Can you tell me how this is done? I need it badly. at present

What you don't understand is that you are the simulation of that part, and then you can set up a gui to display the sampling diagram.

Select a voice signal as the analysis object, or record a voice signal;

2)

Sampling a voice signal, and drawing a time domain waveform and a frequency spectrum diagram of the sampled voice signal;

3)

The random function in MATLAB is used to generate noise and add it to the speech signal, so that the speech signal is polluted, and then the spectrum analysis is carried out.

4)

FIR and IIR digital filters are designed to filter the speech signal polluted by noise, draw the time domain waveform and spectrum of the signal before and after filtering, compare the signals before and after filtering, and analyze the changes of the signal;

5)

Playback voice signal