Active noise control system

An active noise control (ANC) method that includes the following:

• providing a reference signal, which represents noise at a noise source position;
• measuring a plurality of error signals at a respective plurality of listening locations at which the noise is to be reduced;
• calculating a cost function, which represents a weighted sum of squared error signals;
• supplying a plurality of loudspeaker signals to a respective plurality of loudspeakers that radiate corresponding acoustic signals that superpose with the noise at listening positions;
• and
• filtering the reference signal using an adaptive filter bank to provide the plurality of loudspeaker signals as filtered signals,
• wherein filter characteristics used for the filtering are adapted such that the cost function is minimized, and
• wherein calculating the cost function includes:
• weighting each squared error signal with a weighting factor that depends on a difference or a ratio between a power level of the error signal and a predefined reference level, and wherein the weighting factor is determined by applying a conversion function.

A computer program product which, when executed on a signal processor, performs an active noise control (ANC) method that includes the following:

• providing a reference signal, which represents noise at a noise source position;
• measuring a plurality of error signals at a respective plurality of listening locations at which the noise is to be reduced;
• calculating a cost function, which represents a weighted sum of squared error signals;
• supplying a plurality of loudspeaker signals to a respective plurality of loudspeakers that radiate corresponding acoustic signals that superpose with the noise at listening positions;
• and
• filtering the reference signal using an adaptive filter bank to provide the loudspeaker signals as filtered signals,
• wherein filter characteristics used for filtering are adapted such that the cost function is minimized,
• wherein calculating the cost function includes weighting each squared error signal with a weighting factor that depends on a difference or a ratio between a power level of the error signal and a predefined reference level, and wherein the weighting factor is determined by applying a conversion function.

An active noise control (ANC) system that includes:

• a plurality of microphones, each microphone being configured to provide an error signal which represents a residual noise signal;
• a plurality of loudspeakers, each loudspeaker being configured to receive a loudspeaker signal and radiate a respective acoustic signal;
• and
• an adaptive filter bank supplied with a reference signal and configured to filter the reference signal and to provide, as filtered signals, the loudspeaker signals, wherein filter characteristics of the adaptive filter bank are adapted to minimize a cost function that represents a weighted sum of squared error signals that is weighted with a weighting factor,
• wherein the weighting factor depends on a difference or a ratio between a power level of the error signal and a predefined reference level, and wherein the weighting factor is determined by applying a conversion function.