> The service could present a phrase for the user to say That might work, although it might be a bit like an audio-captcha (i.e. frustrating): "Please repeat

> The service could present a phrase for the user to say That might work, although it might be a bit like an audio-captcha (i.e. frustrating): "Please repeat this phrase: Mary had a little lamb, its fleece was white as snow." "Mary had a ... what did you say it was? Oh, a little lamb. OK, and its fleece was white as snow." "Please repeat the exact phrase: Mary had a little lamb, its fleece was white as snow." "Mandy had a lamb whose fleece was white as snow." "Please repeat the exact phrase ..." I can see certain types of user not thriving at this activity.