If you want a #CAPTCHA, maybe this?

Or we should say was, the original site (#ejeliotDotCom) is gone, but seems one can still get it from the #InternetArchive. Not an endorsement — it doesn't do things in a way we fully recommend but could help:
https://web.archive.org/web/20170716204040/http://www.ejeliot.com/pages/php-captcha

For #accessibility it used a voice/#speech system, #FLite. A link that works and has basic SSL, again courtesy of the #WaybackMachine here:
https://web.archive.org/web/20170709113809/http://www.festvox.org/flite/download.html

#FreeBSD licensed.

#CMU #CarnegieMellon #PHP