I had no clue what I was supposed to do.
That is especially true for a foreign language teacher. Students need to hear the target language being spoken as they read the text.
Quite a bit of research on language comprehension reveals that sub-vocalization improves comprehension in individual's struggling to read.
Beyond the research, I would also argue that subtle intonations and pauses in the text lead to natural speech, which is critical for students who seek to use their language abroad and be comprehended by others.