| 摘要 |
PURPOSE:To eliminate deterioration and to attain the system with high sound quality by providing a microphone receiving a sound wave and transducing directly into a digital audio signal thereby building up the audio system processing a digital input signal and eliminating the need for A/D conversion required for a conventional system. CONSTITUTION:A diaphragm 1 receiving directly a sound wave is used and the diaphragm 1 is used for capacitor electrodes, which are used to form an oscillator 4 employing the capacitor and an FM wave from the oscillator is gated by a period of a sampling frequency and the gated FM wave count and a difference between the count and an FM frequency at no sound being a reference value 8s calculated to obtain digital audio data with a specified quantization bit number. Or the FM wave is mixed with a wave of a predetermined frequency and the difference frequency signal is gated at a period of the sampling frequency to obtain digital audio data. |
