US 11,678,105 B2
Noise canceling headphones
Vu Hoang Co Thuy, Paris (FR)
Assigned to DEVIALET, Paris (FR)
Filed by DEVIALET, Paris (FR)
Filed on Sep. 30, 2021, as Appl. No. 17/490,636.
Claims priority of application No. 20 10064 (FR), filed on Oct. 1, 2020.
Prior Publication US 2022/0124431 A1, Apr. 21, 2022
Int. Cl. A61F 11/06 (2006.01); H04R 1/10 (2006.01); G10K 11/178 (2006.01); G10K 11/16 (2006.01)
CPC H04R 1/1083 (2013.01) [G10K 11/17813 (2018.01); G10K 2210/1081 (2013.01); H04R 2460/01 (2013.01)] 5 Claims
OG exemplary drawing
 
1. Noise canceling headphones comprising:
an electro-acoustic transducer placed in a sound reproduction cavity;
at least one noise-canceling processing chain comprising:
a microphone to capture ambient sound;
a noise-canceling filter to process a signal from the microphone to produce a noise-canceling signal;
means for applying the noise-canceling signal to drive the electro-acoustic transducer;
wherein, for the or each noise-canceling processing chain, the noise-canceling filter comprises in series:
a stabilisation filter whose transfer function is substantially equal to the inverse (HFBcorr, HFFcorr) of a transfer function of a processed secondary path (Plant FB, Plant FF), and
a noise cancellation filter whose transfer function is a noise cancellation transfer function (HFB2, HFF2),
the secondary path being formed between the electro-acoustic transducer and a user's eardrum, and
the transfer function of the processed secondary path being the transfer function of the secondary path combined with a transfer functions of various components providing processing up to the transducer in the noise-cancellation processing chain, except for the noise-canceling filter,
wherein the noise-canceling headphones further comprise an external noise-cancellation processing chain with an external microphone placed in the sound reproduction cavity; and
wherein in the external noise-cancellation processing chain, a noise cancellation transfer function (HFF2) is substantially equal to the opposite of the quotient of a transfer function corresponding to a passive attenuation of the cavity and a transfer function between an outer envelope of the cavity and the external microphone.