NOISE CONTROLLER

Japanese Patent JP3414426

B2

PURPOSE: To improve the resolution of a small signal level at the time of digitizing a remaining sound canceled by a cancel sound.
CONSTITUTION: This device is a noise controller forming an error signal by catching the remaining sound, converting the error signal to a digital signal, revising the filter coefficient of an adaptive filter by the error signal and a reference signal for forming a cancel signal by controlling the reference signal and correcting the reference signal used for revising the coefficient according to the simulated characteristic of the space transmission characteristic of the cancel sound mainly. Then, this device is provided with an error signal level detector 13 detecting the level of the error signal from a microphone, a first gain control part 14 provided on the input stage of an A/D converter and adjusting a gain so as to enlarge the level of the error signal as the level of the detected error signal becomes small and a second gain control part 15 adjusting the level of the reference signal for preventing the filter coefficient from being affected by the adjustment of the error signal.

Toshitaka Yamato
Kazuya Sako
Masaaki Nagaumi
Kazuhiro Sakiyama
Masahiro Babasaki
Hideki Kitao
Osamu Ishikawa

JP1179093A

June 09, 2003

January 27, 1993

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FUJITSU TEN LIMITED

B60R11/02; F01N1/00; G10K11/16; G10K11/178; H03H17/00; H03H17/02; H03H17/04; H03H21/00; H04B3/04; (IPC1-7): G10K11/178; B60R11/02; F01N1/00; H03H17/02; H03H21/00

JP63148709A
JP1314500A
JP2306845A
JP3172095A
JP4124906A
JP4128895A
JP4318897A
JP4359297A
JP511770A
JP580781A
JP588685A
JP5289679A
JP5313672A
JP6130968A
JP6161464A

Shoichi Ui (4 others)

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