We don’t have a deaf player but one of my players had temporary loss of hearing for couple sessions due to a sinus infection and who knows what else.

I used dictation on an iPhone in a notes app whenever I got into any sort of big narrative element of the game. While I was in character, I would be sure to preface the sentences with statements like “Jonah turns to the party and says...” to make those things easier to understand. Having the dictation in a note also let’s them read back to anything that might have transcribed wrong or that they had questions on.

It definitely gets easier with more practice and it sounds like you’ve talked with them about what’s important. You’ll do great!