Both must be optional!
My wife from Poland is raised with dubbed TV. It is the most horrific dubbing you can imagine: ALL voices are READ by ONE old man without ANY acting talent, just plain reading. The original sound plays simultaneously, a little toned down. She and all other people from Poland that I know, are totally OK with this. https://www.youtube.com/watch?v=LTnscwlKV_k
In short: you can get accustomed to almost anything - hence make everything optional always.
While we are on the subject of options: If possible I always turn down game music to zero. Nintendo games seldom give this opportunity so I play them VERY silent.