I have not been able to correlate it to any event in steam. I watched the volume mixer to find out that it was steam. I tried to turn off all notifications but obviously I have missed something. There is no visual cue just this sound in the background.
I appreciate any hints.
It’s not the music. It might be the big picture mode. I think I changed some settings a while ago thinking it was only active while in big picture mode. Currently I can’t open it because it asks me to sign in?!? I will try to reinstall the steam client.