I am visual impaired so I am looking for software to hear the written code. The biggest problem is CAPTCHA? . Most of the time it is impossible to read. There is a choice to hear the code. When they were speaking numbers it was not that hard to get it right but not they use audio clips from TV or movies and because in our language we slur things at times or run them together this is harder to understand. Even worse the first and last words are cut off. It also goes by to fast to type in. I was do a keyword search for audio for stuff like this but I don;t know what this kind of software is called. Let me know if you canhelp
If you are talking about this site: http://recaptcha.net/ They use phrases from books and TV, they are a bit hard to understand but just enter your best guess of the whole phrase and it should work.
I'm sorry that you are a person suffering from being visually impaired ( not making fun, thats how you refer to someone with a disability even though it sounds weird), but you could have a friend help you out with signing up right?