1　问题提出通常卡拉OK机的组成如图1所示。图1　卡拉OK机组成音调和激励电路均在混响延迟处理之前,目的是对人声进行修饰后再混响输出。假如延迟时间设定为150ms,则直达声为0ms,回声依次为150ms、300ms、…、n×150ms,设人声为正弦波,即U0=A0sinωt,则回声依次为:U1=A1sin(ωt 1 questions put forward the composition of the karaoke machine is shown in Figure 1. Figure 1 karaoke machine OK tone and excitation circuit are in the reverberation delay treatment before, the purpose is to modify the human voice after the reverb output. If the delay time is set to 150ms, the direct sound is 0ms, the echo is 150ms, 300ms, ..., n × 150ms, and the human voice is sine wave, that is, U0 = A0sinωt, the echo will be U1 = A1sin