Let's start with a couple of basic premises about the expectations that your listener has:

• More than anything, your listener wants you to focus on telling your story. Your listener wants you to grip his attention from the first line and never let go. Do that, and you don't need to worry about how your voice sounds.
• Because you are the book's author and not just a narrator, your listener is hoping that you will give him some unique insights into your work. Those insights will come from the dramatic emphasis that you put into the narration. That means you have to do more than just read your book out loud. You have to think about the message you are conveying all the time.

What standards should you be meeting? At a minimum, your narration should come up to the level of quality that the National Library Service for the Blind and Physically Handicapped, of the Library of Congress, says that narrating a book should attain: “1. Ideally, narration is translating the written word to the spoken word in a way that is as consistent as possible with the intent of the author.” “2. At the least, it is translating the written word to the spoken word in a way that is intelligent and agreeable to the listener.”

Those are not very high standards, and probably not very helpful either. What does it mean to be consistent with the intent of the author, if you are the author? Does that mean you can read it any way you want, and then say, “That's what I intended”, even if it makes no sense to a listener?

And “intelligent and agreeable” is a standard that may satisfy your friends and family, but may fall far short of the expectations of an experienced audiobook listener.

Your listener wants a presentation that reflects skill, insight, and most of all, imagination. You have to provide the spark, and turn it into a flame, if you want people to rave about your audiobook. You have to exude energy. You have to get the timing down perfectly. You have to show off your ability to raise the level of tension, conflict, and suspense in your story to the highest level.

How are you going to do that? To start, you are going to focus on developing your vocal skills. The voice of a skilled speaker may appear to have a seamless quality, but that is only the illusion that comes from having developed a lot of separate skills. Vocal skill breaks down into lots of smaller parts that you can practice one at a time. Think about an NBA professional basketball player. When it is game time, the player gives the fans a quality performance. But between games, the basketball player practices all kinds of techniques over and over, such as jump shots, corner shots, passing, and all the separate aspects of the game. Just like a basketball player develops his skills, there are equivalent skills which you can practice for making an audiobook. Some skills will come easy to you, but other you will need to practice a lot to get good at them.

You have to learn to crawl before you can walk. So direct your first efforts toward speaking in a way that is 'intelligent and agreeable' to your listener.