By Ben Herrington, Sound Sculpture Inc.
For hundreds of years, the orchestra has remained an enduring sonic example. From the contrabassoon to the piccolo, this collection of instruments spans the musical range of the audible frequency spectrum, bringing us works that are rich, clear, and emotionally impactful all at once.
Compositional styles have changed dramatically over the generations, but this collection of instruments has remained surprisingly consistent. It represents a functional spectral blueprint. For years, composers have used this blueprint to intuitively maintain clarity and create a sense of balance through the arrangement of the instruments.
Sonic orchestration provides a precise framework to connect with listeners in a deeply profound way.
A matter of survival
In the natural world, sonic orchestration can be a matter of survival.
Dr. Bernie Krause began exploring the concept of the acoustic Niche Hypothesis in the 1980s. This is the idea that animals within a habitat avoid overlapping their vocalizations by staying within unique timelines and frequency bands, much like the instruments in the orchestra.
This natural partitioning of vocalizations avoids audio frequency masking and helps ensure clear communication within species. When new sounds (such as human-induced noise pollution) are introduced into these soundscapes, dramatic changes in animal behavior have been observed. Often with severe repercussions on the ecosystem.
As recently as last month, researchers observed a notable increase in aggressive behavior among male Galápagos yellow warblers when they were in the presence of traffic sounds. In some cases, frequency masking may cause animals to struggle to find food, fail to mate, have difficulty detecting predators, or vanish entirely.
The Cocktail Party Effect & The Lombard Effect
Audio frequency masking impacts humans as well. Back in 1953, Colin Cherry identified “The Cocktail Party Effect”. This is our surprisingly effective ability to use spatial cues (localization) and vocal characteristics (such as contrast and timbre) to understand a single voice within a room full of conversations.
However, this ability has its limitations. Frequency masking can begin to break down our cocktail party filters in high-noise floor environments with large amounts of overlapping sounds (of which themed attractions offer an excellent example).
Masking can subject overwhelmed guests to a higher cognitive load in a sonically active attraction. Guest focus becomes more difficult, and the illusions we work so hard to achieve can be ruined. In addition to attraction clarity and quality issues, safety issues can arise due to impeded cast/guest communication.
Many will recognize the phenomenon known as the Lombard Effect. This is the tendency of people to (automatically and unconsciously) boost their vocal volume when speaking in loud environments.
Certain sounds added into themed spaces reveal the volume war that the Lombard Effect can unleash. Introduced sounds are set at a level that can be heard above the noise of a crowd, the crowd increases their volume to overcome the introduced sound, and the vicious cycle continues to an absurd volume.
However, evidence indicates this phenomenon is frequency-specific. The Lombard Effect is significantly reduced (and, in some cases, may be eliminated) when we remove frequencies similar to speech from the sounds we introduce.
See also: Sonic storytelling: using sound to enhance the narrative
Sonic orchestration is a critical tool in themed spaces
Observations like this bring us to the key point. Sonic orchestration, the deliberate and artful distribution of sounds across audible frequency bands, is a critical tool within themed spaces for achieving rich, clear, and emotionally impactful sound.
In queue lines, sounds deliberately avoiding vocal frequency bands can be created. This permits impactful, show-level audio that doesn’t impede guest communication or prompt the Lombard Effect.
This same orchestration approach can be applied in critical cast communication areas (such as load/unload platforms), ensuring the themed audio doesn’t impede essential communication.
Within shows and attractions, sonic orchestration helps ensure that dialog tracks are clear and easily understood.
Sonic orchestration addresses clarity issues far beyond dialog. Some immersive experiences have the potential for descending into absolute sonic chaos. Dozens (if not hundreds) of unique sound sources, rapidly changing show environments, variable timelines, tricky acoustic spaces, high content density, and overwhelmed riders are just a few of the challenges to consider.
Interactive attractions add additional challenges since guest behavior can drive the timeline and impact sonic density. Contextually appropriate sonic orchestration becomes a key design strategy in these situations. Sounds are created to occupy unique frequency bands, preventing frequency masking, preserving clarity, and reducing the cognitive load of guests.
Considering the soundscape as a whole
These approaches are most effective when the entire audio team is in alignment. When composers and sound designers are both working in consideration of the whole soundscape, unified sonic tapestries are achievable.
I once worked on an attraction with a finale scene set within a cartoon-style factory. The scene featured complex story beats and called for heavy stylized machinery sounds distributed over dozens of localized sound sources. It also included a dense, orchestral score.
By partnering closely with the composer, we ensured that each respected the frequency requirements of the other. Sound effects became an extension of the orchestra, forming the song’s rhythmic elements and featuring musical factory whistles. Because of this close collaboration, what would have been confusing cacophony became a well-orchestrated show moment.
Maintaining authenticity with sonic orchestration
These examples have stressed the importance of avoiding frequency masking, but there are opportunities to use masking to our advantage.
In one attraction, a sonic buffer “spaceship crash site” scene wasn’t enough to keep horns from an adjacent scene from causing significant musical dissonance in a neighboring space. By introducing metal groan sounds to the crash site that matched the frequency and timeline of the horns, we effectively masked the horns. Thus, resolving the dissonance through contextually appropriate sounds.
When it’s impossible to mask a sound completely, we can consider intrusive sounds a part of our baseline soundscape and change how guests perceive them by presenting them in a new context.
In one supernatural-themed attraction, show-action doors did not provide enough isolation to prevent screaming guests from being heard in an adjacent show space. By orchestrating a bed of supernatural sounds around these scream moments, we presented the screams in a new context. This allowed guests to perceive these “ghostly wails” as part of the experience.
We’ve adapted similar philosophies to sci-fi attractions, orchestrating sounds that re-contextualize coaster actuators as part of the themed mechanisms that power the ships.
Sonic orchestration is a powerful tool for maintaining sonic authenticity in our experiences. Whether maintaining clarity in dense soundscapes, authentically mirroring the patterns found in nature, or naturally masking intrusions in service to the story, orchestration is a core characteristic of an effective, compelling experience.
