Abstract: An active vibration noise control device is preferably used for cancelling a vibration noise by making a speaker generate a control sound. The active vibration noise control device includes a step-size parameter changing unit which changes a step-size parameter used for updating a filter coefficient. The step-size parameter changing unit calculates a parameter-for-change based on the filter coefficient updated by using a basic step-size parameter, and changes the basic step-size parameter by a minimum value in the previously calculated parameter-for-change. Therefore, it is possible to appropriately change the step-size parameter by using the minimum value of the parameter-for-change. Hence, it becomes possible to effectively suppress a divergence of an adaptive notch filter due to a secular change of the speaker.

Abstract: An active vibration noise control apparatus uses an adaptive control process, which predicts rear road wheel noise canceling sounds by correcting a front road wheel reference signal or a rear road wheel reference signal with a corrective filter, based on different characteristics of front road wheel suspensions and rear road wheel suspensions.

Abstract: A method and system for masking pure tones within sound generated from a noise generating source. The method includes detecting one or more pure tones within sound being generated from the noise generating source, and generating one or more masking sounds capable of masking only the one or more pure tones detected within the sound.

Abstract: The invention concerns a listening device (1) for transmitting electroacoustic signals comprising an earphone (2) and means for connecting said earphone (2) with a remote electroacoustic source (3). The invention is characterized in that it comprises an acoustic filter (4) and that its shape is perfectly adapted to the external auditory canal of the ear so as to provide sufficient soundproofing to the external environment. The invention also concerns a headphone comprising one or two such listening devices.

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.

Abstract: A wireless speaker and mounting system for use with a resonating surface of an automobile includes a wireless speaker mechanism including a vibrator, the wireless speaker mechanism configured to receive and convert a wireless signal representative of sound from a separate wireless electronic device into vibrations transmitted by vibrator to the resonating surface of the automobile for creating sound waves by the resonating surface; and a mounting mechanism configured to directly mount the wireless speaker mechanism to the resonating surface of the automobile.

Abstract: A wireless audio distribution system may have a wireless transmitter, responsive to a plurality of audio input channels, for transmitting signals carrying the audio, a receiver, responsive to the transmitted signals for selecting one or more of the audio input channels to be reproduced in accordance with local setting selectors at the receiver. Speaker audio channel anti-noise signals can be subtracted from the head audio channel to cancel the noise related to the playing of the speaker audio on the speakers while the headset audio is played on the headset. Analog anti-noise signals can be produced by use of a microphone associated with the headset and later subtracted from the headset audio.

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.

Abstract: An audio reproduction system includes: a first speaker arranged near a listener and behind a head of the listener with a speaker unit being held by first holding means to make it possible to mix sounds emitted from front and rear of a vibration plate of the speaker; second and third speakers held by second holding means and arranged near the listener and on left and right of the first speaker; separating means for separating and obtaining low-frequency components and medium- and high-frequency components for left and right channels from an input audio signal; means for supplying the low-frequency components separated by the separating means to the first speaker; and means for supplying the medium- and high-frequency components for the left and right channels separated by the separating means to the second and third speakers.

Abstract: An active control of an unwanted noise signal at a listening site radiated by a noise source uses a reference signal that has an amplitude and/or frequency such that it is masked for a human listener at the listening site by the unwanted noise signal and/or a wanted signal present at the listening site in order to adapt for the time-varying secondary path in a real time manner such that a user doesn't feel disturbed by an additional artificial noise source.

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.

Abstract: A double-talk detector finds an estimated power value of near end background noise based on a residual signal by a noise estimator; the average power of a transmitter input signal by a transmitter average power calculator; the average power of a receiver input signal by a receiver average power calculator; and an estimated echo path attenuation value through a predetermined echo path attenuation value estimating process based on the estimated power value of the near end background noise, the average power of the transmitter input signal and the average power of the receiver input signal by an attenuation value estimator. The double-talk detector detects a double-talk state based on the estimated echo path attenuation value, the average power of the transmitter input signal and the average power of the receiver input signal by a double-talk determiner to control update of the coefficient of an adaptive filter.

Abstract: A noise control system is directed to the path along which the noise is transmitted from the source of the noise being generated to the receiver of the noise in the passenger compartment of an automotive vehicle. The noise control system is deployed in a box structure, such as the dual bulkhead of the dashboard of the vehicle, to provide a constrained volume within which engine noise can be controlled. The dual bulkhead plenum houses an active noise control apparatus, such as a speaker or a vibrating device, between the bulkheads to be operable with a control algorithm to generate sound that can control the noise or vibrations generated by the engine. The plenum can also be treated with passive noise control materials, such as viscoelastic damping materials, acoustical foam or heavy vinyl barrier and foam to block airborne sound and vibrations, in addition to the active noise control.

Abstract: The invention relates to simulation of sound fields in enclosures, for instance for application in listening tests, where test subjects assess the sound quality or other sound perception characteristics of the sound field. According to a specific embodiment, the system comprises a binaural synthesis portion which synthesizes sound for instance from a sound-reproduction equipment based on measured impulse responses of an actual room stored in a data base (31) and a binaural recording portion comprising a data base 32 for storing binaural recordings of other sound signals made in the room. Data from these databases are mixed (41) and reproduced by means of a headphone (39) provided with a head tracker (42) for tracking the movements of the listener's head. The invention furthermore comprises the use of cross-fading functions (36, 37) to enable the dynamic listening conditions, where the movements of the listener's head are taken into account during the simulation process.

Abstract: A noise control device includes: four or more noise detectors each for detecting a plurality of noises arriving thereat, and outputting the noises as a noise signal; a control speaker for radiating, to a control point, a control sound based on each noise signal; and a filter section for signal-processing noise signals from the noise detectors by using filter coefficients which respectively correspond to the four or more noise detectors and which are set such that the control sound from the control speaker reduces the plurality of noises arriving at the control point, and for adding up all the signal-processed noise signals, and for outputting a resultant signal to the control speaker. The control point and the control speaker are provided within a polyhedral-shaped space whose apexes are placement positions of the noise detectors.

Abstract: An active vibratory noise control apparatus has a speaker for canceling vibratory noise in the passenger compartment of a vehicle, the speaker being used as a speaker of one of different audio devices that can be installed on the vehicle. Each of the audio devices has a command key switch assembly. When the command key switch assembly is operated to turn off the transistor, a control signal is applied to a switching control circuit in an active vibratory noise control unit, which identifies the audio device installed on the vehicle. The active vibratory noise control unit generates a canceling signal matching characteristics of the speaker of the identified audio device for canceling vibratory noise in the passenger compartment.

Abstract: An active noise control system includes a filter coefficient updating unit including an imaginary term estimator. The imaginary term estimator estimates an imaginary term Ie from a real term Re of an error signal e supplied from a microphone. The filter coefficient updating unit updates a filter coefficient W of an adaptive filter based on the imaginary term Ie, the real term Re, and a corrective signal supplied from a reference signal corrector. The filter coefficient updating unit updates the filter coefficient W successively in respective sampling periods.

Abstract: A system improves the perceptual quality of a speech signal by dampening undesired repetitive transient noises. The system includes a repetitive transient noise detector adapted to detect repetitive transient noise in a received signal. The received signal may include a harmonic and a noise spectrum. The system further includes a repetitive transient noise attenuator that substantially removes or dampens repetitive transient noises from the received signal. The method of dampening the repetitive transient noises includes modeling characteristics of repetitive transient noises; detecting characteristics in the received signal that correspond to the modeled characteristics of the repetitive transient noises; and substantially removing components of the repetitive transient noises from the received signal that correspond to some or all of the modeled characteristics of the repetitive transient noises.

Abstract: A method of controlling sounds associated with a vehicle is provided. The method includes: performing on a processor, monitoring engine torque; and selectively controlling the generation of one or more tones associated with the vehicle based on the engine torque.

Abstract: Disclosed is an acoustic device comprising an enclosed housing defining an inner volume and having a front and a back; an acoustic port penetrating the front of the enclosed housing; a first and second sense structure attached to the inside of the housing and defining a gap between the first and second sense structures; a front volume defined by the portion of the inner volume between the first sense structure and the front of the housing; a back volume defined by the portion of the inner volume between the second sense structure and the back of the housing; and at least one vent in the first sense structure operatively connecting the front volume and the gap, wherein the acoustic device has a cutoff frequency above approximately 100 Hz.

Abstract: A noise control system operable within a box-like structure provided by the dual bulkhead plenum of the vehicle dashboard positioned within the transfer path along which the noise is being transmitted from the source of the generated noise to the receiver of the noise in the passenger compartment of an automobile. The plenum is divided into discrete chambers into each of which is provided smart materials affixed to the walls of the plenum to be operable for selectively changing a property characteristic of the chambers to vary the acoustic resonance of the plenum and change the effectiveness of controlling the transmission of noise energy therethrough. A controller is coupled to the smart materials to change said property characteristic of the smart material in response to noise cancellation requirements.

Abstract: A method and a device for suppressing noise in the passenger compartment of a vehicle, which include at least one transducer, a programmable computer, at least one acoustic sensor, the computer being configured such as to apply an electro-acoustic model of the passenger compartment to a correcting system model including a central controller with fixed coefficients joined to a block of variable coefficients, including a Youla parameter in the form of a Youla block Q. The first phase includes determining and calculating the electro-acoustic model and the control law for at least one predetermined noise frequency. In a second phase, in real time, the computer applies the control law to the electro-acoustic model in accordance with the current frequency of the noise to be suppressed.

Abstract: A noise reduction system for an automotive vehicle powered at least in part by an electric motor located separately from the passenger compartment. The system includes at least one sensor which produces an output signal having a frequency, amplitude and phase representative of noise generated by the electric motor. At least one speaker is positioned closely adjacent the electric motor. A speaker output controller receives the output from the sensor as an input signal and generates an output signal to the speaker so that the speaker produces an audible signal having substantially the same frequency and amplitude but inverted in phase relative to the output from the sensor.

Abstract: Embodiments of a computer system that includes a vibration-cancelling mode, and a related method and computer-program product (e.g., software) for use with the computer system, are described. During operation, a processor monitors operations in the computer system, and may select either the vibration-cancelling mode or an inactive mode based on the monitored operations. For example, the processor may select the vibration-cancelling mode when there are input/output-(I/O) intensive workloads to an array of one or more hard disk drives (HDDs) in the computer system. In this way, the processor may reduce the energy consumption associated with vibration-induced retries to the HDDs (and reduced I/O throughput) without increasing the energy consumption associated with active vibration damping at other times, such as when the computer system is idle or during processor-intensive workloads.

Abstract: Speakers deployed in a space and divided into groups associated with different zones produce a mix of sounds that create internal noise pollution and, combined with external noise, an unpleasant environment for occupants. The present invention contemplates sound systems and methods for creating personalized sound zones to address these and related problems.

Abstract: An in-vehicle sound control system structured so that sound sources, a vehicle speed detection unit for detecting a vehicle running speed, and an acoustic reproduction apparatus are connected to in-vehicle communications network. The in-vehicle sound control system controls, in accordance with a vehicle speed signal transmitted from the vehicle speed detection unit, a reproduction acoustic signal. The acoustic reproduction apparatus switches, in accordance with a plurality of inputted sound sources and media information of a sound source, a control amount to sound control section determined based on a vehicle speed signal. In this manner, such an in-vehicle sound control system is provided that can provide an optimal automatic sound control for human ears even when the medium is exchanged or when a channel for a sound source in the medium is switched to another channel.

Abstract: A subtractor subtracts an echo canceling signal from a canceling error signal to estimate the resonant noise to be silenced at a position of a microphone, and outputs a first basic signal representing the estimated resonant noise as an input signal supplied to a controller. In the controller, a delay filter generates a second basic signal by delaying the first basic signal by a time value. The controller generates a control signal based on the first basic signal and the second basic signal.

Abstract: A frequency detecting circuit estimates the frequency fp of a propeller shaft based on the frequency fc of vehicle speed pulses, and calculates a control frequency fp? which is a harmonic of the frequency fp. A basic signal generator generates a basic cosine wave signal xp1 and a basic sine wave signal xp2 of the control frequency fp?. Adaptive filters and an adder generate a control signal Scp for canceling a driveline noise produced in a passenger compartment by the propeller shaft. A speaker outputs a canceling sound based on the control signal Scp into the passenger compartment.

Abstract: A sound reproduction system provided for in-vehicle use includes: a music signal source; a first group of a first transducer, a second transducer, a third transducer and a fourth transducer connected to the music signal source; a signal processor shifting the phase of first sound signals output from the music signal source; and a second group of a first transducer, a second transducer, a third transducer and a fourth transducers connected to the signal processor.

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: When the frequency of an engine rotation signal reaches a predetermined frequency, a comparator of a switching unit outputs a switching control signal to selectors and a filter coefficient updater. Based on the switching control signal, the selector switches from a connection between one memory and a corrector to a connection between another memory and the corrector, thereby changing the transfer characteristics C^rr of the corrector from C^11 to C^10. Based on the switching control signal, the selector switches from a connection between one ADC and a filter coefficient updater to the connection between another ADC and the filter coefficient updater, thereby supplying the filter coefficient updater with an error signal, rather than an error signal.

Abstract: A feedback calibration system and a method for controlling an electronic signal are disclosed. The feedback calibration system includes an input controller adapted to modify an input signal in response to a control signal and generate a modified input signal, a signal processing block including a signal analyzer, wherein the signal processing block is adapted to process the modified input signal to generate an output signal and the signal analyzer is adapted to detect an undesirable condition of the output signal and transmit a detection signal corresponding to the undesirable condition, a transfer function estimator adapted to model and transmit a transfer function estimate of the signal processing block in real-time in response to the detection signal, and a programmable device adapted to transmit the control signal to the input controller for modifying the input signal, wherein the control signal is based upon the transfer function estimate.

Abstract: A subtractor subtracts a first control signal output from a first bandpass filter from an error signal, and supplies a differential signal to a second bandpass filter. The second bandpass filter, which has a central frequency of 70 Hz, is affected by an operation of the first bandpass filter, i.e., a first control signal, which has a central frequency of 40 Hz. The first bandpass filter is not affected by an operation of the second bandpass filter, i.e., the second control signal.

Abstract: An occupant detection system with noise reduction, a controller having noise reduction for an occupant detection system and a method for reducing noise in an occupant detection system. A high order digital filter is used to filter harmonics of a noise signal from an electrode signal used to determine an occupant presence or absence of the occupant. A way of sampling the electrode signal and the implementation of the high order digital filter cooperate such that the signal processing can be performed by a lower cost general purpose microprocessor as opposed to using a higher cost digital signal processor.

Abstract: An overhead audio system for use in a vehicle, the overhead audio system includes multiplexor for receiving an input signal from a plurality of audio sources and for transmitting an output signal; a noise detection sensor for detecting a noise and providing noise data; an audio processor for processing the output signal received from the multiplexor and for receiving the noise data from the noise detection sensor, wherein the audio processor processes the output signal based on the noise data and transmits the processed output signal to a speaker; and wherein the overhead audio system is housed within a headliner of the vehicle.

Abstract: A vehicle has an electric drive mode, a body defining a vehicle interior, a first and second set of audio speakers positioned outside and inside of the interior, respectively, and a controller. The controller generates an acoustic signal, broadcasts the acoustic signal via the first set of speakers during an electric drive mode, and generates and broadcasts a cancelling signal via the second set of speakers. The broadcasts are coordinated to substantially cancel an attenuated portion of the acoustic signal resulting from propagation of the acoustic signal into the interior. A method cancels a synthesized sound within a vehicle interior by collecting vehicle operating values, generating an acoustic signal as the synthesized sound during an electric drive mode, and processing the acoustic signal to generate a modified acoustic signal approximating an attenuated portion of the acoustic signal propagating into the vehicle interior.

Abstract: A sound generator is provided capable of generating vehicle sound that will be produced when a specific sound element is changed out of a plurality of sound elements arising from the operation of a plurality of components mounted on a vehicle.

Abstract: A vehicular active vibratory noise control apparatus includes an adaptive notch filter (second control signal generating unit) for generating a corrected error signal representative of a road noise only by removing the component of a rotational frequency (the component of an engine muffled sound) from an error signal, generates a first control signal from the corrected error signal and a reference signal, and reduces the component of the rotational frequency (engine muffled sound) at a position where a microphone is located (evaluating point).

Abstract: An in-vehicle communication system includes a control unit which locates coupling points of each one of active speaker units to in-vehicle network. The plurality of the active speaker units includes a plurality of acoustic characteristics set data and programs for determining their own addresses. The respective active speaker units thus can be coupled to in-vehicle network without changing their software, and acoustic characteristics values in response to their coupling points in the vehicle can be established.

Abstract: Microphone is arranged at an evaluation point at the front seat; a signal for controlling vibration noise at this position is sent out from speaker at the front seat; secondary sound for canceling an influence of secondary sound at the front seat on the rear seat is sent out from speaker at the rear seat; microphone is arranged at an evaluation point at the rear seat; a signal for controlling vibration noise at this position is sent out from speaker; and secondary sound for canceling an influence of secondary sound at the rear seat on the front seat is sent out from speaker at the front seat.

Abstract: A noise reduction device is disclosed, in which noise reduction device, a controlling sound generator outputs a white noise generated by a white-noise generator, and this white noise is sensed by an error sensor for identifying an acoustic transmission function covering a path from the controlling sound generator to the error sensor. At this time, an identification controller prompts the white noise generator to generate a white noise for identifying the acoustic transmission function provided that an ambient noise level sensed by the error sensor is not greater than a given threshold.

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.

Abstract: A method and apparatus for providing simultaneous enhancement of transmission loss and absorption coefficient using activated cavities is presented. A layer of material is provided, and a backing plate having a plurality of cavities on the top surface of said backing plate, is disposed adjacent a top surface of said layer of material. A screen is disposed along the top surface of said cavities on said backing plate and at least one cavity includes an actuator disposed within the cavity and a control system receiving a signal from the microphone and receiving a signal from the accelerometer and providing a drive signal to the actuator to provide an acoustic output to provide simultaneous insertion loss and absorption which serves to minimize a linear combination of the signal from the microphone and the signal from the accelerometer.

Abstract: In an acoustic control system an operation range of an active type noise control device (an ANC device) and an operation range of an active type effect sound control device (an ASC device) are exchanged in accordance with the number of working cylinders of an engine.

Abstract: A noise control system is operable within a box-like structure provided by the dual bulkhead plenum of the vehicle dashboard positioned within the transfer path along which the noise is being transmitted from the source of the generated noise to the receiver of the noise in the passenger compartment of an automobile. The plenum is divided into discrete chambers into each of which is provided a counter noise generating apparatus to create a counteracting noise offsetting the noise generated at the source. The acoustic resonance of the chambers amplifies the noise control energy. The geometry of the individual chambers can be varied to optimize the packaging and sound control or shaping strategy. The sound energy permitted to pass through the plenum to the driver's side of the passenger compartment can be tuned to be different than the noise received in the passenger's side.

Abstract: A voice acquisition system for a vehicle includes an interior rearview mirror assembly. The mirror assembly may include a microphone for receiving audio signals within a cabin of the vehicle and generating an output indicative of these audio signals. The microphone may provide sound capture for a hands free cell phone system, an audio recording system and/or an emergency communication system. The system may include a control that is responsive to the output from the microphone and that distinguishes vocal signals from non-vocal signals present in the output. The microphone may provide sound capture for at least one accessory of the equipped vehicle, and the accessory may be responsive to a vocal signal captured by the microphone. The interior rearview mirror assembly may include at least one accessory, such as an antenna, a video device, a security system status indicator, a tire pressure indicator display and/or a loudspeaker.

Abstract: A vehicle mounted audio multimedia system has a variable audio volume adapted to changes in the condition of a road surface. A vehicle occupant manually sets a desired audio volume level. Motion is sensed within a suspension system of the vehicle during travel of the vehicle. A roughness value is determined in response to the motion. The roughness value is transformed into a volume boost, the volume boost generally increasing with an increase in the roughness value. The volume boost is added to the desired audio volume level to provide the audio gain.

Abstract: In a sound field control apparatus including multiple speakers, multiple microphones gathering sound radiated from the multiple speakers, a mode decomposition filter that performs mode decomposition on a sound pressure distribution, and a control filter that controls the input signals to be input to the multiple speakers such that the mode amplitudes of the modes decomposed by the mode decomposition filter can have a predetermined value, a sound pressure distribution in the acoustic space is measured, and the sound pressure distribution in the acoustic space is expressed by using a sinusoidal function and cosine function of a space frequency of the mode to be controlled in amplitude. The mode space frequency is corrected such that the expressed sound pressure distribution can be equal to the measured sound pressure distribution, and the filter coefficient for the mode decomposition filter is determined based on the mode space frequency obtained by the correction (corrected mode space frequency).

Abstract: An active noise control apparatus includes a road surface input detector, a reference signal generator, an adaptive filter, a noise-cancellation sound generator, an error detector, a reference signal corrector, a filter coefficient updating unit, a transfer characteristic variation detector, and an update amount controller. The transfer characteristic variation detector is configured to detect a variation in transfer characteristic between the road surface input detector and the error detector. The update amount controller is configured to increase an amount of updating of a filter coefficient to a value greater than a value that is used in a normal mode in accordance with the variation in transfer characteristic detected by the transfer characteristic variation detector.

Abstract: A method of analyzing time coherence in the noisy signal including the steps of: a) determining a reference signal from the noisy signal by applying treatment (10, 18) to the noisy signal that is suitable for attenuating speech components more strongly than the noise component, in particular by an adaptive recursive predictive algorithm of the LMS type; b) determining (24) a probability of speech being present/absent on the basis of the respective energy levels in the spectral domain of the noisy signal and of the reference signal; and c) deriving (26) a denoised estimate of the speech signal from the noise signal as a function of the probability of the speech being present/absent as determined in this way.