The Audio Commons Ontology has been created in the context of the European project [Audio Commons](https://www.audiocommons.org/), which were aimed at favouring sharing and reuse of audio content (both of musical and non-musical nature), specially using [Creative Commons](https://creativecommons.org/) licenses. It is designed specifically to integrate access to multiple heterogeneously structured audio content providers. In particular the following ones have been considered in the project: - [Freesound](https://freesound.org/), a collaborative database of Creative Commons Licensed sounds; - [Jamendo](https://www.jamendo.com/), a music website for independent artists; - [Europeana Sounds](https://www.eusounds.eu/), a European project collecting and sharing data from several archives of sounds and sound-related media; - [Internet Archive](https://archive.org/), a non-profit library of millions of freely accessible media contents. ### The base model <center>  </center> The Audio Commons ontology is based on [Functional Requirements for Bibliographic Records (FRBR)](https://en.wikipedia.org/wiki/Functional_Requirements_for_Bibliographic_Records), a bibliographic model designed for user tasks of retrieval and access in online library catalogues and bibliographic databases. FRBR distinguish the products of intellectual or artistic endeavor in four main classes: work, expression, manifestation, item. It is available as RDF vocabulary at https://vocab.org/frbr/core. For further information on FRBR, check the [standard](https://repository.ifla.org/handle/123456789/811). Another important model related to audio is the [Music Ontology](http://musicontology.com/), which is also based on the FRBR model. Our ontology is more generic than the Music Ontology but is interoperable with it to support the specificities of music-related audio content. The Audio Commons ontology works also in conjunction with - [Dublin Core](https://www.dublincore.org/specifications/dublin-core/dcmi-terms/) for basic metadata, - [EBU Core](https://www.ebu.ch/metadata/ontologies/ebucore/) for technical properties of audio files, - [SKOS](https://www.w3.org/TR/skos-primer/) to support taxonomic classifications, - [Creative Commons Licensing schema](https://creativecommons.org/ns) to represent media licensing, - [Event ontology](http://motools.sf.net/event/event.html) for the formalisation of events, - [Audio Features Ontology](https://w3id.org/afo/onto/) for the characterisation of audio features. ### Ontology overview  The figure above shows the most general classes and properties of the Audio Commons ontology and their relationship with classes of the FRBR and the Music Ontology: - **`ac:AudioExpression`**, the specific intellectual or artistic form that a work takes each time it is _realised_, in the audio domain, e.g., the recording or synthesis of music or sounds; - **`ac:AudioManifestation`**, the physical embodiment of an audio expression, e.g., a musical track, a sound, an album; - **`ac:AudioItem`**, a single exemplar of an audio manifestation, e.g., a copy of a CD or a specific media file. The FRBR class Work, representing a distinct intellectual or artistic creation on a more conceptual level, has not been specialised in Audio Commons. The Audio Commons ontology provides a generic schema for audio classification through the property **`ac:audioCategory`** that associates any audio expression, manifestation, or item to some generic **`ac:AudioCategory`**. These two terms can be specialised to provide spefic categorisations. ### Manifestations: audio clips and collections  The figure above shows classes and properties related to audio manifestations. An instance of **`ac:AudioClip`**, a subclass of `ac:AudioManifestation`, is any audio segment that has been published in some form or uploaded for consumption, for example, a track in a music label's repository or a sound in an audio repository, library or archive. The class **`ac:AudioCollection`**, another subclass of `ac:AudioManifestation`, is used to represent collections of audio clips. The class **`ac:AudioCollectionNode`** is used to represent single nodes of a collection, offering local information like the index in the collection and pointers to previous and next nodes. The separation between the collection node and its actual content (e.g., an `ac:AudioClip`) permits the same content to be shared in multiple collections. The content of each node of a collection is not limited to an `ac:AudioClip`, but may contain any `ac:AudioManifestation`. Collections can thus contain other collections to support specific cases, e.g. a mapping to the Music Ontology model where an `mo:Release` can contain multiple `mo:Record`(s) that can in turn contain multiple `mo:Track`(s). ### Items: audio files  An `ac:AudioItem` is a concrete exemplar of an audio manifestation. In our domain, the main exemplars are the actual audio files. The corresponding class **`ac:AudioFile`** is a subclass of `ac:AudioItem`. It is subclass of `ebu:MediaResource` too and the corresponging properties of EBU Core can be used to describe the file (e.g., `ebu:hasEncodingFormat`, `ebu:fileSize`). ### Expressions: audio signals  While `ac:AudioFile` represents a concrete file encoded in a certain format, **`ac:DigitalSignal`** is the representation of the corresponding digital signal. `ac:DigitalSignal` is a subclass of `ac:MusicalExpression`. The data properties `ac:sampleRate`, `ac:bitsPerSample`, and `ac:channels`, associate a signal with its basic features specific to digital representations. The property `ac:publicationOf` can be used to associate an `ac:AudioClip` with the corresponding digital signal. The property `ac:encodes` instead, associates an `ac:AudioFile` with the encoded digital signal. ### Events: recording/syntesis  The description of temporal events is crucial to formalise and document transitions in the workflow of audio production and publication. The class `event:Event` of the Event Ontology is thus specialised for specific actions that are interesting for the audio domain. Using the `event:Event` class, details of an event such as its location in time and space, its factor and its products may be explicitly described. Moreover, events can be composed using the property `event:sub_event`, to build complex events. The class `ac:SignalProduction` represents the act of producing a `ac:Signal`, which could be either an `ac:AnalogSignal` or a `ac:DigitalSignal`. This is complemented by **`ac:Recording`**, representing the process of recording a sound (`ac:Sound`) or the product of **`ac:Synthesis`**, in case of artificially generated sounds. ### Events (continued): publication  The event **`ac:AudioPublication`** represents the public release of a piece of work, e.g., the release of a new album by a band. ### Usage Example  The figure above shows an example of use of the Audio Commons ontology to represent a sound from the Freesound database. For simplicity only the classes `ac:AudioClip`, `ac:AudioFile`, and `ac:AudioCategory` are used in this case.

Prefix

tib.n0

Keywords

engineering nfdi4ing

Links

Homepage

Contact

Missing Contact

Pattern for Local Unique Identifiers

Missing LUI pattern

Example Local Unique Identifier

AnalogSignal   Resolve

Example CURIE

tib.n0:AnalogSignal

A summary of the relations in the Bioregistry schema can be found here.

In Collection

NFDI4Ing Ontologies

The metaregistry provides mappings between the Bioregistry and other registries. There are 1 mappings to external registries for this resource with 1 unique external prefixes.

A provider turns a local unique identifiers from a resource into a URI. Many providers are also resolvable as URLs (i.e., they can be used in a web browser).

The local unique identifier AnalogSignal is used to demonstrate the providers available for The Audio Commons Ontology. Some providers may use a different example, which is displayed in the table below. A guide for curating additional providers can be found here.