XPS 13 9380, crackling noise with headphones, #2

Hi: I decided to make this as a reply to your old post since with my diminished eyesight (along with rest of the problems!), I could not find the tab to start a new post. So, here is my laundry list of questions

CHIRPING OR CAR ENGINE BACKFIRING SOUND
Comes when waking up (not me; the laptop) from sleep, some time moving the attached mouse, when a knock in the table etc.
Also when I move the slider on the volume control; two sounds chirping when I move the slider up; little different (like some part vibration?) when I move down; as I played moving up and down, the intensity increased a lot and remains so.
Ah, the sounds went away when a wired headphone (earbud? not the over the ear) is connected.
Came back via speakers when the headset is removed.
Reinstalled Realtek drivers from the Dell download portal and no difference.
Looked at the device manager, saw two devices under Sound, video and game controllers: Intel display audio and Realtek audio. Disabled Intel audio and chirp remains. The Intel audio drivers got installed by the system automatically (I did not reinstall). So, I suppose that is also needed.
That brings to my another question as well. When I select show all hidden devices using the View tab of Device manager, I see innumerable number of such devices and some repeats. One under Network adapters, Realtek USB GbE Family controller caught me by surprise. This Dell laptop is a brand new system and we never installed any such hardware (none for that matter; only a wired mouse and the headphone so far). How did that device handler came into this new system? Could my laptop be a resent one and recycled by Dell? Luckily I took a picture of it as it seemed to have disappeared when I did a Feature update to Windows 10, V 1903, yesterday.
I went to Dell portal for help and it asked me to install Support Assistant (the new App. like those in Microsoft store) though I had the program pre-installed (I guess that is the regular windows version, Dell SupportAssist, that shows up in the start list). They both started conflicting when I opened the windows regular version (it will hang up for ages before opening; when I tried updating some available drivers, it will stop saying Setup wizard ended prematurely; when I tried the update again, I got the message, A problem occurred when checking for updates. And the Retry was grayed out leaving me with the only option to close and wait ages for it to come back to life). So, I installed the updates from Dell portal one by one manually. I also removed the regular Dell Assist program from the system and the MS store version started opening quickly.

Updated the BIOS.

After all these efforts and reading innumerable complaints and suggestions on the web (and exhausting most), I talked to the Dell support in Philippines and it was an irritating one. First, they would repeat like a parrot the basic steps. Then out of exasperation, I tried to tell them who I am (a professor of Electrical and computer engineering with 40 years of research experience; has been a program director at the National Science Foundation when all these product ideas were just in the dream stage and we nurtured them by selecting and funding the best ones; I had QualComm in my own program under the SBIR - small business independent research - category :)). He will just repeat those baby steps and tried to remote connect with my PC. He wanted to use only the web version saying the MS store DellAssist is too new to be used! Then I did the web version with the link he has to spell one letter at a time: https://www.dell.com/support/remoteassist. But the browser would change the link to the US portal regardless of what I tried and hence the code he gave to connect would end up with server failure. Then he insisted I try a different browser and I obliged with two other with the same error.

He gave up and escalated to his supervisor who called me after 3 hours in the one to two hour window that he promised :). And with the supervisor, it was back to basic 101 as in our university course numbering lingo. No; it was really like the remedial course for students who didn't learn what they should have learned in their school years!! Finally, she gave up and said she will arrange for Dell Warranty support.

But I don't want to waste resources if the issue can be resolved with my background and some hints. Please provide me some answers to some problems I mentioned (like why he cannot remote connect to my PC). Then I will contact some upper management folks and let them know in a very pleasant manner (?) what is happening.

Thank you.

Oh, dxdiag.exe did not find any errors; changing sampling rate did not either.