用dm642做声卡的初级学习程序，可以实现对外的声音输出，频率为1hz！-voice well

对着麦克风发点声音看看程序画面显示,本程序演示了声音的快速FFT变换(需要声卡和麦克风),对分析显示其各频率分量的程序.-Whistle a melody and watch this program graph the pitch in real time. The Frequency Analyzer technically speaking performs a Fast Fourier Transform of the sound (you need a sound card and a