation signal to remove a signal component representative of the sound waves based on the desired audio signal and generate an error signal. The active noise control adjusts the anti-noise signal based on the error signal. The active noise control system converts the sample rates of an input signal representative of the undesired sound, the desired audio signal, and the error signal. The active noise control system converts the sample rate of the anti-noise signal.
    Type: Grant
    Filed: November 20, 2008
    Date of Patent: March 13, 2012
    Assignee: Harman International Industries, Incorporated
    Inventors: Vasant Shridhar, Duane Wertz
  • Patent number: 8111836
    Abstract: A performance venue with a main speaker system is provided having a target coverage area within the performance venue. A performance area is located within the performance venue outside the target coverage area of the main speaker system. A low frequency directed audio source is positioned with respect to the performance area for active cancellation of low frequency sound spilling over into the performance area from the main speaker system. Control of the low frequency directed audio source is effected by an audio sensor is located in the performance area for generating an output correlated with low frequency spill over into the performance area.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: February 7, 2012
    Inventor: Curtis E. Graber
  • Patent number: 8085943
    Abstract: A noise extraction method in which an environmental input which includes a noise indicia is selectively modified in accordance with an algorithm that includes one or more factors representing time response, amplitude of response, and error correction. The algorithm may also include thresholding, delay or convergence, among other techniques.
    Type: Grant
    Filed: November 29, 2000
    Date of Patent: December 27, 2011
    Inventor: Karl M. Bizjak
  • Patent number: 8085945
    Abstract: In a communication machine room wideband noise suppression system, a sensing unit detects a noise source produced by a fan during the operation thereof and generates a noise input signal and a feedback signal, which are sent to a signal amplifying unit for signal amplification. The amplified signals are then sent to a signal converting unit and converted into digital signals. A multi-channel hybrid controller receives the digital signals and makes corrections and conduct rapid convergence algorithm to derive a reverse digital signal, which is sent to the signal converting unit and converted into a reverse analog signal. The reverse analog signal is sent to the signal amplifying unit for power amplification to generate a control signal for driving a loudspeaker unit to produce interfering acoustic wave, so as to cancel out the noise source and achieve the purpose of eliminating wideband noise.
    Type: Grant
    Filed: April 22, 2008
    Date of Patent: December 27, 2011
    Assignee: Asia Vital Components Co., Ltd.
    Inventors: Fu-Cheng Su, Yuan-Liang Liao, Jyh-Ren Lee, Yi-Hong Liao
  • Patent number: 8085944
    Abstract: The invention relates to an active noise cancellation device. The invention proposes a device and a method used to cancel the noise in an exhaust gas channel of a vehicle A noise signal is received form the exhaust gas channel, using a sound sensor, a frequency signal which has same amplitude as of noise signal but opposite phase, is generated, the generated frequency signal is acoustically mixed with the noise signal in the exhaust gas channel, using a sound converter, there by reducing the noise in the exhaust gas channel. The device also takes into account the reflection of the sound caused by an obstacle near the exhaust gas channel. A distance measuring device which is external to the active noise cancellation device provides the information about the distance between the obstacle and the exhaust gas channel. Based on the distance, the frequency signal is suitably modified to reduce the effect of sound reflections caused by the obstacle.
    Type: Grant
    Filed: April 14, 2009
    Date of Patent: December 27, 2011
    Assignee: Robert Bosch GmbH
    Inventor: Uwe Kassner
  • Patent number: 8054984
    Abstract: A sound altering apparatus for altering predetermined sound levels of a sound producing device, the sound altering apparatus includes at least one piezoelectric foil sensor disposed relative to the sound producing device with the at least one piezoelectric foil sensor being operable to convert such sound wave energy into an electric sound signal one or more electric circuits in electrical communication with the at least one piezoelectric foil sensor for receiving the electric sound signal and shunting the electric sound signal to a ground connection, or to produce cancelling sound wave energy in the vicinity of the sound producing device, thereby reducing sound heard outside the sound producing device.
    Type: Grant
    Filed: October 16, 2006
    Date of Patent: November 8, 2011
    Assignee: BSH Home Appliances Corporation
    Inventor: Uwe Klossowski
  • Patent number: 8045724
    Abstract: A signal processing circuit is intended for use in a noise reduction system, which produces a target filter characteristic that would achieve optimal noise cancellation, the target filter characteristic including a resonant peak at a first frequency. The signal processing circuit comprises an analogue filter, which has an amplitude response that has a peak or trough at a center frequency, and has a phase response that switches polarity at the center frequency and tends to zero with increase or reduction in frequency away from the center frequency. The center frequency in the amplitude response is substantially equal to the first frequency. The analogue filter may be in the form of a series inductive-capacitive-resistive circuit, where the inductive component is in the form of a gyrator.
    Type: Grant
    Filed: November 12, 2008
    Date of Patent: October 25, 2011
    Assignee: Wolfson Microelectronics plc
    Inventor: Alastair Sibbald
  • Patent number: 8014538
    Abstract: An active noise reducing device includes switchover frequency memory which stores a speaker having weaker influence of level drop or dips in gain characteristics of transmission from first speaker and second speaker both working as secondary noise generators to microphone working as a residual signal detector, and also stores a frequency band of that speaker. Output switcher appropriately and selectively switches first speaker over to second speaker in response to the noise frequency at present calculated based on the rpm of engine by frequency calculator. This structure allows the active noise reducing device to work steadily even if level drop or a dip occurs in the gain characteristics of transmission from the speaker to the microphone, and allows suppressing the occurrence of abnormal sound due to divergence or distorted sound due to excessive output. Ideal noise reduction effect can be expected.
    Type: Grant
    Filed: July 21, 2006
    Date of Patent: September 6, 2011
    Assignee: Panasonic Corporation
    Inventors: Masahide Onishi, Yoshio Nakamura, Shigeki Yoshida
  • Patent number: 7934582
    Abstract: A noise and vibration reduction system for an engine affixed to a body and a method for reducing vibrations in the body produced by that engine during operation. The present invention is particularly related to noise and vibration reduction in auxiliary power units installed on long-haul trucks and similar types of transportation vehicles. The primary noise and vibration reduction components of the present invention include an air intake silencer, a vibration tuner, and an engine speed limiter.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: May 3, 2011
    Assignee: Go Green APU LLC
    Inventors: Edward Joseph O'Malley, Glenn Thomas Williamson, Richard Glen Shaff
  • Patent number: 7928886
    Abstract: Described herein is a system and method of emulating characteristics of an output signal of a first analog-to-digital converter by a second analog-to-digital converter employing signal processing. A signal processing module may receive a digital signal from the first analog-to-digital converter and alter the digital signal to define an altered digital signal such that the altered digital signal emulates a second digital signal that is characteristic of the second analog-to-digital converter, the second analog-to-digital converter differing from the first analog-to-digital converter.
    Type: Grant
    Filed: July 1, 2009
    Date of Patent: April 19, 2011
    Assignee: Infineon Technologies AG
    Inventor: Rudolf Koch
  • Patent number: 7876913
    Abstract: Gain characteristics depending on the frequency of a reference signal from speakers to a passenger position in a motor vehicle, i.e., gain characteristics which are an inversion of vehicle cabin sound field characteristics, are set in a first acoustic corrector. At the passenger position, a gain characteristic curve that is flat at various frequencies is achieved to prevent gain peaks and dips from occurring at the passenger position. A sound effect generated at the passenger position is made linear depending on the state of a noise source, or more specifically, a noise source caused by an accelerating action on the motor vehicle.
    Type: Grant
    Filed: March 21, 2006
    Date of Patent: January 25, 2011
    Assignee: Honda Motor Co., Ltd.
    Inventors: Yasunori Kobayashi, Toshio Inoue, Akira Takahashi, Kosuke Sakamoto
  • Patent number: 7865338
    Abstract: Disclosed are a method and a device for suppressing vibrations (18) in an installation comprising an actuator (14) for actuating a flap (12) or a valve (70) used for metering a gas or liquid volume flow (16), especially in the area of HVAC, fire protection, or smoke protection. Vibrations (18) of the flap (12) or valve (70) caused by an unfavorable or wrong adjustment or configuration of the controller and/or by disruptive influences are detected and dampened or suppressed by means of an algorithm (1) that is stored in a microprocessor (49). Said algorithm is preferably based on the components recognition of vibrations (46), adaptive filtering (48), and recognition of sudden load variations (50).
    Type: Grant
    Filed: March 21, 2006
    Date of Patent: January 4, 2011
    Assignee: Belimo Holding AG
    Inventors: Silvano Balemi, Martin Wild, Marc Thuillard
  • Patent number: 7818168
    Abstract: A method of measuring the degree of enhancement made to a voice signal by receiving the voice signal, identifying formant regions in the voice signal, computing stationarity for each identified formant region, enhancing the voice signal, identifying formant regions in the enhanced voice signal that correspond to those identified in the received voice signal, computing stationarity for each formant region identified in the enhanced voice signal, comparing corresponding stationarity results for the received and enhanced voice signals, and calculating at least one user-definable statistic of the comparison results as the degree of enhancement made to the received voice signal.
    Type: Grant
    Filed: December 1, 2006
    Date of Patent: October 19, 2010
    Assignee: The United States of America as represented by the Director, National Security Agency
    Inventor: Adolf Cusmariu
  • Patent number: 7792312
    Abstract: An active noise control system prevents a continuous muffled sound from being generated as an abnormal sound under a high sound pressure from a speaker when a microphone as a sound detector is covered, and reduces noise immediately when the microphone is uncovered. A first threshold value as an upper limit value and a second threshold value as a lower limit value are provided for the filter coefficient of an adaptive notch filter. When the filter coefficient is greater than the first threshold value, a control sound is faded out according to a forgetting process. When the filter coefficient is smaller than the second threshold value, an adaptive control process is resumed. Even if the microphone is covered, the filter coefficient does not exceed the first threshold value as the upper limit value.
    Type: Grant
    Filed: August 8, 2006
    Date of Patent: September 7, 2010
    Assignee: Honda Motor Co., Ltd.
    Inventors: Toshio Inoue, Akira Takahashi, Kosuke Sakamoto, Yasunori Kobayashi
  • Patent number: 7773760
    Abstract: While a vehicle incorporating an active vibration noise control apparatus is decelerating, hysteresis is given if an operating point moves from an operating point on a sampling period characteristic curve to an operating point on another sampling period characteristic curve. Even if a base period detected depending on noise contains fluctuations, a smooth noise control process is performed. Since a division number produced when the base period is divided by a sampling period is a real number, the freedom of design is widened. Less strict limits are posed on the processing capability of a CPU of the active vibration noise control apparatus to provide a wider control range.
    Type: Grant
    Filed: November 29, 2006
    Date of Patent: August 10, 2010
    Assignee: Honda Motor Co., Ltd.
    Inventors: Kosuke Sakamoto, Toshio Inoue, Akira Takahashi, Yasunori Kobayashi
  • Patent number: 7769186
    Abstract: A system and method facilitating acoustic echo cancellation convergence detection is provided. The invention includes an acoustic echo cancellation convergence detector having a center clipping component, a convergence calculator, a convergence filter and a convergence statistic component. The invention provides for the acoustic echo cancellation convergence detector to provide an output regarding convergence of an adaptive filter based, at least in part, upon a filtered convergence statistic. Optionally, the acoustic echo cancellation convergence detector can provide an output associated with convergence history.
    Type: Grant
    Filed: March 2, 2006
    Date of Patent: August 3, 2010
    Assignee: Microsoft Corporation
    Inventors: Jack Wilson Stokes, III, Henrique S. Malvar
  • Patent number: 7697700
    Abstract: Reduction of noise in a device having a console with one or more microphones and a source of narrow band distributed noise located on the console is disclosed. A microphone signal containing a broad band distributed desired sound and narrow band distributed noise is divided amongst a plurality of frequency bins. For each frequency bin, it is determined whether a portion of the signal within the frequency bin belongs to a narrow band distribution characteristic of the source of narrow band noise located on the console. Any frequency bins containing portions of the signal belonging to the narrow band distribution are filtered to reduce the narrow band noise.
    Type: Grant
    Filed: May 4, 2006
    Date of Patent: April 13, 2010
    Assignee: Sony Computer Entertainment Inc.
    Inventor: Xiadong Mao
  • Patent number: 7693292
    Abstract: One embodiment of the present invention provides a system that cancels fan noise in a computer system. During operation, the system obtains a fan noise signal using a microphone. Next, the system generates a spectral pattern based on the obtained fan noise signal. The system then uses the spectral pattern to identify a corresponding cancellation spectrum in an anti-spectra library. Next, the system generates a noise-canceling signal using the cancellation spectrum. Note that the amount of computation required to cancel fan noise is reduced because generating the noise-canceling signal using the anti-spectra library requires less computation than generating the noise-canceling signal using dynamic noise-cancellation techniques.
    Type: Grant
    Filed: August 16, 2005
    Date of Patent: April 6, 2010
    Assignee: Sun Microsystems, Inc.
    Inventors: Kenny C. Gross, Aleksey Urmanov, Anton Bougaev
  • Publication number: 20090180635
    Abstract: Some embodiments of the present invention provide a system that attenuates noise from a fan exhaust of a computer system. During operation, the system monitors the noise from the fan exhaust and calculates a frequency spectrum of the noise from the monitored noise. Next, the system generates an antiphase spectrum from the frequency spectrum and generates a flow of air which exhibits a property of the antiphase spectrum. Finally, the system directs the flow of air into the fan exhaust so that the noise is attenuated by a reduction of turbulence in the fan exhaust by the flow of air.
    Type: Application
    Filed: January 10, 2008
    Publication date: July 16, 2009
    Applicant: SUN MICROSYSTEMS, INC.
    Inventors: Kenneth C. Gross, Aleksey M. Urmanov, Charles E. Kinney
  • Patent number: 7536018
    Abstract: In an active noise cancellation system having an adaptive filter that outputs a control signal, first and second speakers that emit a canceling signal generated based on the control signal, a microphone that detects an error signal, a correction filter that corrects the base signal by a correction value to generate a reference signal and a filter coefficient updater that successively updates the adaptive filter coefficient based on the error signal and reference signal such that the error signal is minimized, the correction value of the correction filter is set to a sum obtained by adding the transfer characteristic from the first speaker to the microphone, and a product obtained by multiplying the transfer characteristic from the second speaker to the microphone by the prescribed value, thereby enabling to reduce the number of microphones and avoid the increase in parts, the amount of work to provide complicated wiring to the microphones, and the computational load involved in updating the adaptive filter co
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: May 19, 2009
    Assignees: Panasonic Corporation, Honda Motor Co., Ltd.
    Inventors: Masahide Onishi, Yoshio Nakamura, Toshio Inoue, Akira Takahashi
  • Publication number: 20090123003
    Abstract: A signal processing circuit is intended for use in a noise reduction system, which produces a target filter characteristic that would achieve optimal noise cancellation, the target filter characteristic including a resonant peak at a first frequency. The signal processing circuit comprises an analogue filter, which has an amplitude response that has a peak or trough at a centre frequency, and has a phase response that switches polarity at the centre frequency and tends to zero with increase or reduction in frequency away from the centre frequency. The centre frequency in the amplitude response is substantially equal to the first frequency. The analogue filter may be in the form of a series inductive-capacitive-resistive circuit, where the inductive component is in the form of a gyrator.
    Type: Application
    Filed: November 12, 2008
    Publication date: May 14, 2009
    Inventor: Alastair Sibbald
  • Patent number: 7489789
    Abstract: The invention regards a method for noise reduction in an audio device whereby an electrical and/or digital signal which represents sound is routed simultaneously through:—a signal analysis path, and—a signal processing path wherein the signal amplification is individually controllable in specific frequency bands by attenuation values derived from the signal analysis path, whereby the signal in the signal analysis path is routed simultaneously through:—a first detector which identifies the presence of speech indicators in the overall signal, and—a second detector which in a predefined number of frequency bands detects the modulation amplitude, and—where attenuation values in each of the predefined frequency bands are calculated based on the combined results of the first detector and the modulation amplitude in the specific frequency band detected by the second detector,—where the attenuation values in the predefined number of frequency bands are routed to the signal processing path in order to attenuate the si
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: February 10, 2009
    Assignee: Oticon A/S
    Inventor: Thomas Kaulberg
  • Patent number: 7457422
    Abstract: A method and implementation for detecting and characterizing audible transients in noise includes placing a microphone in a desired location, producing a microphone signal wherein the microphone signal is indicative of the acoustic environment, processing the microphone signal to estimate the acoustic activity that takes place in the human auditory system in response to the acoustic environment, producing an excitation signal indicative of the estimated acoustic activity, processing the excitation signal to identify each impulsive sound frequency-dependent activity as a function of time, producing a detection signal indicative of audible impulse sounds, processing the detection signal to identify an audible impulsive sound, and characterizing each impulsive sound.
    Type: Grant
    Filed: November 29, 2001
    Date of Patent: November 25, 2008
    Assignee: Ford Global Technologies, LLC
    Inventors: Jeffry Allen Greenberg, Michael Alan Blommer, Scott Andrew Amman
  • Publication number: 20080107282
    Abstract: Disclosed herein is a digital filter circuit for producing a noise reduction signal for reducing noise based on a noise signal outputted from a microphone which collects the noise, including: an analog/digital conversion section; a first digital filter section; an arithmetic operation processing section; a second digital filter section; and a digital/analog conversion section. The first digital filter section and/or the second digital filter section are configured such that a predetermined attenuation amount is obtained within a predetermined range in the proximity of a sampling frequency around the sampling frequency.
    Type: Application
    Filed: October 19, 2007
    Publication date: May 8, 2008
    Applicant: Sony Corporation
    Inventor: Kohei ASADA
  • Patent number: 7327849
    Abstract: A system and method of reducing noise in an enclosure is disclosed. The method includes receiving at least one reference signal; receiving pressure signals from no more than two substantially orthogonally placed pairs of acoustic sensors, where one pair of acoustic sensors is in the x-direction and one pair of acoustic sensors is in the y-direction, and where the acoustic sensors are placed in a plane which is substantially parallel and in proximity to an inner surface of the enclosure; using the pressure signals and the reference signal to generate an output signal to minimize energy density at a location of the acoustic sensors; and sending the output signal to an acoustic actuator.
    Type: Grant
    Filed: August 9, 2004
    Date of Patent: February 5, 2008
    Assignee: Brigham Young University
    Inventors: Scott David Sommerfeldt, Benjamin Mahonri Faber
  • Publication number: 20070297619
    Abstract: An active noise reduction system using adaptive filters. A method of operation the active noise reduction system includes smoothing a stream of leakage factors. The frequency of a noise reduction signal may be related to the engine speed of an engine associated with the system within which the active noise reduction system is operated. The engine speed signal may be a high latency signal and may be obtained by the active noise reduction system over audio entertainment circuitry.
    Type: Application
    Filed: June 26, 2006
    Publication date: December 27, 2007
    Applicant: BOSE CORPORATION*EWC*
    Inventor: Davis Pan
  • Patent number: 7305094
    Abstract: A system and method for actively damping boom noise within an enclosure such as an automobile cabin. The system comprises an acoustic wave sensor, a motion sensor, an acoustic wave actuator, a first electronic feedback loop, and a second electronic feedback loop. The enclosure defines a plurality of low-frequency acoustic modes that can be induced/excited by the enclosure cavity, by the structural vibration of a panel of the enclosure, by idle engine firings, and a combination thereof. The acoustic wave actuator is substantially collocated with the acoustic wave sensor within the enclosure. The motion sensor can be secured to a panel of the enclosure.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: December 4, 2007
    Assignee: University of Dayton
    Inventor: Reza Kashani
  • Patent number: 7272234
    Abstract: A multi-channel active noise control system and method of reducing tonal noise emanating from a tonal noise source are disclosed. The system may include an adaptive controller, a plurality of loudspeakers driven by the loudspeaker, one or more microphones for generating one or more error signals to feedback to the adaptive controller and optionally a reference signal source to provide the adaptive controller with frequency information associated with the tonal noise source. The system and method of the present invention are applicable to any tonal noise source, including but not limited to axial fans.
    Type: Grant
    Filed: April 4, 2003
    Date of Patent: September 18, 2007
    Assignee: Brigham Young University
    Inventors: Scott D. Sommerfeldt, Kent L. Gee
  • Patent number: 7190796
    Abstract: A system for actively damping the low-frequency coloration of sound in a listening room is provided comprising an acoustic wave sensor, an acoustic wave actuator, and an electronic feedback controller. The listening room defines at least one mode of low-frequency coloration. The acoustic wave actuator is substantially collocated with the acoustic wave sensor within the listening room. The electronic feedback controller is operative to generate a signal at its output by applying a feedback controller transfer function. The feedback controller transfer function comprises a second order differential equation including a first variable representing a predetermined damping ratio and a second variable representing a tuned natural frequency and creates a 90 degree phase lead substantially at the resonant frequencies of at least one mode of low-frequency coloration. The feedback controller output signal represents a rate of change of volume velocity to be produced by the acoustic wave actuator.
    Type: Grant
    Filed: December 11, 2001
    Date of Patent: March 13, 2007
    Assignee: Design, Imaging & Control, Inc.
    Inventor: Ahmad Reza Kashani
  • Patent number: 7181021
    Abstract: The invention provides an apparatus and related method for acoustically improving an environment. In an embodiment of the present invention, an electronic sound screening system includes a portion for receiving acoustic energy and converting it into electrical signals, a portion for performing an analysis of the electrical signals and for generating data analysis signals, a portion responsive to the data analysis signals for producing signals representing sound, and an output portion for converting the sound signals into sound.
    Type: Grant
    Filed: May 15, 2002
    Date of Patent: February 20, 2007
    Inventors: Andreas Raptopoulos, Volkmar Klein, Dominic Robson, Eugene Scourboutis, Jeremy Hugh Welter