It will be a while before CAPTCHAs are stopped. This might happen,
once compatibility with mobile browsing becomes a universal standard.
But the provider of online info related to my Visa card, for example,
requires me to verify a CAPTCHA every time I sign in. Not just to
change account settings or to do some other specialized or sensitive
task--just to log in to check my points!
The muddy/hard-to-understand nature of the audio CAPTCHA is the whole
point. They want something that requires subjective, human perception
to understand--not just a clear voice-print that dictation software
could translate automatically into text in the way that Grasshopper
does with a voicemail message.