function E = ShortTimeEnergy(signal, windowLength, step);
signal = signal / max(max(signal));
curPos = 1;
L = length(signal);
numOfFrames = floor((L-windowLength)/step) + 1;
%H = hamming(windowLength);
E = zeros(numOfFrames,1);
for (i=1:numOfFrames)
    window = (signal(curPos:curPos+windowLength-1));
    E(i) = (1/(windowLength)) * sum(abs(window.^2));
    curPos = curPos + step;
end
