Audio Signal Processing in MATLAB

Example 1

%audio signal processing using lowpass Filter
clear all; close all;
 fs=44100;
 y=audioread('dsp.mp3');  %VideoReader(filename) or                           
 p=audioplayer(y,fs);      %VideoReader(filename,Name,Value) for video Signal 
 play(p);                              % You can choose any MP3 file which need to save in the folder where                                                  %main program is store
 stop(p);

 k=awgn(y,10);
 sound(k,fs);
 clear sound;

filtering=fdesign.lowpass('Fp,Fst,Ap,Ast',2000,2500,0.5,50,fs);
  d=design(filtering);
  s=filter(d,k);
  sound(s,fs);
  clear sound;

  subplot(411);
  plot(y);
  subplot(412);
  plot(k);
  subplot(413);
  plot(s);

%  %creating echo in a audio signal
 sterio=y;
  N=fs/2;
  for n=N+1:length(y);
      sterio(n,1)=y(n,1)+y(n-N,2); %procrastinating signal from right to left
      sterio(n,2)=y(n,2)+y(n-N,1); %procrastinating signal from left to right
  end
 sound(sterio,fs);
 clear sound;
  subplot(414);
  plot(sterio);
%
 y_left=y(:,1);
 y_right=y(:,2);
 left_minus_right=y_left-y_right;
 sound(left_minus_right,fs);
 clear sound;
% plot(sterio);
%
 %reducing or removing echo (some portion of the signal)