I would not choose the term because authenticity means that there is some essential truth about oneself that has yet to be revealed, when really we are always growing and changing. Instead, I prefer the phrase “relateable” teaching voice.
Relateable might not be exactly what those mean when they say authentic, but this is something I value in my teaching voice. Channeling bell hooks, I find my voice in my attempts to engage in conversation with students rather than by lecturing to them.
I don’t always succeed in teaching this way because I feel that strict lecturing is an easy fallback—you can plan ahead and you know exactly what to expect. However, so far, I have found that engaging in conversation with students as a form of class discussion keeps the classroom energetic.