title: How to find similarity between two signals with xcorr in matlab
body: <p>I'm writing a code for speech recognition. I have a number <em>n</em> of database, each db contains the same number of words recorded by different persons.</p>
  
  <p>I want to do the <code>xcorr</code> between, for example, the reference word "hello" with all the words in the "hello" db and all the words in the "door" db and then the code has to say to me which word is it. I need to make some mathematical paragon in order to make a decision. </p>
  
  <p>Now, I know that the auto correlation between the same word has a symmetric graph. But if I compare the word "hello" said by a male and the same word said by a female it is not symmetric, and I obtain the same result if I compare the word "hello" with the word "door". </p>
  
  <p>My question is: how can I find similarities between the two words doing the xcorr function? Do I need to find the lag or the maximum of the xcorr? </p>
  
  <p>Thanks for the help.</p>