{"id":"tib.n0","reasoner":"none","oboSlims":false,"is_foundary":false,"ontology_purl":"https://raw.githubusercontent.com/AudioCommons/ac-ontology/master/aco.ttl","creator":["Converted to OWL by Charles Tapley Hoyt (cthoyt@gmail.com), no primary contact information is available."],"preferredPrefix":"tib.n0","title":"The Audio Commons Ontology","description":"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.\n\nIt is designed specifically to integrate access to multiple heterogeneously structured audio content providers. In particular the following ones have been considered in the project:\n- [Freesound](https://freesound.org/), a collaborative database of Creative Commons Licensed sounds;\n- [Jamendo](https://www.jamendo.com/), a music website for independent artists;\n- [Europeana Sounds](https://www.eusounds.eu/), a European project collecting and sharing data from several archives of sounds and sound-related media;\n- [Internet Archive](https://archive.org/), a non-profit library of millions of freely accessible media contents.\n\n### The base model\n<center> ![A diagram showing the entities Work, Expression, Manifestation, Item](./img/FRBR-Group-1-entities-and-basic-relations.svg.png) </center>\nThe 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).\n\nAnother 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.\n\nThe Audio Commons ontology works also in conjunction with\n- [Dublin Core](https://www.dublincore.org/specifications/dublin-core/dcmi-terms/) for basic metadata,\n- [EBU Core](https://www.ebu.ch/metadata/ontologies/ebucore/) for technical properties of audio files,\n- [SKOS](https://www.w3.org/TR/skos-primer/) to support taxonomic classifications,\n- [Creative Commons Licensing schema](https://creativecommons.org/ns) to represent media licensing,\n- [Event ontology](http://motools.sf.net/event/event.html) for the formalisation of events,\n- [Audio Features Ontology](https://w3id.org/afo/onto/) for the characterisation of audio features.\n\n### Ontology overview\n\n![A diagram showing the main classes of the Audio Commons ontology](./img/AC-Ontology-Skeleton.png)\n\nThe 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:\n- **`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;\n- **`ac:AudioManifestation`**, the physical embodiment of an audio expression, e.g., a musical track, a sound, an album; \n- **`ac:AudioItem`**, a single exemplar of an audio manifestation, e.g., a copy of a CD or a specific media file.\n\nThe FRBR class Work, representing a distinct intellectual or artistic creation on a more conceptual level, has not been specialised in Audio Commons.\n\nThe 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.\n\n### Manifestations: audio clips and collections\n\n![A diagram showing the main classes of the Audio Commons ontology](./img/AC-Ontology-Manifestation.png)\n\nThe 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.\n\nThe 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.\n\nThe 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).\n### Items: audio files\n![A diagram showing ac:Item class and related class and properties](./img/AC-Ontology-Item.png)\n\nAn `ac:AudioItem` is a concrete exemplar of an audio manifestation. In our domain, the main exemplars are the actual audio files. \n\nThe 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`).\n\n### Expressions: audio signals\n![A diagram showing ac:Expression class and related class and properties](./img/AC-Ontology-Expression.png)\n\nWhile `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`. \n\nThe data properties `ac:sampleRate`, `ac:bitsPerSample`, and `ac:channels`, associate a signal with its basic features specific to digital representations.\n\nThe 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.\n\n### Events: recording/syntesis\n![A diagram showing ac:SignalProduction class and related class and properties!](./img/AC-Ontology-SignalProduction.png)\n\nThe 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.\n\nUsing 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.\n\nThe 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. \n\n### Events (continued): publication\n![A diagram showing ac:Publication class and related class and properties!](./img/AC-Ontology-Publication.png)\n\nThe event **`ac:AudioPublication`** represents the public release of a piece of work, e.g., the release of a new album by a band.\n\n### Usage Example\n![A diagram showing an example of ontology usage!](./img/AC_Example-AudioClip.png)\n\nThe 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. Licensed under CC0-1.0.","uri":"http://www.audiocommons.org/ac-ontology/aco.html","homepage":"http://www.audiocommons.org/ac-ontology/aco.html","label_property":"https://www.w3.org/2000/01/rdf-schema#label","definition_property":["http://purl.org/dc/terms/description"],"synonym_property":["http://www.geneontology.org/formats/oboInOwl#hasExactSynonym","http://www.geneontology.org/formats/oboInOwl#hasNarrowSynonym","http://www.geneontology.org/formats/oboInOwl#hasBroadSynonym","http://www.geneontology.org/formats/oboInOwl#hasCloseSynonym"],"hierarchical_property":["https://www.w3.org/2000/01/rdf-schema#subClassOf"],"hidden_property":[],"base_uri":["https://w3id.org/ac-ontology/aco#"]}