freq=4;
amp=0.3;
decay=0.5;

if (numKeys>1 && time>key(2).time) {
v=velocityAtTime(key(2).time-0.01);
x=time-key(2).time;
s=amp*v*Math.sin(x*freq)/Math.exp(x*decay);
value+s; }
else
{value}