XPS coil whine. This is a consistent problem. I notice it on my 9570 (2018), and I saw a review of this year's XPS 13 9380 (2019) mention the problem. Googling shows it has been a problem since at least the XPS 9530 (2013).

I also don't annoying that the fan speeds up for a few seconds every minute while the workload doesn't vary (needs a more analog variable speed control?)

Other than the noises, it's been a really good Linux laptop, and the only reasonable option with a fast i9 at the time I got it.