How do you get positional audio to work in SceneKit?

Question

I am having trouble getting positional audio to work in SceneKit. Starting with the SceneKit game template generated by Xcode I have added the following code to the end of the h

Answer 1

As mentioned by Jed Soane, and confirmed by Apple in a Radar, the issue was my audio file was stereo instead of mono. Only mono audio files will work for positional audio.