title: How to detect how similar a speech recording is to another speech recording?
body: <p>I would like to build a program to detect how close a user's audio recording is to another recording in order to correct the user's pronunciation. For example:</p>
  
  <ol>
  <li>I record myself saying "Good morning"</li>
  <li>I let a foreign student record "Good morning"</li>
  <li>Compare his recording to mine to see if his pronunciation was good enough.</li>
  </ol>
  
  <p>I've seen this in some language learning tools (I believe Rosetta Stone does this), but how is it done? Note we're only dealing with speech (and not, say, music). What are some algorithms or libraries I should look into?</p>