发明名称 |
NOISE CANCELLATION AND NOISE REDUCTION APPARATUS |
摘要 |
Disclosed is a transducer for use in a noise cancellation apparatus for reducing background noise. The transducer includes a housing having first microphone means for receiving a first acoustic sound composed of speech originating from an operator operating the apparatus and background noise, and for converting the first acoustic sound to a first signal, and second microphone means arranged at a predetermined angle phi in close proximity with respect to the first microphone means for receiving a second acoustic sound composed of substantially the background noise and for converting the second acoustic sound to a second signal. The first and second microphones are connected to a differential amplifier means of the noise cancellation apparatus so as to obtain a signal representing substantially speech. The amplifier means is for receiving acoustic sounds from each microphone and has a first terminal and a second terminal, wherein the second terminal is grounded. The transducer further includes a transistor means for receiving and amplifying an AC signal representative of the audio input from each microphone; and means for filtering the amplified AC signal from the DC signal, so that the DC signal powers the amplifier means. Also disclosed is a method for calibrating an active noise reduction apparatus including a housing having a speaker to produce an acoustic anti-noise signal in the housing, a microphone to detect an external noise signal, and an amplitude adjustment means to calibrate the acoustic anti-noise signal to create a quiet zone in the housing for operation with an independent electrical assembly, wherein the apparatus is calibrated separately from the electrical assembly. The method includes the steps of: inputting the external noise signal received by the microphone to produce an anti-noise signal; transmitting to the speaker the anti-noise signal having an equal gain and opposite phase response to the external noise signal detected by the microphone; and balancing the gain and phase response of the anti-noise signal by the amplitude adjustment means located in the noise reduction apparatus to match the gain and phase response of the external noise signal to yield a theoretical zero in the quiet zone. |
申请公布号 |
WO9725790(A3) |
申请公布日期 |
1998.01.15 |
申请号 |
WO1996IB01506 |
申请日期 |
1996.06.04 |
申请人 |
ANDREA ELECTRONICS CORPORATION |
发明人 |
ANDREA, DOUGLAS;TOPF, MARTIN |
分类号 |
G10L15/20;G10K11/16;G10K11/178;G10L21/02;H04B1/12;H04M1/03;H04M1/05;H04M1/19;H04M1/60;H04M1/74;H04R1/04;H04R1/10;H04R3/00;H04R3/02;H04R29/00 |
主分类号 |
G10L15/20 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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