% Set number of points in waveform.
if(~exist('N'))
  N = 128;
end

% Create vector of time values.
t = 0:3.2/N:3.2;

% Generate speechlike waveform
s = 5*exp(-t).*sin(2*1.3*pi*t) ...
    + 3*exp(-2*t).*sin(2*3.4*pi*t) ...
    + exp(-3*t).*sin(2*7.2*pi*t);

figure(1)
plot(s)

figure(2)
plot(abs(fft(s)))

% Low values of N, such as N=16, illustrate aliasing and blurring
%  of spectrum.