https://unix.stackexchange.com/questions/336790/how-to-disable-white-noise-with-headphones-in-dell-xps

Set Headphone Mic Boost gain to 10dB. Any other value seems to cause the irritating background noise in headphones. This can be done with amixer:

amixer -c0 sset 'Headphone Mic Boost' 10dB

To make this happen automatically every time you headphones are connected install acpid.

Start it by running: sudo systemctl start acpid.service

Enable it by running: sudo systemctl enable acpid.service

Create following event script /etc/acpi/headphone-plug

event=jack/headphone HEADPHONE plug
action=/etc/acpi/cancel-white-noise.sh %e

Then create action script /etc/acpi/cancel-white-noise.sh:

#!/bin/bash
amixer -c0 sset 'Headphone Mic Boost' 10dB

Now Headphone Mic Boost will be set to 10dB every time headphones are connected. To make this effective you need to restart your laptop.