% Figure 9a of "Cancellation model of pitch perception" (JASA 97)

global sr;
sr = 8000;

D = 0.1;
start = 0.018;	% s
stop = 0.055;	% s
chunk = [start *sr : stop * sr] ;		% s, portion to plot
lag = 0.00125;	% s, period of 800 Hz carrier

y = synth_damp;
y = hwrect(y);		% half-wave rectify
y = cfilt(y, lag*sr);
y = hwrect(y);		% half-wave rectify

x = abscissa(D) * 1000;
plot(x(:,chunk) - start*1000, y(:,chunk));

set(get(gca, 'XLabel'), 'String', 'time (ms)');
set(get(gca, 'title'), 'String', '"Cancellation model of pitch perception" - Fig. 9a');