Sian Heder’s first feature film, “Tallulah,” a quirky indie 2016 film about truth and lies, compassion and responsibility and creating your own family. It was well-reviewed but didn’t make much of a splash. However, her second film, “CODA” made plenty of noise, shattering all records when it sold to Apple for $25 million at this year’s Sundance Film Festival.

“CODA” stands for Children of Deaf Adults and the film is a coming-of-age tale about Ruby Rossi (Emilia Jones), whose parents Jackie (Marlee Matlin) and Frank (Troy Kotsur) and brother Leo (Daniel Durant) are all deaf. Ruby has her own dreams but she’s the link to the hearing world for her parents. Frank and Leo are fishermen in Gloucester, Massachusetts  and the industry’s struggles add another burden to the family and to Ruby’s plans. Despite all that, the film, while poignant and emotional is frequently laugh out loud funny.

The film, which will be available on Apple TV+ and in theaters Aug. 13, was adapted from a French hit “La Famille Beliere,” which drew flak for casting only one deaf actor. But Heder says her ability to get it made with three deaf actors and then to have Apple pay so much for it is a positive sign, as is the fact that it follows on the heels of the Oscar-nominated films “Sound of Metal” and “Crip Camp” as well as the “Quiet Place” sequel, which featured a deaf actor (Millicent Simmonds) using American Sign Language.

“It sends a message that these projects are viable, and it feels like this isn’t a fluke that Hollywood is finally opening up to these kinds of stories,” Heder said recently by Zoom while discussing her film. “We are really making a change in terms of putting deaf characters on screen and normalizing these families and their lives.”

This interview has been edited for length and clarity.

Q: How did you approach re-making a foreign film?

A: I watched it once. I never looked at the script. The scenes that emotionally touched me found their way into my film, but I also had the freedom to wholly invent the world and this particular family and their dynamic. I felt free to make it personal. I wrote a family that felt like my family – my embarrassing parents, who are way too upfront about their sex life and swear all the time.

Q: Were there challenges in casting three deaf actors in major roles?

A: This started as a studio film, and studios function with a financial model driven by stars and foreign box office. We were getting pressure that we needed to have stars. I was the only one pushing for three deaf actors but once Marlee was cast there were two of us and we said, ‘You guys need to juggle the way you finance things to find a way.’ Those were tricky conversations. Ultimately, it did not happen at the studio and happened independently.

Q: You learned American Sign Language to make the film. How did influence your writing and directing?

A: I was so new to ASL that I didn’t try to write with ASL in mind. I wrote the jokes as spoken punchlines. My favorite part of the process came while working with my ASL master Alexandria Wailes translating the script. Some jokes that were kind of funny on the page became hilariously funny when signed while some dialogue just didn’t work. There was a lot of discovery there. Then the actors had their own ideas about sign choices. It was fun seeing the script as this fluid thing that could come alive with all these different collaborators.

Q: Your father is Hungarian and your mother Welsh. They speak English but did being the child of immigrants help you understand Ruby?

A: I grew up feeling my parents were different from everyone around us—there were little things like being mortified when my dad wearing a speedo on the beach while the American dads were in their Bermuda shorts. There was that feeling of being outsiders in the town, of finding your way within your own community with these boundaries and barriers because of the different cultures. But that’s obviously so much more heightened in this deaf family.

Q: How important was shooting in Gloucester?

A: Gloucester was central to my pitch to get the job. The struggles in the fishing community reflected a working-class America that is dying. Gloucester pressurized the story in a way that made it more realistic. In Boston, the family would have an interpreter at the hospital but that’s not the case in small towns or for people of a certain financial means.

The line producers wanted to go to Canada and cheat it for Gloucester, but I fought hard to film in Gloucester to make it a character and to explore it the way you’d explore scenes with an actor. As we were unloading our boat, real fishing boats were coming in and I would grab guys and throw them in the scene. They’d come into the bar where we were shooting and sit in the background. They infuse the movie with an authentic feel. The specificity was so important. This is the story of one family, and they are just as much defined by their identity as Gloucester fishermen as they are by their deaf identity.

Q: In “Tallulah” and “CODA” you create memorable moments from intimate scenes yet seem to relish taking big swings in terms of plot and emotion.

A: I love the small moments, the human connection — my favorite scene in “Tallulah” is the scene where Tallulah and Margo are lying in bed and talking about death and they have a laughing fit about how they’re both going to die. That conversation was one I had with my best friends on my birthday, with the laughing fit, too.

But as a writer I’m also interested in the transformative moments in a human being’s life, so I go for big swings in terms of emotional catharsis or plot.

Q: Do you create that balance while writing or fix it in editing?

A: I definitely overwrite. I cut 36 scenes that I shot out of “CODA.” As a writer I’m very invested in every character having a full and complete journey. Then you go to edit and you say these fishermen’s struggles are interesting, but we don’t care so much about Fisherman #4.

But digging into each character is time well spent for me — it ends up informing the movie. So while it may seem like a waste of time and energy and money shooting all those scenes you can feel the scenes that aren’t there.

I’ve heard people talk about it being frustrating with writer-directors because they’re attached to their own words on set but I feel the opposite. I’ll say, “This is crap, let’s rewrite it.” The script is the blueprint and then you start building and there’s a lot of freedom to make changes. In the edit I become the writer again but a different writer, looking at it with fresh eyes. It is a collaboration of sorts between these different versions of myself.

Q: Are some scenes especially tough to cut?

A: It can be brutal when you’re very attached to the things you’ve written but sometimes you don’t know the heart of the story until you’re in the edit room and it’s a process.

In “Tallulah,” my daughter was only two and I mostly cut her, but she’s still in a couple of shots. I cut her out of “CODA” and she will not let me hear the end of it.

I cut my parents out of “Tallulah” and my dad would say, “This is my daughter, and she made this movie, and she cut me out of it.” With “CODA” I had to make sure they were in a scene I would never cut. It’s the scene at the concert where Frank is looking at all these strangers. But my dad kept looking straight down the barrel of the camera and I kept saying “Dad, stop.” He’d say, “I’m not” and my mom would say, “I saw him doing it.”

At our screening in Gloucester, my dad was so laser focused on finding himself on screen he said, “Mom wasn’t in the movie.” I said, “She is, she’s sitting right next to you.”

Q: It sounds like a very personal experience.

A: I grew up in Cambridge but we’d go to Gloucester every summer. I went to those quarries as a teen. We used the home of my mom’s best friend to film in. So the town is like home.

Also, my parents were moving out of my childhood home as I was making the movie. On weekends, my dad would arrive with boxes of books and my sixth-grade diorama and ask, ‘Do you want this stuff?’ It was very emotional and thematically on point to be saying goodbye to my childhood home.

There was this amazing Icelandic print sweater I knit when I was 16 and I was very proud of it but it’s full of moth holes now and I’m probably going to throw it away so I wanted to immortalize it in the movie. I put it on my sister and made her walk through this shot in the high school as an extra when Miles apologizes to Ruby. She had to walk the entire length of the hallway in this hot wool sweater for hours. But now everyone can look for it.