Simulating Sound in Space: What is Spatial Audio 2.0?
Updated: Sep 23, 2022
Spatial Audio 2.0 is a step change in how digital audio assets can be effected to make them appear virtually in the space around the listener. Kinicho's mission is to improve the realism of the listening experience for the end user of spatial audio. Their solution makes it easier for developers and content creators to deliver high quality, realistic experiences that are physically accurate simulations of sound in space.
The innovation from the Sonic Reality Engine solution brings order of magnitude improvements in sonic quality, spatial resolution and, when head-tracking is in place, responsiveness. These combine to make the spatial audio experience more like hearing sound in the physical world, so more like reality..
In October 2020, Apple Inc lit the touch paper for Spatial Audio with the release of the Airpods Pro and the introduction of Dolby Atmos into their media content ecosystem. Initially, they launched with Apple TV, giving movie-watchers a cinema-theatre audio experience, Then, in March 2021, they really went stratospheric with Apple Music, making spatial audio music available to the majority of subscribers. While Apple's reach and brand power is rocket fuel spatial audio, they're currently relying on an old technology . Prior to Apple's announcement, Spatial Audio was more often referred to as binaural audio or 3D audio. But names aside, this approach to presenting externalised, 3D audio in headphones is through the Head-Related Transfer Function (HRTF). The HRTF approach was first described in 1971, more than 50 years ago. While Apple did not coin the term Spatial Audio to mean HRTF process, they have popularised it. Since 2015, Kinicho have been working on a new method to update and improve the spatial audio experience. The Kinicho approach moves away from HRTF by introducing a revolutionary new method for creating the spatial effect through physical simulation. This massively improves the realistic qualities of the experience. That's why Kinicho make the bold claim for the Sonic Reality Engine as being the first processor to define Spatial Audio 2.0. Stefan Kazassoglou and Garry Haywood, Kinicho's founders had been working in Surround Sound and Spatial Audio for over two decades as producers and artists. This history inspired them to innovate a new solution for spatialisation of sound because of their love/hate relationship with HRTFs .
As Haywood, Kinicho's CEO, says: "We loved the promise of spatial audio. Being able to put headphones on an hear sounds in our environment wherever they were - above, behind, everywhere - is such a compelling idea. Yet the practical reality from an audio quality perspective, based on the many HRTF-enabled solutions we heard over the years, were inadequate . While we always searched out every incremental innovation - because we really wanted spatial audio to be a success - pretty quickly we would hate the actual experience because of the negative impact on the source audio. We always longed for a solution with more fidelity that HRTF can deliver. "
"As producers," adds Kazassoglou, "you think first about fidelity of the sound. So much effort goes into sonic qualities of the audio. With HRTFs, there was always unintended shifts in the timbre, it would introduce unwanted artefacts and there would problems with phase. So the experience was always unsatisfying.. But we always felt there was a way to get closer to reality of sound in space."
In 2015, the pair started Kinicho to tackle the quality issue from 3D Audio in Virtual Reality. Diving deep into the mechanics of HRTFs, they discovered there were also problems with spatial resolution, a lack of distance and problems with head-tracking latency. Kazassoglou, who as Chief Audio Research Officer headed up their investigations explains: "The more we understood about HRTF, the stronger our conviction became that we needed a new approach."
Haywood offers a simple insight into their thinking: "At its most basic, an HRTF set is a database of recordings that describe the differences between each ear for a given head direction at a fixed distance - effectively, from the surface of a sphere centered around the head. That points directly to the problem. Each person has their own an experience of sound in space - that is our, own personal database of experience and its much richer and more complex that what an HRTF can contain. This over-simplified account of spatial hearing that creates a lot of challenges - some of them intractable."
Producer/artists/engineers feed their sound design into the HRTF to give it a direction. It emulates directional audio from the database capture but any other spatial cues need to be mixed into the sound design. Haywood adds "The very process of emulating the original recording set-up leads to the many problems that have been identified in the HRTF process. So it was important for us to move away from the emulation approach and separate sound design from the spatial effect. "
Instead, Kinicho focuses on simulating the spatial effect as a physical relationship in a virtual space. Kazassoglou explains, "we went back to first principles to consider how sound works in nature. We follow the laws of physics as they apply to sound in space. This makes the sonic reality effect more realistic. Because we were building from scratch, we got to choose the best components, like mastering grade EQs,. that would help us to simulate sonic reality more effectively. "
Spatial Audio 2.0 changes the approach from emulation to simulation. This switch delivers order of magnitude gains in quality, spatial resolution and responsiveness. Kazassoglou sums up the step change; "The human auditory system is incredible in the way it resolves soundwaves in our environment into a visceral experience. We always believed that Spatial Audio 2.0 should be more closely aligned with our hearing sense that has evolved over millions of years. That's what we've built with the Sonic Reality Engine. It is revolutionary in the way it excites the auditory system into believing sound is in the space. around the listener."
Kinicho's customers now have access to this exciting development in Spatial Audio. Haywood concludes "The products and solutions we're making available have all been built with our approach to innovation. We make Spatial Audio 2.0 available to our customers with easy-to-adopt solutions where they can leave the physics of sound in space to the Sonic Reality Engine. Together, with our customers, we can deliver on our mission to give the end user the best spatial audio experience available."