Outer Echo is a research-driven company grounded in scientific innovation and fueled by a deep passion for sound and music. We engineer technologies that prioritize sound quality, physical coherence, and computational efficiency, with a clear focus on real-time applications.
Alongside advancing established audio methods, we are building a portfolio of proprietary technologies protected by patents in major international jurisdictions. Although these technologies are developed and get validated through our own engines and products, they are not limited to a single use case or implementation: they are designed from the outset to be modular, adaptable, and extensible.
Physical Modeling
Physical Modeling lies at the core of Outer Echo’s approach to audio technology. By physical modeling, we refer to the numerical simulation of physical phenomena—such as wave propagation and coupled resonant behavior—applied directly to sound synthesis and spatial rendering.
Physically-modeled sound rendering is inherently challenging, as it requires:
- Mathematically sound formulations
- Stable and efficient numerical methods
- A deep understanding of both physics and human perception
When physical modeling is designed carefully and implemented efficiently, it stops being exotic and becomes uniquely powerful. Our philosophy is simple: the emulation of complex physical behavior should not result in complex tools. Through mathematical abstraction, optimization, and perceptually informed design, we couple time, frequency, and modal representations to translate acoustic phenomena into lightweight, flexible simulation technologies that are:
- Efficient enough for real-time execution
- Robust under dynamic and interactive conditions
- Practical to integrate into production environments
Our commitment to physical modeling provides a natural ground for spatial audio in media, interactive applications, games, and XR. As we do not limit spatial audio to merely placing sound sources in three-dimensional space, standing on physics-supported representations enables us to effectively introduce unconventional physical modeling abstractions that allow the efficient simulation of diverse wave propagation and diffusion phenomena, to support:
- Real-time navigation of virtual acoustic environments
- Dynamic interaction between sources, listeners, obstacles, and coupled spaces
- Extremely low latency for immersive and XR applications
6D Spatial Audio
At Outer Echo we develop physical-modeling 6D Spatial Audio technologies to deliver perceptual realism without the typical computational cost compromises. By 6D Spatial Audio we understand six-degree-of-freedom (6DOF) immersion that goes beyond standard 3D audio—where sound sources are merely placed around a stationary listener. Thanks to approaching spatial audio from a physical modeling perspective, it is possible to enable true volumetric movement where the entire acoustic environment responds coherently to listener and source motion, behaves according to real-world acoustic principles and sustains a seamless and believable sense of space.
Instead of relying on brute-force numerical simulations and/or interpolated convolution of pre-computed impulse responses, we combine physics-based abstractions and perceptual compression techniques to construct a self-balancing physical model of the acoustic environment, defined from first principles. This allows for dynamically regulating the trade-off between perceived spatial resolution and required computational cost while faithfully simulating, in real time and low latency, diverse acoustic phenomena such as:
- Reflection
- Diffraction
- Emitter and Receiver Directivity
- Occlusion
- Doppler
- Near-Field Effects
- Head-Related Transfer Function (HRTF)
- Diffusion
- Reverberation
- Large-Scale Sound Propagation
- Acoustic Coupling
Our framework enables the creation of virtual acoustic environments—including multiple obstacles, sources and listeners in continuous movement and rotation—that can be flexibly modified and freely navigated, and empowers artists with the ability to apply updates instantly without baking. To achieve this, we take advantage of integrating two key proprietary technologies on which Outer Echo has spent years of research and development: Adaptive Wavefront Resolution Auralization (AWRA), and Acoustic Resonator Graph Optimization (ARGO).
3D Ambisonics
One of the well-established techniques exploited in some of our 3D Spatial Audio work is Higher-Order Ambisonics (HOA). Ambisonics provides a powerful and widely supported framework for representing surrounding sound fields in 3DOF (three-degrees-of-freedom) immersive applications.
Our Ambisonics portfolio comprises highly efficient implementations of modular Encoding, Rotation and Decoding pipelines up to HOA Order-7, including diverse encoding and decoding configurations to fast modulation schemes on hundreds of processing channels by means of platform-specific vectorization routines. By extending the efficiency and flexibility of Higher-Order Ambisonics, we enable dense, detailed spatial 3DOF scenes that remain practical in real-time interactive contexts. Our current Ambisonics work is focused on:
- Increasing spatial resolution without prohibitive computational cost
- Improving robustness under fast listener rotation and dynamic scenes
- Enabling time- and frequency-domain transformations in signal chains involving multiple adaptive beamformers
- Integrating Ambisonics within physically-based acoustic models