AUTOMATIC SOUND VOLUME CONTROL DEVICE

Japanese Patent JP3306600

B2

PURPOSE: To obtain an automatic sound volume control device in which the effect of a speaker sound is excluded from a microphone detection signal and the output sound volume of the speader is controled in response to the level of only surrounding noise.
CONSTITUTION: Outputs of control amplifiers 102, 103 are inputted respectively to adaptive filters 113, 114 via A/D converters 110, 111. Each output is subtracted from the surrounding noise signal obtained from a microphone 119, an amplifier 106 and an A/D converter 112 and the level of the resulting output is converted and formed to be an amplification quantity control signal by an amplifier quantity adjustment device 119 and given to the control amplifiers 102, 103 to control the sound volume automatically. The output of a substractor 110 is given to a coefficient revision input of the adaptive filters 113, 114. Furthermore, after the level of the output of the A/D converters 110, 111 is converted, and the result is compared with a reference value and when the output level is less than the reference level, the coefficient of the adaptive filters 113, 114 is not revised.

WO/2002/015395	VOICE ENHANCEMENT SYSTEM
JP2022108131	REMOTE CONTROLLER, AUDIO OUTPUT DEVICE, AND CONTROL METHOD THEREOF

Tadatoshi Ohkubo
Kenichi Taura

JP14756193A

July 24, 2002

June 18, 1993

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Mitsubishi Electric Corporation

H03G3/32; H03H17/00; H03H17/02; H03H17/06; H03H21/00; H04B3/04; H04N5/60; H04R3/00; H04S1/00; H04S7/00; (IPC1-7): H03G3/32; H03H21/00; H04R3/00; H04S7/00

JP1248799A
JP2244099A
JP447705A
JP3271039A
JP5259779A
JP1240099A
JP1500952A

Norio Kawano

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