Decoding the sound of The Imitation Game

It’s always nice to be rewarded for hard graft in audio, especially when it’s a BAFTA nomination for Best Sound. Adam Savage spoke to Lee Walpole and Stuart Hilliker about their work on The Imitation Game.

This time of year is probably best known for its trade shows and big product launches, but for one area of the pro-audio industry it’s a period to look forward to for another reason.

For the world’s top film audio crews, February is awards season, and nominated for a prestigious BAFTA this year is the widely acclaimed period drama The Imitation Game – also a finalist in a whopping eight other categories.

The film stars Benedict Cumberbatch as mathematics genius and computer pioneer Alan Turing – the man responsible for cracking the thought-to-be-unbreakable codes of Nazi Germany’s Enigma machine during World War II, and therefore significantly shortening the length of the conflict, according to numerous historians.

Cumberbatch’s portrayal of Turing, Morten Tyldum’s direction and Billy Goldenberg’s editing explain most of the film’s multiple nominations, but its sound quality can be largely attributed to the work of Soho, London-based Boom Post. Crucial to the success of this project were supervising sound editor Lee Walpole and re-recording mixer Stuart Hilliker.

At first it might not seem like your usual candidate for a Best Sound gong, until you discover how much effort went into creating the aural characteristics of the film’s main prop.

“A key thing that Morten wanted to get right from the very beginning was the sound of Christopher, the [code-breaking] machine that Turing built. He was keen to find a sound and language for Christopher and he wanted it to become a character in its own right,” explains Walpole.

“He described it to me as the sound of a thousand knitting needles all working simultaneously and creating a deafening racket. The machine they shot with on set was a replica they built themselves, but it had no real merits for sound – it made a rhythm but that was it.”

Not the easiest of briefs to meet, then, although the crew did gain access to the only existing replica of the original machine – real name Bombe – giving them the ideal starting point on which to build. The replica at Bletchley Park – Turing’s base during the war – was built from the old plans, enabling them to hear what the great man’s actual machine would have sounded like.

“The one they shot with on the film was just built for the aesthetics and had electronic motors, whereas the machine at Bletchley looks very similar to the one in the film, but makes the authentic sound,” Walpole continues.

“Together with Andy Kennedy [sound designer], Joe Beal [sound effects editor] and Forbes Noonan [ADR mixer], I went along to record the sound of that; we took along a couple of sound devices and recorded multi-track. The mics we used were a Schoeps CMIT 5 U, Neumann KM 104s, a RØDE NT4 and JRF contact mics. We recorded every whirr, click and buzz from multiple microphone perspectives with the machine on a full run.”

The results of this initial recording were more than satisfactory, but there was still a lot of work to be done to elevate the sound of the machine to a level that would meet Tyldum’s expectations.

“When we got back with our sounds we discovered that the authentic machine actually matched up rather well with the replica they built on set in terms of the rhythm, rotar speed and pace. It was a good mimic of the real thing, but what the authentic recording lacked was detail, complexity and intricacy,” Walpole reveals.

“When we were there [at Bletchley] we had access to the National Computer Museum next door as well, and they’ve got a whole ton of machines appropriate to the era. We were able to record a lot of these and that gave us a massive pallette of genuine sounds from Turing’s time.

“So we constructed an initial version of the Bombe machine primarily using our Bletchley recordings and a little bit of stuff from the Computer Museum, and sent it over to Billy and Morten to lay into the cut and get an original round of feedback.

“They felt we needed to bring a sense of scale to the machine and suggested a heart-like element be incorporated into the rhythm, implying a life force, which tied into Morten’s desire for the machine to become a character in its own right. After a number of failed attempts we found our answer in some old clunky elevator server recordings, which had a wonderful natural reverberant acoustic, suggesting the sound was originating from deep within the machine, so this additionally served to provide us with the sense of scale we were looking for.

“We also began to pick out and enhance the visual detail of the rotars as they whirr and click on close-up. Some of the recordings of the machines were running at different rhythms but we were able to fit them to work with the visuals, and they could be tailored to fit the metronome of what the machine was doing.

“We also used handheld cranked movie cameras, telephone relays, clockwork sounds, old sewing machines – they all provided a palette of high-frequency ticks and ratchets. And then finally we used the contact mics that we’d used on the machine at Bletchley, which added another bass element to it, and again helped enhance the scale.”

Walpole has been involved with several award-winning movies in the past, including Les Misérables, so he’s used to these tricky jobs, but trying to recreate the sound of a hugely complex device for a sound-passionate perfectionist like Tyldum can’t have been easy.

“Everything in sound follows the same pattern – you build it up from the bottom, but it was difficult to tailor it because Morten wasn’t entirely sure what he had in his head, but he did know what didn’t work, and so we sent out four versions before it felt like we were on the right path.”

“He loves sound and encouraged us to experiment, which was liberating. He knew what he liked and that didn’t change throughout the process,” recalls Walpole.

Hilliker adds: “We never felt inhibited in the way we approached the mix or the sound design. He was so open to ideas.”

While re-recording mixer Martin Jensen handled the FX in the mix, Hilliker took care of the dialogue and music, and there was plenty of good material for him to get stuck into as well, which he was able to combine with Alexandre Desplat’s music to excellent effect.

“We were given some of the most solid dialogue I’ve ever had and from my perspective that was complemented by Alexandre’s score, which was recorded at Abbey Road and has the most beautiful sound to it,” enthuses Hilliker.

Bringing Bletchley to life

Due to its strategic importance, Bletchley Park would have been a hive of activity in the 1940s, which gave the sound crew another opportunity to experiment with various sound ideas.

“Throughout the exterior-shot Bletchley scenes there are soldiers walking around constantly and bikes coming and going, so the challenge for us was keeping this sense of active offscreen life on the base throughout the often dialogue-driven interior scenes,” states Walpole.

The team’s choice of participants for the loop group recording process allowed them to add further accuracy to the soundtrack too. “In addition to shooting traditional studio-based loop group we contacted a local college in Highgate, got a group of sixth form drama students and took them to Waterloo Park, along with Forbes Noonan, to record the students for some exterior crowd,” says Walpole. “We took a list of topics with us and got them to perform wild tracks. They also brought with them the sort of accents you would associate with wartime England and it just felt so natural. I think that was a huge thing when it came to bringing Bletchley to life in a fashion where you just didn’t question it.”

Hilliker notes: “As well as the film being firmly grounded in reality there are moments when we follow the thoughts of Alan into different times and spaces. It’s often the subtraction of sound that helps. When Alan’s world is falling apart and he’s completely alienated from his colleagues the mix subjectively reinforces the despair he is feeling.”

“That was another thing for Morten – what is happening when this genius is thinking and how do we tell the story of what’s going on inside his head? One of our key ways of internalising it was drifting the world away and making it very subjective, almost like a reverby, underwater space,” explains Walpole.

Cross-continental collaboration

Going back to Boom Post’s relationship with their colleagues over in the US, did the distance between them geographically create much of a problem?

“It was interesting with them being in Los Angeles and us being here but we quickly settled into a workflow and the nice thing about that was I was probably getting more feedback than I would if they were over here,” reveals Walpole. “There was more of a conscious effort on both of our parts to ensure we were consistently on the same page. I was doing a lot of uploading and Skyping and discussing what was and wasn’t working.”

This regular back-and-forth will certainly have helped with the development of the movie’s sound, which could see the Anglo-American partnership justifiably rewarded when the 2015 BAFTA winners are announced on 8 February.

Walpole and Hilliker were understandably delighted when they got the good news in January – it’s also been nominated for an MPSE Golden Reel Award for Best Sound Editing, Dialogue and ADR in an English Language Feature, as well as an AMPS nomination for Excellence in Sound in a Feature Film – but the pair seem more pleased with the standard of what they’ve produced than the fact that they could be adding to their prize collection later this month, as Hilliker concludes.

“It’s a soundtrack we’re certainly very proud of. Usually when it all goes through there will have been something that you weren’t quite able to fix, but this one doesn’t have any of that. When we had test screenings I hit Play and never wanted to press Stop.”