Immersive audio experiences are increasingly created, distributed, and consumed using representations based on Audio Objects rather than fixed audio channels. In an object-based representation, each Audio Object carries audio content together with metadata describing its properties, behaviour, and relationship to the surrounding Audio Scene. This approach enables a listening experience that can be adapted to different rendering environments, devices, user preferences, and points of view.
However, the availability of Audio Objects and Audio Scene Descriptors alone does not guarantee that a satisfactory listening experience can be delivered to an end user. The final audio presentation depends on the characteristics of the Audio Scene, the user commands applied to the input objects and scene, such acoustic environment, and the user commands that may modify the presentation of the scene in real time. Different users may require different versions of the same scene, for example because they wish to change the listener position, emphasise a dialogue source, modify the balance among objects, or adapt the reproduction to a specific listening environment.
Technical Specification: Context-based Audio Enhancement (MPAI-CAE) – Audio Scene Management (CAE-ASM) V1.0 addresses this need by specifying a standard framework for editing Audio Objects and Audio Scene Descriptors into an audio presentation suitable for human fruition. The standard provides AI-based components (AI Modules) and associated Data Types enabling interoperable implementations capable of generating a rendered audio experience from object-based audio scene descriptions. The specification supports the dynamic adaptation of the rendered scene according to contextual information and User Commands.
CAE-ASM is designed to operate within the MPAI-specified AI Framework (MPAI-AIF) standard, where processing functions are implemented as AI Modules (AIMs) exchanging standardised Data. By relying on common MPAI frameworks and data representations, CAE-ASM promotes interoperability among content creators, service providers, application developers, and device manufacturers. The use of standard interfaces also facilitates the integration of Audio Scene Management capabilities into larger multimedia and metaverse systems.
A distinctive feature of CAE-ASM is its support for user-driven interaction with the Audio Scene. The specification enables a user to modify relevant aspects of the listening experience, including the Listener Point of View, the Audio Object Position, the remixing of audio programme elements, the substitution of Audio Objects, the introduction of object motion, and the modification of characteristics of the Acoustic Profile. These capabilities make it possible to create personalised and context-aware audio experiences while preserving interoperability among independently developed implementations.
The CAE-ASM V1.0 Standard defines the architecture, AI Modules, and Data Types required to implement Audio Object Rendering functionality. Together, these specifications provide a common basis for the development of interoperable systems capable of transforming Audio Objects and Audio Scene Descriptors into rich, flexible, and interactive audio experiences for a broad range of applications.
In all Chapters and Sections, Terms beginning with a capital letter are defined in Table 1. All MPAI-defined Terms are accessible online. All Chapters are Normative unless they are labelled as Informative.
