Now on Librivox as a free audio reading, The Book of the Thousand Nights and a Night (aka The Arabian Nights), Volume 11.

There are apparently 10 volumes in the main Burton set, plus another six Supplemental Nights and other related material. Presumably this appearance on Librivox of the new Vol. 11 means the team has now started working through the Supplemental Nights volumes, and aims to get a completist reading finished for the whole set.