Hello! Self-voicing is available in the game and image captions have been included where necessary in the story (the game is narrative-heavy so much of the description happens naturally in the narration, but additional image captions have been added for moments where something is not described).
Having said that, it hasn't been tested all the way through the entire game. I'd be happy to look into any potential bugs or oddities that may arise that I wasn't aware of though.