If you normally browse here with Safari and you've recently upgraded to Mavericks (10.9), then you've just lost a little bit of functionality. At some point, you may have installed the QuickTime component called XiphQT. This was the only way that Mac users had of playing .ogg audio files through QuickTime and therefore iTunes. QuickTime is what powers audio and video streaming in Safari. It's therefore what's required to play back our audio clips, such as in the infobox at The Light at the End.
But the problem is that XiphQT is an old 32-bit application. And Mavericks is the first iteration of OS X which requires 64-bit apps. The result: no audio playback of our files in Safari once you upgrade to Mavericks.
Happily, Firefox and Chrome (and Opera, but Opera's not supported by Wikia) easily play audios, even after a Mavericks upgrade.