An active noise control device controls a speaker so as to output a canceling sound for canceling noise transmitted from a vibration source. The active noise control device includes a control signal generating unit configured to perform signal processing on a basic signal corresponding to a predetermined frequency by a feedback filter and a extraction filter, which is an adaptive notch filter, to generate a control signal that control the speaker, a secondary path filter updating unit configured to update sequentially and adaptively a secondary path filter, and a feedback filter setting unit configured to set the feedback filter based on the secondary path filter.

A vehicle includes an engine and/or powertrain producing noise that is audible in a passenger compartment of the vehicle when the engine and/or powertrain is running. An active noise control arrangement includes a first loudspeaker disposed within a passenger compartment of the vehicle. A digital signal processor receives audio data and transmits an audio signal to the first loudspeaker dependent upon the audio data. A microphone is disposed within the passenger compartment and converts the sound from the first loudspeaker and the noise within the passenger compartment into a microphone signal. The microphone signal is transmitted to the digital signal processor, and the digital signal processor modifies the audio signal such that the audio signal attenuates the noise in the passenger compartment. A vehicle processor transmits a simulated noise signal to a second loudspeaker for use in testing effectiveness of the active noise control arrangement in attenuating noise when the engine and/or powertrain is not running and not producing noise.

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.

Differing from conventionally-used exhaust pipe utilizing discontinuous section area(s) and sound-absorbing material(s) to abate the noise produced by an engine, the present invention provides a waste air exhausting device consisting of: a housing, a supporting plate disposed in the housing, a miniature microphone disposed at the end of the housing, and a loudspeaker disposed on the supporting plate. Therefore, according to the noise produced by the engine, a noise controller system coupling to the miniature microphone and the loudspeaker is able to produce an anti-noise signal through the loudspeaker for abating the engine noise. On the other hand, the noise controller system can also produce an anti-noise signal having specific frequencies components according to the frequency of the engine noise and a reference signal, so as to modulate the frequency of the engine noise by broadcasting the anti-noise signal having the specific frequencies components in the housing through the loudspeaker.

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 method performed by an audio system that includes a headset with a left headset housing and a right headset housing. The method includes driving a speaker of the left headset housing with an audio signal, determining whether audio howl is present within the left headset housing by comparing spectral content from a first error microphone signal produced by a first error microphone of the left headset housing and spectral content from a second error microphone signal produced by a second error microphone of the right headset housing, and, in response to determining that audio howl is present, filtering the audio signal to mitigate the audio howl.

An active noise control device includes a secondary path filter coefficient updating unit. The secondary path filter coefficient updating unit is configured to update a coefficient of a secondary path filter by using a coefficient of the secondary path filter after previous updating as a previous value, when a phase characteristic of the secondary path filter that sets an initial value as the coefficient and a phase characteristic of the secondary path filter that uses the previous value as the coefficient are not approximate to each other.

An active noise control device includes a first adaptive filter configured to generate a control signal by performing a filtering process on a reference signal corresponding to noise, and a first filter coefficient updating unit configured to update a filter coefficient of the first adaptive filter based on based on the reference signal and an added error signal acquired by adding a first error signal acquired by detecting residual noise by a first microphone and a second error signal acquired by detecting residual noise by a second microphone.

A method performed by an audio system comprising a headset. The method sends a playback signal containing user-desired audio content to drive a speaker of the headset that is being worn by a user, receives a microphone signal from a microphone that is arranged to capture sounds within an ambient environment in which the user is located, performs a speech detection algorithm upon the microphone signal to detect speech contained therein, in response to a detection of speech, determines that the user intends to engage in a conversation with a person who is located within the ambient environment, and, in response to determining that the user intends to engage in the conversation, adjusts the playback signal based on the user-desired audio content.

Noise abatement within a signal stream containing unwanted signal referred to as noise is performed by acquiring a digitized noise signal and using a digital processor circuit to subdivide the acquired noise signal into different frequency band segments and thereby generate a plurality of segmented noise signals. Then individually for each segmented noise signal, the processor shifts in time the segmented noise signal by an amount dependent on a selected frequency of the segmented noise signal to produce a plurality of shifted segmented noise signals. The precise time shift applied to each noise segment considers the frequency content of the segment and the system processing time. Individually for each segmented noise signal, amplitude scaling is applied. The shifted and amplitude-scaled segmented noise signals are then combined to form a composite anti-noise signal which is output into the signal stream to abate the noise through destructive interference.