It seems this was a red herring. I was testing on battery power which is why the audio was being runtime suspended. The hissing remains constant when the laptop is plugged in.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1809856 Title: [XPS 13 9370, Realtek ALC3271, Headphone Out, Right] Static/Electric background noise when volume is not muted To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1809856/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
