Entries |
Document | Title | Date |
20080232606 | SYNCHRONOUS DETECTION AND CALIBRATION SYSTEM AND METHOD FOR DIFFERENTIAL ACOUSTIC SENSORS - A synchronous detection and calibration system is provided for expedient calibration of differential acoustic sensors in a manufacturing and testing environment. By processing a series of sequentially received tones, respective portions of a system using differential acoustic sensors are tuned for optimum individual operation, following which corresponding control data are generated and stored for use in selecting among predetermined calibration vectors which establish and maintain optimum system operation. | 09-25-2008 |
20090323977 | SOUND SOURCE SEPARATION SYSTEM, SOUND SOURCE SEPARATION METHOD, AND ACOUSTIC SIGNAL ACQUISITION DEVICE - The invention provides a sound source separation system, a sound source separation method, and an acoustic signal acquisition device which can precisely separate a target sound and a disturbance sound coming from an arbitrary direction, and which ensures miniaturization of a device. A sound source separation system | 12-31-2009 |
20100002891 | APPARATUS AND METHOD FOR DETECTING ACOUSTIC FEEDBACK - An acoustic-feedback detection apparatus includes: a first level detecting section configured to detect a signal level of sound signals obtained from a position in a sound-signal system in which a microphone and speaker are connected; a first extracting section configured to extract, from the sound signals of which the signal level is detected, signals in a band having a bandwidth predetermined for each of at least one predetermined center frequency; a second level detecting section configured to detect a signal level of the signals in each band, the signals being extracted by the first extracting section; and a determining section configured to determine whether or not acoustic feedback is occurring, on the basis of a threshold determined according to the signal level detected by the first level detecting section and a waveform of each signal level detected by the second level detecting section. | 01-07-2010 |
20100061566 | APPARATUS FOR PROCESSING AN AUDIO SIGNAL AND METHOD THEREOF - An apparatus for processing an audio signal and method thereof are disclosed, by which a local dynamic range of an audio signal can be adaptively normalized as well as a maximum dynamic range of the audio signal. The present invention includes receiving a signal, by an audio processing apparatus; computing a long-term power and a short-term power by estimating power of the signal; generating a slow gain based on the long-term power; generating a fast gain based on the short-term power; obtaining a final gain by combining the slow gain and the fast gain; and, modifying the signal using the final gain. | 03-11-2010 |
20100111318 | ACTIVE NOISE CONTROLLER - An active noise controller using an adaptive notch filter performs a coefficient update operation by using only a signal obtained by processing an error signal with ½ cycle of the frequency of noise to be reduced for a predetermined period. This eliminates the necessity of product operation for the coefficient update operation, and in turn significantly reduces an operation load. | 05-06-2010 |
20100183164 | GENERATION OF PROBE NOISE IN A FEEDBACK CANCELLATION SYSTEM - The invention regards a scheme for generating a probe noise signal to be used in an anti feedback system of an audio system. The audio system comprises e.g. a microphone for capturing an audio signal, an audio signal processor for adaptation of the audio signal and a receiver for generation of an audible signal. According to an embodiment of the invention, a noise signal is injected into the audio signal path between the microphone and the receiver and used for estimating acoustical feedback, the noise signal being generated by the following steps:
| 07-22-2010 |
20100195843 | SILENCER WITH FAN AND SILENCING METHOD USING THE SAME - A silencer includes a cooling fan unit that cools a component which gives off heat during operation by blowing wind to the component and that outputs signal including rotational frequency information and information about timing of initiation of one cycle of noise; a storage section that stores an opposite phase waveform for the noise given off by the cooling fan unit; and a control section that detects the signal from the cooling fan unit and that adjusts the timing of initiation of one cycle of the opposite phase waveform. The configuration obviates a necessity for a microphone used for previously storing an opposite phase waveform and complicate arithmetic processing, and hence a phase lag in the opposite phase waveform can be prevented. Accordingly, the speaker can be disposed in proximity to the cooling fan. An opposite phase waveform output from the speaker can eliminate noise given off by the cooling fan over a wide range. Further, an opposite phase waveform for only the cooling fan is previously stored, and hence the silencer is not affected by noise other than the noise given off by the cooling fan. | 08-05-2010 |
20100208910 | ACOUSTIC FIELD CORRECTION METHOD AND AN ACOUSTIC FIELD CORRECTION DEVICE - An acoustic field correction device corrects effect of frequency characteristics by indoor standing waves, determines a frequency range in which resonance due to standing waves occur, and adjusts an attenuation amount of a filter which suppresses the determined frequency range. In this adjustment, adjustment is made to reduce the amount of attenuation at the time of initial rise of the signal in the frequency range of the standing wave. | 08-19-2010 |
20100272284 | Feedforward-Based ANR Talk-Through - An ANR circuit, possibly of a personal ANR device, reduces the degree of feedforward-based ANR that it provides in response to receiving an indication of the operation of a manually-operable control. The reduction of degree of feedforward-based ANR may be effected by turning off or otherwise deactivating the provision of feedforward-based ANR, reducing a range of frequencies of environmental noise sounds attenuated by the feedforward-based ANR to provide less attenuation of sounds detected by a feedforward microphone that are in a range of frequencies deemed to be those of human speech, and/or creating a notch in the range of frequencies of environmental noise sounds attenuated by the feedforward-based ANR to provide less attenuation of sounds detected by the feedforward microphone that are in a range of frequencies deemed to be those of human speech. | 10-28-2010 |
20100322433 | ACTIVE NOISE CANCELLATION EARPHONE - An active noise cancellation (ANC) earphone for coupling to a host having a first jack and a second jack includes a sound source module, a sensing source module, a first connection module, and a second connection module. The sound source module is used for playing an audio signal. The sensing source module is coupled to the sound source module for sensing a noise near the sound source module. The first connection module has one end coupled to the sound source module and the other end inserted in the first jack, for transferring the audio signal generated by the host to the sound source module. The second connection module has one end coupled to the sensing source module and the other end inserted in the second jack, for transferring the noise sensed by the sensing source module to the host to generate a suppression signal for cancelling the noise. | 12-23-2010 |
20110007907 | SYSTEMS, METHODS, APPARATUS, AND COMPUTER-READABLE MEDIA FOR ADAPTIVE ACTIVE NOISE CANCELLATION - An adaptive active noise cancellation apparatus performs a filtering operation in a first digital domain and performs adaptation of the filtering operation in a second digital domain. | 01-13-2011 |
20110026724 | ACTIVE NOISE REDUCTION METHOD USING PERCEPTUAL MASKING - A method of active noise reduction is described which comprises receiving an audio signal ( | 02-03-2011 |
20110110527 | ACTIVE MUFFLER - In an active muffler having improved response characteristics, a speaker section includes a diaphragm adapted to generate sound, a voice coil for driving the diaphragm, and a distance sensor to detect the movement of the diaphragm. A light generated by the LED is reflected by the diaphragm, the reflected light is detected by a phototransistor to thereby measure the distance to the diaphragm, so that the movement of the diaphragm is detected. Noise is detected by a microphone, and a signal having opposite phase to that of the noise is generated by an opposite-phase generating section. The difference between the opposite-phase signal and the signal of the distance to the speaker from the distance sensor is calculated and inputted to a PID control section. Such a difference indicates the delay of the speaker movement. Feedback control is performed in a direction in which the difference is canceled out. | 05-12-2011 |
20110249826 | ACTIVE AUDIO NOISE CANCELLING - A noise canceling system comprises a microphone ( | 10-13-2011 |
20120230505 | MANAGING THE EFFECT OF TDMA NOISE ON AUDIO CIRCUITS - Broadly speaking, the embodiments disclosed herein describe an apparatus, system, and method for managing the effects of TDMA noise emitted by a communication device on an audible circuit. | 09-13-2012 |
20120288112 | METHOD AND CONTROLLER FOR CONTROLLING NOISE OF ROTATING DEVICE - A method for controlling noise of a rotating device includes: obtaining a sound wave signal of noise generated by the rotating device, where the sound wave signal is fed back by a reference sensor; obtaining rotational speed information of the rotating device; and searching a predefined function mapping table according to the rotational speed information to obtain transfer functions; generating a sound emitting command according to the transfer functions and the sound wave signal; and sending the sound emitting command to a secondary source emitting device, so that the secondary source emitting device emits a secondary sound wave, where the secondary sound wave is used to suppress the noise generated by the rotating device. | 11-15-2012 |
20120314883 | APPARATUS AND METHOD FOR TRANSMITTING HUMAN SOUND FOR REMOVING INTERFERENCE SIGNAL - Disclosed are an apparatus and a method for transmitting human sound that cancel an interference signal generated by a non-linear property of a human body around an ear by synthesizing and transmitting a sound signal modulated by a single side band (SSB) transmission method and a carrier to one output unit and by synthesizing and transmitting the sound signal modulated by the single side band (SSB) transmission method and a carrier in which a phase of a signal is transited to the other output unit, by using two signal output units in a sound transmitting apparatus. | 12-13-2012 |
20130083938 | INSTABILITY DETECTION AND AVOIDANCE IN A FEEDBACK SYSTEM - In one aspect, in general, an active noise reduction system detects actual or potential instability by detecting characteristics of the system related to potential or actual unstable behavior (e.g., oscillation) and adapts system characteristics to mitigate such instability. In some examples, the system adapts to variation in characteristics of an acoustic component of a feedback path that has or may induce unstable behavior to improve a user's acoustic experience. | 04-04-2013 |
20130182865 | ACOUSTIC FAULT DETECTION OF MECHANICAL SYSTEMS WITH ACTIVE NOISE CANCELLATION - An active noise cancellation fault detector (NCFD) is presented that is configured to cancel normal machine noise in an operator cabin, while allowing noise associated with a machine failure mode to remain so that an operator can hear when a machine component is beginning to fail or is in a failure mode. An NCFD can generate a model waveform of normal noise scaled to machine operating parameters. The model waveform can be inverted and adjusted in gain and phase to provide a cancellation waveform. The invention can be configured to determine operator location within a machine cab so that cancellation signals can be configured with the proper phases to destructively interfere with normal machine noise within a quiet zone or noise suppression envelope around an operator. Noise within the quiet zone can be detected and compared to various fault waveforms to determine whether a machine component is beginning to fail. | 07-18-2013 |
20130259251 | INSTABILITY DETECTION AND AVOIDANCE IN A FEEDBACK SYSTEM - In an aspect, in general, a feedback based active noise reduction system is configured to detect actual or potential instability by detecting characteristics of the system related to potential or actual unstable behavior (e.g., oscillation) and adapt system characteristics to mitigate such instability. | 10-03-2013 |
20130279711 | A PID CONTROLLER - An adaptive control unit is described for receiving an analog input signal containing at least an indication of a parameter to be controlled to generate an analog output signal for control of the parameter. The analog input signal contains a fed back component resulting from the analog output signal. The adaptive control unit comprises an analog filter having an adjustable gain, a gain adjuster for adjusting the gain of the analog filter using a feedforward adjustment method, and a filter for compensating for the fed back component in the analog input signal. | 10-24-2013 |
20130329902 | PRESSURE-RELATED FEEDBACK INSTABILITY MITIGATION - An apparatus includes a member configured to form an acoustic seal around a portion of an acoustic environment, and active noise reduction circuitry. The active noise reduction circuitry includes: detection circuitry configured to detect a change in pressure within the acoustic environment caused by movement of the member, and gain compensation circuitry configured to change a loop gain of a feedback loop in response to the detected change in pressure. | 12-12-2013 |
20140037100 | MULTI-MICROPHONE NOISE REDUCTION USING ENHANCED REFERENCE NOISE SIGNAL - Systems and methods of improved noise reduction include the steps of: receiving an audio signal from two or more acoustic sensors; applying a beamformer to employ a first noise cancellation algorithm; applying a noise reduction post-filter module to the audio signal including: estimating a current noise spectrum of the received audio signal after the application of the first noise cancellation algorithm, wherein the current noise spectrum is estimated using the audio signal received by the second acoustic sensor; determining a punished noise spectrum using the time-average level difference between the audio signal received by the first acoustic sensor and the current noise spectrum; determining a final noise estimate by subtracting the punished noise spectrum from the current noise spectrum; and applying a second noise reduction algorithm to the audio signal received by the first acoustic sensor using the final noise estimate; and outputting an audio stream with reduced background noise. | 02-06-2014 |
20140105413 | NOISE CANCELLATION - A noise cancellation signal is generated by generating an ambient noise signal, representing ambient noise, and generating a noise cancellation signal, by applying the ambient noise signal to an feedforward filter, where the feedforward filter comprises a high-pass filter having an adjustable cut-off frequency, and by applying a controllable gain. The noise cancellation signal is then applied to a loudspeaker, to generate a sound to at least partially cancel the ambient noise. An error signal is generated, representing unwanted sound in the region of the loudspeaker. The phase of the ambient noise signal is compared to a phase of the error signal, and the gain is controlled on the basis of a result of the comparison, taking account of a phase shift introduced by the high-pass filter when performing the comparison. | 04-17-2014 |
20140205107 | ADAPTIVE NOISE REDUCTION USING LEVEL CUES - A system utilizing two pairs of microphones for noise suppression. Primary and secondary microphones may be positioned closely spaced to each other to provide acoustic signals used to achieve noise cancellation/suppression. An additional, tertiary microphone may be spaced with respect to either the primary microphone or the secondary microphone in a spread-microphone configuration for deriving level cues from audio signals provided by the tertiary and the primary or secondary microphone. The level cues are expressed via a level difference used to determine one or more cluster tracking control signal(s). The level difference-based cluster tracking signals are used to control adaptation of noise suppression. A noise cancelled primary acoustic signal and level difference-based cluster tracking control signals are used during post filtering to adaptively generate a mask to be applied to a speech estimate signal. | 07-24-2014 |
20140307887 | SYSTEMS AND METHODS FOR HYBRID ADAPTIVE NOISE CANCELLATION - In accordance with methods and systems of the present disclosure, a processing circuit may implement a feedback filter having a response that generates a feedback anti-noise signal component from a playback corrected error, the playback corrected error based on a difference between an error microphone signal and a secondary path estimate, and wherein the anti-noise signal comprises at least the feedback anti-noise signal component, a secondary path estimate filter configured to model an electro-acoustic path of the source audio signal and have a response that generates a secondary path estimate from the source audio signal, and a secondary coefficient control block that shapes the response of the secondary path estimate adaptive filter in conformity with a source audio signal and the playback corrected error by adapting the response of the secondary path estimate adaptive filter to minimize the playback corrected error. | 10-16-2014 |
20140307888 | SYSTEMS AND METHODS FOR MULTI-MODE ADAPTIVE NOISE CANCELLATION FOR AUDIO HEADSETS - In accordance with the present disclosure, an integrated circuit for implementing at least a portion of a personal audio device may include an output and a processing circuit. The output may provide an output signal to a transducer including both a source audio signal for playback to a listener and an anti-noise signal for countering the effect of ambient audio sounds in an acoustic output of the transducer. The processing circuit may implement an adaptive noise cancellation system that generates the anti-noise signal to reduce the presence of the ambient audio sounds heard by the listener by adapting, based on a presence of the source audio signal, a response of the adaptive noise cancellation system to minimize the ambient audio sounds at the acoustic output of the transducer, wherein the adaptive noise cancellation system is configured to adapt both in the presence and the absence of the source audio signal. | 10-16-2014 |
20150063585 | METHOD AND APPARATUS FOR REDUCING CROSSTALK IN AN INTEGRATED HEADSET - An audio system has a first channel for receiving a first input signal and driving a first speaker and a second channel for receiving a second input signal and driving a second speaker. A first feedforward circuit couples an input of the second channel circuit to an input of the first channel circuit. A second feedforward circuit couples an input of the first channel circuit to an input of the second channel circuit. Circuit parameters of the first and the second feedforward circuits are determined such that a first detected output signal is zero when the first input signal is non-zero and the second input signal is zero, and a second detected output signal is zero when the second input signal is non-zero and the first input signal is zero. The audio system is configured to operate using the determined circuit parameters for the first and the second feedforward circuits. | 03-05-2015 |
20150078571 | ADAPTIVE PHASE DIFFERENCE BASED NOISE REDUCTION FOR AUTOMATIC SPEECH RECOGNITION (ASR) - Embodiments of a system and method for adapting a phase difference-based noise reduction system are generally described herein. In some embodiments, spatial information associated with a first and second audio signal are determined, wherein the first and second audio signals including a target audio inside a beam and noise from outside the beam. A signal-to-noise ratio (SNR) associated with the audio signals is estimated. A mapping of phase differences to gain factors is adapted for determination of attenuation factors for attenuating frequency bins associated with noise outside the beam. Spectral subtraction is performed to remove estimated noise from the single-channel signal based on a weighting that affects frequencies associated with a target signal less. Frequency dependent attenuation factors are applied to attenuate frequency bins outside the beam to produce a target signal having noise reduced. | 03-19-2015 |
20150086031 | ACTIVE NOISE-REDUCTION APPARATUS AND METHOD - According to an embodiment, an active noise-reduction apparatus includes following elements. The microphone converts a sound including a target sound into an error signal. The control filter generates a control signal in accordance with a control characteristic. The first control effect estimation filter converts the control signal into a first signal in accordance with an estimated secondary path characteristic. The second control effect estimation filter converts the control signal into a second signal in accordance with a processed secondary path characteristic obtained by shortening a delay of the estimated secondary path characteristic. The updating unit updates the control characteristic based on the error signal, the first signal, and the second signal. | 03-26-2015 |
20150310845 | SILENT MOBILE DEVICE VIBRATION - A mobile device vibrational sound system includes a processing circuit configured to activate a selectively vibratable element based on a triggering event, and control operation of a speaker to provide a mitigation sound configured to at least partially cancel a vibrational sound resulting from activation of the vibratable element. | 10-29-2015 |
20150356966 | ACTIVE VIBRATION/NOISE CONTROL APPARATUS - A control signal filter | 12-10-2015 |
20160037266 | CAPACITANCE TYPE SENSOR, ACOUSTIC SENSOR, AND MICROPHONE - A chamber that penetrates vertically is formed in a silicon substrate. A diaphragm is arranged on the upper surface of the silicon substrate so as to cover the upper opening of the chamber. The diaphragm is divided by slits into a region located above the chamber (first diaphragm) and a region located above the upper surface of the silicon substrate (second diaphragm). A fixed electrode plate is arranged above the first diaphragm, and a low-volume first acoustic sensing portion is formed by the first diaphragm and the fixed electrode plate. Also, a high-volume second acoustic sensing portion is formed by the second diaphragm and the upper surface (electrically conducting layer) of the silicon substrate. | 02-04-2016 |
20160057534 | ACOUSTIC ECHO CANCELLATION METHOD AND SYSTEM USING THE SAME - The present disclosure illustrates an acoustic echo cancellation method and system using the same. The acoustic echo cancellation method comprises the following steps. Firstly, a prior-knowledge matrix comprising a plurality of space vectors is built. Then, an initial filter vector is generated by the prior-knowledge matrix and an initial weighting vector. The weighting vector is updated based on the difference of the echo signal and the estimated signal in an iteration algorithm, and the coefficient of the filter vector is updated according to the updated weighting vector. An estimated signal is generated according to the updated filter vector and the original signal. Finally, the next echo signal is cancelled by the near-end estimated signal. | 02-25-2016 |
20160196817 | SYSTEMS AND METHODS FOR NOISE CANCELING | 07-07-2016 |
20160253988 | Self-Organized Acoustic Signal Cancellation Over a Network | 09-01-2016 |
20180025716 | System and Method for Providing a Quiet Zone | 01-25-2018 |