At the Tip of the Spear of Soldier Care by Will Martin

Spatial audio emerging as a health and wellness tool for military and law enforcement

Toward the end of World War I, a handful of British soldiers gathered on a damp airfield, just outside London, hoping to see with their ears. Two of the soldiers stood tethered to a device with four trumpet-shaped cones turned to the sky. They intensely listened through stethoscope-style earpieces with the hope of capturing low-frequency sounds that might alert them to the altitude and azimuth of incoming aircraft.

The clouds, of which England had plenty, provided consistent cover for enemy aircraft, rendering British anti-aircraft weaponry almost obsolete. But this effort rested its hopes on binaural listening, where each ear receives distinctive sounds that provide clues about the whereabouts of the sound’s source. While primitive and largely ineffective, it was an early step in the tactical use of spatial audio. 

At its essence, spatial audio moves us closer to how we naturally process sounds. Because each of us lives—and listens—in a 3-dimensional world, traditional audio technologies fail to offer its users a complete audio picture. Their flat, 2-dimensional audio feeds typically carry identical sounds simultaneously to both ears. Spatial audio, on the other hand, places competing sounds in specific locations for the listener. With each audio stream distinct from the other, we encounter sounds the same way our brains expect to experience the noises and voices that make up our lives.

The tactical applications for spatial audio are obvious. A precise, 3-dimensional audio picture of the battlefield could be the difference between mission success and failure, especially amid the conflicting voices of combat. But a growing number of researchers and innovators are turning to the healing potential of spatial audio, indicating it might hold promise not only for tactical victory, but also soldier care.

The Rise and Promise of Spatial Audio
Spatial audio isn’t new. Early efforts include the Theatrophone, which in 1881 transmitted a Paris opera to listeners in a separate suite. Though isolated from the performance, they were able to sense the location of singers by using separate receivers for the left and right ears, each ear receiving a distinctive audio feed from microphones placed strategically across the stage. 

Though more than a century old, in our present Decade of Sound, spatial audio is in its heyday. Much of the recent buzz has centered on its capacity for immersive entertainment or shoring up Zoom meetings in the workplace. But recent efforts are exploring spatial audio as a health and wellness tool.

“Whether it’s on a battlefield or in the boardroom, we hear our world in 3D,” said Dan Stanek, Vice President and General Manager at OTTO Engineering, Inc., a leading manufacturer of spatial audio devices for military and law enforcement professionals. “When hearing multiple audio sources at one time our brains kick into overdrive to try and make sense of overlapping audio feeds, particularly when we’re using traditional headsets.”

Combat and crises carry enough stressors of their own, but for tactical operators and first responders, the extra mental energy required to focus on processing multiple audio streams on a 2-dimensional platform can be prove overwhelming.

Chris Vernon, an expert in audio technology, summed it up this way in a 2021 Forbes article on spatial audio and digital health: “The extra processing required for the human brain to ‘decode’ badly processed audio causes measurable stress, anxiety, and decreases cognitive and physical performances all-round.”

“By supplying standard, non-spatial audio equipment, we're diminishing the efficiency of our military personnel and first responders,” added Stanek. “The end result can be crippling anxiety and fatigue.”

Researchers have also determined, though, that spatial audio works to mirror the dimensionality of sound in the naturally occurring world, eliminating unnecessary stress on the user. A 2021 study, published in the journal Music & Science, found that spatial audio had an immense positive effect on users with depression and anxiety, helping operators return more easily to a state of homeostasis, even amid stressful environments.

Some airlines, for instance, have begun fielding spatial audio technology for their pilots to help them more clearly navigate the competing streams of voices they encounter while in flight. The immersive and intuitive nature of spatial audio empowers users to discern and prioritize voices based on their location in the headset, freeing operators to focus on the mission. The implications for soldier care in a tactical setting are significant.

“By imitating how we all process sounds, spatial audio works in harmony with our brains,” said Stanek. “It prioritizes the mental health of the operator and improves their sense of well-being, whether they’re down range or supporting from a FOB.”

Spatial audio technology, such as OTTO’s Enhanced Spatial Positioning (E.S.P.) device, enables a user to intuitively distinguish between competing audio feeds by assigning each to specific quadrant within the headset.

“It separates, rather than overlaps audio feeds,” said Stanek. “The directional cues enhance situational awareness, while lowering stress on the operator. This is how our brains work, so why would we ask anything else of those we send into the fight?”