Select all the files you want to combine to make the audiobook.

Hold down theCtrlkey in Windows or theCommandkey on a Mac to select multiple files.

These files need to be spoken word mp3s, not music, or it won’t work.

Music dropdown menu and Library tab in iTunes

Right-nudge the highlighted files and chooseGet Info.

In theDetailstab of the information window that opens, chooseSpoken Wordas theGenre.

Place a check in the box next toAlbum is a compilation of songs by various artists.

Multiple audio files selected in iTunes

In theOptionstab, smack the drop-down menu next tomedia kindand chooseAudiobook.

you could find the audiobook iTunes created in theAudiobookssection.

Choose it from the drop-down menu.

Get Info contextual menu item in iTunes

Double-hit the newly made audiobook to start playing it.

You should also see that the audiobook has multiple chapters that are the individual tracks that you combined.

Note that this does not create aM4B(audiobook)file.

Spoken Word genre dropdown in iTunes Get Info box

For that, you will need a third-party app, likeLibriVox.

In theDetailstab, uncheck that box next toAlbum is a compilation of songs by various artists.

In theOptionstab, changemedia kindback toMusic.

Album is a compilation of songs by various artists checkbox in iTunes

Audiobook media type dropdown in Options tab of iTunes' Get Info box

OK button in iTunes Get Info box

Audiobooks media dropdown menu in upper left corner of iTunes

Audiobook Info contextual menu item in iTunes

Music media kind drop down menu item in iTunes