similar to mine, but mine still does it, all the time and is horribly loud. Dell says it is normal, but i can hear it over the speakers at 100% or in a lound room. They say they are working on a driver update to significantly remove coil whine and replacement motherboards, both ready for mid november.

I had the problem like you wouldn't believe after the Win 10 anniversary update loaded in some Microsoft provided driver. The latest Dell driver hasn't been a problem for me, but you might want to hit the Realtek support site for the generic driver. I used that after the anniversary update and before the latest Dell driver and it solved the problem for me entirely.

Speakers/keyboard area are making a beepy/coil whine sound now after I updated my audio driver via Dell Update. Frustrating, annoying. I just want it back to how it was.

XPS 13 9350 coil whine/speaker sounds after driver update