The APA Publication Manual doesn't specify what to do with a book on tape when you would like to credit both the author of the book and the narrator (when they are different), but our suggestion is to provide the names as shown here:

Rowling, J. K. (Author), & Fry, S. (Narrator). (2000). Harry Potter and the chamber of secrets [CD]. Bath: Cover to Cover.

This is similar to what you do with names when you want to cite several contributors to a motion picture (for example, the writer, director, producer, etc.).