I've taken the easy way out here and subscribed to Odiogo.
What that does is automatically add a computer generated "podiocast" capability to each of my posts, so that people can hear the post being read. Admittedly there are some quirks: the voice is American, and if you have URLs it tends to read them letter by letter, but in general it works well enough. You need to check your spelling carefully though, and put full stops and commas in so that it punctuates verbally. Otherwise you get run on sentences.
I have been using it successfully over on my other blog Mysteries in Paradise for some weeks now. What I have found is that although it has only been there a couple of weeks, you can access the podiocast on each of the posts in the archive. Occasionally it does take a while for the audio to become available, but usually it comes up within 15 minutes of the post being published. Visually impaired friends have reported that it makes "reading" my blogs much easier.
In order to use it you have to have "ownership" of the blog. So for example, I can't add it to my education.au blog because my status is sort of "sub-domain blogger". Nor can I add it to my me.edu.au blog, for the same reason.
The other thing that I've discovered is that you can save the file as an mp3 onto your computer for using elsewhere. So I am using them as part of a presentation that I am giving at a workshop in Darwin this week.