title: Sprite Kit sound issue, how to prevent stop user sound
body: <p>I have an issue using Sprite Kit and when I want to play a sound after an user interaction.</p>
  
  <p>User is listening music with an App (Spotify for example).<br>
  User want to play my game while he's listening his song, Currently when Use launch my app, his song is put to stop.</p>
  
  <p>I would like to prevent this behavior, in fact : How can I do to either don't play sound if an other app is using the "sound" or how can I play my sound AND keep the user's music playing.</p>
  
  <p>Currently this is my code :</p>
  
  <pre><code>@property (strong, nonatomic) SKAction *hitSound;
  </code></pre>
  
  <p>In the init Method:</p>
  
  <pre><code> _hitSound = [SKAction playSoundFileNamed:@"laugh.caf" waitForCompletion:NO];
  </code></pre>
  
  <p>After user press the screen:</p>
  
  <pre><code>-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
  {
   SKAction *sequence = [SKAction sequence:@[_hitSound]];
      [node runAction:sequence completion:^{
         //Stuff
  }];
  </code></pre>
  
  <p>}</p>