Image copyright Getty Images Image caption South Korean director Bong Joon-ho

The South Korean dark comedy film Parasite had a historic awards season sweep - and in the process, reignited the debate over whether subtitles or dubbing is the best way to watch a movie that isn't in your native language.

As director Bong Joon Ho accepted the first-ever best foreign language picture Golden Globe for a South Korean film, he said: "Once you overcome the one-inch tall barrier of subtitles, you will be introduced to so many more amazing films."

Fast forward a month, and he was making history again, accepting the best picture award once more at the Oscars. Parasite's Oscar win introduced it to a broad US audience - but not everyone was in favour of watching the award winner in its original language.

Dubbing takes the stress out of enjoying a foreign film, some argued, and performances are meant to be heard, not read. The angered response from subtitle fans ranged from accusations of racism to pointing out the needs of deaf viewers.

How you watch a foreign film is a clearly personal matter, tangled in pet peeves and accessibility. But as foreign flicks are gaining more screen time before American audiences, here's a deeper dive into how we got here, and where the industry is headed.

In the early days of film, on-screen text was far from a "one-inch barrier" - it was the only way to express dialogue. Title cards were the precursor to subtitles, and they, too, were controversial in a way that mirrors the modern debate.

Stage actors would try to hide their work in silent film as many felt the lack of sound diminished the quality of the performance, Professor Marsha McKeever of the undergraduate Film and Television department at New York University's Tisch School of the Arts, told the BBC.

Image copyright Getty Images Image caption Silent era film stars (from left) Mary Pickford, David Griffith, Charlie Chaplin and Douglas Fairbanks

But when conversations took place through cards instead of sound, adapting films to other languages was straightforward. As "movies" turned into "talkies", subtitling emerged as a way to hold onto a lucrative foreign market.

It has since become the preferred way for film critics and connoisseurs to view foreign language features. NYU faculty, for example, would be unlikely to show a dub in class, the university's graduate film department said.

For Prof McKeever, who is also a sound and picture editor, much of enjoying a movie boils down to what you hear.

"We react so emotionally to sound. That's why films are scored, that's why dialogue is important."

If a dub has sub-par voice acting or doesn't properly sync with what you see on screen, it can negatively affect your perception, Prof McKeever says. With subtitles, the audience both sees the original performance and hears the original emotion.

"Your brain is so used to hearing emotion in language that it will get the meaning behind the subtitle through the performance by the actor in the original language. You hear if they're sad, if they're happy."

Regardless of what film purists say, however, dubbing is on the rise.

For that, you can blame Netflix.

In October, Netflix reported it had more subscribers outside the US - nearly 100 million - than domestically, where just over 60 million pay for the service.

Image copyright Getty Images

The streaming giant is driving the dubbing business by producing content around the world and localising it for a number of markets, says Jeff Howell, a vocal coach and director who works with Netflix.

To "localise" a production, the original studio hires professionals to analyse scenes and translate them to a new language.

Mr Howell has worked both as a vocal director and an "adapter" who works on casting and direction. "We spend quite a bit of time casting, sometimes we have to read-to-picture to make sure the voice sounds like it's coming out of that mouth," he says.

Dubbing has a bad reputation because, for years, it was badly done, he says - there was a lack of attention to detail to the voice acting and post-production processes.

But today, professionals are focusing on ways to make it better, carefully interpreting scripts and taking into consideration things like "lip flap" - when the mouth movement and dubbed-over voice do not sync up.

Dubbing defenders say that modern viewing habits make it superior to subtitles.

Mr Howell argues that dubbing is better for audiences as they increasingly view films and series on small, portable screens. "You can't read subtitles on a phone or iPad, really," he says.

And dubbing is easier on the brain. Getting information from a caption requires eye movements across a screen, cognitive input to interpret the words while also paying attention to the action on the screen.

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An educated US adult can do all three fluently, says Prof Charles Perfetti, a cognitive science professor at the University of Pittsburgh, but a less skilled reader will find it taxing.

For viewers with visual impairments, those cannot read or have conditions like dyslexia, dubbing is the only way they can enjoy media in non-native languages.

Outside the English-speaking world, dubbing has been less controversial. Much of Europe opts for dubbing in lieu of subtitles, though the latter is cheaper. Germany, Italy and France have dubbed foreign films since the 1930s - even as early critics blasted the process as "witchcraft" and an "amputation" of the original. China has also dubbed films into Standard Mandarin.

Netflix's dubbing efforts seem to be converting some Americans to the cause. Most US viewers preferred the dubbed versions of its most popular foreign shows, the streaming service told the New York Times.

As a dubbing director in this new streaming-heavy world, Mr Howell emphasises that he works to respect the original content - "to protect it", not change it- though he admits some alterations are unavoidable.

"There are cultural nuances in language that we can't possibly recreate," he says. "We can have the greatest adaptation and it could line up almost perfectly but there are going to be subtle differences that don't translate.

"It's not 100% but I'd say we get as close as we possibly can, directing it in such a way that we're protecting the creative integrity of the culture that created the material."

And to be fair, alterations happen with subtitles too - language can be simplified to allow for quick reading in time with the action on screen.

Debates aside, outside of the streaming realm, foreign-language films still struggle to reach US markets.

As of 2020, only 12 have ever been released in more than 1,000 American theatres, according to data viewed by Quartz. Before Parasite, the last was Jet Li's Fearless in 2006. When it debuted in October, the 2020 Best Picture Oscar winner was screened in only three theatres.

Yet, as its awards success has shown, a good film will captivate audiences no matter in what language. Subtitled films have rarely grossed over $100m (£77m), but Parasite has already surpassed $200m worldwide.

The biggest foreign language film to find success in the US to date is the Chinese drama Crouching Tiger Hidden Dragon, which grossed $128m in 2000 and won the Oscar and Golden Globe awards for best foreign language film.

"What it speaks to more than anything is we're looking at filmmaking as the craft, not being bogged down in where it's made and who is saying what in what language," says Prof McKeever. "Is it a good story, is it done well, are we there emotionally with the actors?

"Regardless of language, that's the heart of moviemaking."