To embed a presentation select Slides from the Google Embeds section of the Insert menu.  After inserting a presentation click the settings (gear) icon to use the auto start, loop playback and delay time options. 

You should publish the presentation so that it will appear for everyone.

You can insert audio on a slide like on slide 1 here.  Not everyone will see the add audio option however. See the update.

Note: on a mobile device the slideshow doesn't start until the viewer clicks on it to open it.  And then instead of a slideshow  all of the slides appear together in the page.

Field Day 2

See also the Photo Gallery From Drive page

Want to embed just one slide from a presentation?