| 摘要 |
PURPOSE:To extract voice command words at high S/N from the noises generated by an acoustic appliance by providing a noise cancellation unit which subtracts the output signals of plural driving units from the electric signal converted by a microphone. CONSTITUTION:The microphone 13 for detecting the voice command words is fixed near a driver's seat and is connected to a voice input device 12. This input device 12 has the noise cancellation unit 21 which subtracts the output signals of the driving units 195 to 198 of speakers 17R, 17L, 18R, 18L from the electric signal converted by the microphone 13. The noises radiated from the speakers 17R, 17L, 18R, 18L are offset by the output signals of the respective driving units 195 to 198 and are thereby erased even if such noises are mingled in the electric signal converted by the microphone 13. Only the command words are extracted at the high S/N from the electric signal converted by the microphone 13 in this way. |
