A noise-reducing fan system, comprising a motor, a fan body, a plurality of magnetic-inducing elements, a magnetic field generator and a noise-reducing sound source device, is provided. Here, the fan body is mounted on the motor. The fan body comprises a plurality of blades, on which the plurality of magnetic-inducing elements are disposed, respectively. The magnetic field generator, which may generate a magnetic field, is employed for driving the plurality of magnetic-inducing elements to vibrate the plurality of blades and generate a vibration sound, so that at least one portion of the noise emitted from the fan body as rotating may be counterbalanced. The noise-reducing sound source device is disposed on a predetermined position and may send out a noise-reducing sound, so that the noise-reducing sound may counterbalance at least the other portion of the noise emitted from the fan body as rotating.

Systems and methods for reducing noise or vibration generated by an internal combustion engine are described. An engine controller is arranged to operate the working chambers of the engine in a cylinder output level modulation manner. A noise/vibration reduction unit actively control of a device that is not a part of the powertrain. The device is controlled in a feed forward manner to alter an NVH characteristic of the vehicle in a desired manner based at least in part on a characteristic of the cylinder output level modulation operation of the engine.

A microphone system may include a measuring device that includes a plurality of sound elements and a semiconductor chip connected to the sound elements and receives a vibration signal and a noise signal from the outside to cancel the vibration signal and changes a phase of the noise signal to output a reverse phase noise signal; and a driver that is connected to the semiconductor chip and is included in a front glass of a vehicle and vibrates in response to the reverse phase noise signal to cancel a noise signal inputted from the outside.

An apparatus (100) for damping vibrations in electrical lines (10) through which modulated currents flow has at least one sound or vibration sensor (102) oriented towards the line (10) or attached to the line, at least one actuator (104) connected to the line, and a control circuit (200) which is supplied, via respective signal lines (108), with signals generated by the at least one sound or vibration sensor (102) that represent sound or vibrations. The control circuit controls the at least one actuator (104) via respective control lines (110) such that this actuator counteracts the vibration of the line (10).

Provided is an active noise cancellation apparatus capable of reliably reducing road noise by reducing vibration of a vehicle component part which generates road noise by using a vibration generator. A plurality of reference signal detectors are placed respectively on right and left knuckles for respectively supporting right and left wheels. A vibration generator and an error signal detector are placed on a vehicle component part. A controller performs respective adaptive controls based on each of reference signals and an error signal so as to reduce the error signal, and controls the vibration generator based on a sum of respective output values of the adaptive controls.

A motor vehicle includes a body comprising a chassis, walls delimiting a passenger compartment, at least one actuator applied to a corresponding wall between said walls and controllable through a control input signal to transmit a vibration corresponding to the control input signal to the corresponding wall, thereby producing a corresponding sound inside the passenger compartment, an error sensor configured to detect a quantity indicative of a residual sound produced by a superposition of said sound with an interior noise inside the passenger compartment and to generate a related error signal, and a control unit coupled to the error sensor to receive the error signal, configured to execute an active noise cancellation algorithm based on the error signal, so as to determine the control input signal adapted to minimize or reduce the residual sound, and further configured to control the actuator with the determined control input signal.