Ubuntu 20.04 - After last update, speakers are buzzing unless I open the sound settings window

I've had the same thing and followed the instructions on this solved thread and it hasn't had any fuzz/buzzing since.

https://ubuntuforums.org/showthread.php?t=2417018

Really simple open the terminal, sudo su and then password. Then enter gedit /etc/modprobe.d/alsa-base.conf. It will open a text document, at the end of the document copy and paste the following code:

options snd-hda-intel power_save=0 power_save_controller=N

Save, restart and it should be fixed!

Hope this helps.

If, like me, the accepted answer didn't work for you, it could be because your power saving settings are managed by tlp. Those settings can be found in this file here:

/etc/default/tlp

If you open that file with your favourite editor, you should find something like:

# Enable audio power saving for Intel HDA, AC97 devices (timeout in secs).
# A value of 0 disables, >=1 enables power saving (recommended: 1).
SOUND_POWER_SAVE_ON_AC=1
SOUND_POWER_SAVE_ON_BAT=1

And you can disable by changing those values to 0

You'll need to restart tlp as so:

sudo tlp start

In my case the accepted answer did not work. What resolved the issue was turning off power safe features.

Thanks kgsw.de!

https://www.linuxquestions.org/questions/ubuntu-63/weird-static-noise-in-headset-on-ubuntu-20-04-a-4175681180/

Verify how is your sound card's power_save parameter:
cat /sys/module/snd_hda_intel/parameters/power_save

If it returns 1, do the following to change it temporally:
echo "0" | sudo tee /sys/module/snd_hda_intel/parameters/power_save

EDIT: Unfortunately it is one time solution that works until the computer turn off, suspend. I didn't find the long-term solution.