Abstract: Systems and methods for audio source separation include receiving a single-track audio input sample having an unknown mixture of audio signals generated from a plurality of audio sources, and separating one or more of the audio sources from the single-track audio input sample using a sequential audio source separation model. Separating one or more of the audio sources may include defining a processing recipe comprising a plurality of source separation processes configured to receive an audio input mixture and output one or more separated source signals and a remaining complement signal mixture, and processing the single-track audio input sample in accordance with the processing recipe to generate a plurality of audio stems separated from the unknown mixture of audio signals.

Abstract: A method for noise cancellation includes monitoring a system for a current operating point, monitoring the system for a predetermined disturbance, and in response to the predetermined disturbance, determining the disturbance to be in one of a transient or steady state response period. A set of data is selected corresponding to the current operating point of the system, the disturbance, and the response period from a database containing predetermined noise cancellation waveform data. A noise cancelling waveform is output to audio transducers based upon the selected set of data.

Abstract: An unmanned air vehicle is provided. The unmanned air vehicle includes one or more generators, each of which generates a force that drives the unmanned air vehicle to fly and also generates an airflow. Each of one or more first microphones is located in an external region that is not included in any of one or more first airflow regions. Each of the one or more first airflow regions corresponds to the airflow generated by one of the one or more generators. Each of one or more second microphones is located in the external region between at least one of the one or more generators and the one or more first microphones. A processor performs processing on one or more first signals output from the one or more first microphones and one or more second signals output from the one or more second microphones.

Abstract: Exemplary engine order and road noise control systems and methods include directly picking up road noise from a structural element of a vehicle to generate a first sense signal representative of the road noise, detecting harmonics of an engine of the vehicle to generate a second sense signal representative of the engine harmonics, and combining the first sense signal and the second sense signal to provide a combination signal representing the combination of the first sense signal and the second sense signal. The systems and methods further include broadband active noise control filtering to generate a filtered combination signal, and converting the filtered combination signal from the active noise control filtering into anti-noise and radiating the anti-noise to a listening position in an interior of the vehicle. The filtered combination signal is configured so that the anti-noise reduces the road noise and engine sound at the listening position.

Abstract: An example active noise control filtering with an adaptive filter structure includes a controllable filter matrix with reference and error input signals, and updating the filter coefficients dependent on an optional filtered reference signal and an error signal, the error signal being representative of a performance criterion of the filter module. Further, a leakage functionality and a convergence functionality is applied to the updated filter coefficients. The leakage functionality is controlled by at least one of a flush functionality, freeze functionality, spatial freeze functionality and leakage threshold, and the convergence functionality is controlled by the freeze functionality and spatial freeze functionality.

Abstract: An active noise reduction device includes a standard signal generator, an adaptive filter unit, a control sound output unit, and an error signal detector. The adaptive filter unit includes a control signal generator, a filter coefficient update unit, and a step size setting unit. The control signal generator multiplies a standard signal by a filter coefficient to generate a control signal. Based on a reference signal and an error signal, the filter coefficient update unit updates the filter coefficient so as to minimize the error signal. The step size determiner sets a step size parameter indicating an update amount of the filter coefficient. The filter coefficient update unit sets a step size adjustment coefficient for adjusting the step size parameter based on an audio information feature amount and a change of the control signal.

Abstract: A method, system, and/or computer program product mitigate vibration caused by sympathetic resonance in a structure that is physically proximate to a machine. One or more processors, based on readings from a resonance sensor, detect vibration caused by sympathetic resonance in a structure that is physically proximate to the machine. One or more processors then direct a machine component controller to adjust the machine component in order to mitigate the vibration.

Abstract: A method to suppress noise emanating from an electrical power generator including the steps of: receiving sound emanating from the electrical power generator, wherein the sound is received in a duct for cooling air having passed through the generator; analyzing the received sound and, based on the analysis, generating a sound signal which represents a destructive sound to the received sound, and broadcasting a destructive sound into the duct, wherein the destructive sound corresponds to the sound signal.

Abstract: Disclosed is a system for controlling acoustic radiation from an aircraft. The system comprising a plurality of rotor systems (one or more) and a noise controller configured to regulate acoustic radiation from the plurality of rotor systems. The noise controller can be configured to regulate a commanded flight setting from the flight control system and to output a regulated flight setting to the plurality of rotor systems. Based on the regulated flight setting, the plurality of rotor systems are configured to generate, individually and in aggregate, acoustic radiation having a target acoustic behavior. The target acoustic behavior may be achieved using beamforming techniques to, for example, change the directionality of acoustic radiation from the plurality of rotor systems, or otherwise tune the acoustic radiation to reduce detectability and/or annoyance.

Abstract: Aspects of the present invention relate to an active noise system (4), a vehicle (1) with an active noise system (4), a method for controlling an active noise system (4), a computer program for controlling an active noise system (4) and an active noise controller (40). The wading detection system (3) includes sensors (30, 31, 32, 33) for detecting a wading depth and a wading detection controller (34). The active noise system (4) includes speakers (41, 42) for modifying the exhaust noise emitted from the vehicle (1). The wading detection controller (34) is operable to detect or anticipate a predetermined wading depth (W1, W2) at which the speakers (41, 42) will come into contact with the water. The active noise controller (40) is configured to deactivate the speakers (41, 42) when the predetermined wading depth (W1, W2) is detected or anticipated by the wading detection controller (34).

Abstract: A method and system for reducing ambient noise distraction with an electronic personal display is disclosed. One example determines when the electronic personal display is in reader mode. In addition, ambient noise around the electronic personal display is also detected. Noise cancelling sound waves are generated at the electronic personal display for reducing ambient noise distraction. The noise cancelling sound waves are then output from at least one speaker coupled with the electronic personal display.

Abstract: Some demonstrative embodiments include devices, systems and methods of noise control. For example, a device may include a controller to control noise within a predefined noise-control zone, the controller is to receive a plurality of noise inputs representing acoustic noise at a plurality of predefined noise sensing locations, which are defined with respect to the predefined noise-control zone, to receive a plurality of residual-noise inputs representing acoustic residual-noise at a plurality of predefined residual-noise sensing locations, which are located within the predefined noise-control zone, to determine a noise control pattern, based on the plurality of noise inputs and the plurality of residual-noise inputs, and to output the noise control pattern to at least one acoustic transducer.

Abstract: A throttle control system includes a target pressure module, a torque determination module, and a target opening module. The target pressure module determines an induction noise value based on an engine operating parameter and determines a target pressure downstream of a throttle valve of an engine based on a pressure at an inlet of the throttle valve and the induction noise value. The torque determination module determines a torque request for the engine based on the target pressure. The target opening module determines a target opening for the throttle valve based on the torque request and selectively adjusts opening of the throttle valve based on the target opening.

Abstract: An exhaust device (2) for an internal combustion engine (3) has an exhaust line (5) with a rear section X with two exhaust pipes (11) connected to an acoustic actuator (12) in a sound-transmitting manner. Better acoustic characteristics and increased number of noises audible from the outside is guaranteed by the exhaust pipes (11) being of different designs and/or by the actuators (12) being able to be actuated individually. A process for controlling the actuators (12) uses a control device (25) that actuates the actuators (12) individually to generate different acoustic signals (23) of the respective actuators (12). A motor vehicle (1) is provided with such an exhaust device (2) with acoustic actuators (12) controlled by such a process. The motor vehicle (1) has additional actuators (29, 31), which are especially associated with an intake line (30) and are arranged in the interior of motor vehicle (1).

Abstract: A device and method that is configured to operate an active noise reduction system for a motor vehicle, where there is an active noise reduction system input signal that is related to the vehicle engine speed, and where the active noise reduction system comprises one or more adaptive filters that use a filter coefficient to modify the amplitude and/or phase of a noise cancellation reference signal and output noise reduction signals that are used to drive one or more transducers with their outputs directed to reduce engine noise, where the value of the coefficient is related to an adaptive filter leakage factor. Changes in the engine speed, based on the input signal that is related to the vehicle engine operation, are monitored. In response to changes in the engine speed, the adaptive filter leakage factor is temporarily modified.

Abstract: An acoustical noise reduction system which comprises a primary acoustic to electric transducer, digital signal processor (DSP), an electric to acoustic transducer, and a secondary acoustic to electric transducer is disclosed in the present invention. The active noise reduction system is located close to the noise source with the sound being sensed by a primary transducer before the noise enters the active noise reduction area. The system functions to generate an anti-noise cancellation sound wave with an acoustic propagation speed of approximately 330 m/sec and an electromagnetic propagation speed of approximately 3×10^8 m/sec.

Abstract: Provided are methods and systems for noise suppression within multiple time-frequency points of spectral representations. A multi-feature cluster tracker is used to track signal and noise sources and to predict signal versus noise dominance at each time-frequency point. Multiple features, such as binaural and monaural features, may be used for these purposes. A Gaussian mixture model (GMM) is developed and, in some embodiments, dynamically updated for distinguishing signal from noise and performing mask-based noise reduction. Each frequency band may use a different GMM or share a GMM with other frequency bands. A GMM may be combined from two models, with one trained to model time-frequency points in which the target dominates and another trained to model time-frequency points in which the noise dominates. Dynamic updates of a GMM may be performed using an expectation-maximization algorithm in an unsupervised fashion.

Abstract: A personal audio device, such as a wireless telephone, includes noise canceling circuit that adaptively generates an anti-noise signal from a reference microphone signal and injects the anti-noise signal into the speaker or other transducer output to cause cancellation of ambient audio sounds. An error microphone may also be provided proximate the speaker to estimate an electro-acoustical path from the noise canceling circuit through the transducer. A processing circuit uses the reference and/or error microphone, optionally along with a microphone provided for capturing near-end speech, to determine whether one of the reference or error microphones is obstructed by comparing their received signal content and takes action to avoid generation of erroneous anti-noise.

Abstract: A system includes a first housing that houses a plurality of mechanical keys. A first microphone that is configured to detect a dynamic noise is located within the first housing and under the mechanical keys. A second microphone is configured to detect acoustic waves that include speech and to convert the acoustic waves into an electrical audio signal. The dynamic noise is not associated with the detected speech. The system further includes a dynamic audio signal filter that is configured to suppress, in the electrical audio signal, dynamic noise, and the dynamic audio signal filter is activated in response to the first microphone detecting the dynamic noise.

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.

Abstract: An active vibratory noise control apparatus includes a basic signal generator configured to output a basic sine wave signal and a basic cosine wave signal. An adaptive finite impulse response filter is configured to output a control signal to cancel the vibratory noise. A vibratory noise cancelling device is configured to generate vibratory-noise canceling sound. An error signal detector is configured to output an error signal. A reference signal generator is configured to output a reference signal and corrects the basic cosine wave signal and the basic sine wave signal based on correction values. A buffer is configured to accumulate a number of reference signals corresponding to a number of taps of the adaptive finite impulse response filter. A filter coefficient updating device is configured to sequentially update filter coefficients of the adaptive finite impulse response filter to minimize the error signal.

Abstract: An audio processing system processes an audio signal that may come from one or more microphones. The audio processing system may use information from one or more non-acoustic sensors to improve a variety of system characteristics, including responsiveness and quality. Especially those audio processing systems that use spatial information, for example to separate multiple audio sources, are undesirably susceptible to changes in the relative position of any audio sources, the audio processing system itself, or any combination thereof. Using the non-acoustic sensor information may decrease this susceptibility advantageously in an audio processing system.

Abstract: An active noise cancellation system includes an adaptive filter, a signal source, an acoustic actuator, a microphone, a secondary path and an estimation unit. The adaptive filter receives a reference signal representing noise, and provides a compensation signal in response to the received reference signal. The signal source provides a measurement signal. The acoustic actuator radiates the compensation signal and the measurement signal to the listening position. The microphone receives a first signal that is a superposition of the radiated compensation signal, the radiated measurement signal, and the noise signal at the listening position, and provides a microphone signal in response to the received first signal. The secondary path includes a secondary path system that represents a signal transmission path between an output of the adaptive filter and an output of the microphone.

Abstract: Methods and systems for reducing noise relating to an electronic system are disclosed. The methods and systems determine a noise signature, which characterizes a targeted noise of the electronic system. A cancellation signal is then generated based on this noise signature, so that if the cancellation signal is transmitted, the targeted noise is at least partially reduced.

Abstract: Secure outsourced aggregation of data using one-way chains is discussed in this application. Each input data source such as a sensor generates a Verifiable Synopsis (“VS”) which includes sensor data, an Inflation Free Proof (“IFP”) generated using a cryptographic function and a Self-Authenticating Value (“SEAL”) chain generated using a one-way function. An aggregator takes a plurality VSs from multiple data sources and aggregates them together into one. Maximum value, top-k, count, count distinct, sum, average, and other aggregate functions may be used. Folded VS provides a concise proof that no value greater than the maximum value was reported by a sensor, thus providing a check against deflation of sensor data. Similarly, the cryptographic function of the IFP provides a mechanism to prevent inflation of the sensor data. Thus it becomes possible at a portal to verify that aggregated data has not been inflated or deflated by the aggregator.

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.

Abstract: An encoding apparatus comprises a frame processor (105) which receives a multi channel audio signal comprising at least a first audio signal from a first microphone (101) and a second audio signal from a second microphone (103). An ITD processor 107 then determines an inter time difference between the first audio signal and the second audio signal and a set of delays (109, 111) generates a compensated multi channel audio signal from the multi channel audio signal by delaying at least one of the first and second audio signals in response to the inter time difference signal. A combiner (113) then generates a mono signal by combining channels of the compensated multi channel audio signal and a mono signal encoder (115) encodes the mono signal. The inter time difference may specifically be determined by an algorithm based on determining cross correlations between the first and second audio signals.

Abstract: An active noise cancellation system that reduces, at a listening position, power of a noise signal radiated from a noise source to the listening position. The system includes an adaptive filter, at least one acoustic actuator and a signal processing device. The adaptive filter receives a reference signal representing the noise signal, and provides a compensation signal. The at least one acoustic actuator radiates the compensation signal to the listening position. The signal processing device evaluates and assesses the stability of the adaptive filter.

Abstract: An active noise cancellation system reduces, at a listening position, the power of a noise signal being radiated from a noise source to the listening position. The system includes an adaptive filter that receives a reference signal representing the noise signal, and provides a compensation signal. A bass management unit receives the compensation signal and applies a phase shift to the compensation signal to provide a phase shifted compensation signal. A first acoustic radiator receives the phase shifted compensation signal and radiates audio indicative thereof to the listening position. A second acoustic radiator receives the compensation signal and radiates audio indicative thereof to the listening position. The transfer function characteristics from the input of the bass management system to the listening position approximately matches a desired transfer function.

Abstract: A method and system for implementing an acoustical front end customization are disclosed. The customization is implemented to optimize the sound level for each individual cochlear implant user. A known audio signal is generated using a sound source and captured by a microphone system. The captured sound signal is sampled at one or more locations along the signal processing pathway, and a spectrum is determined for the sampled signal and the known signal. A ratio of the two spectrums is related to the undesired transformation of the sampled signal, and a digital filter is designed based on the ratio to filter out the undesired transformation.

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.

Abstract: A system, method, and program product are provided for filtering sound from a selected application on a computer without interrupting voice communications on the computer. The method comprises: monitoring a selected program for an outgoing digital audio signal from a selected application; detecting said digital audio signal; and filtering an analog microphone input with the digital audio signal.

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.

Abstract: A noise reducing apparatus includes: a voice signal inputting unit inputting an input voice signal; a noise occurrence period detecting unit detecting a noise occurrence period; a noise removing unit removing a noise for the noise occurrence period; a generation source signal acquiring unit acquiring a generation source signal with a time duration corresponding to a time duration corresponding to the noise occurrence period; a pitch calculating unit calculating a pitch of an input voice signal interval; an interval signal setting unit setting interval signals divided in each unit period interval; an interpolation signal generating unit generating an interpolation signal with the time duration corresponding to the noise occurrence period and alternately arranging the interval signal in a forward time direction and the interval signal in a backward time direction; and a combining unit combining the interpolation signal and the input voice signal, from which the noise is removed.

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.

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.

Abstract: A subtractor subtracts an echo canceling signal ?·y1(n?1) from a canceling error signal e(n) to estimate a residual noise to be silenced at the position of a microphone, and outputs a first basic signal x1(n) representing the residual noise. A first control circuit section generates a first control signal y1(n) based on the first basic signal x1(n) and a second basic signal x2(n) that is generated by delaying the first basic signal x1(n) by a time Z?n. A second circuit section generates a second control signal y2(n) based on the first basic signal x1(n) and an engine rotation signal.

Abstract: The invention relates to an energy saving headset 100. The headset 100 comprises a power management unit 150 that is operable to reduce the power consumption of the headset 100 when a user 110 is not present. The power management unit 150 uses capacitive sensing to detect the presence of the user 110. Capacitive sensing is advantageous since it provides a flexible and reliable sensor that can accurately detect the presence or absence of a user 110 either by detecting user proximity or user contact. Moreover, in various embodiments, the sensitivity of a capacitive sensor may be adjusted to account for user movement or changes in environmental conditions, such as, for example, the presence of water, or sweat, on the headset 100 to further improve sensing reliability. The invention further relates to headsets using user presence signals based on capacitive sensing to control other functions of the headset or to control external devices to which the headset is connected, either wirelessly or by wires.

Abstract: An electronic device having a first motor which rotates a rotating body (for example, blades) about a rotation axis and a second motor which vibrates a vibrator including the rotating body in the axial direction is provided. A control IC unit has a first circuit which subjects the rotation to control drive by a first waveform, and a second circuit which subjects the vibration to control drive by a second waveform. Rotation and vibration of a rotating and vibrating unit driven by the first and second motors generates an airflow and output sound by a synthesized output of a first output corresponding to the rotation and a second output corresponding to the vibration. The control IC unit generates a second waveform by using a reversed-phase waveform with respect to the first waveform or the like and suppresses the output sound by control of the first and second waveforms.

Abstract: A method and system for implementing an acoustical front end customization are disclosed. The customization is implemented to optimize the sound level for each individual cochlear implant user. A known audio signal is generated using a sound source and captured by a microphone system. The captured sound signal is sampled at one or more locations along the signal processing pathway, and a spectrum is determined for the sampled signal and the known signal. A ratio of the two spectrums is related to the undesired transformation of the sampled signal, and a digital filter is designed based on the ratio to filter out the undesired transformation.

Abstract: A system for sound cancellation includes a source microphone for detecting sound and a speaker for broadcasting a canceling sound with respect to a cancellation location. A computational module is in communication with the source microphone and the speaker. The computational module is configured to receive a signal from the source microphone, identify a cancellation signal using a predetermined adaptive filtering function responsive to acoustics of the cancellation location, and transmit a cancellation signal to the speaker.

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.

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.

Abstract: A method for attenuating the low-frequency noise generated at the outlet (18) of an exhaust line (14). A signal representing the noise to be attenuated is defined; a first high-frequency acoustic wave (F1) is emitted from a first transducer (22) into an attenuation region (26) of the exhaust line (14), the first acoustic wave having a carrier frequency higher than 50 kHz; and a second high-frequency acoustic wave (F1+?fcb) is emitted by a second transducer (24) into the attenuation region (26) of the exhaust line, the second acoustic wave having the carrier frequency of the first high-frequency acoustic wave (F1) and containing a low-frequency counter-noise signal (?fcb) which is out of phase with the signal representing the noise to be attenuated.

Abstract: The invention is directed to a system and method for noise cancellation for an apparatus such as an electric motors or generator. The system may comprise a plurality of actuators, a plurality of phase controllers, each phase controller receiving an input signal representing a movement of an apparatus and outputting an output signal based on the input signal and at least one predetermined phase shift, and a plurality of amplifiers, each amplifier receiving an output signal from one of the phase controllers and outputting an amplified signal to drive one of the actuators. The method may comprise the steps of generating a first signal representing a movement of the apparatus, generating at least one second signal based on (a) the first signal, (b) at least one predetermined phase shift, and (c) at least one predetermined amplitude, and driving at least one actuator with the at least one second signal.

Abstract: An active noise cancellation system (20) includes digital modeling of the physical path that is compensated for using a digital filter (34). An initial estimate of the time domain response of the system (20) is achieved using inverse time domain convolution to determine the signal values of a speaker (24) and a microphone (26) in the system. The estimated time domain response of the system is used to determine the initial estimate of the modeled digital filter. In one example, the initial estimate is then used as part of a convergence technique, such as a least mean squares algorithm. In another example, a plurality of initial estimates are determined and then averaged to arrive at the filter value used during noise cancellation.

Abstract: An adaptive noise reduction method and apparatus capable of reducing efficiently variable period noise from a main input is provided. The pitch of a noise waveform to be reduced can be variable with a change in a period of motor noise occurring when the revolution period is changed by disc motor control of DVD-RAM, by revolution speed control of other motors, and revolution period change on starting a motor and the like. Therefore, the renewal of adaptive filter coefficient becomes almost unnecessary, thus allowing noise reduction to be performed without degrading a noise canceling effect.

Abstract: Digital audio data with error detection bits added thereto is inputted to an error detecting and correcting device (4). The correcting device (4) corrects an error when the error is detected in the digital audio data. The digital audio data outputted from the error detecting and correcting device (4) is inputted to an impulse noise suppressing circuit (6). The suppressing circuit (6) operates for a predetermined time period when the correcting device (4) detects an error.

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.

Abstract: An engine is supported on a vehicle body frame through an active vibration-isolating device. The vibration of the engine is prevented from being transmitted to the vehicle body frame by controlling the active vibration-isolating device. A speaker is disposed within a vehicle compartment. The noise is reduced by adaptively controlling the speaker based on a rotational speed of the engine and a noise detected by a microphone disposed within the vehicle compartment. Thus, the vibration and noise characteristics of the vehicle can be improved by a synergic effect of reducing both the vibration and the noise. Further, because the microphone is inexpensive and the speaker for an audio set can be used without any modification, the present invention can be achieved with a low cost.