Provide alternate audio CAPTCHAs to support visual CAPTCHA tasks
Make sure alternate audio CAPTCHAs are also provided and serve the same purpose
Regular CAPTCHA images rely on a user’s ability to see an image and report what it contains, but not everyone can do that easily. When users are visually impaired or simply can’t figure out what characters the image contains, the only option is often to rely on a different version of the CAPTCHA. By providing alternate CAPTCHA tasks that use different modalities, such as audio, users are more likely to be able to complete one of the tasks successfully.
To do so, simply make sure that alternatives to the default distorted text CAPTCHA images are also provided, whenever CAPTCHA tasks are required. These alternatives will often take the form of audio versions of the exact same CAPTCHA test, so that people who cannot see (or simply recognize) the CAPTCHA image still have a chance at successfully completing the test through other means. By combining an image version of the CAPTCHA with an auditory version of the same CAPTCHA, all users, including non-sighted users using assistive technologies, stand a slightly better chance of successfully completing the test. While doing so will [...]