Apple has launched a new catalog of audiobooks in the Apple Books service, which are distinguished by their voiceover without humans. These books are voiced by artificial intelligence, and maybe that’s why Apple hasn’t advertised the launch in any way.

Apple was originally supposed to launch the project in November, but delayed the launch due to market turmoil, including Elon Musk’s acquisition of Twitter.

Interestingly, the site now states in the audiobook section that it is “told by a digital voice based on a human narrator.” It is unclear how exactly this is implemented. Audiobook sales have been increasing rapidly in recent years. For example, they grew 25% last year to $1.5 billion, and by 2030 analysts expect the market to grow to $35 billion.

Using artificial intelligence instead of humans to dub a book is very beneficial for publishers. A process with live players or at least one player can take weeks and cost thousands of dollars. The machine will process orders of magnitude faster and will only require initial investment.