Kubuntu 20.04 LTS
Problem: wired headphones reproduce constant hissing sound, noise changes with the cursor movement etc.
Solution:
sudo hda-verb /dev/snd/hwC0D0 0x1d SET_PIN_WIDGET_CONTROL 0x0
Sources:
https://www.reddit.com/r/thinkpad/comments/8j8208/audio_crackling_through_both_headphone_jack_and/
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1805079/comments/20
