Patent ID: 11942068
Assignee: AIROHA TECHNOLOGY CORP.
Field: Other consumer goods (Other fields)
Classification: CPC G | IPC G

Claim 10:
11. An adaptive active noise control (ANC) method comprising:
generating, by an ANC circuit, an anti-noise signal for noise reduction, wherein the ANC circuit comprises at least one adaptive filter;
receiving a first input signal derived from a reference signal that is generated by picking up ambient noise;
receiving a second input signal derived from an error signal that is generated by picking up remnant noise resulting from the noise reduction; and
performing a transfer function variation detection based on the first input signal and the second input signal to control the at least one adaptive filter, wherein the transfer function variation detection is arranged to detect transfer function variation of a path between the first input signal and the second input signal, and performing the transfer function variation detection based on the first input signal and the second input signal to control the at least one adaptive filter comprises:
estimating a previous transfer function of the path between the first input signal and the second input signal and a current transfer function of the path between the first input signal and the second input signal;
determining a path change degree value according to difference between the previous transfer function and the current transfer function;
comparing the path change degree value with a pre-defined threshold to generate a comparison result;
setting a flag signal according the comparison result; and
outputting the flag signal to the at least one adaptive filter;
wherein the at least one adaptive filter is controlled by the flag signal.