MPEG-I immersive audio

MPEG-I immersive audio is a new standard that enables six degrees of freedom (6DoF) rendering of objects, channels, and Higher-Order Ambisonics (HOA) for extended reality (XR). It keeps listeners fully immersed while they move and interact within virtual or augmented worlds.

MPEG-I immersive audio pairs encoded audio with compact scene metadata and efficiently renders it in real time to headphones or loudspeakers, adapting to listener movement and 3D space. It enables lifelike audio in VR and AR and is designed for interoperability across devices and services, supporting efficient production.

At the heart of MPEG-I is a clean split between audio signals and a compact description of the scene. Creators can author channels, audio objects, and HOA, then encode them with physics-informed metadata describing source positions, sizes, materials, rooms, portals, and what can change.

On the device, a renderer fuses that stream with listener tracking (head and, when available, position) and an optional Listener Space Information (information about the playback room) to compute what you should hear. This includes direct sound with appropriate distance and Doppler, early reflections and late reverberation, occlusion and diffraction around surfaces, and smooth updates as the scene evolves.

The MPEG-I immersive audio standard was recently finalized by the MPEG Audio group (ISO/IEC JTC1/SC29/WG6). Nokia’s key contributions include late-reverberation rendering, AR support, and rendering of multiple HOA captures.