45 Gran Cursos Audio

For expanding educational access with a massive collection of audiobooks in Portuguese

A major edtech player in Brazil, Gran Cursos Online has a clear mission: democratize education for all who seek a better future, especially those without access to in-person classes. Yet the company’s robust course offerings—which includes approximately 28,000 books—weren’t available to the roughly 7 million people in Brazil who are vision-impaired or blind. (Or those folks who just prefer to learn via audio.)

To remedy that with a radical accessibility boost, the company partnered with BRLink, which had previously developed an automated system for adding subtitles to Gran Cursos’ smaller library of video courses. The goal: convert all of the company’s content into audiobooks, creating the largest collection of Portuguese language audiobooks in the world. 

It was a bold goal—and so were the means to achieve it. 

Audiobooks are typically recorded in a studio with the help of voice actors, unidirectional microphones, amplifiers and computers. On average, it takes about 20 hours to record a 10-hour audiobook, not including editing time. But Gran Cursos didn’t want to turn the effort into a manual slog, so the 40-member team of data scientists, reviewers and developers leaned into AI, transforming what could have been a years-long undertaking into a short sprint. 

Following a successful proof of concept, the team was ready for action. BRLink recorded the books using Amazon Polly, the tech giant’s neural text-to-speech voice delivered through a new machine learning approach. Then BRLink created Python algorithms to extract the text from the courses (more than 4 trillion characters in total) and format it in PDFs. After that, the text was converted into the Speech Synthesis Markup Language, which strips the text of data that isn’t relevant to audiobooks, like header and footer texts.

Once the text was extracted and recorded, Portuguese language experts at Gran Cursos embarked on an intensive review process, listening to more than 700 hours of audio to pick up on word pronunciation mistakes and correct them using Amazon Polly. Finally, BRLink generated the audiobooks for the Gran Cursos class catalog. The initial project schedule spanned just two months: one week to generate first drafts of the entire audio library, and then seven weeks for the meticulous review and audio edits necessary to make the resulting 86,000 hours of audio user-ready. 

This July, Gran Cursos rolled out additional features, such as online access to complement its app and a feature that lets users pause listening and pick back up later. 

The project puts the company—which has been dubbed “the Netflix of employment exams”—one step closer to its ultimate goal: helping learners pursue better employment opportunities by studying how and when they want.