How to insert 5ms rise and fall to my signal (sound) ?

Hello everyone i have a task for my collage, to generate white noise and i did it but i have a problem which is i hear a click sound at the beginning of the sound ( signal ).

so to solve this issue i have to insert a slope at the beginning and ending of the sound of 5ms, but how?

thank you.

Answer 1

[Star Strider]

Try this:

Fs = 44100*2;                                                                                               % Sampling Frequency (Hz)
ms5 = fix(Fs * 0.005);                                                                                      % Samples/5ms

t = 0:5*Fs-1;                                                                                               % Time Vector
f = 500;                                                                                                    % Frequency
s = sin(t*(2*pi)*f/Fs)';                                                                                    % Signal
cos_slope = [(1-cos((0:ms5-1)*pi/ms5))/2 ones(1, size(s,1)-(2*ms5)) fliplr((1-cos((0:ms5-1)*pi/ms5))/2)]';  % ‘Slope’ Vector
cos_slope = repmat(cos_slope, 1, size(s,2));                                                                % ‘Slope’ Matrix
s_with_slope = s.*cos_slope;                                                                                % ‘Corrected’ Signal

figure
plot(t, s)
hold on
plot(t, s_with_slope)
hold off
grid
xlim([0 2*ms5])

pause('on')
sound(s, Fs)
pause(6)
sound(s_with_slope, Fs)

It creates a cosine-taper ‘slope’ at the beginning and the end, adjusting for the sampling frequency and signal length, as well as the signal having two columns (stereo).

[Oddineus]

thank you for your help.

[Star Strider]

As always, my pleasure.