Removing random noise from audio signal

Hi, guys below are my code .. I am a newbie in Matlab and in my code audio file I add random noise in my audio file and after adding it I want to design a filter which removes that noise. Any hint or comment will be helpful to me. I also attached the audio file. Thanks

clear
close all
clc
[x,fs] = audioread('D.wav');
whos x;            % Name           Size              Bytes  Class     sampling frequency
                    % x           556542x2            8904672  double      44100      
% pOrig = audioplayer(x,fs);
% pOrig.play;

N = size(x,1); % Determine total number of samples in audio file
figure;
subplot(2,1,1);
stem(1:N, x(:,1));
title('Left Channel'); 
subplot(2,1,2);
stem(1:N, x(:,2));
title('Right Channel');

   pause
   %Adding Noise in audio signal
   y=x;
   y = y + randn(size(y));
  % pOrig = audioplayer(y,fs);
  % pOrig.play;

figure;
subplot(2,1,1);
stem(1:N, y(:,1));
title('Left Channel with Noise');  
 subplot(2,1,2);
 stem(1:N, y(:,2));
 title('Right Channel with Noise');

   %nyquist frequncy = fs/2;44100/2=22050

   %plot the spectrum

   df = fs/N;
   w = (-(N/2):(N/2)-1)*df;
   y1= fft(y(:,1),N)/N;
   y2 = fftshift(y1);
   figure;
   plot(w,abs(y2));

   pause  
    n = 7;
  beginFreq = 50 / (fs/2);
  endFreq =   150  / (fs/2);
  [b,a] = butter(n, [beginFreq, endFreq], 'stop');

fout = filter(b,a,y2);
% A = audioplayer(fout,fs);
% pOrig.play;

figure;
plot(b,a);

[Image Analyst]

I fixed your code for you. Read this link for next time.

I couldn't attach the file for you though. You forgot to attach the audio file.

[Ali Khan]

Sorry, I added it but it did not let me add it because it is in rar format and now I add zip file. Thanks

[Justin Koester]

Has the fixed code been uploaded? I am trying to do something similar and would appreciate being able to see the fixed code.

Thank you,

[Jan]

@Justin: The question contains the fixed code already.

[Ameer Hamza]

I am looking for zip file, and it does seem to be present here. Kindly someone mention here

[Jan]

For which zip file are you looking?

Answer 1

[harsini j]

clear
close all
clc
[x,fs] = audioread('D.wav');
whos x;            % Name           Size              Bytes  Class     sampling frequency
                    % x           556542x2            8904672  double      44100      
% pOrig = audioplayer(x,fs);
% pOrig.play;
N = size(x,1); % Determine total number of samples in audio file
figure;
subplot(2,1,1);
stem(1:N, x(:,1));
title('Left Channel'); 
subplot(2,1,2);
stem(1:N, x(:,2));
title('Right Channel');
   pause
   %Adding Noise in audio signal
   y=x;
   y = y + randn(size(y));
  % pOrig = audioplayer(y,fs);
  % pOrig.play;
figure;
subplot(2,1,1);
stem(1:N, y(:,1));
title('Left Channel with Noise');  
 subplot(2,1,2);
 stem(1:N, y(:,2));
 title('Right Channel with Noise');
   %nyquist frequncy = fs/2;44100/2=22050
   %plot the spectrum
   df = fs/N;
   w = (-(N/2):(N/2)-1)*df;
   y1= fft(y(:,1),N)/N;
   y2 = fftshift(y1);
   figure;
   plot(w,abs(y2));
   pause  
    n = 7;
  beginFreq = 50 / (fs/2);
  endFreq =   150  / (fs/2);
  [b,a] = butter(n, [beginFreq, endFreq], 'stop');
fout = filter(b,a,y2);
% A = audioplayer(fout,fs);
% pOrig.play;
figure;
plot(b,a);

Answer 2

[harinie Jr]

clear

close all

clc

[x,fs] = audioread('D.wav');

whos x; % Name Size Bytes Class sampling frequency

% x 556542x2 8904672 double 44100

% pOrig = audioplayer(x,fs);

% pOrig.play;

N = size(x,1); % Determine total number of samples in audio file

figure;

subplot(2,1,1);

stem(1:N, x(:,1));

title('Left Channel');

subplot(2,1,2);

stem(1:N, x(:,2));

title('Right Channel');

pause

%Adding Noise in audio signal

y=x;

y = y + randn(size(y));

% pOrig = audioplayer(y,fs);

% pOrig.play;

figure;

subplot(2,1,1);

stem(1:N, y(:,1));

title('Left Channel with Noise');

subplot(2,1,2);

stem(1:N, y(:,2));

title('Right Channel with Noise');

%nyquist frequncy = fs/2;44100/2=22050

%plot the spectrum

df = fs/N;

w = (-(N/2):(N/2)-1)*df;

y1= fft(y(:,1),N)/N;

y2 = fftshift(y1);

figure;

plot(w,abs(y2));

pause

n = 7;

beginFreq = 50 / (fs/2);

endFreq = 150 / (fs/2);

[b,a] = butter(n, [beginFreq, endFreq], 'stop');

fout = filter(b,a,y2);

% A = audioplayer(fout,fs);

% pOrig.play;

figure;

plot(b,a);