waveFile='whatMovies.wav';
au=myAudioRead(waveFile);
% Filter parameters
delay=0.2;
gain=0.8;
a = [1 zeros(1, round(delay*au.fs)), -gain];
b = [1];
y = filter(b, a, au.signal);
% Plot the result
time = (1:length(au.signal))/au.fs;
subplot(2,1,1);
plot(time, au.signal); title('Original signal x[n]');
subplot(2,1,2);
plot(time, y); title('Filter output y[n]');
au.signal=y;
myAudioWrite(au, 'echo02.wav');	% Save the output signal