Source: https://jmrplens.github.io/phonometry/start/support/ # Support the project phonometry is maintained by one person, and its real cost is not hosting or tooling: it is the primary sources. Every metric in the library is implemented from the governing standard's own text, and standards are paid documents that go out of print, get superseded and occasionally resist every legitimate acquisition route there is. This page lists the ways to help, from free to concrete. ## Use it, and tell me when a number looks wrong The cheapest support is using the library and reporting the number that does not match your reference. A report that names a standard and a clause is the most valuable issue this project receives: the [errata register](https://jmrplens.github.io/phonometry/reference/errata/) exists because sources get read closely, and several of its entries began as a user's raised eyebrow. [Open an issue](https://github.com/jmrplens/phonometry/issues) with what you measured and what you expected. ## Sponsor [GitHub Sponsors](https://github.com/sponsors/jmrplens) funds the project directly, and the money goes where the cost is: buying the standards and editions the implementations are written from. A one-off sponsorship that names one of the documents below buys exactly that document, and the entry leaves the table when it lands. ## The sources I could not obtain Everything below stands between the library and work it would otherwise do. Each entry has survived the whole acquisition effort: my own library, the official stores, the open-access indexes and every other legitimate channel I could find, re-checked on the date shown. Four routes help: - **Fund the purchase.** A one-off sponsorship naming the document; where a link goes to an official store, the price is on that page, and for the rest name the item and I will quote it in the issue. - **Send me a copy.** Whatever its origin. It stays private, it is used only to implement and to verify, and it is never republished: the repository only ever carries the derived numeric values. Write to [mail@jmrp.io](mailto:mail@jmrp.io). - **Verify against your licensed copy.** If your lab or employer already holds one, you can check the implementation and its reference values against your copy. What lands in the tree are the derived numeric values, which is how the [conformance suite](https://jmrplens.github.io/phonometry/reference/conformance/) is built. - **Point me at a channel I missed.** A lending library, an author's own copy of a thesis, a proceedings archive that actually resolves. [Open an issue](https://github.com/jmrplens/phonometry/issues). | Source | What it would unlock | Last checked | | :--- | :--- | :--- | | [IEC 60268-16:2020 (Ed. 5)](https://webstore.iec.ch/en/publication/26771) | The STI edition in force. The library implements the numerically identical Ed. 4 chain and holds Ed. 5 store previews and Corrigendum 1:2025; the full text would let the four new annexes and the ten-page Annex M be verified instead of described | 2026-09-01 | | [IEC 61252:2025](https://webstore.iec.ch/en/publication/68929) | The edition that superseded IEC 61252:1993+A1+A2 on 17 October 2025. The suite transcribes the 1993+A2 text for `sound_exposure()` and `lex_8h()`; the 2025 text is needed to review the delta | 2026-09-01 | | [VDI 2081 Part 1:2022-04](https://www.vdi.de/richtlinien/details/vdi-2081-blatt-1-raumlufttechnik-geraeuscherzeugung-und-laermminderung) | The edition in force of the German HVAC noise method. The library holds the 2001-07 print, two editions behind: the 2019 revision renumbered every clause and added whole chapters on air-handling units and on outdoor propagation, so the delta cannot be reviewed from what is here | 2026-09-04 | | [VDI 2081 Part 2:2022-10](https://www.vdi.de/richtlinien/details/vdi-2081-blatt-2-raumlufttechnik-geraeuscherzeugung-und-laermminderung-beispiele) | The worked examples that anchor Part 1, and the spreadsheet the current edition ships with them. The 2005-05 print in hand is the conformance oracle for the fan, splitter-silencer and cross-talk chain; the current one would say whether those printed values still hold | 2026-09-04 | | [ASTM E413-22](https://doi.org/10.1520/E0413-22) | The two appendix figures. The body text is transcribed in full, Table 1 and Appendix X1 included, but Figures X1.1 and X1.2 are graphs and carry the worked STC 24 and STC 30 examples, which is exactly the part that would anchor `sound_transmission_class` against the classification's own arithmetic | 2026-09-04 | | ISO 20816-3:2022 | The zone boundaries in force for industrial machines above 15 kW, the part of the series a plant reaches for most often. Every legitimate route came back empty, so `industrial_machine_zone` is written from the direct predecessor it replaced, ISO 10816-3:2009; the current edition widened the speed range to 30 000 r/min and would say whether the printed boundaries moved with it | 2026-09-05 | | Widmann (1992), *Ein Modell der psychoakustischen Lästigkeit von Schallen und seine Anwendung in der Praxis der Lärmbeurteilung*, doctoral thesis, Technische Universität München | The primary source of the psychoacoustic-annoyance model, implemented from Fastl & Zwicker (2006). The chair that supervised it lists the thesis but deposits no file, unlike others on the same page, so it appears to exist only in print | 2026-09-04 | | Bowdler & Leventhall (eds.), *Wind Turbine Noise* (Multi-Science, 2011) | The standard reference behind the wind-turbine noise guide; only its book reviews circulate | 2026-09-01 | | Hopkins, *Sound insulation measurements with intensity techniques: flanking transmission* (Proceedings of the Institute of Acoustics, 1997, [doi:10.25144/19134](https://doi.org/10.25144/19134)) | Intensity-measured flanking data beside the ISO 15186 implementation. The DOI resolves to the Institute's own site and returns 404, and no repository preserves it; the author lists his work at [his ResearchGate profile](https://www.researchgate.net/profile/Carl-Hopkins/research) | 2026-09-04 | | Recuero López, *Ingeniería acústica* (Paraninfo, 2000, 670 pp., ISBN 84-283-2639-8) | Canonical Spanish textbook; print only, and it would enrich the terminology and worked examples of the Spanish guides | 2026-09-04 | Second-hand print copies count, through the same routes.