US 12,394,403 B2
Active noise control system
Ryosuke Tachi, Fukushima (JP); and Keita Tanno, Fukushima (JP)
Assigned to Alps Alpine Co., LTD., Tokyo (JP)
Filed by Alps Alpine Co., LTD., Tokyo (JP)
Filed on May 11, 2023, as Appl. No. 18/196,008.
Claims priority of application No. 2022-081550 (JP), filed on May 18, 2022.
Prior Publication US 2023/0410783 A1, Dec. 21, 2023
Int. Cl. G10K 11/178 (2006.01)
CPC G10K 11/17825 (2018.01) [G10K 11/17823 (2018.01); G10K 11/17881 (2018.01); G10K 2210/1282 (2013.01); G10K 2210/3026 (2013.01); G10K 2210/3027 (2013.01); G10K 2210/3028 (2013.01); G10K 2210/3044 (2013.01); G10K 2210/3046 (2013.01); G10K 2210/3055 (2013.01); G10K 2210/3056 (2013.01); G10K 2210/3221 (2013.01)] 8 Claims
OG exemplary drawing
 
1. An active noise control system that reduces noise, the active noise control system comprising:
a first microphone that is disposed in a position displaced in a first direction relative to a user;
a second microphone that is disposed in a position displaced in a second direction relative to the user;
a first speaker configured to emit sound toward an area around the position where the first microphone is disposed;
a second speaker configured to emit sound toward an area around the position where the second microphone is disposed;
an error signal generator configured to generate an addition signal by adding an output of the first microphone and an output of the second microphone;
an adaptive filter configured to perform an adaptive operation of minimizing an error using a signal correlated with the noise as a reference signal and the addition signal as the error so as to generate a noise canceling sound to be output from the first and second speakers; and
a gain adjustment section configured to adjust a ratio between a loudness level of a first noise canceling sound which is the noise canceling sound to be output from the first speaker and a loudness level of a second noise canceling sound which is the noise canceling sound to be output from the second speaker;
wherein the gain adjustment section is configured to perform the adjustment so that the ratio of the loudness level of the second noise canceling sound to the loudness level of the first noise canceling sound matches a ratio of a loudness level of noise transmitted from a noise source of the noise to the second microphone to a loudness level of noise transmitted from the noise source of the noise to the first microphone.