How do you know when a sound is right?
Two recordings may represent exactly the same physical event. One feels convincing, inevitable and emotionally satisfying. The other feels strangely artificial, despite being technically more accurate. A sound designer can spend hours recording, editing, layering and processing material, refining transients, balancing frequencies and positioning every element within an increasingly sophisticated spatial environment, yet the finished scene can still seem somehow incomplete. At other times, the smallest adjustment suddenly allows everything to settle into place. A barely perceptible atmosphere makes a location believable. A slight change in perspective gives an object convincing weight. Removing a sound proves more effective than adding another. Technical expertise explains how a soundtrack has been assembled. It does not entirely explain why one version feels right.
That question lay quietly beneath Nigel Christensen’s online guest lecture for Edinburgh Napier University. Although he never reduced his work to a single principle, almost every example returned to the same underlying challenge. Across more than three decades in film and television, Christensen has worked on productions as different as Neighbours, The Promise, Mad Max: Fury Road, The LEGO Movie, The LEGO Ninjago Movie, Colin from Accounts, Boy Swallows Universe and Sentient. The productions differ enormously in genre, scale and audience, yet each required him to solve a remarkably similar problem. Faced with countless possible creative decisions, how does a sound designer recognise the one that truly belongs?
Christensen’s answer was never framed as a technique or a method. Instead, it emerged through the way he spoke about listening. Recording, Foley, editing, restoration, sound effects and mixing remain indispensable parts of the profession, yet audiences never experience them separately. They experience conversations unfolding within spaces, footsteps revealing character, environments establishing place, music shaping emotional direction and silence becoming as expressive as any sound surrounding it. Individual recordings rarely possess dramatic meaning on their own. They acquire it through the way they interact with dialogue, image, performance and everything surrounding them. A beautifully crafted sound can weaken a scene once placed alongside other elements, while something almost imperceptible can quietly transform the emotional weight of an entire sequence.
As the lecture unfolded, Christensen repeatedly returned to this idea from different directions. One project demanded months of experimentation to create the sound of an event that could never occur in reality. Another relied upon extensive recordings of heavily modified vehicles before the smallest mechanical detail felt convincing. Comedy rewarded restraint where action encouraged energy, while documentary required a different form of responsibility altogether. The practical solutions changed from production to production. The process of listening did not.
Perhaps the most revealing aspect of Christensen’s lecture was his insistence that this process cannot be reduced to a formula. Professional experience gradually develops a way of hearing that extends beyond technical knowledge. Designers learn to recognise when attention is drifting towards the wrong element, when a soundtrack feels unexpectedly crowded or when apparently unrelated sounds suddenly begin supporting one another in ways that make the entire scene feel more convincing. Christensen described constructing an internal three-dimensional framework in which dialogue, music, ambience and effects occupy relationships of frequency, perspective, depth and dramatic importance rather than existing as isolated events. Dialogue often provides the centre of gravity, while every other element continually negotiates its place around it. Success rarely depends upon making every sound equally noticeable. More often, it depends upon recognising what deserves attention and what should remain quietly in support.
His own fascination with sound began long before he imagined a professional career. One of his earliest memories involved his grandfather’s Acme whistle, manufactured during the Second World War. Years later, while watching a Warner Bros. cartoon, he recognised exactly the same sound emerging from the television. The experience left a lasting impression. An everyday object had somehow become part of a completely different world, attached to movement, timing and character until audiences accepted it without question. Around the same period he discovered that sounds could also be recreated. Having become adept at imitating the distinctive trill of his school’s classroom intercom, he once produced such a convincing imitation that his teacher crossed the room, answered the handset and began speaking to an office that had never called. Looking back, both experiences pointed towards the same observation. Sounds are never interpreted through acoustics alone. Context, expectation and previous experience continually influence what listeners believe they are hearing.
Those early discoveries did not immediately suggest a future in sound design. Christensen’s interests ranged across music, photography and writing until one of his teachers recognised that filmmaking offered a place where those interests might converge. Entering the Australian post-production industry in 1989, he arrived during a period of considerable technological change. Analogue workflows still dominated everyday practice, while digital editing systems were only beginning to appear. Film workprints, synchronised magnetic tape and physical editing remained routine, and Christensen recalled demonstrations of early digital systems being met with understandable scepticism. Looking back, however, the technological transformation itself seemed less significant than another lesson emerging from those years. Every advance expanded the range of available creative possibilities. None removed the need to listen carefully, understand the dramatic needs of a scene and decide what genuinely belonged.
That understanding developed rapidly during Christensen’s work on the long-running television series Neighbours. Part of his role involved preparing international music and effects tracks from which dialogue had been removed, allowing episodes to be dubbed into other languages. Working alongside Foley artists, editors and mixers, the team completed five episodes every day. Such a schedule left little opportunity for prolonged experimentation. Sounds had to be found or created, evaluated within the scene and completed before attention immediately shifted to the next problem.
Working at that pace encouraged a discipline that remained visible throughout Christensen’s later career. Every additional sound had to earn its place. A convincing footstep, a carefully judged atmosphere or a subtle mechanical detail succeeded not through individual brilliance but through the contribution it made to the scene as a whole. Television therefore became an education in priorities. Decisions needed to be made quickly and confidently, yet always in service of the film rather than the sound itself.
As Christensen’s career expanded into larger productions, the budgets, schedules and creative possibilities changed dramatically. The underlying challenge, however, remained remarkably familiar. More recording time, more sophisticated processing and more powerful technology did not simplify creative decision-making. They simply increased the number of possible solutions. Learning how to create a sound was only the beginning. The more demanding task was recognising which of those possibilities truly belonged within the world of a particular story.
The increasing range of creative possibilities became particularly apparent as Christensen moved into feature filmmaking. Television had taught him to make confident decisions under relentless production schedules. Larger productions presented a different challenge. More time, larger budgets and increasingly sophisticated technology did not necessarily make the work easier. Instead, they multiplied the number of possible solutions. Every additional recording, every new processing technique and every creative option demanded another decision about whether it genuinely strengthened the film or merely demonstrated what could be done.
One of the clearest examples came from Chen Kaige’s The Promise. Christensen was asked to create the sound of a character running through the wall of time, an event with no equivalent in the physical world. There was nothing to record, no existing reference and no audience memory against which the result could be measured. The task therefore became one of invention rather than recording reality. Months were spent exploring combinations of recordings, processing techniques and layered textures, searching for sounds capable of suggesting impossible movement without disrupting the internal logic of the film.
Christensen’s account revealed something fundamental about cinematic realism. Audiences do not judge a soundtrack solely by comparing it with everyday experience. They judge whether it feels convincing within the world the film has established. Nobody has heard a person move through time, yet viewers recognise when such a moment appears believable. Credibility emerges from consistency. Every element supports the same dramatic proposition until the impossible begins to feel strangely inevitable.
At first glance, Mad Max: Fury Road appears to present exactly the opposite problem. Rather than inventing sounds for imaginary events, George Miller’s production provided an abundance of authentic material. Vehicles were extensively recorded under different operating conditions, capturing engines, transmissions, exhaust systems and countless mechanical details from multiple perspectives. Christensen’s responsibilities included many of the motorcycles, the Vuvalini vehicles and several machines surrounding the War Rig, giving him access to recordings that reflected the unique personalities of the actual vehicles.
Authenticity, however, proved to be only the beginning of the creative process. Christensen recalled George Miller focusing intently on the sound of a chain swinging during one sequence. Numerous chains were recorded, performed repeatedly and compared before one finally possessed the character the scene demanded. Nothing about the exercise suggested that a genuine recording automatically produced the most convincing result. A chain needed to do more than resemble a chain. Its movement had to reinforce rhythm, weight, performance and dramatic tension without distracting from everything else unfolding on screen.
Listening in this way gradually changes the role of the sound designer. Rather than collecting impressive recordings, Christensen described himself as continually organising a shifting network of interactions. Throughout the lecture he referred to an internal three-dimensional framework within which dialogue, ambience, music and effects occupy different positions according to their dramatic importance. Dialogue often anchors the listener’s attention, while surrounding sounds establish scale, movement, physicality and emotional colour. Introducing a single element alters the function of every other element nearby. Nothing exists independently for very long. This also explains why Christensen rarely discussed recordings in isolation. A beautifully captured sound can become unexpectedly intrusive once dialogue, performance and music are added around it, while an apparently ordinary recording may become indispensable after finding its place within the larger dramatic structure.
The same principle extends across the soundtrack as a whole. Dialogue, music, ambience, Foley and effects continually reshape one another. Raising one element alters the significance of another. Simplifying a sequence can sometimes reveal emotional details that had previously been hidden beneath unnecessary complexity. Christensen’s descriptions repeatedly suggested that the soundtrack behaves less like a collection of separate tracks than like a living system in which every adjustment influences the whole.
Experience gradually transforms this way of listening into instinct. Christensen described recognising physically when a scene remained unresolved. A sequence could feel crowded, awkward or strangely unsettled long before he could identify the precise technical cause. Rather than reaching immediately for another process or another recording, he would continue listening, adjusting perspective, emphasis and texture until everything seemed to settle naturally into place. Only afterwards would it become possible to explain why the solution worked. Analytical understanding and intuition were not opposing ways of working but different stages of the same creative process.
Professional development therefore means more than acquiring new technical skills. Software evolves, workflows change and tools become increasingly powerful, yet none of these developments removes the need to listen critically. Over time, designers become less concerned with demonstrating what technology can achieve and more interested in recognising when a scene has reached the point where nothing further needs to be added. Restraint becomes a sign of growing confidence rather than limited imagination.
Animation appears to encourage limitless invention. Worlds such as The LEGO Movie and The LEGO Ninjago Movie overflow with movement, visual detail, rapid editing and comic incident, inviting sound designers to populate every available moment with activity. Christensen described arriving at almost the opposite conclusion. As visual complexity increases, audiences become less able to attend consciously to every sound. Organisation therefore becomes more important than accumulation. The objective is not to make everything audible, but to ensure that listeners instinctively recognise what matters at any particular moment.
This approach shaped the soundtracks of both films. Dialogue, music, ambience and effects coexist in remarkable density, yet they rarely compete for attention. Some sounds carry narrative information, others reinforce physical movement or establish the scale of an environment, while many remain almost unnoticed until repeated viewings reveal their contribution. Rather than treating every recording as an opportunity to impress, Christensen spoke about allowing individual elements to emerge and recede according to the changing needs of the scene. Richness becomes a consequence of careful organisation rather than sheer quantity.
Comedy makes this balancing act especially demanding. A joke succeeds as much through timing as through content, and sound participates in that timing just as fully as dialogue or editing. A visual action may need to arrive a fraction before its accompanying effect. Elsewhere, delaying a sound by only a moment can strengthen surprise or allow a performance to land more naturally. Christensen’s observations suggested that comic sound design depends less upon creating amusing noises than upon understanding precisely when audiences are ready to hear them. Rhythm, expectation and restraint become inseparable.
Those same principles reappear in Colin from Accounts, although expressed in a completely different register. Here humour grows from recognisable people navigating awkward situations rather than exaggerated cinematic spectacle. Sound therefore works quietly. Everyday actions, body movements and small environmental details were adjusted repeatedly, not to attract attention but to preserve the fragile credibility upon which the comedy depends. An effect that feels too carefully emphasised risks reminding audiences that somebody has designed the moment. Christensen repeatedly returned to the importance of preserving the illusion that events are simply unfolding before the viewer.
This distinction reveals something broader about realism itself. Literal accuracy and perceptual credibility are not necessarily the same thing. Everyday life rarely presents sounds in perfect isolation or with equal clarity. Attention shifts continually between conversations, environments and passing events, while the brain filters enormous amounts of information without conscious effort. A soundtrack attempting to reproduce every available detail with equal prominence would often feel less convincing than one carefully shaped around the way people actually experience the world. Christensen’s decisions consistently reflected this understanding. The aim was not to reproduce reality mechanically, but to recreate the experience of listening within it.
Bottle Top Bill and His Best Friend Corky offered another unexpected perspective on this philosophy. Rather than removing every trace of the performers manipulating the miniature characters, Christensen allowed subtle handling noises and hints of human presence to remain within the finished soundtrack. Conventional post-production might regard these as imperfections. Here they became part of the programme’s identity, quietly reminding viewers that imagination begins with physical performance. The result feels neither unfinished nor technically compromised. Instead, those traces contribute warmth and authenticity, strengthening the audience’s relationship with the world rather than diminishing it.
A similar sensitivity informed Christensen’s work on Boy Swallows Universe. The series moves naturally between everyday realism, memory and moments approaching magical realism without drawing sharp boundaries between them. Less experienced designers might have emphasised those transitions through conspicuous effects or dramatic sonic transformations. Christensen preferred a subtler approach. Small changes in perspective, texture and atmosphere gently alter the audience’s emotional orientation without announcing themselves as technical interventions. By the time viewers become aware that the world has shifted, they have already accepted the transition.
Across these productions, Christensen continually returned to the same way of listening. Individual sounds mattered, but never as isolated achievements. Their significance emerged through timing, proportion and context. A footstep, an atmosphere or a carefully judged silence gained expressive power only through its contribution to everything surrounding it. Attention remained directed towards characters and narrative rather than towards the soundtrack itself.
That philosophy also shaped Christensen’s understanding of collaboration. Every sound designer accumulates recordings that required considerable effort to obtain and solutions that feel particularly satisfying. Filmmaking has little interest in personal attachment. Directors, editors, composers and producers respond to complete scenes, not individual technical accomplishments. Christensen spoke openly about learning when to defend an idea and when to let it go. Removing an effect that no longer served the film was not a creative defeat but another way of improving the work. The objective was never to preserve favourite sounds. It was to strengthen the audience’s experience.
Professional confidence often reveals itself through flexibility rather than certainty. It allows practitioners to contribute decisively while remaining willing to abandon their own solutions whenever a better one emerges. Cinematography, editing, music, production design and sound each illuminate different aspects of the same film. Christensen’s lecture suggested that the strongest collaborations develop when specialists maintain deep expertise within their own discipline while remaining attentive to the wider dramatic picture.
This balance between technical possibility and creative restraint became particularly clear in Christensen’s discussion of the documentary Sentient. Fiction allows designers considerable freedom to invent or reshape sonic worlds, provided audiences continue believing them. Documentary introduces different responsibilities. Recordings often carry evidential weight alongside dramatic value, and modern restoration tools make it increasingly tempting to remove imperfections or reconstruct missing material. Christensen approached those possibilities with notable caution.
Background noise, recording limitations and environmental interruptions were not automatically problems waiting to be solved. In many cases they formed part of the circumstances under which the events had actually occurred. Eliminating them indiscriminately risked altering the audience’s understanding of the material itself. Christensen therefore described restoration as an exercise in careful discernment rather than technical demonstration. Clarify what genuinely prevents communication, preserve what belongs to the recorded reality and resist interventions that merely produce a cleaner soundtrack. Sometimes the most accomplished decision is recognising that nothing more should be done.
Placed alongside the productions discussed throughout the lecture, Sentient brings Christensen’s wider philosophy into particularly sharp focus. Fantasy, action, animation, comedy and documentary all present different technical challenges, yet none ultimately asks a different artistic question. Every project depends upon understanding how audiences listen, recognising what deserves their attention and shaping sound so naturally that the process itself quietly disappears behind the experience.
Seen across more than three decades of work, Christensen’s career reveals a remarkably consistent philosophy. Technologies have changed, production methods have evolved and audiences now encounter films through an ever wider variety of formats and devices, yet the central responsibility of the sound designer has altered very little. Every project begins with the same challenge: to understand how sound can shape an audience’s experience without ever distracting from the experience itself.
It is striking how little Christensen spoke about technology for its own sake. His professional life has encompassed one of the most transformative periods in the history of film sound, from analogue editing and magnetic tape through digital workstations, immersive formats and increasingly sophisticated restoration tools. Each innovation expanded the range of available creative possibilities. None simplified the underlying task. More powerful tools inevitably produce more possible solutions, yet no technology can determine which of those possibilities belongs within a particular film. That decision continues to depend upon careful listening, experience and an understanding of dramatic purpose.
This perspective feels increasingly relevant as machine learning and artificial intelligence become more deeply integrated into post-production. Processes that once required hours of specialised work can now be completed within minutes. Dialogue can be separated from background noise, damaged recordings restored, voices synthesised and entirely new sounds generated with remarkable accuracy. Christensen’s lecture quietly suggested that such developments change the mechanics of production far more profoundly than they change its artistic purpose. As technical barriers continue to diminish, creative discernment becomes even more valuable. Producing convincing sounds remains an essential skill. Recognising which sounds genuinely strengthen a scene becomes the defining one.
Every production discussed during the lecture reinforces that conclusion from a different direction. The Promise demonstrated that audiences willingly accept impossible events when every aspect of the soundtrack supports the same dramatic world. Mad Max: Fury Road showed that authentic recordings still require interpretation before they acquire dramatic force. The LEGO Movie illustrated how increasing complexity demands greater clarity rather than greater density, while Colin from Accounts revealed that realism often depends upon carefully controlled understatement. Bottle Top Bill and His Best Friend Corky questioned conventional assumptions about technical perfection, and Sentient demonstrated that documentary sometimes requires consciously resisting interventions that modern technology makes entirely possible. Different productions posed different creative problems, yet each ultimately returned to the same discipline of listening carefully before deciding how, or whether, to intervene.
Listening, in Christensen’s work, extends well beyond identifying frequencies or evaluating recording quality. It becomes a way of understanding narrative itself. Designers gradually learn to recognise where attention naturally settles, when emotional emphasis begins to overwhelm a performance or when apparently minor adjustments transform the balance of an entire sequence. Such understanding develops through repeated encounters with practical problems rather than abstract rules. Experience teaches practitioners not simply how to manipulate sound, but how to recognise when a scene has found its natural equilibrium.
From that perspective, sound design becomes less concerned with creating memorable individual sounds than with shaping the conditions in which those sounds acquire meaning. Dialogue, music, ambience, Foley, effects and silence continually influence one another, while every adjustment subtly reshapes the audience’s perception of the whole. A soundtrack resembles an ecological system more than a collection of recordings. Once a new element enters the scene, every existing element is heard a little differently. What finally reaches the audience is not a series of isolated sounds but a carefully organised pattern of interactions.
Collaboration reinforces this understanding. Editors, cinematographers, composers, production designers and sound teams each bring different forms of expertise to the same film, and none can fully determine the finished experience alone. Christensen’s reflections suggested that specialist knowledge becomes most valuable when it remains responsive to the broader needs of the production. Strong ideas deserve thoughtful advocacy, yet they also require enough flexibility to be abandoned whenever another solution serves the film more effectively. Professional maturity lies as much in recognising what can be removed as in discovering what can be added.
By the end of the lecture, the opening question has acquired a rather different meaning. Knowing when a sound is right is not primarily a technical problem. It is an interpretative one. A sound belongs when it reinforces performance, clarifies dramatic intention and helps audiences inhabit the world unfolding before them without becoming conscious of the craftsmanship involved. Technical expertise makes such moments possible. Careful listening allows them to emerge.
Audiences rarely become aware of the countless decisions that shape this experience. They never hear the recordings that were rejected, the alternative mixes that were abandoned or the hours spent adjusting perspective, texture and timing until everything settled into place. Instead, they remember the weight of a machine crossing the desert, the awkward silence between two characters, the energy of an animated world or the quiet authenticity of a documentary moment. Those memories contain the work of the sound designer, even though the individual decisions have disappeared into the larger experience.
Perhaps that is Christensen’s most enduring insight. Sound design has never been an exercise in demonstrating technical virtuosity. Recording, editing, restoration, Foley and mixing remain indispensable crafts, yet they all exist in service of something larger. Their purpose is to help audiences believe in a world that does not exist until sound, image and performance begin working together.
The most successful soundtrack, then, is not necessarily the one containing the greatest number of remarkable sounds. It is the one that allows those sounds to disappear into the experience so completely that audiences stop noticing them altogether. Their attention remains with the characters, the unfolding drama and the emotional movement of the film rather than the techniques used to construct it. By that point, the soundtrack has achieved something more valuable than technical perfection. It has become inseparable from the world it was created to support.