US 12,075,219 B2
Noise-cancelling headphone
Akihito Tamamura, Fukui (JP); and Hideki Matsui, Fukui (JP)
Assigned to AUDIO-TECHNICA CORPORATION, Tokyo (JP)
Appl. No. 17/995,013
Filed by Audio-Technica Corporation, Tokyo (JP)
PCT Filed Dec. 1, 2020, PCT No. PCT/JP2020/044725
§ 371(c)(1), (2) Date Sep. 29, 2022,
PCT Pub. No. WO2021/199498, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 2020-067948 (JP), filed on Apr. 3, 2020.
Prior Publication US 2023/0164486 A1, May 25, 2023
Int. Cl. H04R 3/04 (2006.01); H04R 5/033 (2006.01)
CPC H04R 3/04 (2013.01) [H04R 5/033 (2013.01); H04R 2460/01 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A noise cancelling headphone comprising:
a headphone unit configured to output a sound wave corresponding to an audio signal;
a baffle plate to which the headphone unit is attached;
an ear pad attached to the baffle plate;
a housing attached to the baffle plate;
a first microphone configured to collect external noise outside the housing,
a first buffer amplifier unit configured to perform impedance conversion to a signal from the first microphone and output the impedance-converted signal;
a second microphone configured to collect internal noise inside a front air chamber formed by the headphone unit, the baffle plate, the ear pad, and a head of a user when the noise cancelling headphone is worn on the user's head;
a second buffer amplifier unit configured to perform impedance conversion to a signal from the second microphone and output the impedance-converted signal; and
a noise cancelling signal generation circuit configured to generate a noise cancelling signal, based on a combined signal by combining a signal from the first buffer amplifier unit with a signal from the second buffer amplifier unit.