envelope function

So enveloping a sound signal is probably more complex than this but I want to create an envelope with a 3 ms decay. I have a sound wave (A) that has been rectified by using absolute value and time points have been assigned by using the code "plot((0:length(A)-1)/44.1, A)" as the sampling rate is 44.1 KHz/sec (time is in Msec). What code can I use to create such an envelope?

Answer 1

[Image Analyst]

See our answers and code here http://www.mathworks.com/matlabcentral/answers/31957-how-to-make-an-envelope-of-a-signal, which is basically the same question.

Answer 2

[Honglei Chen]

For a signal x, you can use the following code to get the envelope

t = 0:0.01:1;
x = exp(-t).*sin(2*pi*10*t);
plot(t,x)
y = abs(hilbert(x));
hold on;
plot(t,y,'r')