A cooperative control unit is configured to cause a muffled sound control signal processing unit to start feedforward signal processing, and set, when a secondary path filter has converged, a narrow band noise control signal processing unit to the converged secondary path filter and cause the narrow band noise control signal processing unit to start feedback signal processing.

A loudspeaker unit for producing sound at bass frequencies an array of two or more diaphragms. The first radiating surface and the second radiating surface are located on opposite faces of the diaphragm, and one or more of the diaphragms are included in a first subset of the diaphragms and one or more of the diaphragms are included in a second subset of the diaphragms; a plurality of drive units.

A first cancellation signal output from a first speaker cancels noise at a first cancellation point, which is a typical position of the right ear of a user, together with a second cancellation signal output from a second speaker. In addition, the second cancellation signal output from the second speaker cancels noise at a second cancellation point, which is a typical position of the left ear of the user, together with the first cancellation signal output from the first speaker. The first speaker and the second speaker are arranged side by side on a second line segment, which passes through the midpoint of a first line segment connecting the first cancellation point and the second cancellation point to each other and is perpendicular to the first line segment, and a range where the relationship between noise and the first cancellation signal and the second cancellation signal is the same as that at the cancellation point is extended.

A vehicle noise cancellation system and method, operable for: receiving local contextual information affecting a soundwave present in a vehicle; receiving remote contextual information affecting the soundwave present in the vehicle; receiving vehicle occupant information; processing the local contextual information, the remote contextual information, and the vehicle occupant information to generate an augmented anti-soundwave; and delivering the augmented anti-soundwave to an occupant of the vehicle to mitigate the soundwave present in the vehicle. Delivering the augmented anti-soundwave to the occupant of the vehicle to mitigate the soundwave present in the vehicle may include delivering the first augmented anti-soundwave to an occupant present in the first zone of the vehicle and delivering the second augmented anti-soundwave to an occupant present in the second zone of the vehicle using a plurality of speakers.

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.

A transfer function measuring method includes: outputting a first signal to each of a plurality of loudspeakers to cause the plurality of loudspeakers to simultaneously output sounds with mutually different frequencies; acquiring second signals output from a microphone as a result of acquiring the sounds with the mutually different frequencies; and calculating a transfer function of each of the sounds with the mutually different frequencies based on the first signal and the second signals.

Adjustment of active noise cancellation (ANC) systems can include determining a noise within a vehicle; detecting a movement of a head of a listener; adjusting one or more parameters of the ANC system based at least on the noise and the movement of the head of the listener; determining an anti-noise based at least on the adjusted one or more parameters; and outputting the anti-noise.

In accordance with an embodiment, a method for canceling noise in a vehicle includes receiving noise information from an earphone worn by a user inside the vehicle; generating a compensating signal based on the noise information; and outputting the compensating signal through the earphone and an internal speaker of the vehicle.

A method for reducing noise within a vehicle cabin comprising at least one error sensor and at least one sound transducer, the method comprising: the at least one error sensor measuring at least one first noise at a first location; selecting at least one sound zone from a plurality of sound zones within the cabin for reducing noise in said at least one sound zone, based on a presence of a driver and passenger(s) within the cabin; estimating at least one second noise that would have been measured at a second location within the selected at least one sound zone, based on a primary transfer function describing a primary acoustic path from the first location to the second location; the at least one sound transducer generating at least one secondary noise for reducing the at least one second noise that would have been measured at the second location.

A sound control device controls an interior sound in a vehicle based on a slope of a road on which the vehicle travels. The sound control device includes: a sound canceling circuit for generating a first correcting sound for lowering a level of an interior sound measured in the vehicle; a sound boosting circuit for generating a second correcting sound for increasing the level of the interior sound; and a controller for setting a level of a second target sound to be less than a level of a first target sound. In particular, the second target corresponds to a ramp in which an absolute value of the slope is greater than a reference value and the first target sound corresponds to a flatland in which the absolute value of the slope is equal to or less than the reference value.