Super impressive. My wife just spoke full-speed Vietnamese into a Google Doc, 100% correct, even the tone marks.
Is there something particular about Vietnamese that makes it easier than other languages for dictations? Like, does it lack homophones, are letters always pronounced the same way? 100% correct sounds incredible.
phonemic orthographies (These languages should work better) - https://en.wikipedia.org/wiki/Phonemic_orthography
English is highly non-phonemic the only language I would think is worst is French/Greek with silent letters and the different accents and in Modern Greek /i/ can be written in six different ways: ι, η, υ, ει, οι and υι. My Italian and most Eastern European languages would be easier European languages for voice translation.
This seriously reminds me of my days in college and grad school learning/teaching dead languages. The dead languages (Latin, ancient Hebrew, Classical/Koine Greek and Aramaic) we really don't know how they were pronounced so we just made them phonetic, which tells you that we don't speak them correctly since no language is 100%.
Vietnamese is interesting because there are several dialects that would trip this up but doesn't appear to. https://en.wikipedia.org/wiki/Vietnamese_language