I just finished the book The Princess Bride. Of course, I've seen the movie dozens of times. Normally, I like to read the book before I see the movie. But I started watching The Princess Bride in college when I didn't have much time to read for fun.
At any rate I was very impressed with how well the story translated between the two mediums. Even elements of the narrator's voice seemed to be portrayed to some extent both in the book and the movie. The humor, tone, and style did not suffer in either method of telling the story.
Contrast that with The Hitchhiker's Guide to the Galaxy. Hilarious book. Mildly entertaining BBC TV depiction from what I saw. The movie released a couple of years ago was simply awful. It was just not funny. So much of what made the book work was the voice of the narrator and the movie version just wasn't able to convey the same nuances. Sure, they changed elements of the story but that wasn't the problem. It just didn't feel like the same story without the voice of the author.
Words convey information and tell stories. But it's more than that. Who is telling the words and in what context is important. How the words are shared is also important. Tone and style really make a difference in effective storytelling, and effective communication for that matter.