<-Scope Go to ToC References ->
Capitalised Terms have the meaning defined in Table 1. All MPAI-defined Terms are accessible online.
Lower-case terms have the meaning commonly defined for the context in which they are used. For instance, Table 1 defines Object and Scene but does not define object and scene.
Table 1 – Terms and Definitions
| Terms | Definitions |
| Acoustic Profile | The acoustics of a Basic Object (frequency range, spectrogram, loudness, Directional Patterns) or of a Basic Scene (reflectivity, reverberation, diffusion, absorption, Doppler). As the Qualifier, it belongs to Basic Objects and Basic Scenes only. |
| Audio Object | A collection of Basic Audio Objects and Audio Objects, each placed by its Space-Time within the collection. |
| Audio Qualifier | A Data Type including Sub-Types, Format (e.g., compression and transport), and Attributes (e.g., semantic information) of an Audio Data Type instance. |
| Audio Scene | The digital representation of a sound field for a defined region of Space and interval of Time. |
| Audio Scene Descriptors | A collection of Basic Audio Objects, Audio Objects, Basic Audio Scene Descriptors, and Audio Scene Descriptors, each placed by its Space-Time. |
| Basic Audio Object | Audio data with its Audio Qualifier: a single sound whose features can be identified. |
| Basic Audio Scene Descriptors | Basic Audio Objects placed in a space, heard from a User Point of View, with the acoustics of the space. |
| Basic Multimodal Object | Basic Objects of different media – in CAE-ASM, Basic Audio and Basic Speech Objects – representing one entity. |
| Basic Multimodal Scene Descriptors | Basic Scene Descriptors of different media – in CAE-ASM, Basic Audio and Basic Speech Scene Descriptors – at least one, heard from a User Point of View. |
| Basic Speech Object | Speech data with its Speech Qualifier. |
| Basic Speech Scene Descriptors | Basic Speech Objects placed in a space, heard from a User Point of View, with the acoustics of the space. |
| Closed Space | A space enclosed by walls: a Simple Location of Right Parallelepipeds, with the Material of each wall. |
| Directional Patterns | How a source radiates by direction relative to its orientation: gain by azimuth and elevation, optionally by frequency band. |
| Material | What a surface absorbs, scatters, and transmits, by frequency band. |
| Multimodal Object | A collection of Basic Multimodal Objects and Multimodal Objects. |
| Multimodal Scene Descriptors | A collection of Objects and Scene Descriptors of different media – in CAE-ASM, audio and speech – each placed by its Space-Time. |
| sound field | The spatial and temporal distribution of sound pressure in a defined region of space and period of time (physical). |
| Spatial Rendering | Producing what a User hears from a Scene: each source attenuated by distance and air, weighted by its Directional Patterns, and placed by direction, binaurally or on a loudspeaker layout. |
| Speech Object | A collection of Basic Speech Objects and Speech Objects, each placed by its Space-Time within the collection. |
| Speech Scene Descriptors | A collection of Basic Speech Objects, Speech Objects, Basic Speech Scene Descriptors, and Speech Scene Descriptors, each placed by its Space-Time. |
| Transport | The function of moving an Audio Object from an encoder to a decoder. |
| User Command | Data with which a User directs an AI Module, one per User action. |
| User Point of View | Where a Scene, or an Object heard alone, is heard from. A member’s own User Point of View overrides the Scene’s. |
