Filmmaker Sian Heder reinvented her way of directing while making “CODA,” which will premiere on Jan. 28 at the 2021 Sundance Film Festival.

Heder learned American Sign Language because the feature film is about a 17-year-old girl, played by Emilia Jones, who is torn between pursuing her love of music and the fear of abandoning her deaf family, portrayed by deaf actors Marlee Martin, Troy Kotsur and Daniel Durant.

“CODA” is an acronym for Child of Deaf Adults, and is a remake of Éric Lartigau’s 2014 French film, “La famille Bélier,” according to Heder.

“The producer who produced that, Philippe Rousselet, had the rights to do an American version of the film,” she said. “One of the things that was interesting to me was they were interested in adapting the film, but they wanted someone to make it unique and take the premise from the original and, also, reinvent it.”

Heder learned sign language while writing the script, because 40% of it was in ASL.

“I knew I was going to be directing in a language that I didn’t speak, and it was important for me to at least have a basis,” she said.

In addition, Heder hired a rotating cast of interpreters to facilitate communication between her and the deaf actors, as well as the communication between the actors and other crew and staff.

Adding the extra person in the mix proved to be difficult, because she didn’t know if any of the nuances of her directing were lost in translation, according to Heder.

“Directing actors is probably my favorite part of directing, and it’s a very close relationship,” she said. “A lot of times there are some incredible subtleties in the word that you’re using to give an acting note. So, there is a lot that’s happening on my face and body that was not being communicated.”

Midway through the first day of shooting, Heder and her cast decided on a new method of operation.

“I would come up to them and sign first, and if we needed clarification, the interpreter would come in and help us to have the conversation,” she said. “Also, you can’t call ‘action’ and ‘cut’ in the same way. You have to have visual cues. I got used to running into a scene and touching someone’s shoulder and moving them around physically.”

The new routine worked out, and Heder quickly learned more signing.

“I’m sure half the time my signs were nonsense, but they were very patient with me,” she said, laughing. “It was really important because it forged a very strong connection with all of us.”

Heder wanted to hire deaf actors from the beginning of the project.

“I knew there was no way to achieve the authenticity that I wanted in this family and these characters without finding amazing deaf actors who could embody those roles,” she said.

Academy Award-winning actress Matlin was the first person Heder cast.

“I thought it was a fun opportunity for her, (because) so often she’s playing these ‘put-together’ and classy characters,” Heder said. “Marlee, in real life, is much more funny, and she has a dirty sense of humor. This (role) was a working-class fisherman’s wife, and she has a lot of elements of her personality that were very right for this character.”

Matlin, through her connections in Deaf West, a theater company, helped Heder find the right actors from the deaf community.

Heder first saw Troy Kostur, who plays Matlin’s husband Frank, in a Deaf West production.

“I thought he was incredible on stage,” she said. “He came in to audition for me and was so right for the part. He’s funny, mischievous and also emotionally tapped in. He felt like Frank.”

Rounding out the family is Durant, who plays the older brother. Heder found him through auditions.

“I saw him on tape and Skyped with him,” she said. “He (embodies) this young, fit working-class guy, but also someone who’s holding all this anger and frustration.”

The cast already had some chemistry because they had worked together before in Steven Sater’s Broadway musical, “Spring Awakening.”

“They already forged a connection with each other,” Heder said.

The filmmaker also took meticulous measures to find the actors to play 17-year-old daughter Ruby and her music teacher Bernardo Villalobos.

“Whoever I found to play Ruby, the lead, needed to be very serious about going into training and learning ASL and looking like she was a native speaker,” Heder said. “Most CODA’s are raised culturally deaf, and ASL is their first language. So I knew that was going to be essential for that actress.”

Plus, the actress was going to have to learn to sing and learn to fish on a commercial fishing boat, she added.

After looking at “hundreds” of girls, Heder met Jones.

“She has so much charm and vulnerability, but (she also has) that working-class toughness to her where you believe that she’s that girl who is out on those fishing boats,” Heder said.

Once cast, Jones took voice lessons and did nine months of ASL before the film started shooting.

“It was a rigorous process, and I think she was amazing,” Heder said.

Villalobos is an amalgamation of Heder’s college rhythm teacher and her high school drama and English teachers.

“(The high school teachers) were tough, but you really knew they were invested in you and wanted you to succeed,” she said. “(The) teacher in college was from Peru and an amazing teacher in my life.”

So when Heder met Eugenio Derbez, she knew he was right for the part.

“He’s known for doing comedy, but as a human being, he’s very open, warm and present,” she said. “I knew he was capable of tapping into this more dramatic serious side. I loved working with him. He gave such a grounded, lovely performance.”

Heder thinks it’s significant to screen “CODA” at this year’s Sundance Film Festival, because of the coronavirus pandemic.

“This is a story that is a love letter to a family, and I do think that if anything good has come from this pandemic for me and for a lot of people in my life (is) more family time and connection between parents and kids,” she said. “As hard as it is being home all the time, I think a lot of people have found amazing joys in that. And I think it’s a good marker for the time we’re in.”