% ...1 means "constant tone"
% ...2 means "pitch"

%---------------------------------------------

clear all

% load andreas_constant_tone_10second;
% load alex_constant_tone_10second;
load vince_constant_tone_10second;

x = A;

clear A;

n = [1:length(x)];
Ts = 1./(40e3);

plot(n,x)

N = 40000;
n1 = 20000;
n2 = 300000;

% Cut out 1 s of "control data":
x0 = x(n1:n1-1+N);
X = fft(x0);
S0 = abs(X).^2;

% Cut out 1 s of voice data:
x1 = x(n2:n2-1+N);
X = fft(x1);
S1 = abs(X).^2;


%====================== Plot results ====================

figure(1)
plot(n,x)
xlabel('n')
ylabel('y([n]')

figure(2)
semilogy([2:N/2]/(N*Ts),S0(2:N/2),'b-')
hold on
semilogy([2:N/2]/(N*Ts),S1(2:N/2),'r-')
xlim([10 4000])
xlabel('Frequency [Hz]')
ylabel('Power spectrum [arb. units]')
hold off