audio narration requires the Quicktime version 3 or 4 plug-in. If you have the
correct plug-in you should see a control panel below.
If you do, click the play button and adjust your volume if needed. You can now start the audio version of the tour by clicking the arrow you see to the right.
If you don't see a control panel, received some sort of error message, or a control panel is somewhat present but does not function, you can either view the non-audio version or download the Quicktime plug-in by clicking on this icon: