| 摘要 |
The invention relates to a device intended to carry out sound captures without the useful signal being cluttered with ambient noise. It consists of two microphones 1, 2 each connected to an input of a differential amplifier 3 which is supplied positively and negatively with respect to the reference point of the microphones, which is generally zero volts. It is possible to insert two impedance matchers 4, 5 between the microphones 1, 2 and the differential amplifier 3 at the points A, A' and B, B'. It is also possible, so as to use only a single positive supply voltage, to add a load pump 6 to the device so as to provide it with the negative voltage which it requires. The device according to the invention is particularly intended to allow sound captures even in a very noisy environment such as for example communications between airport runway staff. <IMAGE>
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