SoListenerPositionElement(3) on Linux
The text ff9eff5c2a7d, as Debian 8 (Jessie) shipped it.
The SoListenerPositionElement holds the position of the current listener. This position is set by SoListener nodes and SoCamera Nodes during audio rendering. When a SoListener is visited by the SoAudioRenderAction, it will add a new SoListenerPositionElement to the state, holding it's position and with the setbylistener flag set. When a SoCamera is visited by SoAudioRenderAction, it will add a new SoListenerPositionElement only if there are no previous elements with the setbylistener flag set.