Not all publishers contract for audio book rights. As with print books, the production costs can be immense, and small publishing houses especially will focus their energies to where they can make the most money: eBooks.
Theoretically, anyone with a copy of a book and a voice recorder can narrate an audio book. Many authors do just that to make their books available through platforms like Audible. It should be noted, however, that certain quality and content standards do apply, and not meeting them will get a book rejected by the platform.
Another option is for authors to hire a professional voice actor. Depending on the terms of the contract, voice actors can either be paid in one lump sum, calculated based on their hourly rate and the final length of the narrated book, or through a portion of the royalties. Rates will vary, and authors will usually be responsible for holding auditions and negotiating rates and timelines, unless a publisher or agent is involved.
The final product can take physical or digital form as audio CDs or MP3 files. These would then have pros and cons similar to print and digital books, including the risk of piracy. However, there are additional benefits, too. Having a professional audio book available in stores makes books discoverable to readers with impaired vision, or those who simply prefer to listen to books, rather than read them. Amazon now offers a text-to-speech option which links a purchased Kindle book with its Audible version, if one is available, for an additional cost. This provides a smoother and more enjoyable listening experience than the generic text-to-speech option.
NOTE ON PRICING:
The price of an audio book will be determined by the cost of production, which is dependent on the length of the book. Longer books will cost more and get priced higher than shorter books. Note that the producer’s fee does not factor into this, unless they are paid out of sales royalties. Audio books are usually priced higher in stores than even print versions.