Yule Walker Power Spectral density matching

Hi

I've written the codes to give psd for spoken digits... e.g. 1,2,3 etc. Now, I want to compare the YW psd (given by pyulear(signal,12,512,22050)) of the test pattern with one of the yw psd patterns available in the database.. i.e. comparison based on number of peaks in the psd, peak position, etc. Also, how can I store psd's in a variable.

I came across one paper that says this can be done using gmmmodel and posterior.. Any clue how to apply them or any other function that can help to compare two psd's and tell me the matching score ?

The paper I'm referring to is at http://www.mathworks.in/company/newsletters/articles/developing-an-isolated-word-recognition-system-in-matlab.html

Thanks,