title: Observing AVAudioSession not firing notifications
body: <p>In the app I am currently building, I need to process a few things depending on <code>[AVAudioSession sharedInstance]</code>'s current category. This category will change during runtime, and I am trying to keep track of the changes by observing <code>AVAudioSessionRouteChangeNotification</code> in NotificationCenter.</p>
  
  <p>However, no matter what I try the notification is not being fired (or at least nothing is being received by my selector method).</p>
  
  <p><strong><em>Some test sample code;</em></strong></p>
  
  <p><strong>AppDelegate.m</strong></p>
  
  <pre><code>- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
     [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(sessionRouteDidChange:) name:AVAudioSessionRouteChangeNotification object:nil];
     return YES;
  }
  - (void)sessionRouteDidChange:(NSNotification *)notification
  {
      NSLog(@"SESSION ROUTE CHANGED");
  }
  </code></pre>
  
  <p><strong>ViewController.m</strong></p>
  
  <pre><code>- (void)changeAudioCategory:(AVAudioSessionCategory)category{
         [[AVAudioSession sharedInstance] setActive:NO error:nil];
          AVAudioSession *audioSession = [AVAudioSession sharedInstance];
          NSError *setCategoryError = nil;
          BOOL success = [audioSession setCategory:category error:&amp;setCategoryError];
          if (!success) {
              NSLog(@"ERROR");
          }
          [audioSession setActive:YES error:nil];
  
          /* Logging the current category */
          NSLog(@"AVAUDIOSESSION CATEGORY %@", audioSession.category);
  }
  </code></pre>
  
  <p>I am expecting the observer I have set up in <code>AppDelegate</code> to send a notification to <code>sessionRouteDidChange</code> upon changing category inside this method, but nothing happens.</p>
  
  <p><strong><em>What I have tried;</em></strong></p>
  
  <ul>
  <li>Testing on multiple iOS versions and iPhone models, but none worked</li>
  <li>Double and triple checked that I am not removing the observer anywhere</li>
  </ul>
  
  <p>Any ideas about what I am missing?</p>