SoListenerOrientationElement(3) on Linux
The text 255fa7fb6344, as Debian 7 (Wheezy) shipped it.
The SoListenerOrientationElement holds the orientation of the current listener. This orientation is set by SoListener nodes and SoCamera Nodes during audio rendering. When a SoListener is visited by the SoAudioRenderAction, it will add a new SoListenerOrientationElement to the state, holding it's orientation and with the setbylistener flag set. When a SoCamera is visited by SoAudioRenderAction, it will add a new SoListenerOrientationElement only if there are no previous elements with the setbylistener flag set.