what we listen to is primarily influenced by its source, and the source is primarily defined not by the words but by the visual interpretation of the source.
you pose an interesting question about literature. i would say that literature smacks the nonverbal problem right in the side of the head, and i would say that this is a good thing, a very very good thing.
with no nonverbal cues to go off of, literature places all the importance on the written word, so we can write ideas and scenes, etc, without having to overcome the problem of nonverbal communication.
all the world's problems would be solved if we were all blind.