An acoustic conversion device for an active noise control is provided. The acoustic conversion device can effectively suppress or remove noise by controlling variation in a lowest resonance frequency. A volume of a closed space is smaller than an equivalent compliance air volume of a speaker unit. Therefore, motion of a vibration plate, an edge and a damper is suppressed, it is possible to restrain the edge and the damper from being deteriorated with time, variation in lowest resonance frequency can be suppressed, phase of emitted sound can be less prone to be deviated from opposite phase of noise, and it is possible to effectively suppress or remove noise.

An acoustic echo cancellation (AEC) system that detects and compensates for differences in delay times between the AEC system and a set of wireless speakers. The filter coefficients used for AEC are adjusted based on the determined delay time to correct for frequency domain signal rotation.

The present invention provides for a surface acoustic transducer optimally structured to produce sound within an aircraft cabin by vibrating the interior cabin walls. Specifically, the surface acoustic transducer comprises a primary assembly comprising a voice coil assembly having a voice coil former and wire, and a transducer housing for retaining said primary assembly and a magnet therein such in movable relations. The present surface acoustic transducer may further include a spider structured to provide an improved excursion. An external housing may additionally be provided comprising a rigid retaining wall for protecting the surface acoustic transducer from potential externally applied forces and a malleable excursion cover allowing for an excursion of the primary assembly thereof.

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 acoustic conversion device for an active noise control is provided. The acoustic conversion device can effectively suppress or remove noise by controlling variation in a lowest resonance frequency. A volume of a closed space is smaller than an equivalent compliance air volume of a speaker unit. Therefore, motion of a vibration plate, an edge and a damper is suppressed, it is possible to restrain the edge and the damper from being deteriorated with time, variation in lowest resonance frequency can be suppressed, phase of emitted sound can be less prone to be deviated from opposite phase of noise, and it is possible to effectively suppress or remove noise.

The invention relates to a method (30) for damping and/or amplifying a sound introduced into a passenger compartment (10) of a motor vehicle, in particular an electrically driven motor vehicle, said sound being generated (32) by a sound source (22) arranged outside of the passenger compartment (10). A correction signal is generated (40) by means of correction signal means (16) which are paired with the sound source (22) and/or a sound-transmitting structure (20) of the motor vehicle, and the correction signal is determined (38) such that the sound is introduced into the passenger compartment (10) in a damped or amplified state.

The present invention provides for a surface acoustic transducer optimally structured to produce sound within an aircraft cabin by vibrating the interior cabin walls. Specifically, the surface acoustic transducer comprises a primary assembly comprising a voice coil assembly having a voice coil former and wire, and a transducer housing for retaining said primary assembly and a magnet therein such in movable relations. The present surface acoustic transducer may further include a spider structured to provide an improved excursion. An external housing may additionally be provided comprising a rigid retaining wall for protecting the surface acoustic transducer from potential externally applied forces and a malleable excursion cover allowing for an excursion of the primary assembly thereof.

The invention relates to an acoustic device capable of producing active noise reduction, which may be positioned on the head of a user, comprising at least one microphone capable of sensing a sound signal representative of ambient noise, including at least one active noise reduction acoustic module comprising an osteophonic transducer, capable of being positioned on a side flank of the head of the user and of transmitting a vibratory signal transformed by bone conduction into an acoustic signal which may be perceived by the user, connected to said microphone, while said at least one acoustic module includes an electronic circuit capable of generating a vibratory signal giving the possibility of attenuating perception of said ambient noise by the user.

A system for providing an enhanced audible environment within an aircraft cabin includes at least one, but possibly, a plurality of transducers mounted symmetrically about a window of the aircraft cabin on a mounting flange of the window. The transducers are cooperatively disposed and configured to excite at least a viewing pane of said window so as to provide a desired audible environment within an aircraft cabin, without obstructing the view from the window.

The present disclosure is directed to controlling, reducing, and/or altering sound generated by an aerial vehicle, such as an unmanned aerial vehicle (UAV), while the aerial vehicle is airborne. For example, one or more transducers, such as piezoelectric thin-film transducers, or carbon nanotube transducers may be applied or incorporated into or on the surface of propeller blades that are used to aerially navigate the aerial vehicle. As the propeller blade rotates and generates sound, the transducers may be activated to generate one or more anti-sounds that cancel, reduce, or otherwise modify the sound generated by the rotation of the propeller blade. The anti-sound combines with the sound and causes interference such that the combined, or net-effect, is an overall cancellation, reduction, or other modification of the sound.