The extraterrestrial “heptapods” at the center of the new sci-fi thriller “Arrival” aren’t the only strange, poorly understood creatures in the film. The other aliens, it turns out, are linguists, represented by Amy Adams’s Dr. Louise Banks, an academic field researcher who is recruited by U.S. military intelligence to help communicate with a race of seven-legged E.T.s that have descended on Earth, with intentions unclear, from another world.

“A lot of people don’t know what linguists do, or even that we exist, apart from some idea that we just translate lots of languages,” says Jessica Coon, an associate professor of linguistics who consulted on the film and provided a loose model for Louise. Coon unsuccessfully lobbied the filmmakers to change a line describing Louise, arguing that it misrepresents what linguists do: “You’re at the top of everyone’s list,” Forest Whitaker’s Army colonel says to Louise, “when it comes to translations.”

Coon also tried — and failed — to get screenwriter Eric Heisserer (“Lights Out”) to change Louise’s backstory. The character is said to have security clearance from an earlier mission, translating Farsi. “I said, ‘No, no, no. The military is going to already have Farsi translators,’ ” Coon says with a laugh. “[Louise] needs to be working on a minority language that nobody is a translator for, like Burushaki.” (That language is spoken by the Burusho people of northern Pakistan.)

Amy Adams, with Jeremy Renner (left), plays a linguist trying to teach herself an alien language in the brainy sci-fi thriller “Arrival.” (Jan Thijs/Paramount Pictures)

Linguists, Coons explains, aren’t so much glorified translators as they are theoreticians, more interested in the why of humankind’s natural affinity for language acquisition, when other species aren’t hard-wired for it. According to Coon, real linguists just aren’t all that interested in the Sanskrit word for “war.” (As the film notes, intriguingly, it literally translates as “a desire for more cows.”)

In preparation for the shoot, a design team visited Coon’s office at McGill University in Montreal, where the film was shot, poring over her bookshelf and even inspecting the kind of bag she carries in the field. In one scene, set at the military encampment at the foot of the hovering alien spacecraft, you’ll see some of Coon’s handiwork in the background. “Imagine a military officer has helicoptered you here,” Coons recalls the set designers telling her. “You’re getting ready to start working with aliens. You have a team of 50 military cryptographers at your service. You’re in charge. What’s written on the whiteboard?”

Her answer?

Lots and lots of questions: Is there air coming out of the aliens’ “mouths,” or is it going in? What are their “articulators”? (Meaning: Do the aliens have tongues and teeth, or perhaps something more like blowhole-like orifices with flapping diaphragms?) In Ted Chiang’s 1998 short story, on which the film is based, the sound the aliens make is described as vaguely resembling “a wet dog shaking the water out of its fur.” In Heisserer’s screenplay, it’s described as a mixture of “whispers and clicks and low whale song.” In the finished film, what we hear is a little of all that, plus some bestial vocalizations, courtesy of Coon’s McGill colleague Morgan Sonderegger and the film’s sound department, who collaborated on the aliens’ spoken language, known in the film as Heptapod A.

As it happens, Heptapod A isn’t just unrecognizable, but irreproducible by human vocal chords, leading to what Coon calls a temporary “dead end” in the film’s narrative. Enter Heptapod B, a written language that the aliens squirt from one of their limbs, like squid ink. Chiang’s story called the calligraphic text an evocation of “fanciful praying mantids drawn in a cursive style, all clinging to each other to form an Escheresque lattice.” When writing his screenplay, Heisserer included his own prototype of these “logograms,” crafted from a digitally altered version of J.R.R. Tolkien’s Elvish language but rendered in a closed circle. Production designer Patrice Vermette took that circular theme home to his artist wife, who created beautiful drawings. These ended up in the film, along with several of Coon’s pen-and-ink notations on them.

The fact that Heptapod B text is non-linear — there is no beginning, middle or end — figures prominently in the plot, as well as in the movie’s key twist. So does something called the Sapir-Whorf hypothesis, a linguistic theory positing that the language we use influences the way we see the world.

Now, before your eyes glaze over while reading those words, relax. The most famous example used to explain Sapir-Whorf comes from anthropologist Franz Boas’s research: Because the Inuit language has so many different words for snow, as Boas reported, Eskimos may see snow differently from the rest of the world. They may even think about snow differently.

Although Sapir-Whorf is applied in “Arrival” with a healthy dose of poetic license — as it is in Chiang’s story — Heisserer says he struggled mightily to excise some of the writer’s other, even wonkier references: Fermat’s Principle of Least Time, for instance, along with something called Snell’s Law and Bayes’s Theorem (as applied to global population). If he hadn’t, Heisserer jokes, “Arrival” would have arrived in theaters as little more than “a series of TED talks that we tuned into a film.”

As it happens, the movie is not just a brainy meditation on how communication affects cognition, but also a deeply poignant, heartfelt rumination on memory, connection and love. As the author of the book “Aspects of Split Ergativity,” Coon jokes that anything that raises the profile of her field, while making linguists not just more down to earth but also heroes, is “a very, very good thing.”

Arrival (PG-13, 116 minutes). At area theaters.