Supervising sound editor Jane Tattersall, sound designer Brennan Mercer and re-recording mixers Matthew Chan and Lou Solakofski knew the stakes were high for Paramount+ series “Halo,” based on the wildly popular Xbox video game, which for years had been trying to make the leap to movie theaters.

“There was enormous pressure,” says Tattersall of the series, which is in the middle of its nine-episode first-season run on the streamer. Also head of sound for Toronto’s Formosa Group, which was responsible for post-production sound work on the show, Tattersall says producer Sheila Hockin had told them that “it’s very important to learn not only the world of the game, but also respect the fans.” Set in the 26th century, “Halo” focuses on a cybernetically enhanced super soldier known only as Master Chief (Pablo Schreiber), who leads his fellow Spartans in defending humanity from an alien race.

Hockin connected the sound designers with 343 Industries, the studio behind the video game. That was “the root of everything,” says Mercer who masterminded the sounds. “Every vehicle, every weapon, we got a source session,” he adds. These include a vast array of plasma weapons and vehicles. For the artifact, a mysterious object that generates visions each time Master Chief holds it, Mercer created the sound by using a different blend of energy pulses and crackling electricity.

Once they had that foundation, the team could begin to build an aural future world at war with aliens. Mercer says it was important to establish a separation between the humans and their foes. For instance, the Spartans’ mainland vehicle, the Warthog, has the familiar sound of a V8 engine. “A lot of futuristic shows [would] have electric engines, or it’s assumed that things would be more environmental,” he says. The V8 creates a contrast with the aliens and their plasma technology.

Solakofski, meanwhile, concentrated on the dialogue and enjoyed exploring what Master Chief might sound like with his helmet on, or how other characters’ voices would come through his headset. A particularly challenging mix comes when we meet the prophets Mercy, Regret and Truth (Julian Bleach, Hilton McRae and Karl Johnson) in a cavernous chamber made of alien materials rather than metal or brick — meaning that words needed to carry in an unusual way. “When the prophets spoke, I put in a fluttery, low-frequency reverb that their voices triggered,” Solakofski says. “But I didn’t put it with the dialogue. I put it off to the sides and above you, so it kind of felt like the room was reacting to their speech.”

For Chan, an area of focus was the design of the Spartan suit. “We knew pretty early on that we were going to deviate from the game, because they needed to sound really heavy” but not immovable, he says. “We didn’t want it to sound like a clunky metal pile of junk.”

Though the team’s job was to create a wide array of unusual sounds, Mercer says a starting point for much of the work was to touch on something familiar — a door, for instance. “Then you can build a foundation,” he says. “Usually there’s one in every scene, and you chip away at that.” Adds Tattersall, “It also feels like you’re making progress.”