Fadein fadeout in a wav file

Hi there, I have a problem I am stuck with...

 1. The WAV file will have  the first Hallelujah repeated twice (and no other sound),
 The initial allelujah will gradually increase in volume, the second Hallelujah will gradually
 decrease in volume.

so far I have this as my code, I cannot find out how to fade in or out the sound,** Thanks

load handel.mat;

hfile= 'handel.wav';

wavwrite(y, Fs, hfile);

nsamples= 2.5*Fs;

[t,Fs]= wavread(hfile, nsamples);

v= [ t'/5 t'];

sound(v);

Answer 1

[Image Analyst]

Try this:

clc;
close all;
fontSize = 22;

% Load sound file.
load handel.mat;
hfile= 'handel.wav';
% Plot original signal.
sound(y);
subplot(4,1,1);
plot(y);
grid on;
title('Original Wave File', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Write out wave to a file.
wavwrite(y, Fs, hfile);

promptMessage = sprintf('Wait until the sound finishes.\nDo you want to Continue processing,\nor Cancel processing?');
titleBarCaption = 'Continue?';
button = questdlg(promptMessage, titleBarCaption, 'Continue', 'Cancel', 'Continue');
if strcmpi(button, 'Cancel')
  return;
end
% Read it back in.
nsamples= 2.5*Fs;
[t,Fs]= wavread(hfile, nsamples);
% Construct attenuated portion next to original portion
v= [ t'/5 t'];
subplot(4,1,2);
plot(v);
title('Two Choruses', 'FontSize', fontSize);
grid on;
sound(v);

promptMessage = sprintf('Wait until the sound finishes.\nDo you want to Continue processing,\nor Cancel processing?');
titleBarCaption = 'Continue?';
button = questdlg(promptMessage, titleBarCaption, 'Continue', 'Cancel', 'Continue');
if strcmpi(button, 'Cancel')
  return;
end
% Construct ramps
amplitudeEnvelope = [linspace(0, 1, length(t)), linspace(1, 0, length(t))];
subplot(4,1,3);
plot(amplitudeEnvelope);
grid on;
title('Amplitude Ramp', 'FontSize', fontSize);

% ------ MAIN PART OF THE PROGRAM --------
% Multiply the amplitude envelope by the original waveform
% to produce the signal where the volume ramps up then down.
wave2 = [t' t'] .* amplitudeEnvelope;
%-------------------------------------------
  
subplot(4,1,4);
plot(wave2);
grid on;
sound(wave2);
title('Ramped Sound', 'FontSize', fontSize);

[AngelsaAtWar]

HI I still don't see where it fades in and out at in the Script

[Image Analyst]

How can you not see that? I showed you the original waveform and the one where the waveform ramps up and then down. Plus you can see the code where I multiply the envelope by the original two refrains:

wave2 = [t' t'] .* amplitudeEnvelope;

[AngelsaAtWar]

I see it now, I am sorry I am only trying to understand this stuff, I dont want to just take your answer and use it. I only wanted to learn how to do it, no need to get mad.

[Image Analyst]

I added a comment to make it more obvious where the main part of the program is.

[AngelsaAtWar]

I want to apologize again for not seeing it the first time, now I do understand it better... thank you very much :)