The trick with sound, is to make it unnoticeable 

From complaints about mumbled dialogue to sound effects that are just too loud, Nina Hartstone knows that sound is one of those things that can get viewers grumbling into their popcorn. The trick, says the Oscar-winning sound supervisor, is to make it unnoticeable.  

“If the dialogue you’ve re-recorded doesn’t work, the actor’s performance doesn’t seem genuine anymore, and people will disengage from a story.” 

Ensuring that sound is authentic is a talent that Hartstone has made a hugely successful career out of. Whether she’s editing the recordings of 24 tracks for a singing ensemble in Cats or blending three different voices to create Freddie Mercury vocals in Bohemian Rhapsody, she says it’s authenticity she’s aiming for. 

Sound performance 

Having started her career as a runner in the early 90s, Hartstone worked her way up to supervising sound editor. She now specialises in dialogue and automatic dialogue replacement (ADR). This is the process of re-recording dialogue after filming has wrapped and is often used to either to improve the audio quality, or to make changes to the dialogue. It involves getting actors in the studio, which she loves. 

“It’s the performance aspect I enjoy most, getting to go into the recording studio with the actors,” she says, “Especially nowadays we record quite a lot of ADR for feature films, it feels like a very creative process.”  

With productions getting more and more ambitious, and directors mindful of the option to re-perform sound in post, use of ADR is higher than ever. According to Hartstone it gives directors a greater freedom to bring their vision to life on set in more daring ways.  

Her role on Gravity is a case-in-point: “The actors were in these contraptions that moved around to look like they were in space, but they made a lot of noise which can’t be removed from the dialogue. These are the kinds of scenes you do in ADR. On set, it is all about capturing the visual performance, even if the dialogue is re-recorded in post.” 

“The technology almost evolves because of creativity, they are totally intertwined. You couldn’t be creative without the technology, but the creative side is the driver.” 

Read the room 

But actors don’t always enjoy the ADR process, Hartstone observes. Particularly when they’ve wrapped a film months ago and have to get back into character again and to repeat the same spoken or vocal performance. As a result, she says it’s important for her to be able to read the room and put them at their ease.  

“The best approach is to work the way actors want: if they want to move around great, that always helps, if they want to listen to the line and repeat it afterwards, fine: however they feel comfortable.  It’s about keeping the atmosphere in there positive and that’s a people skill.” 

Her ability to collaborate is essential, not just with other heads of department, but within the sound team itself. A feature might only come with one picture editor, the sound team tends to be quite large and is more of an ensemble: mixers, sound designers, Foley artists, editors, composers and mixers, to name a few.  

Creativity and collaboration  

“It’s a big collaborative effort. Sometimes you need to work fast, other times in a more detailed way, as and when required. You also can’t get too precious about the work, because until you get into the mix and hear everything together, it can be hard to judge how a scene should ultimately play out,” she says.  

A long-time collaboration of Hartstone’s – a creative partnership that has spanned twenty years – is with John Warhurst. “We’ve always come to everything from exactly the same creative standpoint, we communicate really well and we both feel passionately that the dialogue has to be in sync, everything has to be perfect, everything has to feel authentic,” she says.  

But despite the many technical aspects to working on sound editorial, Hartstone says that the ultimate driving force behind sound editorial is always creativity. “The technology almost evolves because of the creativity, so they are totally intertwined – you couldn’t be creative without the technology, but the creative side is the driver.”  

One vision 

A recent production that needed Hartstone to draw on her entire range of skills was 2018’s Bohemian Rhapsody. She was drafted in as supervising dialogue editor by Warhurst, who was the film’s supervising sound and music editor. The challenge was to help re-create Freddie Mercury’s iconic vocals. No small task. 

The vision agreed between them was to ‘glue’ the voice of the Queen frontman – provided primarily by Freddie Mercury, with some sections from Mercury soundalike Marc Martel – onto the moustachioed mouth of actor Rami Malek. Their work bagged Hartstone and Warhurst a 2019 Academy Award for sound editing. 

“I remember thinking it had to feel authentic. You can’t ever question that it’s Freddie’s voice coming out of Rami’s mouth.  

“We only had the one original take of Freddie’s vocal from his Live Aid performance to use in the film. Rami did a fantastic job of recreating the moves and the timing and everything on set. That got us a good part of the way there. 

“I used lots of different lip smacks and breaths and elements from that performance. It’s all those little details that trick the eyes into thinking that the voice really is coming from Rami. Capturing the sound of him blowing into the top of a mic, a sound we’re all familiar with, all helped to sell the illusion.” 

Delivering on a director’s dream 

Read Hartstone’s filmography and you’ll see, it’s no exaggeration to say she’s worked on almost every mid-to big-budget UK feature from the last 20 years. Credits including Evita, The Beach, The Hours, Everest, Enola Holmes and An Education. She recalls one of her defining career moments – and biggest challenges – as supervising dialogue editor on Robert Altman’s 2001 period drama, Gosford Park.  

“It was important to Altman that actors could just ad-lib. In one scene they’re all in a sitting room having these individual conversations as the camera spans from one end of the room to the other, but [because of the improvisation] when it was all cut together these were not cohesive conversations.”  

“For the finished film we needed those conversations to make sense. I spent a really long time getting everyone’s mics, and constructing conversations for each pair of actors that were talking, which remained in sync when the camera returned.” 

While it was a complex technical job in terms of dialogue editing, Hartstone beams as she remembers working with Altman, and calls it one of her best professional experiences: “He was really laid back and collaborative – asked us all what we thought. He was also really decisive about his vision.”