| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an active noise control system which easily updates acoustic characteristics. <P>SOLUTION: A cancel sound signal Sd is generated by an adaptive filter part 41 with a cosine-wave signal S1 and a sine-wave signal S2 of frequency of vibration noise, and a cancel sound is emitted. A filter coefficient update part 42 is included which updates filter coefficients A and B of the adaptive filter part 41 so as to eliminate an error signal Se, based upon a microphone input signal Sm of an error microphone 12 having detected an interference result between the cancel sound and vibration noise, by performing adaptive processing with the error signal Se and first and second reference signals S5 and S6 based upon acoustic characteristics. The cosine-wave signal S1 of measurement frequency ω is emitted as a reference sound, a cancel sound signal Sd based upon the measurement frequency ω is generated, and added to the microphone input signal Sm of the microphone having detected the reference sound to generate the error signal Se, and the adaptive processing is carried out by inputting the cosine-wave signal S1 and the sine-wave signal S2 of the measurement frequency ω to the filter coefficient update part 42 as the reference signals so as to find acoustic characteristics to the measurement frequency ω based upon the updated filter coefficients. <P>COPYRIGHT: (C)2012,JPO&INPIT |
