There is a scene in Saving Private Ryan where someone indicates that he knows a soldier who was in combat with a private named Ryan. He goes fetch him, and the soldier is hard of hearing because of a grenade that exploded near his ears; he says that you need to talk to him with a high volume. Captain Miller doesn't raise his voice much, as if it was annoying for him to do so, and eventually prefers to communicate with the soldier in writing.
Are there elements in the movie that could explain such a reaction from him?