By Hugh Hart

When he was 9, playing in the streets of Belfast one afternoon, Kenneth Branagh thought he heard a distant swarm of buzzing bees coming from down the block. He’d soon learn the buzz was in fact the hum of human rancor generated by rioters storming around the corner.

Fifty-one years later, “Belfast’s” Oscar-nominated sound team re-created that crowd noise at Twickenham Film Studios in West London. “Those sessions were extraordinary,” says sound supervisor James Mather. “Actors who were both Catholic and Protestant were brought into a room to hurl abuse at each other, with Ken directing and writing dialogue as he went. Rarely have I seen a crowd of actors so animated when discussing a sequence.”

Mather and re-recording mixer Niv Adiri, speaking from their homes in England, note that the “Belfast” soundscape, created with their nominated colleagues Simon Chase and Denise Yarde, centered on a clear directive: Branagh’s young stand-in Buddy (Jude Hill) would be the center of this Northern Ireland universe. “It was Ken’s idea that the story be presented from Buddy’s point of view whenever we could and the camera work allowed us to create a virtual world of sound around him that gave the audience an insight into his experience.”

Filmmakers shot most of “Belfast” during COVID lockdown at a regional British airport, where a replica of Branagh’s old neighborhood had been built. Except for dialogue recorded on radio “lapel” mics, virtually all audio elements were captured or curated far from the set. “Knowing that none of the production sounds would get in the way, we had fun building the soundtrack,” says Mather. “We did a car being whacked, windows being broken, explosions. We recorded some nice fire by igniting flame on pre-laid petrol to get that ‘whoosh’ sound.”

The clanking train sounds that permeated Belfast, a busy port city, were recorded near Waterloo station in London. Droning helicopters were heard but not seen, with Adiri using Dolby Atmos audio technology to place the whirring sounds above the audience in theaters’ ceiling-mounted speakers. Mather says, “You hear the trains and you hear helicopters but you don’t have to see them to know what they are. And it saves money!”

The audio palette assembled by Mather and company plays a transformative role in the film’s first five minutes, which go from idyllic childhood to brutal civil war in one sickening moment. “Buddy’s playing football, he’s having a laugh with the neighbors, people are calling his name — we’re setting up this street as one big family. He’s walking down the street with this beautiful [camera] pan around him, and then we do a closeup where we isolate just him with his breath. And then the big explosion in front of him opens up the hellish sounds he’s never heard before.”

Adiri sought sonic clarity amid the chaos. “In the riot scene, you have to clear out so much you don’t need in order to focus on what Buddy would have found disturbing. It comes down to the concept of his memories and mixing in a specific sound for each shot.”

Before “Belfast,” Mather worked on two “Mission: Impossible” movies and four “Harry Potter” films while Adiri won an Oscar for “Gravity” and mixed the “Fantastic Beasts” franchise. Wryly described by Mather as “mega-malist” in scope, the blockbuster aesthetic contrasts quietly with Branagh’s less-is-more concept.

Mather notes, “There’s a sparseness to the [audio] track for ‘Belfast.’ Where you would normally have another layer of generic atmosphere, the background sounds here are really dialed into hearing the story from Buddy’s point of view. Everything about the soundtrack was bespoke.”

Music cues in “Belfast” drew heavily from Irish singer-songwriter Van Morrison’s catalog of emotive Celtic soul songs, which were melded seamlessly into the mix. In a separate email interview, “Belfast” sound supervisor-re-recording mixer Chase points out, “The film doesn’t have a score as such so we used sound design to underscore many of the movie’s emotional moments, and then the through-line of Van’s work helped hang it all together.”

Widely considered Branagh’s most personal filmmaking effort, “Belfast” inspired like-minded contributions from mixer Adiri. He contributed to the film’s kids-at-play background banter by recording his own children romping in the garden. Adiri also borrowed his son’s drum kit and recorded himself playing along to the Motown-style hit “Everlasting Love,” belted out by Jamie Dornan’s Pa character at a local dance hall. “I think our music editor found four bars that were good and maybe kept the crash cymbals, so we were able to bleed that in [to the studio recording] and make you feel like you’re right there, live, with Jamie and the band.”

During post-production, Mather and Adiri worked shoulder to shoulder with Branagh, breezing through the initial sound mix in a nearly unheard-of five days. “It was a joyful sprint rather than a marathon of misery,” says Mather, laughing. “Whereas on ‘Belfast,’ our shorthand with Ken really came into its own and got the film done, quickly, astutely, accurately, with the right tone, the right emotion. So often, you’re slaving away on something into the night thinking: ‘Well, it’s a job. I’m singing for my dinner.’ ‘Belfast’ wasn’t about singing for your dinner. It was about singing for the joy of singing.”