Where does infrared assistive listening work, and where does it fall short?

Why it matters

Infrared is one of the three wireless system types named in the advisory notes of the US ADA Standards and in England's building guidance, and RNID describes it as common in theatres and cinemas^1,2,3. US guidance points to it where speech must stay in the room^1,4. The cited guides show no direct infrared input to hearing aids, so listeners need a receiver with earphones or a neckloop for a telecoil; venues lend receivers, and some listeners bring their own^5,6,7.

What the evidence shows

How venue infrared works

The Hong Kong guidance and IEC 61603-7 cited below concern conference interpretation. They are used here only for the shared infrared transmission path and interference mechanisms, not as tests of venue assistive-listening receivers^8,9.

• Carriers. In the analogue systems described in the 1999 report, the audio frequency-modulates a subcarrier, which in turn modulates the infrared light from the emitter's diodes⁷. A 1999 report to the US Access Board found 95 kHz the subcarrier most used, by informal agreement among makers rather than any standard, with 250 kHz added for stereo, and newer systems moving to 300 kHz, 2.3 MHz and 2.8 MHz, partly because new fluorescent ballasts interfered at 95 kHz⁷. Two makers' current venue systems use 2.3, 2.8, 3.3 and 3.8 MHz^10,11.
• Standards. IEC 61603-2 (1997) sets methods for measuring and specifying wideband audio infrared systems and replaced the part of an earlier standard that covered only two carrier frequencies for analogue audio; its channel allocations are in the paid text¹². One UK maker describes its 2.3 MHz channel as H1 in Band IV of that standard¹³. A Hong Kong government paper reproduces an IEC allocation that places conference systems at 40 kHz to 1 MHz and high-fidelity audio at 2 to 6 MHz⁸, and IEC 61603-7, written for digital conference interpretation, uses 45 kHz to 1 MHz and 2 to 6 MHz⁹.
• Compatibility. Listen Technologies states that its products work with other makers' systems on the same carriers¹⁰, and a federal advisory committee calls receivers compatible with most infrared systems⁴. The 1999 report found systems from different companies not always compatible even on the same subcarrier, giving as reasons possible differences in pre-processing, receiver filters and emitter power, and found no standard for the infrared level needed at a seat⁷.
• Coverage. Makers rate each radiator by receiver model and number of channels. Listen Technologies gives about 10,000 sq ft for one channel with its LR-42 and LR-44 receivers, 2,500 sq ft for four channels, and about 40,000 sq ft for one channel with its LR-4200 and LR-5200, and under-rates its radiators by 40% because emitter output falls that much after about 8,000 hours¹⁰. Williams AV gives up to 32,000 sq ft for one channel with its handheld RX22-4 receiver and 19,000 sq ft with its RX20 under-chin receiver¹¹. Sennheiser rated its SZI 1015 radiator at up to 400 m² (about 4,300 sq ft)¹⁴.
• Line of sight and reflections. In open space infrared is line of sight, while light-coloured, reflective surfaces extend coverage¹⁰; most objects block it¹¹, and blackout curtains and some red and purple paints affect coverage¹³. The 1999 report found that reception "may be uncertain and has to be empirically determined in each venue", and can be lost or distorted when a listener turns away from the emitter or puts the receiver in a pocket⁷. A UK theatre consultancy says many emitters are needed to cover every seat and that the signal is blocked when patrons lean forward, adjust clothing or fold their arms¹⁵; a loop advocate says a hand, clothing or a tall person causes a loud static noise¹⁶.

What interferes

• Sunlight. Direct sunlight saturates the receiver's photodetector, so rooms with large windows need screening or more radiators⁸. The 1999 report says more emitters can overcome all but the most unfavourable light, such as direct sunlight⁷. A maker says coverage can be affected by direct or indirect sunlight¹¹, a consultancy that background infrared would rise to "unsustainable levels in sunlight"¹⁵, and an advocacy page rules out venues with much glass or glossy surfaces in sunlight¹⁷.
• Lamps. Tungsten and halogen lamps emit enough infrared to add noise at the receiver⁸, and the 1999 report counts incandescent light, which contains "a great deal of infrared energy", among the issues for infrared systems⁷.
• Fluorescent lighting and low carriers. A maker's 2012 bulletin says high-efficiency fluorescent lighting interferes with every 95 kHz system, whatever the brand, and advises systems on 250 kHz or higher¹⁸. The Hong Kong paper says fluorescent lamps on fixed electronic ballasts can interfere up to about 280 kHz, and on dimmable ballasts up to about 400 kHz, and recommends digital systems in the 3 to 6 MHz band⁸. Two makers say their 2.3 to 3.8 MHz carriers reduce lighting interference^10,11.
• Screens. Two makers warn that plasma screens can degrade infrared audio^10,11, while a third says its 2.3 MHz system is "largely immune" to high-efficiency lighting and plasma displays¹³. In a maker's case study, patrons of a 1,500-seat theatre were increasingly hearing interference from large LED screens on an infrared system more than 30 years old¹⁹.
• LED room lighting. None of the sources found reports a test of infrared assistive listening under LED room lighting: the Hong Kong paper predates common LED lighting, and the Listen Technologies and Williams AV manuals do not discuss it^8,10,11.
• Radio. Infrared is normally free of radio interference and needs no radio licence^5,11.

Confidential rooms and multiple audio tracks

• The signal stays in the room. The ADA's advisory calls infrared typically the better choice where confidential transmission matters, and a federal advisory committee prefers it for courtrooms and lists it for jury deliberation rooms, where it rules FM out because FM's signal passes through walls^1,4. The Swiss draft standard allows infrared or FM where eavesdropping must be prevented²⁰. Because infrared cannot pass walls and doors, the Hong Kong guidance describes no cross-talk through those opaque boundaries⁸, and any number of systems can run in adjacent auditoriums⁷.
• Windows. Listen Technologies claims infrared "cannot pass through walls, ceilings, or glass"²¹, and Williams AV says its transmitter cannot be concealed behind glass¹¹. An expert guide makes confidentiality conditional on covered windows⁵, and a UK maker says infrared does not reflect off most glass, so radiators should point away from windows¹³. None of these reports a measurement^21,5.
• Several channels. Infrared carries several channels at once, such as a cinema's hard-of-hearing and audio description tracks^5,15; the Hong Kong paper describes up to 16 channels in interpretation systems, rather than establishing a capacity for assistive-listening receivers⁸. Each radiator covers less area as channels are added¹⁰.

Receivers

• A receiver for everyone. An advocacy page lists what borrowing a receiver costs users: they "lose dignity by “outing” their disability", borrowing and returning is inconvenient, and borrowed equipment can fail¹⁷.
• Under-chin and bodypack. The 1999 report describes the common stethoset receiver that hangs under the chin, whose tubing can add resonant peaks to the sound; it notes that body-worn receivers with a front lens suit an overhead emitter poorly, and that some under-chin receivers' jacks do not take standard neckloop plugs⁷. A maker says its under-chin receiver is simple to hand out and avoids tangled cords but is uncomfortable for some guests over long periods, while its lanyard receiver takes many earphones but is harder to hand out²². A loop advocate says hearing-aid users without telecoils may have to remove their aids to fit under-chin receivers, and that companions have reported sound leaking from headphones¹⁶.
• Hygiene. The 1999 report lists cleaning after each return, such as wiping foam cushions with antiseptic and replacing disposable ones⁷. An advocacy page lists hygiene among operators' burdens¹⁷, survey respondents complained of unhygienic headsets²³, and a maker promoting Wi-Fi streaming to listeners' phones calls shared assistive listening devices "a major hygiene and health risk" in and after the COVID-19 era²⁴.
• Neckloops. US rules require at least 25% of receivers, and no fewer than two, to be hearing-aid compatible through neckloops¹, and the 1999 report recommended at least one neckloop for every four headphone receivers⁷. Pro Audito reports that every FM, infrared and Auracast system it had tested reached the required field strength at the ear through a neckloop only with the transmitter fully driven and the receiver near full volume²⁵, and its dummy-head measurements of six neckloops found that many available neckloops lose the high frequencies that matter most for speech²⁶. An advocacy page says a neckloop not matched to the receiver can be too weak and distort when the volume is turned up¹⁷, and a loop advocate that neckloops can become intermittent after rough handling and that staff may not know they exist¹⁶. The Swiss draft requires field strength and frequency response through the neckloop to meet EN 60118-4²⁰. A European federation of hard-of-hearing people warns that hearing aids sold without telecoils burden venues whose infrared systems depend on telecoil connection²⁷.
• Batteries and charging. One maker gives about 30 hours on alkaline batteries and 15 hours on rechargeable packs, which need its charging station²². The 1999 report found no infrared receiver with a low-battery light, and recommended charging rechargeables after each performance, checking disposable batteries before each one and listening to every receiver before lending it⁷. Survey respondents and a loop advocate report receivers handed out with dead or nearly empty batteries^23,16, and a consultancy names the staff time for charging, maintaining and supporting receivers, which grows with the number of channels¹⁵.

Outdoors

US guidance says FM may be better than infrared in some open-air assemblies because infrared is less effective in sunlight¹, and a federal committee notes that many infrared systems work only indoors⁴. An advocacy page says infrared cannot be used outdoors in daytime¹⁷, and a guide, a narrative review in an audiology journal and a consultancy call it impractical or unsuitable outdoors^5,28,15. The 1999 report noted that a few transmitters could reportedly be used in some outdoor venues, though not in direct sunlight⁷. None of the sources reports an outdoor test of an infrared assistive listening system^17,7.

Listener experience and use

• Benefit. In an independent 1986 classroom study, indexed by PubMed as supported by an NIH grant, whose abstract gives no sample size, infrared, FM and loop systems all gave better word scores than a public-address system. This is evidence about the shared direct-to-listener path, not a current venue installation²⁹. The 1999 government-funded report's review of earlier studies found small differences between the three systems⁷. An advocacy guide gives typical delays of about 1 to 20 ms for loops and infrared³⁰.
• Use. In a self-selected survey of 1,519 people with hearing loss, run by hearing-loss advocates with funding unstated, respondents who found a venue system found infrared 14% of the time, FM 51% and a loop 27%; where a system needs a borrowed receiver, 37% always or usually borrow one with a headset and 39% with a neckloop²³. A loop advocate cites a New Mexico survey, without its sample size, method or funding, in which 18% always used borrowed equipment, against 54.5% who always used a loop¹⁶. A 1,500-seat theatre lends 15 to 20 receivers per performance on average and has had 50 to 60 requests on some nights, according to a case study by the maker of its new system¹⁹.
• Preference. The surveys favour loops, but use different questions and do not all separate infrared from FM. In a maker-funded survey of 243 loop users, mostly HLAA members, 81% chose a loop over FM or infrared with a neckloop or headset³¹. In a UK survey of 143 people with hearing loss by the social enterprise Ideas for Ears, whose method and funding are not reported, 77% preferred a loop to infrared or FM³². Asked which single system a city council chamber should install, 11 of 1,335 respondents to the advocates' survey described above chose infrared; of the 312 who chose one of the five listening systems offered, 187 chose a loop, while 492 respondents chose captions. This was a hypothetical recommendation, not a record of a venue buying a system³³.
• Sound quality. A consultancy says infrared audio is "much lower in quality than an induction loop's" because it uses only part of the audible range, and that infrared draws nearly as many negative anecdotes as loops in the UK¹⁵. The journal review lists "excellent sound quality" among infrared's advantages²⁸, and one maker specifies its under-chin receiver at 63 Hz to 15 kHz (±3 dB)²². None of these reports a listening test^15,28.

Market and cost

• Makers still selling. Williams AV announced a new infrared transmitter in 2024 as "the latest addition" to its infrared line, claiming 50% more coverage than its predecessor³⁴, and Listen Technologies promoted its infrared systems in 2025 for rooms that need privacy, such as courtrooms, clinics, boardrooms and government buildings²¹.
• One maker's radiator withdrawn. Sennheiser's catalogue marks its SZI 1015 infrared radiator "no longer available to be purchased"¹⁴. In 2021 the company, promoting Wi-Fi streaming to listeners' phones, wrote that "Infrared systems take a lot of time and resources to implement and properly maintain the hardware"²⁴. None of the sources found states a maker's decision to stop making infrared systems¹⁴.
• Venues and advocates moving on. The theatre in the case study replaced its infrared system with the maker's RF receivers and Wi-Fi streaming¹⁹. RNID now calls Auracast "the preferred solution" in most cases where loops cannot be used, and sees it as a better choice than infrared where loops are impractical because people will in time be able to use their own receivers^3,35.
• Cost. A Bavarian state planning guide for hearing loops, written with a hard-of-hearing association, rates infrared equipment and installation at about 2.5 times the cost of a loop, and FM at about twice³⁶. A guide says infrared costs more and is harder to install in very large areas such as stadiums⁵, and a maker that sells infrared alongside RF, loop, Wi-Fi and Auracast systems calls it complex to design³⁷. An advocacy page calls installation relatively simple¹⁷, and a loop advocate counts easier installation and lower installation cost for the venue among the advantages of RF and infrared¹⁶. None of these gives prices or a costed comparison^36,5.

Where sources disagree

Sources disagree on glass. Listen Technologies says infrared cannot pass through glass, and Williams AV that its transmitter cannot be concealed behind glass^21,11; an expert guide makes confidentiality conditional on covered windows, and a UK maker advises pointing radiators away from windows because infrared does not reflect off most glass^5,13. No side reports a measurement.

Sources disagree on screens and lighting. Listen Technologies and Williams AV say plasma screens can degrade their systems, while Current Thinking calls its 2.3 MHz system largely immune to plasma displays and high-efficiency lighting^10,11,13. Williams AV says carriers of 250 kHz or higher operate effectively with high-efficiency fluorescent lighting, while the Hong Kong paper says ballasts can interfere up to about 280 kHz, and up to about 400 kHz when dimmable^18,8.

On compatibility, a maker and a federal committee describe receivers that work across most systems on the same carriers^10,4, while the 1999 report found that systems on the same subcarrier were not always compatible⁷.

On sound quality, a UK consultancy calls infrared audio much lower in quality than a loop's, while a journal review lists excellent sound quality as an advantage^15,28. Neither reports measurements.

On cost, a German state guide rates infrared the most expensive of loops, FM and infrared, while a loop advocate counts lower installation cost among its advantages and an advocacy page calls installation relatively simple^36,16,17.

What would settle it

Independent measurements of current 2 to 4 MHz systems under daylight through windows, near LED room lighting and near LED and plasma screens, which the sources found do not report^8,19. Measurements of how much infrared escapes through window glass^21,5. A standard for the infrared level needed at each seat, and access to the channel allocations in the paid text of IEC 61603-2^7,12. Occupied-venue tests of under-chin and handheld receivers and of neckloops, measuring speech understanding as well as coverage^11,26. Representative surveys of how often listeners borrow infrared receivers and why they do not, and priced comparisons of installation and running costs, which the sources describe only in guides, advocacy and maker material^23,36.

Planning while it is open

• Where speech must stay in the room, US guidance points to infrared^1,4; cover the windows⁵ and point radiators away from them¹³.
• Avoid infrared for daytime outdoor events, where US guidance says FM may be better^1,17; in rooms with large windows, plan screening or extra radiators⁸.
• Find out what lighting is installed or planned: avoid 95 kHz systems where high-efficiency fluorescent lighting is used, and run a joint site test with the lighting engineer where information is lacking^18,8.
• Keep transmitters away from plasma screens, and test reception with the room's screens and lighting switched on^11,8,19.
• Design from the maker's coverage patterns for the receiver model the venue will lend and the number of channels, allowing for emitter ageing, with at least two radiators except in small rooms and extra radiators for shaded areas such as under balconies^10,11.
• At commissioning, walk the room with a receiver, cover at least 90% of the used seats, and mark seats not covered on a displayed plan^13,7.
• Provide neckloops for at least a quarter of receivers, and no fewer than two, where the ADA applies¹, choose neckloops measured to keep the high frequencies²⁶, and put an automatic gain control or fast peak limiter before the transmitter so that the neckloop field is reached without clipping²⁵.
• Name a trained person to issue, charge, test and clean receivers, charging rechargeables after each performance⁷.
• Post the infrared subcarriers in use for people who bring their own receivers⁷.
• Check the system monthly with a receiver, and the field strength at neckloop receivers yearly¹³.

Sources

1. 2010 ADA Standards for Accessible Design. US Department of Justice. US Department of Justice (ada.gov), 15 September 2010. Government (US Department of Justice) ↩︎ https://www.ada.gov/law-and-regs/design-standards/2010-stds/
2. Approved Document M, Volume 2: buildings other than dwellings (2015 edition incorporating 2020 and 2024 amendments). UK Government. Ministry of Housing, Communities and Local Government (GOV.UK), 30 September 2024. Government (UK Ministry of Housing, Communities and Local Government) ↩︎ https://assets.publishing.service.gov.uk/media/66f6c5eec71e42688b65ee11/ADM__V2_with_2024_amendments.pdf
3. Infrared, FM and Audio Over WiFi. RNID. RNID (Royal National Institute for Deaf People), 27 May 2026. Nonprofit advocacy (RNID, UK charity) ↩︎ https://rnid.org.uk/information-and-support/technology-and-products/assistive-listening/infrared-fm-and-audio-over-wifi/
4. Justice for All: Designing Accessible Courthouses (recommendations from the Courthouse Access Advisory Committee). Courthouse Access Advisory Committee. US Access Board, 15 November 2006. Government (US Access Board federal advisory committee of 35 members, among them the Hearing Loss Association of America, courts, architects, code bodies and disability groups) ↩︎ https://www.access-board.gov/ada/additional-resources/designing-accessible-courthouses.html
5. Comparison of Large Area Assistive Listening Systems. Compton-Conley C. Hearing Loss Association of America (reprint), 2015. Nonprofit advocacy (reprinted by HLAA with the contact address of its Get in the Hearing Loop program; written by Cynthia Compton-Conley, PhD, of Gallaudet University; who paid for the original is not stated) ↩︎ https://www.hearingloss.org/wp-content/uploads/comparison-of-large-area-assistive-listening-systems.pdf
6. Coupling Options: Ways to Connect to Assistive Listening System Audio. Kaneb A (credited on the chart). Hearing Loss Association of America (HLAA), 2026. Nonprofit advocacy (Hearing Loss Association of America, a US consumer organisation for people with hearing loss; the chart is credited to Andrea Kaneb and names no funder) ↩︎ https://www.hearingloss.org/wp-content/uploads/documents/advocacy-resources/hlaa-coupling-options-als-chart.pdf
7. Large area assistive listening systems (ALS): review and recommendations. Bakke MH, Levitt H, Ross M, Erickson F. Final report to the U.S. Access Board; Lexington School for the Deaf, Rehabilitation Engineering Research Center on Hearing Enhancement, December 1999. Government (U.S. Department of Education, NIDRR grant H133E30015; final report to the U.S. Access Board) ↩︎ https://www.access-board.gov/files/research/assistive-listening-systems.pdf
8. Interference Problems of Fluorescent Lamps Operating on High Frequency Electronic Ballasts with Infrared Remote Control Equipment and Infrared Simultaneous Interpretation System. Wu M (Martin Wu Kwok-tin). Energy Efficiency Office, Electrical and Mechanical Services Department, Hong Kong SAR Government, August 2003. Government (Electrical and Mechanical Services Department, Hong Kong SAR Government; written by a department engineer) ↩︎ https://www.emsd.gov.hk/filemanager/en/content_764/infrared_interference_emsdweb.pdf
9. IEC 61603-7:2003 Transmission systems of audio and/or video and related signals using infra-red radiation, Part 7: Digital audio signals for conference and similar applications. IEC Technical Committee 100 (Audio, video and multimedia systems and equipment). International Electrotechnical Commission (webstore abstract), 22 May 2003. Standards body (International Electrotechnical Commission; the full text is sold, the abstract is free) ↩︎ https://webstore.iec.ch/en/publication/5660
10. LT-82 & LA-140 User Manual: Stationary IR Transmitter and Stationary IR Radiator. Listen Technologies, 26 September 2022. Manufacturer (Listen Technologies, maker of the ListenIR transmitter and radiator described) ↩︎ https://www.listentech.com/wp-content/uploads/2021/10/LT-82-_-LA-140-User-Manual-2022-09-26.pdf
11. IR T3 Infrared Transmitter user manual (MAN 295). Williams AV, 6 November 2024. Manufacturer (Williams AV, maker of the SoundPlus IR T3 transmitter described) ↩︎ https://williamsav.com/wp-content/uploads/2024/11/MAN-295-IRT3-User-Manual.pdf
12. IEC 61603-2:1997 Transmission of audio and/or video and related signals using infra-red radiation, Part 2: Transmission systems for audio wide band and related signals. IEC Subcommittee 100C (Equipment and systems in the field of audio, video and audiovisual engineering). International Electrotechnical Commission (webstore abstract and publisher's preview), 28 February 1997. Standards body (International Electrotechnical Commission; the full text is sold, while the abstract and a preview of the first pages are free) ↩︎ https://webstore.iec.ch/publication/5656
13. IRMTX750 Infra Red Modulator & Radiator: Installation and Maintenance Manual (Revision 2). Current Thinking Ltd. Current Thinking Ltd (Infra~Hear range); copy hosted by a French audiovisual reseller, January 2011. Manufacturer (Current Thinking Ltd, a UK maker of the Infra~Hear infrared assistive listening products described) ↩︎ https://www.la-bs.com/Objets/IRMTX750_me.pdf
14. SZI 1015 (product page). Sennheiser. Sennheiser (online catalogue), undated (read 9 October 2026). Manufacturer (Sennheiser, maker of the infrared radiator described) ↩︎ https://sennheiser.com/en-gb/catalog/products/wireless-systems/szi-1015/szi-1015-004394
15. Assistive Listening - Demystified. Lerman K (Theatreplan). Theatreplan (news blog), 29 April 2025. Independent (Theatreplan, a UK theatre planning consultancy; written by its consultant Kit Lerman; no funding is stated) ↩︎ https://theatreplan.com/news/assistive-listening-demystified
16. Hearing Loop – the Preferred Large Area Assistive Listening System: Here's Why. Sterkens J. Canadian Audiologist 6(1), 21 January 2019. Nonprofit advocacy (written by Juliëtte Sterkens, AuD, who according to the author note has worked since 2012 as an advocate for hearing loops and other assistive technology with the Hearing Loss Association of America, with grant funding from the David and Carol Myers Foundation; published in the Canadian Academy of Audiology's magazine) ↩︎ https://canadianaudiologist.ca/hearing-loop-large-area-system-feature/
17. Infrared (IR) Assistive Listening Systems. Center for Hearing Access. Center for Hearing Access, The John G. Shedd Institute, undated (read 9 October 2026). Nonprofit advocacy (Center for Hearing Access, an initiative of The John G. Shedd Institute for the Arts; it states that it accepts no donations from hearing-related vendors) ↩︎ https://centerforhearingaccess.org/infrared/
18. 95 kHz Infrared Systems: High Efficiency Fluorescent Lighting (Technical Bulletin MFRM 017A). Williams Sound. Williams Sound (now Williams AV), 14 February 2012. Manufacturer (Williams Sound, now a brand of Williams AV, which sells infrared systems on 2.3-3.8 MHz carriers) ↩︎ https://williamsav.com/wp-content/uploads/2020/04/tech_bulletin_95kHz_IR_Systems_and_fluorescent_lighting.pdf
19. Lutcher Theater Installs Wi-Fi and RF Assistive Listening (case study). Listen Technologies, 13 January 2023. Manufacturer (Listen Technologies, which supplied the RF and Wi-Fi systems described and also sells infrared systems) ↩︎ https://www.listentech.com/wp-content/uploads/2023/02/RF_LE-Lutcher-Theater-Case-Study-WEB.pdf
20. prSIA 500:2025-07 Hindernisfreie Bauten (obstacle-free buildings), consultation draft. SIA (Swiss Society of Engineers and Architects). SIA; consultation copy with highlights published by Pro Audito Schweiz (in German), July 2025. Standards body (SIA) ↩︎ https://pro-audito.ch/wp-content/uploads/prSIA500_Vernehmlassungsentwurf-mit-Hervorhebungen.pdf
21. Why Use Infrared? The Unique Benefits of ListenIR for Privacy and Security. Listen Team (Listen Technologies). Listen Technologies (blog), 10 October 2025. Manufacturer (Listen Technologies, which sells the ListenIR products described as well as FM, hearing loop, Wi-Fi and Auracast systems) ↩︎ https://www.listentech.com/secure-infrared-assistive-listening-listenir/
22. Stationary IR System Manual (design guide and user manuals for the LT-82 transmitter, LA-140 radiator and LR-42 and LR-44 receivers). Listen Technologies. Listen Technologies; copy hosted by the reseller Full Compass, 4 May 2011. Manufacturer (Listen Technologies, maker of the infrared products described) ↩︎ https://www.fullcompass.com/common/files/24148-ListenTechnologiesStationaryIRSystemManual.pdf
23. Consumer use of and preferences for assistive communication technology in public places. Committee for Communication Access in America (Frazier SO, Bailey A, Cadwell B, Clifford C, Liebe K, Myers D, Sterkens J). Committee for Communication Access in America, 8 January 2024. Nonprofit advocacy (an ad hoc committee of hearing-loss advocates, chaired by Stephen O. Frazier (Loop New Mexico; a founding member of HLAA's Get in the Hearing Loop initiative), the report's correspondence author; funding not stated; data collected and analysed by the Frost Center for Data and Social Research at Hope College. The committee's site lists David Myers (founder of hearingloop.org) and Juliette Sterkens (HLAA hearing loop advocate) among its members, with Abram Bailey (founder of HearingTracker), Blake Cadwell (founder and CEO of Soundly), Kevin Liebe (hearinghealthmatters.org) and Carol Clifford (audiologist, former ReSound training director)) ↩︎ https://www.ccaa.name/Report_Final_1-12-24.pdf
24. On the current situation of people with hearing loss in society. Mros LS (Sennheiser). Sennheiser newsroom, 20 July 2021. Manufacturer (Sennheiser, which sells the MobileConnect Wi-Fi assistive listening system the article promotes and has sold infrared systems) ↩︎ https://newsroom.sennheiser.com/on-the-current-situation-of-hearing-impaired-people-in-society
25. Can Bluetooth Auracast be used as an assistive listening system?. Pro Audito Schweiz. Pro Audito Schweiz (in German), 17 February 2025. Nonprofit advocacy (Pro Audito Schweiz, Swiss hearing-loss association) ↩︎ https://pro-audito.ch/news/kann-bluetooth-auracast-als-hoeranlage-eingesetzt-werden/
26. Which inductive neck loops are suitable for Auracast/FM/IR receivers?. Pro Audito Schweiz. Pro Audito Schweiz; English reprint by the Center for Hearing Access, 8 September 2026. Independent (Pro Audito Schweiz, Swiss hearing-loss association) ↩︎ https://centerforhearingaccess.org/wp-content/uploads/Pro-Audito-Schweiz-Which-inductive-neck-loops-are-suitable-for-AuracastFMIR-receivers.pdf
27. Telecoil and Auracast functionalities should be standard requirements for hearing aids and other hearing devices eligible for public health procurement. European Federation of Hard of Hearing People (EFHOH). EFHOH (position adopted by its members at the 2026 Annual General Meeting), 18 April 2026. Nonprofit advocacy (European federation; EFHOH states that its 2024-2026 publications are co-funded by the EU CERV programme) ↩︎ https://efhoh.org/wp-content/uploads/2026/04/EFHOH-Motion-Telecoil-and-Auracast-functionalities.pdf
28. A review of assistive listening device and digital wireless technology for hearing instruments. Kim JS, Kim CH. Korean Journal of Audiology 18(3):105-111, 22 December 2014. Independent (Hallym University, Korea; the article gives no funding or conflict-of-interest statement) ↩︎ https://doi.org/10.7874/kja.2014.18.3.105
29. Comparison of amplification systems in a classroom. Nábělek AK, Donahue AM, Letowski TR. Journal of Rehabilitation Research and Development 23(1):41-52, January 1986. Government (PubMed indexes US Public Health Service research support and NIH/NINDS grant R01 NS 12035; the abstract gives no funding detail) ↩︎ https://pubmed.ncbi.nlm.nih.gov/3958997/
30. Assistive Listening Systems Quick Guide. Center for Hearing Access (reviewed by Juliette Sterkens, AuD). Center for Hearing Access, The John G. Shedd Institute, 29 October 2025. Nonprofit advocacy (Center for Hearing Access, an initiative of The John G. Shedd Institute for the Arts; it states that it accepts no donations from hearing-related vendors) ↩︎ https://centerforhearingaccess.org/wp-content/uploads/Assistive-Listening-Systems-Quick-Guide.pdf
31. Consumer Perceptions of the Impact of Inductively Looped Venues on the Utility of Their Hearing Devices. Kochkin S, Sterkens J, Compton-Conley C, Beck DL, Taylor B, Kricos P, Caccavo M, Holmes A, Powers TA. Hearing Review (October 2014 issue), 24 September 2014. Manufacturer (paid for by grants from Etymotic Research, Contacta, Listen Technologies, IntriCon and Univox by Edin, which the acknowledgments describe as including two hearing loop makers, an assistive listening company and two hearing-device technology makers; co-author Juliëtte Sterkens runs the Loop Wisconsin advocacy blog, one of the recruitment channels. The article prints no affiliations; from other sources, co-author Douglas L. Beck worked for the hearing-aid maker Oticon, joining as director of professional relations in 2005 (AudiologyOnline, 20 August 2005) and named director of academic sciences in 2016 (Hearing Review, 6 April 2016), and co-author Thomas A. Powers was vice-president of audiology at the hearing-aid maker Siemens Hearing Instruments (Hearing Review, 19 September 2013) and later a vice-president of its successor, Sivantos (Better Hearing Institute biography)) ↩︎ https://hearingreview.com/hearing-products/implants-bone-conduction/cochlear-implants/consumer-perceptions-impact-inductively-looped-venues-utility-hearing-devices
32. Hearing-impaired theatre goers disappointed says survey. Evans J. Lighting & Sound International (LSi Online), 31 May 2016. Independent (survey by Ideas for Ears, which the article calls a specialist social enterprise; reported by a trade magazine; who paid for the survey is not stated) ↩︎ https://lsionline.co.uk/news/hearing-impaired-theatre-goers-disappointed-says-survey--m7402i
33. CCAA Survey on Assistive Communication Technology: Graphs. Committee for Communication Access in America. Committee for Communication Access in America (ccaa.name), 2023. Nonprofit advocacy (an ad hoc committee of hearing-loss advocates chaired by Stephen O. Frazier (Loop New Mexico; a founding member of HLAA's Get in the Hearing Loop initiative), among them hearing loop advocates David Myers and Juliette Sterkens; funding not stated; the survey page says the responses were recorded by the Frost Center for Data and Social Research at Hope College) ↩︎ https://www.ccaa.name/CCAA_Graphs.pdf
34. Williams AV Unveils Three New Products at InfoComm 2024. Williams AV. Williams AV (news release), 6 June 2024. Manufacturer (Williams AV, which announced new hearing loop, intercom and infrared products in this release) ↩︎ https://williamsav.com/williams-av-unveils-three-new-products-at-infocomm-2024/
35. Auracast: a revolution in audio accessibility (RNID Auracast report). RNID (Royal National Institute for Deaf People). RNID, 11 February 2025. Nonprofit advocacy (RNID, UK charity) ↩︎ https://rnid.org.uk/wp-content/uploads/2025/02/Final-Auracast-Report-110225.pdf
36. Induktive Höranlagen beim Freistaat Bayern: Planungsrichtlinien, Stand 01.01.2019 (Hearing loops in Bavarian state buildings: planning guidelines). Bavarian State Ministry for Housing, Building and Transport; text by Ertl F (Government of the Upper Palatinate) and Jaggo T (Landesverband Bayern der Schwerhörigen und Ertaubten). Bayerisches Staatsministerium für Wohnen, Bau und Verkehr, 1 January 2019. Government (Bavarian State Ministry for Housing, Building and Transport, for state building projects; written with the technical officer of the Bavarian association of hard-of-hearing and deafened people, a hearing-loss organisation, and including a comparison table used with the permission of an engineer from the German hard-of-hearing association) ↩︎ https://mobilitaet.bayern.de/assets/stmi/min/181217-induktive-hoeranlagen.pdf
37. Understanding the Assistive Listening Americans with Disabilities Act. Listen Technologies, 25 October 2023. Manufacturer (Listen Technologies, which sells RF/FM, infrared, hearing loop, Wi-Fi and Auracast assistive listening products; owned since February 2023 by Allvida, which also owns the hearing-loop maker Ampetronic) ↩︎ https://www.listentech.com/wp-content/uploads/2019/07/ADA-White-Paper-2023-10-25-vA1-WEB.pdf

Change log

• 10 October 2026Published with 37 sources.
• 13 October 2026Distinguished required receivers from borrowing, scoped shared-path evidence and qualified preference findings.
• 13 October 2026Added the NIH support identified in the classroom study metadata.

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