Using SystemSoundID in UIViewController without Application Delegate?

I ha开发者_运维问答ve an experimental app for iPad with a UIViewController visible on launch connected to my AppDelegate... all good, when I use systemSoundID within this MainViewcontroller it works great however when I try to use systemSoundID in my 3 other ViewController classes, which are connected to my MainViewController but not to AppDelegate they don't work???

I dont understand the significance of the AppDelegate here??

Is there a way to make SystemSoundID work in my other ViewController classes?

Have you imported audiotoolbox header files in other 3 viewControllers. Try to import header files in other view controllers and then play systemSound.