title: iOS SDK - how the iphone audio jack interacts with the attached cable?
body: <p>I seem to be getting several values from kaudiosessionproperty_audioroute property on the iPhone.
  Such as :</p>
  
  <pre><code>ReceiverAndMicrophone
  HeadsetInOut
  HeadphonesAndMicrophone
  SpeakerAndMicrophone
  </code></pre>
  
  <p>How does the iPhone (iPod?) know what property to choose? What does each property mean on the perception of the microphone on the iPhone?</p>
  
  <p>Many Thanks!</p>