On 16/05/10 07:27, emijrp wrote:
Hi all;
Solving captcha during registration is mandatory. Can this be replaced with a sound captcha for visual impairment people? It is a suggestion to the usability project too. Thanks.
Audio CAPTCHAs, like visual CAPTCHAs, are not accessible for all people and do not conform to W3C accessibility guidelines. What's more, they're easier to crack than visual CAPTCHAs due to their one-dimensional nature. This is especially true if you use a public source dictionary of spoken phrases, against which an FFT correlation can be run.
I think we should get rid of the CAPTCHA altogether and just rely on URL blacklists, rate limiting and a semi-automated tag and revert system. At least it's future-proof. Our visual CAPTCHA can already be cracked. Some day, every spammer will have access to a library capable of solving it.
-- Tim Starling