% chauvesouris.m
%
% P. Flandrin

figure(1)
clf 

Fs = 4196;

load veille.mat
Te = 1/230.4; % ms

xx = veille(1:length(veille));
[B,A] = butter(4,.8);
x = filter(B,A,xx);
N = length(x);
t = (0:N-1)*Te;

plot(t,x)
axis([1 t(N) 1.1*min(x) 1.1*max(x)])
xlabel('temps (ms)')
title('signal d echolocation + reverberation')
set(gca,'YTick',[]);
hold on

pause

sound(x/max(abs(x)),Fs)

