OK
This is a little involved - hopefully it will solve your problems
1. This is your monitor
https://downloads.dell.com/manuals/all-products/esuprt_display_projector/esuprt_display/dell-s2716dg-monitor_user's guide_en-us.pdf
2.It has a display port and is connected to the 970 I presume
see page 10
3. The display port carries not only video but also audio
What is the difference between DisplayPort and HDMI? - News
see audio features.
4. The 970 has a display port
Sound via DisplayPort?
and that carries audio from the 970 not requiring your realtek
5. Now see page 10 again of your monitor manual and look at item 3 - line out speakers.
Then page 9 port 3 headphones
NOTE do not connect both
6. Now see page 33 re audio level headphones
The speaker volume is controlled of course from the speakers as they being connected and NOT included in the monitor they must rely on their own volume control.
AFTER a lot of searching, I think this will solve your problem.
Could you kindly work on it and if you have any questions please ask.
You should be able to disable Realtek, enable Nvidia and go from there
Done the other wheel bearing today - not as bad - having done one - but weather conditions were about 10 degrees colder
Luckily the wife kept me supplied with hot drinks.
Goodnight.
Good luck and as I said - I hope you will hear good audio without - the rice crispies
