%dtmfscore.m

function sc = dtmfscore(xx, hh)
%DTMFSCORE
% usage: sc = dtmfscore(xx, hh)
% returns a score based on the max amplitude of the filtered output
% xx = input DTMF tone
% hh = impulse response of ONE bandpass filter
%
% The signal detection is done by filtering xx with a length-L
% BPF, hh, and then finding the maximum amplitude of the output.
% The score is either 1 or 0.
% sc = 1 if max(|y[n]|) is greater than, or equal to, 0.71
% sc = 0 if max(|y[n]|) is less than 0.71
%

xx = xx*(2/max(abs(xx))); %--Scale the input x[n] to the range [-2,+2]

yy = conv(xx,hh); % find convolution to be scored

if max(yy(200:length(yy)-200)) >= .71 %scores 1 if yy is > .71
    sc = 1;
else
    sc = 0; %scores 0 if not
end