Having spent about 10 days trying to get the new beta audio version of the Alexa Presentation Language (APLA) working I finally solved it. So that no one else has to go through this pain I created a tutorial and source code showing how to use it.
If you aren't familiar with APLA it lets you mix audio for your Alexa response. In my case I added background crowd noise to my Premier League's description of various football (soccer for Americans) statistics.
Go to BrianTarbox.org/alexaskills.html for the video and source code.