The present disclosure relates to systems and methods for enhancing active noise cancellation (ANC) in vehicles, particularly for addressing the challenges associated with broadband noise control. The disclosure introduces a novel approach to subband adaptive filtering (SAF) that significantly reduces computational load and improves noise cancellation across a wide frequency spectrum. The noise cancellation system comprises a reference sensor, adaptive weight filter, speakers, error microphones, signal processing unit, subband processing module, gradient determination module, adaptive step size determination module, subband adaptive weight update module, and weight transformation module. The disclosed approaches enable implementation of ANC in environments with limited processing power without sacrificing performance, by reducing complexity and improving convergence speed and stability of the adaptive filter weights.

A harmonic cancellation system including a feedback sensor, a controller, and a speaker is provided. The feedback sensor is disposed within a cancellation zone within a cabin of a vehicle. The feedback sensor produces a feedback signal corresponding to audio within the cancellation zone. The controller is configured to produce a harmonic cancellation signal that, when transduced into an acoustic signal, reduces audible harmonics from a harmonic noise source at a harmonic frequency within the cancellation zone. The harmonic cancellation signal is adjusted according to a comparison of the feedback signal at the harmonic frequency to at least one of a saturation threshold or the feedback signal at one or more sideband frequencies offset from the harmonic frequency. The speaker is disposed within the cabin, receives the harmonic cancellation signal, and transduces the harmonic cancellation signal into an acoustic harmonic cancellation signal within the cancellation zone.

Methods and systems are disclosed for a vehicle audio system. In one example, a method for noise cancellation in a vehicle having a physical microphone configured to acquire a physical microphone signal, and a plurality of virtual microphones acquiring a residual signal is provided, including processing the physical microphone signal with an adaptive weight filter to estimate a virtual secondary path from the physical microphone to the plurality of virtual microphones, decomposing the residual signal and the physical microphone signal into a plurality of subband signals, determining a subband gradient for each subband, determining a subband virtual path convergence speed based on a normalized step size for each subband, determining a subband virtual path for each subband based on the normalized step size and the subband gradient, and applying a weight transformation process to each subband virtual path to update the adaptive weight filter and verify the subband virtual path.

For reducing noise when playing back an audio signal with headphones or a hearing aid, at least one sensor is provided for detecting a sensor signal based on ambient sound and/or structure-borne sound. The sensor signal or the sensor signals are first fed to a preprocessing unit for preprocessing, which carries out filtering and/or summation for active noise suppression, active suppression of the occlusion effect and/or an ambient mode. With a subsequent filter bank, the sensor signal or the output signal of the preprocessing unit is divided into frequency bands by means of several filters. One or more calculation units are provided for calculating weighting factors for the individual frequency bands, which calculate the weighting factors based on a measure of the sensor signal in the respective frequency band and a measure of the noise signal of the sensor or the output signal of the preprocessing unit in silence in this frequency band. The individual frequency bands are multiplied by the corresponding calculated weighting factors using multipliers. The weighted output signals of the filter bank are summed to form an overall output signal using an adder. A compensation signal based on the overall output signal is output using an output unit.