Under Debian / Jessie, the standard back-end to the PulseAudio daemon is ‘gstreamer’. This is a set of programs that perform potentially complex sound-processing under Linux, yet have no real GUI as it stands.
In the past week or so, there was an update to this software-subsystem.
I have not rebooted any of my computers since then, nor have I done a simpler user-session-restart. Therefore, I do not yet know whether this update has broken PulseAudio, nor whether it has improved the performance of the audio-daemon, that is standard for KDE, and that definitely has a GUI.
When I find this out, I will comment on it again.