Project Gutenberg brings free audiobooks to the global community with AI-generated book narration

The original digital public library

“Free access to literature creates better opportunities for people around the world,” says Greg Newby, Director and CEO of the Project Gutenberg Literary Archive Foundation, which operates Project Gutenberg. 

Created in 1971, Project Gutenberg is the oldest digital library and the first organization to make electronic versions of public-domain books available via the internet. It is also the leading distributor of free eBooks and publishes more than 70,000 eBooks on its website. A nonprofit organization, Project Gutenberg’s vision is to support freedom of information, giving people around the world access to great works of literature. 

“We believe everyone should be able to have a library, they should be able to carry it around with them wherever they go, and the works should be freely redistributable,” says Newby. “Our most popular downloads include some of the greatest literary works in history, from Pride and Prejudice to Dracula to Alice in Wonderland.”

As Project Gutenberg’s library continued to grow, its audiobook collection remained small despite the medium’s growing popularity—over the past decade, the share of US adults who listen to audiobooks has grown by more than 100 percent according to statistics reported on WordsRated.com. “There’s a lot of demand for audiobooks, but we discovered we weren’t that good at making them,” says Newby. “Creating high-quality recordings was beyond the capacity of our volunteer-driven team.” To make its collection more accessible to a broader community of members—including people who live in rural communities and don’t have access to a physical library, those with visual impairments, children who are learning to read, and those who prefer to listen to books—Project Gutenberg was interested in a scalable way to create audiobooks. 

An AI-driven solution for rapid audiobook creation

A team from Microsoft approached Project Gutenberg about a collaboration to produce thousands of high-quality audiobooks using an AI-driven solution and then give them back to the Project Gutenberg community. These new audio recordings have made Project Gutenberg’s books more accessible to a wider audience of people around the world, including those facing accessibility challenges.

Project Gutenberg first loads existing electronic books from its collection into Azure Synapse Analytics to allow working with large amounts of data. Then, they parse the books and use SynapseML distributed ML library to create audio recordings using the neural text to speech capability in Azure AI services.

The capability turns the text of each book into audio using advanced human-like voices that can even convey emotion. “This is an AI innovation that reads text in a lifelike voice,” Newby explains. “The voices are trained to mimic humans in order to sound natural, and the result is convincing—a big upgrade over older versions of text to speech.”

Some of the AI-generated audiobooks, such as recordings of Shakespeare’s plays, include different voices to portray various characters. They can also generate human-like voices in other languages and adjust the voices to read with more emotion. 

The generated audiobooks are saved as MP3 files to Azure Data Lake for distribution via the Project Gutenberg site and other podcast platforms such as LibriVox, the Internet Archive, Spotify, Apple Podcasts, and Google Podcasts. 

More free audiobooks for all

The collaboration between Project Gutenberg and Microsoft has increased the number of Project Gutenberg audiobooks with nearly 5,000 AI-generated audiobooks. The project also will spread awareness of Project Gutenberg’s mission, improve their collection’s accessibility, and dramatically increase audiobook quality.

Compared to traditional audiobook production using voice actors or volunteer readers, the AI-driven solution provides dramatic time savings. “When we learned about this neural text to speech technology, the possibilities were obvious,” Newby says. “It creates audiobooks en masse, reducing days of volunteer labor to just 30 seconds per book.”

Microsoft donated much of the technology needed for the project, along with strategic planning to create a large collection of public-domain audiobooks. Once the initial library is launched, Microsoft will work with Project Gutenberg engineers to provide ongoing access to an Azure AI services account. In the future, Microsoft will also support Project Gutenberg to upgrade to Data Science in Microsoft Fabric, the SaaS version of machine learning in Azure Synapse Analytics, a PaaS product. “The goal is to make sure they have access to this solution going forward. They’ll be able to regenerate files that are updated and expand the library to other books.”

“Access to knowledge is a public good and a human right,” Newby says. “And now, with audiobooks, Microsoft AI is helping us expand our reach to whole new audiences. Our library is more accessible than ever.”

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