Acquired by iHeartMedia, the podcast “Stuff You Should Know” is now on track for global expansion. The podcast, which has been downloaded more than a billion times in the last 11 years, tackles topics as diverse as artificial sweeteners, time zones and deepfakes. As part of the expansion, iHeartMedia will make “Stuff You Should Know” and five other podcasts available next year in French, German, Hindi, Portuguese and Spanish. Last year, the radio broadcaster bought StuffMedia, the studio that produces the podcast, for $55 million. A number of other media companies are also taking a global approach to podcasting.

The New York Times reports that “major media companies have fully embraced a medium that was once the province of independent hosts working out of basements and garages.” For iHeartMedia, whose main business has been the 850 radio stations it operates in the U.S. and online music app iHeartRadio, podcasts are a new focus.

According to the company’s chief executive Robert Pittman, he “realized that the behavior of this consumer was the kind of behavior we see on radio.” “It’s companionship; it’s the human voice; somebody is keeping me company,” he said. “We think of podcasts as a way for us to extend that companion relationship.”

Some estimate that there are as many as 700,000 podcasts, which, according to the Interactive Advertising Bureau, generated $479 million in U.S. advertising last year. As big media companies get involved, IAB predicts the market will grow to “just over $1 billion by 2021.”

Up until now, iHeartMedia’s business has been mainly limited to the U.S. — although the app is also available in Australia, Canada, Mexico and New Zealand. The company, which also just emerged from bankruptcy and went public on Nasdaq, has already spent $400+ million to buy “several podcast companies.”

Other companies are getting into the podcast business. Luminary, a new service, debuted in April, backed by $100 million, with the aim of becoming “the Netflix of podcasts, with exclusive, ad-free content,” and “Entercom Communications, the second-largest broadcast radio company after iHeartMedia, announced that it was buying two podcast companies, Pineapple Street Media and Cadence13.” Stitcher and Wondery also inked a partnership “to capture more advertising in Britain.”

International versions of popular podcasts bring their own challenges. Podcast companies must “transcribe and translate scripts and cast voice actors and hosts who can approximate the tone and attitude of the originals.” The “slang and quirky Americanisms” make it more difficult, as well as finding “really good voice talent.”

Gimlet Media managing director Matthew Lieber said the company “once considered international versions, but rejected the idea of mere translations or voice-overs as ‘serving audiences warmed-over American food’.” But once Gimlet Media was acquired by Spotify, with its greater resources, the parent company announced plans to introduce international versions of Gimlet’s fiction podcast “Sandra.”