| 摘要 |
PROBLEM TO BE SOLVED: To eliminate noise in a specific local space, in an environment where ambient noise exists. SOLUTION: A sound including an ambient noise detected by a microphone 11 for reference input is converted by a first input interface 12 into a digital signal and a first noise detection section 13 extracts a noise signal. A noise-eliminating signal generation section 4 inverts the phase of the noise signal to generate a noise-eliminating signal. This signal for noise elimination is D/A-converted by an output interface 5 and then output from a speaker 16, as a noise eliminating sound. The ambient noise and noise eliminating sound cancel each other and then the noise is eliminated. Furthermore, residual noise, after the noise elimination is detected by a microphone 17 for error input and converted by a second input interface 8 into a digital signal, and a second noise detection section 19 extracts a residual noise signal. A noise-eliminating signal generation section 14 performs adaptive control to eliminate the ambient noise more suitably with the noise signal and residual noise signal. COPYRIGHT: (C)2007,JPO&INPIT
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