How to fade sound gradually

hello all

please can ou help me out adding attenuation of sound from the middle to the end of the track to my system

>> [y,Fs] = audioread('1.mp3');
>> N=length(y);
>> T=N/Fs;
>> n1=T/2*Fs;
...
>> audiowrite('2.wav' ,y,Fs);

Thank you so much

Answer 1

[Image Analyst]

Try this:

% Read in audio file.
folder = 'C:\Users\LadyBlack\Music\My Albums\Led Zeppelin\Early Days- The Best of Led Zeppelin, Vol. 1\';
baseFileName = '13 Stairway to Heaven.mp3';
fullFileName = fullfile(folder, baseFileName);
[y,Fs] = audioread(fullFileName);

% Plot original signal.
subplot(3, 1, 1);
plot(y, '-', 'LineWidth', 2);
title(baseFileName, 'FontSize', fontSize);
grid on;

% Create a fading envelope signal.
numSamples = length(y)
midIndex = round(numSamples/2);
T=numSamples/Fs % Seconds.
% Create a fading envelope
fadeSignal = [ones(1, midIndex), linspace(1, 0, numSamples - midIndex)]';
% If stereo, make another column
if size(y, 2) > 1
	fadeSignal = [fadeSignal, fadeSignal];
end
% Plot fading signal.
subplot(3, 1, 2);
plot(fadeSignal, '-', 'LineWidth', 2);
title('Fading Envelope Signal', 'FontSize', fontSize);
grid on;

% Apply the fading by multiplying
yFaded = y .* fadeSignal;
% Plot fading signal.
subplot(3, 1, 3);
plot(yFaded, '-', 'LineWidth', 2);
title('Faded Waveform', 'FontSize', fontSize);
grid on;

% audiowrite('2.wav' ,y,Fs);
fprintf('Done running %s.m.\n', mfilename);