Oto hakase was the post to teach pronunciation of Chinese language in those days when people read Keisho (most important documents in Confucianism) of Confucianism (see Ondo (study of pronounciation of Chinese language) for more information).
これは儒教の経書を読む際に、当時の唐語（漢音）による音読法を教えるための役職であった（詳細は音道を参照）。