FastICA Implementation.. Matlab - matlab

Question

I have been working on a FastICA algorithm implementation using MatLab. Currently the code does not separate the signals as good as id like. I was wondering if anyone here could give me some advice on what I could do to fix this problem?
disp('*****Importing Signals*****');
s = [1,30000];
[m1,Fs1] = audioread('OSR_us_000_0034_8k.wav', s);
[f1,Fs2] = audioread('OSR_us_000_0017_8k.wav', s);
ss = size(f1,1);
n = 2;
disp('*****Mixing Signals*****');
A = randn(n,n); %developing mixing matrix
x = A*[m1';f1']; %A*x
m_x = sum(x, n)/ss; %mean of x
xx = x - repmat(m_x, 1, ss); %centering the matrix
c = cov(x');
sq = inv(sqrtm(c)); %whitening the data
x = c*xx;
D = diff(tanh(x)); %setting up newtons method
SD = diff(D);
disp('*****Generating Weighted Matrix*****');
w = randn(n,1); %Random weight vector
w = w/norm(w,2); %unit vector
w0 = randn(n,1);
w0 = w0/norm(w0,2); %unit vector
disp('*****Unmixing Signals*****');
while abs(abs(w0'*w)-1) > size(w,1)
w0 = w;
w = x*D(w'*x) - sum(SD'*(w'*x))*w; %perform ICA
w = w/norm(w, 2);
end
disp('*****Output After ICA*****');
sound(w'*x); % Supposed to be one of the original signals
subplot(4,1,1);plot(m1); title('Original Male Voice');
subplot(4,1,2);plot(f1); title('Original Female Voice');
subplot(4,1,4);plot(w'*x); title('Post ICA: Estimated Signal');
%figure;
%plot(z); title('Random Mixed Signal');
%figure;
%plot(100*(w'*x)); title('Post ICA: Estimated Signal');

Answer 1

Your covariance matrix c is 2 by 2, you cannot work with that. You have to mix your signal multiple times with random numbers to get anywhere, because you must have some signal (m1) common to different channels. I was unable to follow through your code for fast-ICA but here is a PCA example:
url = {'https://www.voiptroubleshooter.com/open_speech/american/OSR_us_000_0034_8k.wav';...
'https://www.voiptroubleshooter.com/open_speech/american/OSR_us_000_0017_8k.wav'};
%fs = 8000;
m1 = webread(url{1});
m1 = m1(1:30000);
f1 = webread(url{2});
f1 = f1(1:30000);
ss = size(f1,1);
n = 2;
disp('*****Mixing Signals*****');
A = randn(50,n); %developing mixing matrix
x = A*[m1';f1']; %A*x
[www,comp] = pca(x');
sound(comp(:,1)',8000)