OttoAnna only uses material that may be reused, and credits it on every page where it appears. Media and quoted text remain under their original licenses; follow the links on each page for the exact license and author.
| Source | What we use | License |
|---|---|---|
| wikidata | Instruments, music genres, animals (structured facts) | CC0 |
| musicbrainz | Official genre list + MusicBrainz IDs | CC0 core data |
| wikipedia | Intro extracts + glossary terms from acoustics categories | CC BY-SA 4.0 |
| wikibooks | Acoustics / Engineering Acoustics chapter index | CC BY-SA 4.0 |
| commons | Audio + image files with per-file license metadata | per file (free licenses) |
| xenocanto | Bird & insect recordings (needs XENOCANTO_KEY) | per recording, BY/BY-SA kept |
| geonames | Cities/countries for reverse-geocoding field recordings | CC BY 4.0 |
| aporee | Radio Aporee field recordings via Internet Archive | per recording, PD/BY/BY-SA kept |
| nasa | NASA audio (space sounds) | public domain (NASA media guidelines) |
| nps | US National Park Service natural sounds | public domain |
| openverse | CC-licensed sound effects search | per item |
| freesound | Freesound links only (needs FREESOUND_TOKEN) | links only |
| stackexchange | Real questions people ask (titles/links only) | CC BY-SA, titles only |
| gutenberg | Public-domain classics on acoustics (Gutenberg + Internet Archive) | public domain |
| naturalearth | World land outline for location maps | public domain |
| NIOSH / CDC / OSHA / WHO | Noise exposure limits and typical sound levels (cited per page) | US government works / cited facts |
Licenses in short
- Public domain / CC0 – free to use for any purpose. NASA and US National Park Service media are generally not subject to copyright; their use here does not imply endorsement.
- CC BY – free to use with credit to the author.
- CC BY-SA – free to use with credit; adaptations must be shared under the same license. Wikipedia excerpts on this site are CC BY-SA 4.0.
- CC BY-ND – may be shared unchanged with credit; we embed such recordings without modification.
We do not embed recordings that forbid commercial use (NC licenses). Freesound content, whose API is licensed for non-commercial use, is only linked. Stack Exchange questions are shown as titles with links back to the original discussions.
Corrections and takedowns
If you are an author and believe a work is credited incorrectly or should not appear here, email [email protected] and we will fix it promptly.