Just a quick note from Colin Viebrock's weblog this morning:

My article about Turing Protection generated lots of comments about how using image CAPTCHAs restricts access to the visually impaired.

So, I've played around a bit, and added an audio component. If you can’t read the CAPTCHA image, you can listen to a .WAV file of our lovely server, spelling out the characters to you.

While the text-to-speech isn't perfect, this is a good step forward in the use of the turing protection for forms. He chose flite for the text-to-speech portion and modified the script to be case-insensitive (since the voice doesn't distinguish between upper and lower cases.