audio CAPTCHA survey

I've not tried this myself, but I understand it is an interesting and fun survey on audio CAPTCHAs from WebInSight.

CAPTCHAs are those images of letters designed to stop automatic spammers but that don't play well with screen reader software. Audio CAPTCHAs provide a good alternative for some people, but I'm personally hoping someone comes up with something completely different. A visual CAPTCHA and an audio alternative are still no good for deafblind people.

As I'm having a moan about this, I would expect better from W3C who suggest an audio alternative to visual CAPTCHAs in the explanation notes for the new accessibility guidelines, WCAG 2.0. At best, they haven't thought that through.