On my system, whenever no sound comes out of the speakers for a bit, the speaker starts humming, the same sound that comes out of it when my PC is switched off
In my case, I am using Debian 13 with gnome
What is that sound
That sound is basically the speaker picking up the power line frequencies, and because it is an amplified speaker, it amplifies it, and makes it audible !
Why does it come out from my PC after some time
There are two audio drivers for linux, PulseAudio/ALSA and PipeWire, both supporting power saving mode, when no audio comes out of the speaker for some time, power saving mode kicks in, the sound chip (FKA the sound card) is disabled, so you get that sound exactly as if your computer was switched off !
How do i fix it ?
Disable power saving mode is the simplest method !
To disable it for this session, which works instantly, run the command
echo "0" | sudo tee /sys/module/snd_hda_intel/parameters/power_save
To make that change permanent (Later reboots)
sudo tee /etc/modprobe.d/snd-hda-intel.conf <<< "options snd_hda_intel power_save=0"