Here's an excerpt from chapter 6 of Words On Tape to help you toward your goal. Many experienced audio producers believe authors should stick to creating the content. People who are trained in interpreting and delivering a script usually give a better performance.
Performance matters to listeners.
Other authors are great interpreters of their own work. Bringing a book alive in a recording booth is different from amateur theater, reading to children and friends, or talking on the telephone. Some skills are transferable, and some aren't. Recording sessions can have many stops and starts, even with highly paid professional narrators. Inexperienced narrators find these interruptions unnerving.