US 11,756,523 B2
Active noise control system
Ryosuke Tachi, Fukushima (JP)
Assigned to Alps Alpine Co., LTD, Tokyo (JP)
Filed by Alps Alpine Co., LTD, Tokyo (JP)
Filed on Mar. 8, 2022, as Appl. No. 17/689,327.
Claims priority of application No. 2021-038390 (JP), filed on Mar. 10, 2021.
Prior Publication US 2022/0293080 A1, Sep. 15, 2022
Int. Cl. H04B 1/00 (2006.01); G10K 11/178 (2006.01); G10L 21/0208 (2013.01); G10L 25/84 (2013.01); H04R 1/40 (2006.01); H04R 3/00 (2006.01); G10K 11/16 (2006.01)
CPC G10K 11/17817 (2018.01) [G10K 11/17854 (2018.01); G10K 11/17857 (2018.01); G10L 21/0208 (2013.01); G10L 25/84 (2013.01); H04R 1/406 (2013.01); H04R 3/005 (2013.01); G10L 2021/02082 (2013.01); H04R 2499/13 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An active noise control system for reducing noise, the active noise control system comprising:
a first area microphone that is a microphone disposed in a first area;
a second area speaker that is a speaker disposed in a second area;
a second area microphone that is a microphone disposed in the second area;
an echo cancellation adaptive filter configured to receive an output of the first area microphone as an input;
an echo cancellation adder configured to add an output of the second area microphone and an output of the echo cancellation adaptive filter;
a secondary path reproduction filter configured to receive a noise signal representing noise and to share a filter coefficient with the echo cancellation adaptive filter;
a noise cancellation adaptive filter configured to receive the noise signal as an input; and
a noise cancellation adder configured to add the output of the first area microphone and an output of the noise cancellation adaptive filter and to output a resulting sum to the second area speaker;
wherein the echo cancellation adaptive filter is configured to update a filter coefficient such that an output of the echo cancellation adder is regarded as an error and the error is minimized; and
wherein the noise cancellation adaptive filter is configured to update the filter coefficient by a Filtered-X LMS algorithm in which the output of the second area microphone is regarded as an error and an output of the secondary path reproduction filter is regarded as a reference signal.