用声卡进行数据采集，产生一正弦波，计算机通过扬声器把此正弦波用声音的形式发出；用话筒，把声音采集，然后比较这两种信号，得到最终结果，验证一下(Sound card is used to collect data and generate a sine wave. The computer sends out the sine wave in the form of sound through the loudspeaker, and the microphone is used to colle