[nextaccountic]

I just want to note that for many deaf people (including practically all people that were born deaf) sign language is their first language, and thus, technically, English isn't their native language.

edit: I'm also curious to know more about what kinds of analysis/algorithms you do to detect the accent, if you can share a little bit. Can your app distinguish between different American accents? Or could it hear the user talking in African-American English and assume it is "incorrect"?