i like the idea, but i'm not that good in chess so i'm lost here =) my advantage? i could learn it, and solve the problem, but what are blind people doing? they

i like the idea, but i'm not that good in chess so i'm lost here =) my advantage? i could learn it, and solve the problem, but what are blind people doing? they have no chance to solve the captcha. are there any ideas, how to deal with this problem? like a audio file, where all positions are being told? or anything like that? right now i would not have an idea how to solve this in a good way. me as a web-developer often thinks about the common problem, we we need these captchas, and would be a good alternative to them. until now i had no idea )= hopefully someday someone has a idea to replace captchas with an easier protection for all people. the sad part is, that we need stuff like captchas since years... stupid spam!!