Duolingo for the blind
I have a blind friend who would like to learn a language
I did find this post that might be helpful. http://www.fluentu.com/blog/best-audio-language-learning/
Michel Thomas' method sounds to be the best so far. However, your friend would benefit from using JAWS and then working with Technical people at Duolingo to pin point where the JAWS reader does not work. For example, the drop down menus where we choose the "right one" might not work with JAWS. Best Wishes! I know this is a year ago, but thought that maybe it might be useful to you or perhaps someone else.
I think Duolingo would do well to consider a companion application for both the blind and the illiterate. There are over 1 billion people in the world who are either blind or illiterate.
Many of those do not speak a language where there is much in the way of any written material or software support for those with disabilities.
I think a course similar to duolingo could be developed to be delivered almost entirely being a cell phone.
I would look at using Esperanto as an intermediate language because it is learned much more rapidly than natural languages and it can be a useful tool for spring boarding to other languages. Just having any language that gives web access would be very helpful for those that are non literature and the literature suggests many folks with the most problems learning languages can learn esperanto plus a natural language in the same time as learning a natural language by itself.