摘要 |
PURPOSE:To always eliminate or reduce unwanted voices even though the input direction of the unwanted voices changes and regardless of the magnitude of the unwanted voice input level. CONSTITUTION:A reference input microphone 21 is placed at a prescribed distance from a main input microphone 11. The signals, which are approximate of the reduction objective components of the output voice signals of the microphone 11, are formed from the voice signals of the microphone 21 by an adaptive filter means 25. A delaying means is provided between the microphone 21 and the means 25. The output signals of the means 25 are subtracted from the output voice signals of the microphone 11 by a synthesis means 14. The means 25 is adjusted so that the output power of the means 14 becomes a minimum. |