Purpose
Venues, installers, hearing professionals, specifiers and listeners choose and use assistive listening while the field changes: Auracast broadcast audio is new, and many decisions are being made before most standards and the long-term evidence are in place. This site collects what has been published, in one place, around the practical questions those decisions turn on, so that people can plan with incomplete information and see exactly what each statement rests on.
Scope and coverage
The site covers the assistive listening systems that venues provide for people with hearing loss. Auracast broadcast audio and hearing loops are covered in the most depth. Infrared, RF/FM (dedicated venue receiver systems on 72-76 MHz, 216 MHz, the European assistive listening bands or proprietary digital radio) and Wi-Fi streaming to listeners’ phones are covered with lighter depth, mostly in the questions every technology shares: codes and standards, receivers and neckloops, telecoils, who can connect, and what listeners prefer. Personal remote microphones, classroom sound-field systems, conference interpretation and captioning are out of scope. Each question and source is tagged with the technologies it reports evidence on, and the panel below is counted from those tags each time the site is built, so thin coverage shows.
| Auracast | Hearing loops | Infrared | RF/FM | Wi-Fi streaming | Shared | Whole library | |
|---|---|---|---|---|---|---|---|
| Questions | 46 | 39 | 25 | 28 | 22 | 39 | 57 |
| Sources | 156 | 211 | 74 | 69 | 45 | 267 | 523 |
| Data rows with technology tags | 368 | 35 | 10 | 11 | 17 | 21 | 462 |
| Independent | 30 | 41 | 9 | 7 | 10 | 72 | 112 |
| Manufacturer | 49 | 41 | 17 | 15 | 20 | 31 | 130 |
| Standards body | 23 | 13 | 4 | 3 | 2 | 30 | 62 |
| Nonprofit advocacy | 23 | 39 | 16 | 14 | 11 | 38 | 60 |
| Trade body | 26 | 17 | 8 | 4 | 2 | 17 | 43 |
| Government | 5 | 60 | 20 | 26 | 0 | 79 | 116 |
| Newest dated source |
11 evidence tables and a glossary. Data row counts include only tables with a technology column; rows can overlap and are not independent studies.
Counted from the library each time the site is built. A question or source can cover more than one technology, so the technologies add up to more than the whole library. Shared: what applies whichever technology is used: codes and standards, receivers, neckloops, telecoils, who can connect and what listeners prefer, and hearing research that does not depend on the technology. Undated web pages count as sources but not for the newest date.
Technologies are always listed in the same order, alphabetically with Shared last; the order does not rank them. The technology pages list each one’s questions and sources.
Neutrality pledge
This website was created to be the current, comprehensive, vetted and sourced knowledge base that this rapidly developing field needs. It is maintained by Equal Access Audio as a public resource. No advertising or self-promotion is accepted.
Editor: David Harmon. Contact: write to the editors.
How questions work
Each question has six parts: in brief; why it matters; what the evidence shows; where sources disagree; what would settle it; and planning while it is open. Every finding is linked to its source with a numbered citation; each citation names its source and funding label when hovered or read aloud. “Planning while it is open” lists only steps that the cited sources recommend or that follow directly from them. Each question has a status:
- OpenThe published evidence does not yet answer the question.
- DisputedCredible sources reach different conclusions.
- Partly answeredEvidence exists but does not cover all common situations.
- Not reliable yetThe available evidence points to a current limitation.
- SettledConsistent evidence, or a published standard, answers the question.
Sources and labels
The library includes peer-reviewed studies, independent field and bench tests, standards and regulations, industry and advocacy guidance, manufacturer documents and expert statements. Each record gives the type of source, a summary in our own words, the key findings, the limits, and a link to the original. Quotes are short, and copies are never hosted. Claims about products come only from the cited test and are dated, because results depend on firmware. A web page that gives no date is shown as undated, with the day it was read.
The questions and the source records are also published as data, for researchers and software: questions.json and evidence.json, plus data.json for the evidence tables, with a plain-text guide to the site in llms.txt.
Every source is labelled with who produced or paid for it. When an author works for a company or organisation other than the one labelled, the label’s detail says so.
- IndependentUniversities, public research bodies, independent authors, and hearing-loss organisations testing on their own account. Who paid is named where the source says.
- ManufacturerProduced or paid for by a company that makes or sells the products concerned.
- Standards bodyStandards organisations and specification bodies. The Bluetooth SIG, which writes the Bluetooth specifications, is an industry association funded by its member companies and owns the Auracast trademark; its marketing material is labelled Trade body.
- Nonprofit advocacyCharities and associations that speak for people with hearing loss, including their guidance and device lists.
- Trade bodyIndustry associations whose members sell products or services, and their marketing material, including the Bluetooth SIG’s.
- GovernmentLaws, regulations, building codes and government-funded guidance.
Manufacturer work is included and labelled, because it is often the only published evidence; its label appears wherever it is cited.
Wording
Everything here is written from the cited sources only, not from the sponsor’s own practice or opinions, and the site does not recommend products, installers or services. Each question’s “What would settle it” describes, in the editor’s words, the evidence that the cited sources show to be missing.
The site does not describe a product, an installation or a venue as meeting a standard or a law, and makes no promises about performance. When a source makes such a claim, it is quoted in quotation marks and attributed, so that it can be examined.
How “Start here” is chosen
The home page suggests up to 4 questions for each group of readers. They are picked by rule, not by judgment: each question lists the people it affects, and the questions that list a group earliest come first, in tracker order.
Keeping it current
New studies, standards and guidance are looked for at least once a month, from scholarly alerts, the Bluetooth SIG’s specification and news pages, the IEC committees writing the standards, hearing-loss organisations, trade journals, conference programmes and manufacturers’ release notes. A new source updates the questions it bears on first, with a dated entry in each question’s change log, and notable changes appear in the updates. Every question is reviewed again at least every six months.
Corrections
Errors are corrected once they have been checked against the source, and each correction is noted with its date in the change log of the question concerned. To report one, see Suggest a study or correction.
Who writes and reviews
Records and questions are written from the original sources and checked against them before they are published. No outside reviewers take part yet. When independent reviewers do, they will be named here with the questions they reviewed.