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% xprhm = preham(x, pr) 
% preemphasis+hamming windows the signal x 
%    x  : input signal 
%    pr : preemphasis to apply, 0 <= pr <= 1 
%         default pr = 1, note that pr=0 turns 
%         off the preemphasis 
% 
function xprhm = preham(x, pr) 
 
if nargin < 2, pr=1.0; end 
 
% the transfer fcn for preemphasis pr is: 
% P(z) = 1 - pr * z^(-1) 
% (taken from ILS Manual, pp. INA-6, Vol II). 
 
pb = [1 -1*pr]; pa = [1]; 
xpr = filter(pb,pa,x); 
 
% hamming  
  
xprhm = hamming(length(xpr)) .* xpr;