Since you're using a storyboard, you should take all that code out of the app delegate. The storyboard automatically instantiates your initial controller and puts it on screen. By alloc init'ing one, you're just creating another one that doesn't have any custom view.
To add your audio controller, you should add code in the viewDidLoad method of SoundCheckViewController that does that, rather than in an init method. This would be the usual way to do this, but I'm not sure what is possible with the framework you're using.