An attenuation device for attenuating sound waves, and a corresponding system and method, generated by a source emitting sound waves having frequencies between f1 and f2 and wherein the pressure levels are between n1 and n2. The attenuation device comprising at least one acoustic absorber comprising at least one non-linear membrane; the attenuation device being configured in such a way that the first face of the absorber is in acoustic communication with the source. The attenuation device also comprises at least one coupling element for coupling the second face with the source, the coupling element being configured to transmit to the second face sound waves according to the sound waves emitted by the source, and of which the phase and/or the amplitude leads to a pressure differential of the sound waves arriving respectively on the first and second face at the same time.

A noise reduction device includes a plurality of noise microphones, noise controller, and control speakers. Noise controller generates a control-sound signal to reduce a noise, at a control center of a control space, with the noise being detected by the plurality of noise microphones. Noise microphone disposed at a shorter distance from the control center than distance “d” indicated by Relational Expression (1) is smaller in number than noise microphones disposed at longer distances than distance “d” where “λ” is a wavelength corresponding to control upper-limit frequency “f” in noise microphones, “d0” is a distance from the control center to control speakers, “t” is a control delay time in control speakers, and “v” is a sound speed.
d=d0+t×v−λ/2  (1)

A system and method for converting a passive protector earmuff to a communication and/or active noise reduction (ANR) headset include mounting active components to a frame subassembly configured for insertion into the passive earcup to divide the earcup volume into a front cavity without additional passive leak paths and a back cavity having a volume that improves speaker/driver power efficiency with a resistive vent to atmosphere. An earcup having an external shell includes a frame configured for positioning within the external shell and having a first support adapted to contact an interior of the shell and a second circumferential support cooperating with a seal to contact an ear seal plate of the earcup to form the front and back cavities. The frame may support a speaker between the front and back cavity, and secure circuitry within the back cavity.

A method of and a system for generating an acoustic wave representing reverberations from a desired acoustic environment are described including having a recording surface (11) defined by a spatial distribution of recording transducers (o) and an emitting surface defined by a spatial distribution of emitting transducers (x), wherein the emitting surface (12) defines a volume within which the recording surface (11) is located, recording an acoustic wave (14) originating from within a volume defined by the recording surface (11) using the recording transducers (x), extrapolating the recorded wave (14) to the emitting surface using wavefield propagator system (IS) representing the desired acoustic environment, and emitting the extrapolated wave from the emitting transducers (o).

A quiet headspace for the passenger in a vehicle (car/train/bus/aircraft etc.) which comprises a canopy to provide some passive attenuation of the noise coming from the surroundings and within the canopy a noise reduction system comprising, in combination one or more loudspeakers and one or more microphones located close to the passenger's head, and one or more microphones located around the periphery of the canopy.

A kit for attenuation of noise includes a noise source audio transducer, two ear pieces, and a control unit. The two ear pieces have respective resilient bodies that engage outer portions of ear canals of respective ears of a user while respective in-ear transducers of the two ear pieces are respectively positioned in inner portions of the ear canals. The respective in-ear transducers detect discrepancies (e.g., incomplete superpositioning) between the noise and the anti-noise. The respective in-ear transducers optionally detect respective secondary path effects in the ear canals. The noise source audio transducer detects noise generated by a noise source (e.g., snoring noise). The control unit configures an adaptive filter based at least in part on an error signal, and optionally based in part on secondary path effects. The control unit generates signals representative of anti-noise. The two ear pieces produce the anti-noise responsive to the signals. The two ear pieces produce masking noise with sound level that varies in direct correlation with sound level of the noise generated by the noise source.

A headset cup having a front cavity and a rear cavity separated by a driver, with a mass port tube connected to the rear port to present a reactive acoustic impedance to the rear cavity, in parallel with a resistive port, the total acoustic response of the rear cavity remaining linear at high power levels. In some embodiments, the mass port tube is made of metal, while the headset cup is otherwise made of plastic.

Low-loss wireless stereo Bluetooth earphones, which relate to a technical field of communication, include: a left Bluetooth earphone and a right Bluetooth earphone; both the left Bluetooth earphone and the right Bluetooth earphone comprise an earphone shell; a master control PCB with a chip, and a speaker unit are mounted inside the earphone shell, a Bluetooth RF transceiver module, a power module and an antenna module are installed on the master control PCB, and the antenna module is connected to the master control PCB through an RF coaxial wire; a speaker is mounted at a front portion of the earphone shell; a hanger is provided at a middle portion of the earphone shell; and an antenna is mounted at a rear portion of the earphone shell; during wearing, the antenna extends backwards and is behind an auricle. During wearing, the antenna extends outwards to the back of the ear, which is not limited by the structure of the ear. A distance between the antennas of the left Bluetooth earphone and the right Bluetooth earphone is decreased, as well as a barrier caused by the head. According to measurement results, the RF path loss is 60 dB, which is improved by about 20 dB, thereby providing stable audio transmission to the Bluetooth earphones.

The present technology relates to signal processing device and method, and a program for enabling spatial noise cancelling with a saved space and a small computation amount. The signal processing device includes a control section that, on the basis of a first microphone signal obtained by sound collection at a first microphone array, a speaker drive signal of an output sound for cancelling a sound which is propagated from an outside of a predetermined region to the predetermined region and is collected by the first microphone array, and that outputs the output sound from a speaker array on the basis of the speaker drive signal. The first microphone array includes a plurality of microphones. The speaker array includes at least one high-order speaker. The present technology is applicable to a signal processing device.

A system and method for converting a passive protector earmuff to a communication and/or active noise reduction (ANR) headset include mounting active components to a frame subassembly configured for insertion into the passive earcup to divide the earcup volume into a front cavity without additional passive leak paths and a back cavity having a volume that improves speaker/driver power efficiency with a resistive vent to atmosphere. An earcup having an external shell includes a frame configured for positioning within the external shell and having a first support adapted to contact an interior of the shell and a second circumferential support cooperating with a seal to contact an ear seal plate of the earcup to form the front and back cavities. The frame may support a speaker between the front and back cavity, and secure circuitry within the back cavity.