There is an Apple Support Discussion thread about this issue here: Ripping a CD Audiobook in iTunes 12.7
iTunes version 12.7 no longer allows you to batch-edit the “Media Kind” metadata attribute of a ripped audio file. Ergo, it is no longer possible to easily rip a series of CDs comprising an Audiobook straight into iTunes 12.7 and then batch-convert them to an iTunes Audiobook format for ease of use on iPod, iPhone, iPad, etc.
Fortunately, all is not lost, and there are a couple of methods to get around this frustrating, new lack-of-a-feature in iTunes 12.7
Method 1 – using iTunes & Finder
If you want to rip an Audiobook from a set of CDs, you’ll need to import each disc in AAC format first. iTunes will consider these .m4a files “Music” and you would be able to edit one file at a time and change the Media Kind from “Music” to “Audiobook” from within iTunes, however, you will NOT be able to select more than one track and/or more than one Disc and batch edit them.
So instead, after you have finished ripping every disc of your Audiobook into iTunes with the AAC Encoder set to Spoken Podcast, you’ll want to click on one of the tracks on one of the discs and use the command, “Reveal in Finder” (⇧⌘R)
Next, go to the Finder Menu and choose, “Preferences” (⌘,)
Check the box marked, “Show all filename extensions” and uncheck the box marked, “Show warning before changing an extension” (optional)
Unchecking the second box will save you a LOT of time and clicking on a dialogue box which will pop up for each and every file in the subsequent steps.
Now, since you’ve already revealed the files in the Finder, go ahead and select all of the .m4a files and choose, “Rename n items…”
In the “Find:” box, type .m4a
In the “Replace with”” box, type .m4b (this is the filename extension iTunes 12.7 will recognize as an Audiobook)
If you did not uncheck the box, “Show warning before changing an extension” earlier under the Finder Preferences, you’ll get a warning dialogue box. No big deal, but you’re going to have to click the button, “Use .m4b” once for every single file you’re trying to batch rename… which could take a long time.
Once the files have been successfully renamed with their new extensions, you can add them back into iTunes by choosing, “Add to Library…” (⌘O) from the File Menu.
If you’ve done everything right, you’ll be able to Get Info on one of your Audiobook tracks and see that iTunes now recognizes it as such. You’ll also note that, for whatever reason, iTunes will allow you to change the “Media Kind” to some other type, even when selecting an entire Audiobook. ¯\_(ツ)_/¯
Method 2: Audiobook Builder
Turns out that there is a pretty nifty app that makes this process more convenient and allows detailed control over the elements of digitizing an Audiobook. Merging multiple tracks together, creating chapter markers and specific metadata tags is pretty easy with this app.
It’s called Audiobook Builder (App Store)
During the time I wrote this article, I used Audiobook Builder to import and format several Audiobook CD sets with success. The ability to stitch together the many tracks across multiple CDs and turn them into “Chapters” inside of one, single file is quite nice. The app can import directly from CD or import files that have already been transcoded in another program, such as iTunes.
There are a number of other features which I have not yet explored entirely, but on the whole, for $5, it’s well worth purchasing, especially if you have a collection of Audiobooks on CD.