title: AVAudioSession category not working as documentation dictates
body: <p>I have an iOS app that has some audio feedback in certain places, but I want any other music the user has playing in the background to be allowed to play over this. In addition, I want the audio in my app to respect the mute switch. According to the developer documentation, this functionality should all be enabled by the AVAudioSession ambient category. This is the code I'm using:</p>
  
  <pre><code>if (!hasInitialisedAudioSession) {
      AVAudioSession *session = [AVAudioSession sharedInstance];
      [session setCategory:AVAudioSessionCategoryAmbient error:NULL];
  
      [session setActive:YES error:NULL];
  
      hasInitialisedAudioSession = YES;
  }
  </code></pre>
  
  <p>The code is executing just fine, and it does indeed let the app sounds play over iPod music. What it doesn't do, however, is respect the mute switch. I've tried swapping this code out for similar C audio calls (stuff like AudioSessionSetProperty) instead of the Objective-C calls, but I get the same result - the ambient session category simply doesn't want to respect the mute switch, despite what the documentation says it should be doing.</p>
  
  <p>Any ideas? Thanks for the help :)</p>