Updated 10/16/2016 to reflect a small installation change to regain HDMI audio functionality in Sierra . This solution will work in Sierra as well as several previous versions of MacOS. Keep in mind that I didn't create the tools I only figured out how to use them. Credit for the kext goes to andrejkw at macrumors. Your mileage may vary but this is the easiest solution I've found. It has worked for many others. Definitely worth a try.
1. Download package located here...
Clover HDMI audio for NVIDIA & AMD cards. Easy way.
1. Download package located here...
Clover HDMI audio for NVIDIA & AMD cards. Easy way.