Abstract: An apparatus and method to minimize acoustic vibration in a vehicle due to impulsive gear clash loads. Sensors are mounted on the vehicle and are used to sense vehicle vibration generated by the gear clash loads. A first gear, having a plurality of teeth and a second gear, also having a plurality of teeth, are disposed such that upon rotation of the first and second gears, certain ones of the second gear teeth mesh with certain ones of the first gear teeth. An actuator, which is coupled to the first gear, drives the first gear and generates torque pulses. A controller is coupled to the actuator and controls the torque pulses that are transmitted to the first gear. The torque pulses generated by the actuator are adjusted in magnitude and phase so that the first gear teeth vibrate at a predetermined frequencies thereby reducing vibrations and peak tooth loading caused by the meshing of the first gear teeth and the second gear teeth.

Abstract: A noise reduction apparatus is capable of suppressing deterioration of an aural sensing level due to noise existing in a sound field. The apparatus synthesizes a signal obtained by adding a predetermined delay to a sound field noise and reversing and amplifying the signal with an electric signal from a sound reproduction system to obtain a sound pressure output by using a first signal processing part. On the other hand, the apparatus synthesizes a signal obtained by delaying an electric signal from the sound reproduction system by a predetermined period and reversing and amplifying the signal with an electric signal obtained from a sound pressure in the proximity of a concha of a listener to extract a residual noise component by using a second signal processing part. The apparatus controls the delay amounts and the gains set by the first and second signal processing parts so as to minimize an extraction signal.

Abstract: 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 signal which represents the product of a sine corrective value C1 and a reference sine signal, from a signal which represents the product of a cosine corrective value C0 and a reference cosine signal. The filter coefficients of an adaptive notch filter are sequentially updated to minimize the error signal based on the error signal and a second reference signal which is produced by adding a signal which represents the product of the reference sine signal and the cosine corrective value C0 and a signal which represents the product of the reference cosine signal and the sine corrective value C1 to each other.

Abstract: 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 configured such that microphone monitor interrupts a switch to thereby stop the secondary noise from being produced, when an error signal delivered by a microphone used for an adaptive computation in an LMS processing portion has the same sign for a predetermined duration. This allows the system to prevent the user from hearing an abnormal acoustic noise resulting from an abnormal operation or divergence of an adaptive filter even when the output signal from the microphone used for the adaptive computation is indicative of an abnormal level.

Abstract: An air intake noise reduction apparatus is provided which can effectively reduce air intake noise even with simple construction requiring a small number of components. Four air intake passages 24, 25, 26, 27 which each have different passage lengths are formed by connecting an upper wall 17 and a lower wall 18 of an air intake noise reduction duct 11 which are flattened in a vertical direction with three partition walls 21, 22, 23. Air intake noise can be reduced by making pulsating air interfere with one another which is generated in the plurality of air intake passages 24, 25, 26, 27 which each have the different passage lengths in such a manner as to have different phases shifted from one another. In addition, since the partition walls function as a reinforcement rib, the rigidity of the air intake noise reduction duct 11 can be enhanced.

Abstract: An active noise control system (20) includes a controller (34) that receives a signal from a single pressure sensor (36). The controller (34) estimates an engine speed of an engine (30) and a throttle position of a throttle valve associated with an air intake manifold (32). The controller (34) generates a noise control signal that drives a speaker (38), which responsively generates a noise attenuation signal. The disclosed embodiment may be used in an after-market product as it requires minimal interfacing with other vehicle electronics.

Abstract: 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 a stiff, lightweight face plate; a backing structure disposed below the face plate; at least one driver structure disposed between the face plate and the backing structure; and flexible structure flexibly connecting the at least one driver to the face plate.

Abstract: A method of controlling an acoustic system in a vehicle, in which the interior is monitored by an interior sensing system, at least the position of the occupant's head in the interior is recognized by an object recognition system on the basis of the data supplied by the interior sensing system, and a setting of the acoustic system that is optimized for the occupants is performed automatically by a control unit as a function of seat occupancy and the position of the occupant's head in the interior.

Abstract: A method and a device as well as a control unit for controlling at least one aggregate in a vehicle, the noise caused by the aggregate and/or at least one variable representing this noise being ascertained. In this connection, the passenger compartment noises in the vehicle are ascertained, or at least one variable representing these is ascertained. The noise caused by the aggregate and/or the variable representing this is correlated with the passenger compartment noises and/or the variable representing these. Finally, as a function of that, the control or a control signal for the aggregate is generated and/or adapted.

Abstract: The invention relates to a circuit having at least a first electroacoustic transducer (LSL, LSR) for converting electric signals into acoustic signals, a second electroacoustic transducer (MIC) for converting acoustic signals into electric signals, a program-controlled signal processing device (SPU) coupled to said transducers (LSL, LSR, MIC) to process the signals it supplies to the control device and a program storage (ROM) to store a program (AUM) for audio playback of a program (HFM) for hands-free operation for the signal processing device (SPU), wherein, the program (HFM) for hands-free operation is loaded in the signal processing unit and executed by latter in hands-free mode while the program (AUM) for audio playback is loaded in the signal processing device (SPL) and executed by the latter in the audio playback mode.

Abstract: The air induction system comprises an air induction body with a mouth and a speaker forming an interface with the mouth. A fender portion of a vehicle at least partially covers the interface, protecting the interface from environmental conditions. A control unit controls with the speaker to thereby generate a noise attenuating sound.

Abstract: A lightweight self-contained vibro-acoustic device is disclosed for dissipating low frequency vibration and acoustic energy within the payload fairing of launch vehicles. The device can be mounted on the interior surfaces of a fairing and adaptively tuned to match targeted structural and acoustic dynamics using electronic feedback loops.

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: A cabin communication system for improving clarity of a voice spoken within an interior cabin uses a microphone array including a first microphone, positioned at a first location within the cabin, for receiving the spoken voice primarily in a first direction and for converting the spoken voice into a first audio signal, and a second microphone, positioned at a second location within the cabin, for receiving the spoken voice primarily in the first direction and for converting the spoken voice into a second audio signal. A sound source, such as the speaker of an entertainment system, inputs sound into the cabin such that the input sound approaches the microphone array primarily in a second direction different from the first direction.

Abstract: An active noise control system for controlling induction noise of an internal combustion engine having a speaker and a controller. The controller generates a control signal that drives the speaker, wherein the signal is based on at least one current vehicle operating condition. The signal is also based on a determination of a first sound pressure for each order of sound generated by the engine during a run up of the engine. In addition, the signal is based on a determination of a second sound pressure computed for each of a plurality of operating conditions of the engine, wherein the signal controls each of order of sound generated by the engine independently to drive the speaker to generate an audio output to control intake noise.

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.

Abstract: A system and method for suppressing cyclic noise components of a sampled sensor signal generates an error compensation signal that is subtracted from the sampled sensor signal to produce a corrected signal. A moving average of the sampled sensor signal, or sensor error signal, is obtained that corresponds to an error signal free of the non-cyclic component. An adaptive noise compensation algorithm is implemented by a compensation module with a minimum number of multiplications. The compensation module relies upon a unit base vector having a length equal to the number of base functions used to represent the cyclic noise component of the sensor signal, or equal to the number of samples over the sampling interval of the cyclic noise. This base vector is multiplied by an adaptive gain, which is a function of the difference between the sensor error signal and a compensation signal output from the adaptive compensation module.

Abstract: An air introduction system (10) includes an active noise control system (22) having an environmentally protected microphone (24). A microphone support structure (26) defines a louvered cage (38) over a microphone reception cavity (40). The microphone (24) is mounted to a circuit board (42) which fits within the microphone reception cavity (40). A cover (42) fits into the cavity (40) to encase the microphone (24) therein. An open cell foam (60) surround the microphone (24) and a waterproof material (58) encases the foam (60). The waterproof material (58) includes an excess of material such that waterproof material provides for internal air expansion and contraction. By locating the foam (60) between the microphone (24) and the waterproof material (58) improved transmission of acoustic waves is provided which thereby maintains microphone sensitivity.

Abstract: A method and apparatus for actively influencing the intake noise of an internal combustion engine. The apparatus comprises a controller (7) which senses the actual noise (I) via a microphone (16) and compares the actual noise with a reference noise signal which depends on the engine speed D and at least one further engine parameter P, such as, for example, the throttle (12) position. A comparison signal V generated by comparing the actual noise to the reference noise value is used to adjust a control signal Asum, which also depends on the engine speed D. The control signal is fed to an electromechanical transducer (14) which generates a correcting noise (20) which is superimposed on the intake noise (21) to produce the resultant actual noise (22), which should correspond as closely as possible to the reference noise value.

Abstract: A speaker for vehicle has a weight mounted on the backside of a magnetic circuit of a speaker unit. The weight includes a weighting part having a shape in which the thickness in an axial line of the speaker unit is made small and the diameter in a direction perpendicular to the axial line is extended. The outer diameter of the weighting part is made longer than that of the magnetic circuit. The weighting part has a peripheral edge extending forward in the axial direction to cover the outer periphery of the magnetic circuit at least partially. Where a frame of the speaker unit is provided with an opening, the weight is designed to have a shape and position so as not to face the opening.

Abstract: An active noise control system includes a speaker located within an enclosure within a vehicle body component. The speaker enclosure is typically located forward of a vehicle wheel well. An elongated transmission member communicates canceling noise from the speaker enclosure over the wheel well to an outlet adjacent the firewall. The elongated transmission member focuses and directs cancellation noise toward the firewall and bypasses the wheel well and any restriction created thereby.

Abstract: An apparatus for detecting unwanted noise includes a reference sensor that generates a reference signal in response to stimulation by a source. A combined noise detector picks up a combined noise signal, which includes both background noise and the unwanted noise generated by the source. A noise separation synthesis device filters both signals to generate a coherent unwanted noise signal from the combined noise signal as a function of the reference signal generated by the reference sensor. A comparator determines the presence of unwanted noise by calculating the Kurtosis value of the coherent unwanted noise signal.

Abstract: A designing system for adaptively characterizing an audio transmitting system has a white noise generating unit for generating a white noise signal. A speaker radiates the white noise generated by the white noise generating unit into an acoustic space. A microphone is placed at a predetermined position in the acoustic space and collects sound radiated from the speaker. A FIR adaptive filter receives the above white noise signal. An LMS algorithm processing unit updates each tap coefficient of the adaptive filter by using the LMS algorithm. A computation unit calculates the difference between a detection signal output from the microphone and an output of the adaptive filter and outputs the difference as an error signal &egr;. By using a white noise signal having an average power of one, the range of the step size parameter of the LMS algorithm required for stably operating the adaptive filter is fixed.

Abstract: 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 generated and stored in an active noise control module (106). During operation, the active noise control module (106) compares an actual microphone output signal with the calibration signal and compensates for any changes in the actual output signal before any noise compensation or cancellation function occurs.

Abstract: Broadly, this invention resides in apparatus and methods involving a set of soundfield nulling algorithms providing a localized decrease in sound intensity. Among the benefits of the approach, is that there is little, if any, affect on other important positions such as power or spectral content, insofar as energy is directed to unimportant areas. In the preferred embodiment, two separate algorithms are used, depending upon the frequency range of the acoustic signal. For lower frequencies (for example, less than 300 Hz), the algorithm is based on Cepstral techniques and overtly uses the fact that in an enclosed area, the predominant acoustic influence is in the form of standing waves. At higher frequencies, however, (i.e., 300 Hz and above), the sound is due to free-space propagation. Consequently, single free-space algorithms that are applied across the spectrum have great difficulty in providing useful sound nulls without distortion.

Abstract: An air induction system for an internal combustion engine utilizes localized heat generation to produce a desired acoustic profile that attenuates noise propagated through the air induction system. The noise propagated through the air induction system varies over time to form a variable noise profile. A heat generating mechanism, such as a laser array or electric spark generator, produces a predetermined amount of heat within a localized area adjacent to an inlet to the air duct housing. The predetermined amount of heat is an amount of heat sufficient to produce a desired acoustic energy as a result of rapid air expansion at the localized area. A controller varies the predetermined amount of heat over time to produce a desired acoustic profile that cancels the variable noise profile.

Abstract: A vehicle simulation system includes a sound resonant chamber assembly for simulating audio sounds representative of the sounds produced during the operation of the simulated vehicle, comprising a speaker and a sound resonant tube attached to the speaker for enhancing and directing the audio sounds.

Abstract: An active noise control system (26) includes an error microphone (28), a speaker (29) and an active resonator (30) which communicate with an ANC controller (32). The active resonator is a Helmholtz resonator which is coupled to an air introduction body (19). The resonance frequency of the active resonator is varied in response to the ANC controller (32) which provides logic which responds to sensor signals to eliminate low frequency noise such that the ANC system speaker (29) will effectively control and/or spectral shape the remaining noise.

Abstract: A method determines and optionally eliminates a disturbing noise subjectively perceived by an operator, particularly a disturbing noise of a vehicle. The vehicle is operated by the operator complaining of the disturbing noise. Noise effects are recorded during the operation of the vehicle, particularly in the region of the operator's ear. From all sound effects, a noise sequence is taken which contains the disturbing noise. The noise sequence is played to the operator. If the noise sequence is at least similar to the disturbing noise, the noise sequence is converted to a sequential frequency spectrum using a mathematical algorithm. In the present sequential frequency spectrum, at least one frequency or group of frequencies is manipulated; from the manipulated frequency spectrum. A manipulation noise is generated and is played to the operator for evaluation the change of the disturbing noise. If the disturbing noise is reduced or removed in the manipulation noise, a corresponding repair is carried out.

Abstract: An air induction system comprises an air induction body and air filter to provide filtered air to a vehicle engine. A microphone is disposed within the air filter. A control unit may receive signals from the microphone. The control unit may further control a speaker, which produces a noise canceling sound to thereby reduce engine noise associated with the air induction system.

Abstract: A device and a method is presented in which an adjustment to the noise conditions is made for the purpose of controlling the volume and other variables of a desired signal offered in a monitored space, in the course of which, for the purpose of adjustment, a monitoring signal occurring at the monitoring point is picked up and split into a desired-signal component and a noise-signal component. These two components then become the basis for the adjustment.

Abstract: Methods and devices for reducing undesired signals in a communication environment. At least two distinct composite signals (X1 and X2) are transmitted from a first communication environment (260). A noise coefficient of the first communication environment (260) based on the at least two distinct composite signals (X1 and X2) is calculated. At least two noise canceling signals based on the noise coefficient are calculated. The at least two noise canceling signals are added to an incoming signal (Y3) from a second communication environment (280) to produce at least two combined signals. The at least two combined signal are transmitted into the first communication environment (260).

Abstract: A jig is successively mounted on each of the four wheels of a vehicle. The jig is struck in three orthogonal directions independently, and at the same time, a microphone inside the vehicle measures the sound pressure of noise generated due to the exciting force. An FFT analyzer operates a frequency response function from the exciting force to the sound pressure. In a drum testing machine, a tire to be subject to noise prediction is mounted on a shaft, the tire is rotated, and the axial force in the three orthogonal directions is measured. The axial force signal is input to the FFT analyzer and the auto power spectrum in the three orthogonal directions and the cross power spectrum between two different axial directions are operated. The frequency response functions are synthesized with the auto power and cross power spectrums, and the power spectrum of the road noise is operated.

Abstract: A sound reinforcement system (1) comprises at least one microphone (2), adaptive echo compensation (EC) means (4) coupled to said microphone (2) for generating a microphone signal, and one or more loudspeakers (3) coupled to the EC means (4). In addition it comprises a dynamic echo suppressor (DES 7) coupled between the adaptive EC means (4) and said at least one loudspeaker (3) for suppressing remaining echoes by using a time delay between the amplitudes of a microphones signal frequency component and the same remaining echo frequency component.

Abstract: The invention provides an apparatus and related method for acoustically improving an environment. In an embodiment of the invention, an electronic sound screening system comprises means for receiving acoustic energy and converting it into electrical signals, means for performing an analysis of said electrical signals and for generating data analysis signals, means responsive to the data analysis signals for producing signals representing sound, and output means for converting the sound signals into sound.

Abstract: A method and system for determining locations in a design of an assembly likely to result in buzz, rattle, squeak (“BSR”), and/or other noise conditions. The invention uses a finite element model to represent a design. BSR effects are predicted based upon analysis performed on multiple design models. Users may engage in real-time “what if” analyses to determine the effects of various design and component changes on noise source characteristics. Additional intelligence may be applied to limit the number of model points subject to evaluation. Displacements, contact velocities, and force responses at selectively identified subsets of interesting points can evaluate noise characteristics. An “as designed” model may evaluate noise source characteristics at the beginning of the life of an assembly. Degraded models can determine the effects of aging and use.

Abstract: An active noise cancellation system (26) for controlling engine noise propagation through a vehicle induction system (32) is customizable to achieve a desired engine noise profile. A controller (34) of the active noise cancellation system drives a speaker (36) to generate a noise cancellation sound in a manner consistent with an individual's indicated preference for a specific type of available engine noise profile. By customizing how the speaker is driven, the system customizes the resulting engine noise heard in the passenger compartment. In one example, the system is customizable using a hand held communication device (24) such as a cell phone, a personal digital assistant or a so-called palm top computer. In another example, a resident communication bus on the vehicle is accessed through a user communication interface (28) supported on the vehicle.

Abstract: Body or structural noise transmitted through a connector such as a strut, that connects a noise source, such as an engine, to an enclosure, such as a passenger cabin or cell of a helicopter, is suppressed by at least one piezoactuator which is excited to counteract any vibrations of the strut caused by body noise so that body noise vibrations are cancelled or at least substantially suppressed. The excitation of the piezoactuator is controlled in closed loop fashion in response to feedback signals from a sensor secured to the connector.

Abstract: A method and apparatus for actively influencing the intake noise of an internal combustion engine. The apparatus comprises a controller (7) which senses the actual noise (I) via a microphone (16) and compares the actual noise with a reference noise signal which depends on the engine speed D and at least one further engine parameter P, such as, for example, the throttle (12) position. A comparison signal V generated by comparing the actual noise to the reference noise value is used to adjust a control signal Asum, which also depends on the engine speed D. The control signal is fed to an electromechanical transducer (14) which generates a correcting noise (20) which is superimposed on the intake noise (21) to produce the resultant actual noise (22), which should correspond as closely as possible to the reference noise value.

Abstract: An audio system, in particular for motor vehicles, having a loudspeaker installation for supplying sound to an audio chamber and a control unit with a signal detection unit for receiving microphone signals from at least one microphone exposed to the audio chamber outputting the signal to an evaluation unit which extracts interference signals from the microphone signals. The control unit produces control signals on the basis of these interference signals in order to operate the loudspeaker installation. To reduce the complexity for installation of such an audio system, at least one tweeter is connected in the loudspeaker installation as a microphone.

Abstract: An aircraft has a fuselage that defines an interior cabin and an exterior; a first housing located along one side of the fuselage exterior; a second housing located along the second side of the fuselage exterior; and an active vibration control system for limiting fuselage vibration, the vibration control system comprising a plurality of sensors located in the cabin; a controller in signal receiving relation with the sensor means; first actuator means located in the first housing and second actuator means located in the second housing and wherein the actuator means are in signal receiving relation with the controller.

Abstract: A modular air induction assembly comprises an air induction body, an air filter operatively attached to the air induction body, and a speaker operatively attached to the air induction body. The modular air induction assembly is then installed into the air induction system of a vehicle during production. The air induction body may also comprise a first portion and a second portion that permits service of the assembly following initial vehicle installation.

Abstract: An adaptive controller is used to adaptively generate vibration cancellation signals driving a controlled device which effects an associated vibration and noise-producing plant. The adaptive controller has multiple control paths to generate the control signal. In a vibration attenuation control path(s), an adaptive control signal is generated by plant compensation and adaptive filtering techniques to cancel vibrations. In a position control, saturation prevention path, the available operational extents of the controlled device are monitored and compensation signals are generated which direct the movement of the controlled device in such a manner as to prevent the controlled device from reaching the extents of control. The control signals from the multiple paths are then combined and transmitted to the controlled device which alters in some fashion the noise and vibration being generated or transmitted by the associated vibrating plant.

Abstract: An active noise cancellation system is operative to reduce noise transmission through a vehicle air induction system. The active noise cancellation system includes a controller that utilizes computer modelling to ensure adequate noise cancellation. The controller generates a modelling sound to make determinations regarding the noise cancellation system, such as timing constraints associated with a speaker or microphone of the system. The modelling sound is selected to be consistent with a sound typically heard by an individual, given the current engine operating status. In another example, the selected sound masks another modeling sound such as random noise.

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: Different parameters are supplied to a noise reduction algorithm based on the detection of different vehicle conditions, thereby allowing the noise reduction algorithm to process audio input differently depending on the corresponding vehicle conditions, such as speed, motor rpm, radio on/off status, window open/closed status, occupancy and position of vehicle seat(s), or any combination thereof. One or more vehicle conditions are detected by the vehicle and communicated to a noise reduction control device that determines the appropriate noise reduction algorithm parameters to use based on the detected vehicle conditions, advantageously with reference to a plurality of stored sets of noise reduction algorithm parameters previously established through a calibration process and stored in memory.

Abstract: In accordance with the present invention, an apparatus and method for reducing noise in a vehicle is provided. The apparatus uses an interferometer disposed in a headset to measure the sound proximate the driver's ears. An equal and opposite sound is generated and transmitted to the ear thereby reducing the level of noise audible to the driver. A microphone may be provided to make a separate measurement of the background noise to facilitate the noise reduction. A tracking device may be used to find and track the location of the driver's ears.

Abstract: The air induction system comprises an air induction body and speaker supported about the air induction body. A control unit communicates with the speaker, controlling its output. The control unit also receives a reference signal from an alternator of a vehicle engine and uses this signal to generate a noise attenuating signal based on the reference signal.

Abstract: An active noise attenuation system (10) comprises a speaker (26) in communication with a flow body (78). The speaker (26) emits an output for attenuating noise from the flow body (78). A control unit (31) communicates with the speaker (26) and controls the output. A housing (14) has one volume (18) acting as a liquid storage chamber and another volume (22) acting as a speaker chamber.

Abstract: The air induction system comprises an air induction body and speaker disposed about the air induction body. A control unit communicates with the speaker and has at least two modes of noise attenuation signal generation. An engine speed sensor communicates engine speed data to the control unit. An engine load sensor communicates engine load data to the control unit as well. The control unit then selects one of the at least two modes of noise attenuation based on the engine speed data and the engine load data.