| 摘要 |
PROBLEM TO BE SOLVED: To provide a microphone device having a microphone which includes a sharp uni-directionality. SOLUTION: The microphone device comprises an optical microphone 10 for converting a sound into an electric signal by reading a vibration of a diaphragm by an optical sensor, a uni-directional microphone 11 having a diaphragm disposed on a substantially equal flat surface as that of the diaphragm of the microphone 10, and a differential circuit (inverting amplifier circuit 201, and a voltage dividing resistor 218) for outputting a differential signal of an output signal from the microphone 10 and an output signal from the microphone 11.
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