Spatial audio is the talk of the town.
Well, maybe not in your town yet; but ‘spatial’ is one of the latest buzzwords echoing in the ears of millions of music fans, audiotech manufacturers, and entertainment giants.
How did the spatial audio buzz come about?
And what are they really talking about?
Back to the Future
Although no one had the need to name it back then, immersive and 3D audio have been around longer than humankind. Multi-dimensionally is simply the way the human auditory system has evolved to hear in a natural environment. 3D sound is therefore what our brain, on some level, expects to experience as it processes audio input from the outside world – be that music, an approaching storm, a nearby river flowing or a predator preparing to leap from a tree branch overhead. With our ears being our first line of defense and a pathway to coherence, the dimensionality of sound is fundamental to our core sense of safety, wellbeing, and human connection.
The dimensionality of sound
It was about 150 years ago when, thanks to the contributions of Edouard-Leon Scott and Thomas Edison, the world first got to experience recorded audio. This sound of the early phonograph, however, was not dimensional. It was at first monophonic. It wasn’t until the early 1930’s that Alan Blumlein patented and introduced stereophonic (2D) recordings for EMI.
The invention of technology for recording music revolutionized our ability to experience music and sound, especially the music and sounds we might never otherwise have an opportunity to experience in their live and natural setting. It also gave us, for the first time, the option to hear that music whenever we wanted.
As mind-blowing as the birth of recorded music was, and regardless of how much the quality of that monaural or 2D (stereo) audio improved, our very sophisticated human brain and highly sensitive auditory system could still tell the difference between recorded sound and sound in the real world (live sound) .
Because something was missing.
According to a growing number of neuroscientists, audio experts and scientific studies: When sound is “incomplete”, our brain has to work to fill in the gaps – be that due to missing or distorted data that can result from low resolution audio, or from the lack of dimensionality or sense of localization in traditional 2D (stereo) audio. Spatial audio is one attempt to fill in those gaps of what’s missing, or at least to trick the brain into perceiving that it’s all there.
According to a 2019 peer-reviewed music and science research study for SEMPRE (Society for Education, Music, and Psychology Research) led by David Greenberg, the development of spatialized audio helps us more accurately recreate the nature of real-world listening. Spatialized audio is a more immersive and dimensional approach that provides an audio experience that more closely mimics the way people hear music in real life. As the title of the study suggests — Decreasing Stress Through a Spatial Audio and Immersive 3D Environment: A Pilot Study With Implications for Clinical and Medical Settings, the implications of spatial audio may impact us beyond the world of entertainment.
The Birth of Spatial Audio?
In her 2015 article in The Verge, Mona Lalwani traced the history of spatial audio back to the development of a binaural audio experiment run in 1881, even before the invention of stereophonic recordings. Clement Ader, a 19th-century French engineer, devised the Theatrophone to broadcast a Paris Opera show. The audio from the show was transmitted from a pair of microphones on the left and right side of the stage via telephone receivers to listeners on the other end. With a pair of receivers, one mounted on each ear, listeners could hear the show from their designated suites at the gallery of Palais de l’Industrie. Even without seeing the stage, the listeners had a sense of where on the stage the sound was coming from.
Dr. Bell and artificial head
In 1933, AT&T Bell Laboratories brought binaural audio to the Chicago World’s Fair with a mechanical dummy named Oscar. Unfortunately the sound, like that in Ader’s experiment 50 years earlier, was of poor quality and less than impressive.
Around the same time, the imagineers at Disney were experimenting with higher quality audio experiences for the movie theater. Disney released their first theatrical sound, music and animated extravaganza, Fantasia, in 1940, complete with its debut of Fantasound. While a huge leap forward into the world of stereophonic recordings for the cinema (the first commercial film released in stereo), and one with much higher sound quality then anything preceding it, Fantasound was 2D (stereo) – not 3D like spatial audio.
Terms Of Confusion
Due to the mixing of the terms binaural and stereophony by Ader, Blumlein, and other professionals over the years, including by Alexander Graham Bell himself, there has been some confusion in the ranks. The Paris Opera experiment was not truly binaural, nor spatial, as we define binaural technology today. And while Disney broke new ground with Fantasia, it was not designed to be binaural either.
If you want to dig deeper, a far more comprehensive 2009 study on the history of binaural recording technology in the professional journal Acta Acustica by Stephan Paul (from the Laboratory of Vibration and Acoustics) will take you there.
To try to keep it simple, it is fair to say acoustic engineer sand audio professionals today clearly differentiate stereophonic recordings (distinctive left and right signals reproduced via 2 speakers) and surround sound (directional sound) from binaural – the latter being the true basis of spatial.
To summarize Paul’s definition, binaural technology (the basis of spatial) is used to describe the process of recording and/or reproducing two audio signals as they would be found at the eardrum or ear canal of the listener after being modified by the human body, reproducing as closely as possible the signal that is true to the original. In short – closer to what our brain expects to experience in the real world.
Ear the World
Technology Meets Demand for Spatial Audio
While the terminology may still be confusing, the technology to create more 3D listening experiences like spatial audio has come a long way since those early days. In recent decades, the movement toward more immersive, dimensional and realistic listening experiences has been catalyzed by the evolution of advanced sound for theatrical experiences — including surround sound — by companies like Dolby and DTS, and the development of other immersive visual technologies — like VR — that require more realistic and dimensional soundscapes to be believable and processed more naturally by the brain and auditory system.
Spatial Audio Feature
The growing demand for and desire to have more enhanced and natural listening experiences simulated via personal stereo playback systems – headphones and earbuds, has fueled the development of spatial audio and the latest trend we are seeing lead by companies such as Apple today. And the ability to draw upon and combine different approaches to creating that experience, is a big part of what fueled Apple’s collaboration with Dolby.
How does spatial audio help our brains perceive sound differently?
I will address this question further in Part 2 of this article, when I dive deeper into health and wellness implications of spatial audio, and where we are headed in the Amplified Future. For now, I simply want to bring your attention to one key acoustical phenomena that characterizes how our ears perceive sound within space: HRTF (head-related transfer function). HRTFs are a key component required to create spatial audio from a stereo signal, be that through a pair of your favorite stereo speakers or your latest earbuds. No need to worry about the technical jargon, however. Here’s a fun, engaging and informative post from the Los Angeles based immersive audio solutions lab Hear360 that quickly breaks down the mystery behind HRFTs: WTF is an HRTF?
Where we are Now:
While spatial audio is nothing new, the spotlight shining on it from Apple has made a star out of spatial audio. It has also electrified the buzz to give us plenty of good things to talk about. By giving spatial audio a chance to take center stage, Apple has brought both consumer attention back to the value and importance of high quality audio and the reward of more immersive listening experiences. Spatial audio is no longer a concept limited to the conversations exchanged and products consumed by audio enthusiasts. It has entered pop culture and, with Apple at the helm, won’t be going away anytime soon.
Spatial Audio Feature featuring Arianna Grande
Beyond a temporary boost to the bottom lines of the audio content producers (music, film, podcasts, etc.) and hardware manufacturers (speakers, headphones, hearables, mobile, etc), there are long-term and far-reaching implications this concentrated attention to spatial will bring to the marketplace and the consumer experience. While spatial audio may be only one quadrant of the technological and scientific breakthroughs reframing the way we understand and experience music and audio in the new Decade of Sound, it could raise the curtain, and the bar, for the amplified future: Unleashing new opportunities at the intersection of audio, music, health and human potential.
The spatial audio spotlight also opens the gateway for more scientific studies on the impact of sound on the brain and our wellbeing.
The Impact of Spatial Audio on Health and Wellbeing
What does it all mean to our health and wellbeing?
From an oversimplified technical point of view, spatial audio is our attempt to recreate (from the 2D recordings or synthesized sound) that more fully dimensional listening experience that is natural to the development of how we hear and experience sound in the real world. Spatial is one solution to help fill in those missing gaps that leave our brains a bit less satisfied, if not stressed, tired and confused.
In an interview this week, acoustic technology expert Chris Vernon (spatial audio advisor to leading CE companies who formerly worked with Sir George Martin and built immersive audio engines for Sony and Microsoft’s game consoles) explained one part of the issue this way, “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.”
Zoom Fatigue and Stress
Could spatial audio be part of the solution – helping us combine a richer listening experience with a reduction of audio-based stressors on the human brain?
According to the aforementioned SEMPRE research study, there is initial evidence that spatial audio applications can be effective for short-term stress reduction and even have the potential to supplement clinical music interventions.
Want to learn more about the role spatial audio can play in bolstering our health and wellbeing? In Part 2 of this article, we will explore three ways the current spatial audio trend will impact the future of health & wellness. We will also take a closer look at some of the latest science, emerging market opportunities, and rising players in the field.
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