title: Using Audio Units to play several short audio files with overlap
body: <p>I have run through an audio units tutorial for a sine wave generator and done a bit of reading, and I understand basically how it is working. What I would actually like to do for my app, is play a short sound file in response to some external event. These sounds would be about 1-2 seconds in duration and occur at a rate of about about 1-2 per second. </p>
  
  <p>Basically where I am at right now is trying to figure out how to play an actual audio file using my audio unit, rather than generating a sine wave. So basically my question is, how do I get an audio unit to play an audio file? </p>
  
  <p>Do I simply read bytes from the audio file into the buffer in the render callback?
  (if so what class do I need to deal with to open / convert / decompress / read the audio file)</p>
  
  <p>or is there some simpler method where I could maybe just hand off the entire buffer and tell it to play?</p>
  
  <p>Any names of specific classes or APIs I will need to look at to accomplish this would be very helpful.</p>