Audio has been around since, I suppose, the spoken language. The difference now is distribution and availability. Audiobooks, podcasts, smart phones, voice controlled home speaker systems, connected cars, and who knows what will come next.
You have audio. You probably have a book cover. You're all set. Using an online (and mostly free) tool called Headliner, you can easily...
I got introduced to audiobooks because of having a baby. -- Susie Bright
Maybe it's a personal preference but I'm into the atmosphere. [ https://youtu.be/IInkT6n-NiM ]