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7352870 Active sound muffler and active sound muffling method  
An active sound muffler for reducing a sound to be reduced as emitted from a sound source located at one of the opposite sides of a sound insulating wall and diffracted and transmitted to the other...
7352869 Apparatus for and method of actively controlling vibratory noise, and vehicle with active vibratory noise control apparatus  
The filter coefficients of an adaptive notch filter are sequentially updated to minimize an error signal based on the error signal and a first reference signal which is produced by subtracting a...
7343016 Linear independence method for noninvasive on-line system identification/secondary path modeling for filtered-X LMS-based active noise control systems  
A method for noninvasive on-line secondary path modeling for the filtered-X LMS algorithm actively controls periodic noise. The method, based in the frequency domain, uses the concept of linear...
7340065 Active noise control system  
An active noise control system is provided which cancels a noise using a sound radiated from a speaker driven by an output from an adaptive notch filter. The system employs output signals from an...
7340064 Active noise control system  
An active noise control system is provided which cancels a noise using a secondary noise from a speaker that is operated in accordance with an output from an adaptive controller. The system is...
7319399 System and method for monitoring the wearing compliance of hearing protection devices  
A system for monitoring the use of a hearing protection unit comprising a left ear hearing protection device ( 14 ) and a right ear hearing protection device ( 12 ) to be worn by a user ( 10 )...
7317801 Active acoustic noise reduction system  
An active acoustic noise reduction system which comprises a single input transducer and an output actuator that are physically located next to each other in the same location. In one embodiment,...
7305094 System and method for actively damping boom noise in a vibro-acoustic enclosure  
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...
7272234 Multi-channel active control system and method for the reduction of tonal noise from an axial fan  
A multi-channel active noise control system and method of reducing tonal noise emanating from a tonal noise source are disclosed. The system may include an adaptive controller, a plurality of...
7224807 System for computationally efficient active control of tonal sound or vibration  
A noise or vibration control system reduces a sampling rate and reduces a control rate to improve computation efficiency. The present invention permits the use of a sample frequency (f s ) that is...
7197147 Computationally efficient means for optimal control with control constraints  
A system and method reduces undesired noise or vibration in a vehicle. The ambient vibration is measured and command signals are generated over time. The command signals are generated based upon...
7139400 Microphone calibration for active noise control system  
An active noise control system ( 100 ) and method compensates for changes in a microphone output to maintain accurate noise control. A calibration signal reflecting a desired microphone output is...
7092529 Adaptive control system for noise cancellation  
An adaptive noise canceling system for extracting a desired signal, comprising an adaptive noise cancellation filtering circuit for suppressing noise from a first input signal using a second input...
7020288 Noise reduction apparatus  
An active noise control system includes a source unit for generating regenerative signals, an ANC unit for processing signals so as to actively cancel noise, sensors for detecting the information...
6944303 Noise cancellation device, engine-noise cancellation device, and noise cancellation method  
A phase-locked loop (PLL) circuit generates a sine wave signal synchronized with an input signal. The sine wave signal is directly supplied to a first multiplier. The sine wave signal is also...
6831983 Method for controlling an active control system and system using such method  
Method for controlling a control arrangement controlling a predetermined system ( 10 ), the control arrangement comprising a controller ( 6 ), M output sensors ( 4 ) providing an output signal...
6795551 Circuit for removing in-band FSK signals without muting of receiver  
A circuit for blocking reception of in-band frequency-shift keyed (FSK) signals by the reception transducer of a telephone subscriber terminal without requiring muting of the reception transducer....
6788794 Thin, lightweight acoustic actuator tile  
A thin, lightweight electroacoustic actuator device covering a large surface area providing a high piston-like output over the frequency range of from at least 30 to in excess of 500 Hz comprising...
6725066 Method of cancelling echoes in a telecommunications system and an echo canceller for the execution of the method  
A method of canceling echoes in a telecommunications system wherein an exchange of information takes place between a local subscriber and a subscriber at the remote end of a transmission link and...
6683960 Active noise control apparatus  
An active noise control apparatus for transmitting, from a loud speaker, a secondary noise synthesized so as to have the same amplitude as and the opposite phase to a primary noise and for...
6665410 Adaptive feedback controller with open-loop transfer function reference suited for applications such as active noise control  
An adaptive feedback control system ( 7 ) has a feedback loop ( 8 ) and a digital adaptive compensation filter ( 10 ). An auxiliary noise signal ( 30 ) is added to a reference signal ( 26 ) for use...
6594365 Acoustic system identification using acoustic masking  
A system for identifying a model of an acoustic system in the presence of an external noise signal is disclosed. The system includes an acoustic actuator for generating controlled sound within the...
6522753 Active noise control method and receiver device  
In an active noise control method of the present invention, a noise detection signal from a noise referring microphone which detects ambient noise is inputted into noise processing units of...
6434239 Anti-sound beam method and apparatus  
A device generates a directional anti-sound beam by modulating an ultrasonic carrier with a sound canceling signal and exciting an ultrasonic transducer with the modulated signal. When the...
6418228 Noise control system  
A noise control system includes: a control sound generator for generating a control sound; an error detector for detecting an error signal between the control sound and noise; a noise detector for...
6330336 Active silencer  
Pseudo space transmitting signal processing means of the signal processing means simulates the frequency response of the space up to the silencing point from a noise source, while pseudo inverse...
6295363 Adaptive passive acoustic attenuation system  
An adaptive passive acoustic attenuation system implements control techniques to facilitate practical use of adaptive passive acoustic attenuation in industrial and commercial applications. The...
6275591 Method and apparatus for extracting a component signal from a composite signal  
An extracting assembly for extracting a component signal generated by a component source from a composite signal is disclosed wherein a reference sensor generates a reference signal relating to...
6198828 Off-line feedback path modeling circuitry and method for off-line feedback path modeling  
An off-line modeling system (50) is provided for modeling a feedback path by calculating filter taps. The off-line modeling system (50) includes a reference sensor (16), a secondary source (18),...
6151396 Active acoustic resonator for abating noise  
An active acoustic resonator is provided for noise reduction, with a sound generator having a membrane, with a sensor for measuring the membrane motion, with an actuator for driving the membrane,...
6150733 Method and device for influencing an impression which is subjectively perceived by an occupant of a vehicle, in particular of a passenger car, when the vehicle is being operated  
A method and device are provided for influencing an impression which is subjectively perceived by an occupant of a vehicle, in particular of a passenger car, when the vehicle is being operated. The...
6137886 Active vibration control method and apparatus  
An improved active vibration control system using feedback and pseudo-feedforward sensor inputs is provided for solving the problem of random and repetitive active vibration control and noise...
6072884 Feedback cancellation apparatus and methods  
Feedback cancellation apparatus uses a cascade of two filters along with a short bulk delay. The first filter is adapted when the hearing aid is turned on in the ear. This filter adapts quickly...
5991418 Off-line path modeling circuitry and method for off-line feedback path modeling and off-line secondary path modeling  
An off-line modeling system (50) is provided for modeling a feedback path and a secondary path by calculating feedback neutralization filter taps and secondary path compensation filter taps. The...
5979593 Hybrid mode-scattering/sound-absorbing segmented liner system and method  
A hybrid mode-scattering/sound-absorbing segmented liner system and method in which an initial sound field within a duct is steered or scattered into higher-order modes in a first mode-scattering...
5966452 Sound reduction method and system for jet engines  
A method and apparatus for reducing acoustic noise waves in the vicinity of an electrically conductive plasma, such as in the exhaust of a gas turbine engine, having a sensor to detect the noise...
5953428 Feedback method of noise control having multiple inputs and outputs  
A multidimensional feedback system is used to reduce the noise component of a vibrational or acoustic field. The feedback algorithm includes a matrix operator that diagonalizes the feedback system....
5937070 Noise cancelling systems  
A first major aspect of the invention relates to an active noise cancelling system which detects ambient noise and applies electro-accoustic processing thereto to produce an acoustic signal for...
5862234 Active noise cancellation system  
A bilateral transducer (18) for use in an active noise cancellation system both senses ambient noise and produces acoustic waves to cancel the noise. The electrical interface for each bilateral...
5848168 Active noise conditioning system  
An active noise conditioning system for use with a combustion engine exhaust system is provided. A controller receives an exhaust noise signal, along with various other feedback signals for...
5834647 Active device for attenuating the sound intensity  
A device for attenuating noises generated by moving sources includes a set of arranged electroacoustic sources which emit an opposite antinoise wave in response to an incident wave as sensed and...
5809152 Apparatus for reducing noise in a closed space having divergence detector  
An automatic sound suppression system is automatically disengaged whenever noise in an area and generated counter noise deviate in their reverse phase relationship or if the amplitude of the...
5805714 Noise suppressor in image forming apparatus and noise suppressing method  
A noise suppressor in an image forming apparatus suppresses noise from a drive mechanism during operation. An operation start signal of the drive mechanism is detected. A previously stored...
5796849 Active noise and vibration control system accounting for time varying plant, using residual signal to create probe signal  
An active noise and vibration control system is constructed such that the residual signal from the residual sensor is fed back into the controller and used to generate the probe signal....
5771300 Loudspeaker phase distortion control using velocity feedback  
The velocity of the integral speaker coil and cone of the canceling loudspeaker of an ANC system corresponds to the sound being produced by the canceling loudspeaker. By sensing the velocity of the...
5727071 Noise silencing device  
A noise silencer is proposed that is composed of a sensor microphone, a speaker, and a control circuit, and which principally silences noise generated from the outside. Noise emitted from a noise...
RE35574 Communication device apparatus and method utilizing pseudonoise signal for acoustical echo cancellation  
A communication device, an apparatus, and a method for acoustic echo cancellation which makes use of a pseudonoise signal. An audio mixer adds the pseudonoise signal to an input signal received...
5559891 Device to be used for changing the acoustic properties of a room  
The invention relates to a device to be used for changing the acoustic properties of a room, comprising a pressure transducer (1), a loudspeaker (2) and an electronic control circuit (3) adapted to...
5455779 Noise reduction apparatus  
When noise is caused by the mechanical vibration propagated from the engine, the microprocessor calculates from the vibration frequency of the engine the secondary sound signal which is in...
5425105 Multiple adaptive filter active noise canceller  
An active adaptive noise canceller that does not require a training mode and operates over an extended noise bandwidth. The canceller partitions the noise bandwidth into frequency sub-bands, and...
Matches 1 - 50 out of 65 1 2 >