title: How to manipulate audio channels volume with AudioTrack.setVolume after API 21
body: <p>I'm trying to reproduce a mono wav file over just one of the stereo channels (speakers) that my smartphone has. I used to control this with </p>
  
  <p><code>AudioTrack.setStereoVolume (float leftGain, float rightGain)</code> </p>
  
  <p>by setting one of these gains to zero. Reviewing an old code I got a deprecated method warning and after checking Android SDK documentation I've found it is now done by :</p>
  
  <p><code>public int setVolume (float gain)</code> </p>
  
  <p>Added in API level 21. This API is preferred over setStereoVolume(float, float), as it more gracefully scales down to mono, and up to multi-channel content beyond stereo. </p>
  
  <p>My questions are:</p>
  
  <ol>
  <li>How would I control the channels volume individually so that only one channel reproduces at a given time now that I'm supposed to control both channels at the same time with the new version of the method?</li>
  <li>Is there a way to check through Android API if a certain device has stereo or mono speakers?</li>
  <li>Is there another way to reproduce mono audio through a single speaker only?</li>
  </ol>