As far as I'm aware, Box doesn't support interactive content in the rendering of PowerPoint presentations, at least not as far as I can find. They are render similarly to a PDF file.
For presentations with commentary, I would suggest making it into a video, instead.
I recently had great success loading my PowerPoint into google docs and embedding in Canvas. Make sure your google docs setting is set to convert to google docs on import. You would need to verify that audio is imported and converted as well.
The advantage to google docs was that the presentation would either auto-advance or respond to screen clicks.
You might give Office Mix a try. It's a free powerpoint plugin and it can be embedded within Canvas at full functionality. I did an overview a couple of weeks ago: Integrating Office Mix and Microsoft Sway into Canvas.