Patent ID: 7020288

Claim:
An active noise control (ANC) system comprising: a source unit for generating regenerative signals; an ANC unit for processing signals so as to actively cancel noise; sensors for detecting information on the inside and outside of a vehicle; a vehicle interior voice discriminating unit for discriminating voice of conversation in the interior of the vehicle; an amplifier for amplifying the signals processed by said ANC unit; a reproducing transducer for reproducing the signals amplified by said amplifier; a first filter for allowing the output signals outside of a voice band supplied from said sensors to go through; a first adaptive filter for eliminating noises outside of the voice band from the output of said first filter; a second filter for allowing the output signals within the voice band supplied from said sensors to go through; a switching unit for switching operations so as to select one of allowing passage of all the output from said second filter without filtration when voice is present in said vehicle interior and allowing the output from said second filter to pass through a second adaptive filter for eliminating noises within the voice band when no voice is present in said vehicle interior; and a mixer for mixing the output from said first adaptive filter and the output from said switching unit, wherein said ANC unit is structured so as to change processing effect thereof on noise in the voice band according to control signals supplied from said vehicle interior voice discriminating unit.