"Deaf" people have a mind too and what would their internal monologue be since they never heard uttered words but learn signs that are not auditive internally?

"Deaf" people have a mind too and what would their internal monologue be since they never heard uttered words but learn signs that are not auditive internally? Is it abstract internal monologue? Why would it be called monologue? Are they missing the internal tool of thought or maybe there are more tools of thought and some of them don't require internal monologue?