clear all
%
%Parameters
Fs=8000;
Ts=1/Fs;
Nx=2000;
Ny=2000;
Nw=3000;
Nz=1000;
tx=0:Ts:(Nx-1)*Ts;
ty=Nx*Ts:Ts:(Nx+Ny-1)*Ts;
tw=(Nx+Ny)*Ts:Ts:(Nx+Ny+Nw-1)*Ts;
tz=(Nx+Ny+Nw)*Ts:Ts:(Nx+Ny+Nw+Nz-1)*Ts;
x=cos(2*pi*400*tx);
y=cos(2*pi*1500*ty)+cos(2*pi*1540*ty);
w=cos(2*pi*2000*tw);
z=cos(2*pi*800*tz)+cos(2*pi*840*tz);
s=[x y w z];
t=[tx ty tw tz];
plot(t,s)
grid
sound(s,Fs)

%***************************************************
specgramdemo(s,Fs)