FIR低通滤波器设计，运行通过，通过改变滤波器参数，可以得到不同阶数的滤波器，加有随机噪声的语音信号通过滤波器后会有很大改善。-FIR low-pass filter design, to run through, can be obtained by varying the filter parameters, the number of filters of different orders, and added with the random noise of the speech sig