Four ways to get sound to a listener
| Hearing loop | FM / RF | Infrared | Auracast | |
|---|---|---|---|---|
| Carries audio by | A magnetic field from a loop of wire | Radio | Invisible light | Bluetooth LE radio at 2.4 GHz |
| Hearing aids with a telecoil | Work directly, switched to T | Need a receiver and neckloop | Need a receiver and neckloop | Need a receiver and neckloop, unless the aids have Auracast |
| Hearing aids with Auracast | Through their telecoil, if they have one | Only with a receiver | Only with a receiver | Yes, on the Standard Quality stream |
| Visitors' own phones and earbuds | No | No | No | Yes, if they support Auracast |
| Typical weak spots | Field varies; spills into nearby looped rooms | Interference from other radio | Needs line of sight; sunlight | Walls, people's bodies, a busy 2.4 GHz band |
Hearing loops
A loop's great strength is that people whose hearing aids have a telecoil "use their own hearing aids as the receiver", as the Access Board's 1999 research report put it: they walk in and switch to T. The same report notes that the field "is not confined within the looped area" and is weaker further from the wire, which is why neighboring loops need careful design. England's Approved Document M warns that where adjacent spaces each have a loop, "the signals may overlap."
Infrared
Infrared is "line of sight": turning away from the emitter or putting the receiver in a pocket can lose the signal (Access Board research). Its strength is privacy. An advisory note in the 2010 ADA Standards says infrared is "typically a better choice than an FM system where confidential transmission is important because it will be contained within a given space", but "less effective in sunlight."
FM and other radio systems
With FM, every listener needs a receiver, and the Access Board research notes that FM systems "are subject to interference from other radio sources". By the same advisory note's comparison, radio is not contained by the room the way infrared is.
Auracast
Auracast is radio too, in the 2.4 GHz band. Brick and concrete walls take a large share of its signal, and so do people standing or sitting in the way. Its new strength is that visitors can use their own devices: supported phones with LE Audio earbuds, and hearing aids or cochlear implant processors with Auracast. One transmitter can serve any number of listeners. A broadcast can be private, with a code, where neighboring rooms must not listen.
Its limits today are real. Not every phone supports it, not every hearing aid is Auracast-enabled yet, and the Bluetooth SIG has not yet published a standard way to cover a large space with several transmitters. Loan receivers with neckloops are still needed.
Use Auracast alongside other systems
The organizations closest to listeners agree on this.
- A Bluetooth SIG blog post reports that panels at the HLAA 2025 convention called it best practice to "add Auracast broadcasts alongside current systems", so listeners can move over at their own pace.
- HLAA advises people to ask for a hearing aid "that is both Auracast-enabled and contains a telecoil", to keep access to hearing loops.
- The Center for Hearing Access says no venue will be required to switch from loop, FM or infrared to Auracast, and that all of them "can and will coexist for years."
The ADA neckloop rule and Auracast
The 2010 ADA Standards require a quarter of loan receivers (at least two) to be hearing-aid compatible, with neckloops. Exception 2 drops that requirement only "where all seats in an assembly area are served by an induction loop." There is no matching exception for Auracast, so an Auracast-only venue still needs its neckloop receivers. Our ADA guide explains the full table.
Choosing, in practice
- You already have a working loop. Keep it. Add Auracast for phone, earbud and Auracast hearing-aid users.
- You have FM or infrared with ageing receivers. Auracast is worth considering, with a fresh receiver kit and neckloops.
- Privacy matters (courtrooms, side-by-side meeting rooms). Use private broadcasts with codes, keep transmitter power low, and test from the next room. Where confidentiality is critical, compare with a contained technology.
- Large or walled venues. Plan Auracast for a full room and test it on site; walls and crowds decide the number of transmitters. See walls, crowds and 2.4 GHz.
Sources
- 2010 ADA Standards for Accessible Design (Advisory 706.1, §706.3, §219.3 Exception 2). U.S. Department of Justice. Accessed September 30, 2026.
- Large Area Assistive Listening Systems (ALS): Review and Recommendations (December 1999). U.S. Access Board / Lexington School for the Deaf RERC. Accessed September 30, 2026.
- Approved Document M, Volume 2 (paragraph 4.35), England. UK Government. Accessed September 30, 2026.
- Venues worldwide are already deploying Auracast systems (26 August 2025). Bluetooth SIG. Accessed September 30, 2026.
- Auracast simple transmitter best practices guide, Version 3. Bluetooth SIG. Accessed September 30, 2026.
- Auracast Systems. Hearing Loss Association of America. Accessed September 30, 2026.
- Auracast streamed assistive listening. Center for Hearing Access. Accessed September 30, 2026.
- Specifications in development. Bluetooth SIG. Accessed September 30, 2026.
- WLAN obstacle attenuation values at 2.4 GHz. Huawei. Accessed September 30, 2026.
- Analysis of Human Body Shadowing Effect on Wireless Sensor Networks Operating in the 2.4 GHz Band (Sensors, 2018). Ł. Januszkiewicz, via PubMed Central. Accessed September 30, 2026.
We cite the source for every fact and label manufacturer rules of thumb as such. This is general information, not legal or engineering advice for a particular building. Spot something out of date? Write to dave@equalaccessaudio.com.