title: System Sound plays in iPhone simulator but on iphone not playing
body: <p>I want to play a system sound on my iphone, the sound plays very well in the simulator but on the device doesn't work.</p>
  
  <pre><code>- (IBAction)SystemSound:(id)sender {
      NSString *soundFilePath = [[NSBundle mainBundle] pathForResource:@"waterfall"      ofType:@"caf"];
      NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath];
      AudioServicesCreateSystemSoundID((__bridge CFURLRef)soundFileURL, &amp;systemSound);
      AudioServicesPlaySystemSound(systemSound);
  }
  </code></pre>