They probably just use a text-to-speech reader. There are plenty available and some are free. A lot of crap is going to sound horrible. ASCII art is going to sound horrible. And after needing to use the web primarily with a text-t-speech reader for a while, I am thrilled and hope people need to listen to their own typoes. Although depending on the t-t-s reader it may not handle URLs well, which is just unfortunate. Mine did not, and it made them so tedious even though it wasn't a problem on the writer's part.