Which radio bands can venue FM and RF systems use, and what limits them?

Why it matters

In a self-selected survey of 1,519 people with hearing loss or related conditions by the advocacy group CCAA, with funding not stated, FM accounted for 51% of the venue audio systems respondents found, against 27% for loops and 14% for infrared¹. With FM, every listener uses a borrowed receiver, and telecoil users need one with a neckloop^2,3. The band a system uses sets its power, its range, how many channels fit in one place, its audio bandwidth and what it shares the air with, and the rules differ from country to country^4,5.

What the evidence shows

United States

• 72-76 MHz. Part 15's rule for three sub-bands (72.0-73.0, 74.6-74.8 and 75.2-76.0 MHz) restricts its transmitters to use as auditory assistance devices, confines each emission to 200 kHz and limits field strength to 80 mV/m at 3 m⁶, which the FCC equates to an effective radiated power of 1.2 mW⁷. No licence is needed, and under Part 15's general conditions the devices must accept interference from others⁶.
• 216-217 MHz. The Low Power Radio Service allows 100 mW effective radiated power without a licence, shares the band with health care, law enforcement tracking and maritime uses, and forbids harmful interference to TV channel 13 and to the Air Force Space Surveillance system at 216.88-217.08 MHz⁸.
• The 2013 rule change. On a petition from Williams Sound, the FCC let 72-76 MHz devices also carry simultaneous translation for anyone at any location, and cut their permitted unwanted emissions from 1,500 to 100 µV/m at 3 m to protect VHF TV channels 2-6; equipment already installed was grandfathered for its life⁷. The FCC had no reports of harmful interference from these devices, expected their market to "remain limited", and said their low power lets others re-use the same frequencies nearby⁷.
• Higher power under another rule. Comtek's 72-76 MHz base station is type accepted under FCC Part 90 at up to 120 mW, which the maker says gives more range and reliability than Part 15 systems; its manual does not say whether the operator needs a licence⁹.

Canada and Australia

• Canada. RSS-210 sets the same 80 mV/m at 3 m limit in the three 72-76 MHz sub-bands, which it says are used exclusively for auditory assistance and wireless microphones, although another annex lists model aircraft and remote control frequencies in 72-73 and 75.4-76 MHz¹⁰. At 216-217 MHz it allows 100 mW peak (160 mW e.i.r.p.) on a no-interference, no-protection basis, reserves 216.45-216.50 MHz for law enforcement and advises avoiding 216-216.3 MHz because of TV channel 13¹⁰.
• Australia. The 2025 class licence names auditory assistance transmitters at 3.155-3.4 MHz (60 µW EIRP), 41-42 and 43-44 MHz (1.3 mW) and, together with other wireless audio, 88-108 MHz (10 µW); it opens 150.7875-152.49375 MHz to transmitters of any kind at up to 100 mW, and gives receivers of class-licensed transmitters no protection from interference¹¹. Listen Technologies said in 2010 that it sells FM on a 150 MHz carrier in Australia⁴. Australia's standard AS 1428.5 has sections on modulated radio receiver systems, with its requirements in the paid text¹².

Europe

• Bands countries may open. CEPT's Recommendation 70-03 lists 169.4-169.475 and 169.4875-169.5875 MHz at up to 500 mW e.r.p., 173.965-216 MHz at 10 mW, 863-865 MHz at 10 mW (shared with radio microphones and personal cordless audio) and 1656.5-1660.5 MHz for assistive listening systems, and says national rules decide what each country allows⁵.
• The test standard. ETSI EN 300 422-4 tests these devices' use of the spectrum: 10 mW in general, and up to 500 mW at 169 MHz for one fixed transmitter in a large auditorium, which may need an individual licence¹³.
• Sharing with digital radio and microphones. The regulators' 2015 study concluded, from measurements by the hearing instrument makers' association, that devices in 174-216 MHz should stay at least 300 kHz from the edge of an occupied DAB channel¹⁴. It states that the devices are secondary and must move if DAB use changes, and that wireless microphones (typically 50 mW) tend to interfere with them before the reverse¹⁴. It expected DAB block 5A to take away some 22 of 35 channels in the older 173.35-175.05 MHz range¹⁴.
• National rules vary. In a 2014 questionnaire, 13 of 20 European regulators authorised these devices under general authorisations up to 50 mW, four required individual authorisation, and only two reported an interference case¹⁴.
• Makers' European bands. Listen Technologies said in 2010 that it sells FM on an 863 MHz carrier in Europe⁴, and Sennheiser's digital Tourguide 2020-D uses 863-865 MHz in Europe and 926-928 MHz in the US¹⁵.

Proprietary digital RF

• 2.4 GHz. In the US, digitally modulated systems at 2400-2483.5 MHz may use up to 1 W peak conducted power¹⁶. Williams AV's Digi-Wave 400 hops across 2402-2476 MHz at 19 dBm typical, with a stated range of up to 274 m and a Hearing Assistance mode¹⁷. Australia gives class-licensed devices at 2400-2500 MHz no protection from industrial, scientific and medical equipment¹¹.
• 900 MHz. The US version of Sennheiser's Tourguide 2020-D uses 926-928 MHz, and the brochure gives the system 6 channels in tour-guide mode and 8 in conference mode¹⁵. In the US, digitally modulated transmitters at 902-928 MHz may use up to 1 W peak conducted power, and frequency-hopping ones 1 W with at least 50 hopping channels or 0.25 W with 25 to 49¹⁶. Australia's class licence allows frequency-hopping and digitally modulated transmitters at 915-928 MHz at up to 1 W EIRP¹¹.
• Audio bandwidth differs. The two digital systems state 100-7,000 Hz¹⁵ and 100-11,500 Hz in most modes¹⁷; one maker's FM gives 50 Hz-15 kHz at 72 MHz and 50 Hz-10 kHz at 216 MHz¹⁸.

Range

• Makers' figures. Listen gives 305 m at 72 MHz and up to 914 m in line of sight at 216 MHz for its stationary transmitters, and 45.7 m for its portable one⁴; a federal courthouse guide says FM covers up to several hundred feet¹⁹. None of these figures comes from a published measurement.
• Building-scale observations in a school-system study. The regulators' study mainly concerned personal FM systems in schools; its findings concern the shared radio band and do not measure venue coverage. The hearing-instrument manufacturers' association EHIMA made the measurements in one room at Ofcom's laboratory. The report describes 10 mW devices as "more or less limited to the building" and its immediate surroundings, and not noticeable under normal circumstances in neighbouring buildings tens of metres away¹⁴.
• What cuts range. Listen advises mounting the antenna high and vertical, away from metal, and keeping coaxial cable short, giving RG-58 losses of about 4 dB per 100 ft at 72 MHz and 8 dB at 216 MHz; a portable receiver's headset cord is its antenna¹⁸.
• One outdoor test. In an independent Pro Audito Schweiz test at one outdoor event of about 2,000 people, an FM system already in place transmitted stably with 8 ms of delay²⁰.

Interference and sharing

• 72 MHz is shared. Listen calls 72 MHz a secondary band where paging and other licensed transmitters can interfere¹⁸, and a guide describes the band as older and subject to interference².
• TV channel 13 at 216 MHz. Listen warns that a nearby channel 13 transmitter can cause intermodulation and suggests switching to 72 MHz¹⁸; Canada requires the manual to tell installers near an active channel 13 to reduce or adjust power, to test with a TV set at the edge of the coverage area and otherwise to use a channel near 217 MHz¹⁰.
• Neighbours and several transmitters. Listen says interference usually comes from a nearby facility on the same channel⁴, and Comtek warns that more than two transmitters in one area can cause intermodulation unless their frequencies come from one coordinated group⁹.
• Digital radio in Europe. Devices in 173.965-216 MHz must protect DAB reception, and the test standard describes a site check at the boundary, the nearest house and a first-floor window^13,5.
• Magnetic interference reaches neckloop users. Telecoils pick up electromagnetic interference, which also affects neckloop users of FM²; at the outdoor event, neckloop users of the FM system heard interference from nearby tram lines²⁰.
• Nothing found on US microphones or white space devices. None of the sources found measures or discusses interference between US venue FM and wireless microphones or TV white space devices; the FCC's 2013 change dealt with emissions into VHF TV channels 2-6⁷.

Channel planning for several rooms

• How many at once. Listen says at most six transmitters work in the same space at 72 MHz and three at 216 MHz, with adjacent channels at least 300 kHz apart^18,4. Williams AV says eight groups can run at once on its 8-channel set at 72 MHz, which includes channels 200 kHz apart²¹. Comtek's coordinated groups at 72 MHz hold four, three or two channels⁹. For its 2.4 GHz digital system, Williams AV recommends no more than four groups within the same area¹⁷.
• Spreading rooms apart. Listen allows adjacent channels across a large area if the other transmitter is at least 50% further from the receiver than its own¹⁸; Comtek separates frequency groups by twice the operating area, with at least 100 ft (about 30 m) between them⁹.
• Power. Listen advises the lowest power setting when several transmitters share an environment¹⁸, and the European study reports that systems sharing a building usually run below 10 mW for the same reason¹⁴.
• Mixing brands. Listen's noise reduction works only with its own receivers and must be off for others, and its deviation can distort some other makers' receivers¹⁸. A 1999 report to the US Access Board said complete compatibility may be questionable when one maker's FM receiver is used with another's transmitter, and recommended posting the FM frequencies in use²². The ADA lets a building count receivers across several assembly areas only if every receiver works with every system²³.

Privacy and encryption

• Analogue FM leaves the room. Listen says FM signals pass through most walls, ceilings and floors⁴ and lists RF as not secure²⁴. A federal courthouse committee, noting that the signal passes through walls, accepts FM in a jury orientation room and rules it out of the jury deliberation room¹⁹. The FCC noted that some customers may prefer the security and privacy of infrared⁷.
• Encrypted digital systems. A guide notes that encrypted digital systems exist for rooms where privacy matters². Williams AV's Digi-Wave 400 offers 87-bit encryption by default and AES-128 with a four-digit PIN, warns against easily guessed PINs, and notes that its AA-battery receiver cannot use the PIN and an older receiver cannot decode encrypted signals¹⁷.
• The Swiss draft allows FM for eavesdropping-proof systems. The SIA 500 consultation draft allows infrared and FM where eavesdropping must be prevented²⁵.

Receivers and neckloops for telecoil users

• Through a receiver only. FM reaches hearing aids only through a receiver, with a neckloop for telecoil users³; the ADA requires at least 25% of receivers, and no fewer than two, to be hearing-aid compatible through neckloops²³, and a 1999 report to the Access Board recommended at least one neckloop for every four headphone receivers²². Sennheiser's digital bodypack receiver also takes an induction neckloop¹⁵.
• Field strength at the ear. In Swiss tests, FM, infrared and Auracast receivers reached the required field strength at the ear through a neckloop only with the transmitter fully driven and the receiver near full volume²⁶, and a bench test of six neckloops on a dummy head found that many lose the high frequencies that matter most for speech²⁷.

Are the rules changing?

• US: wider use, tighter emissions. The 2013 change described above allowed 18 months for new certifications and 3 years for manufacture and import under the old emission limit⁷. None of the sources found reports a plan to reallocate 72-76 MHz or 216-217 MHz^6,8.
• Europe: broadcasting comes first. Assistive listening devices in 173.965-216 MHz may have to move if broadcast use changes⁵, and DAB block 5A was expected to take channels from the older range¹⁴.
• Analogue or digital. In 2015 European regulators did not expect these systems to become digital in the foreseeable future, citing FM's capture ratio and the latency of digital systems¹⁴. In 2018 they studied a band for digital multichannel "telecoil replacement systems" at 1656.5-1660.5 MHz, indoors, licensed and at no more than 3 dBm e.i.r.p., for which no harmonised standard yet existed²⁸. Digital venue products already use 2.4 GHz, 863-865 MHz and 926-928 MHz^17,15.
• Auracast alongside. Two of the FM makers cited here, Listen Technologies (with Ampetronic, under the Auri name) and Williams AV, also publish Auracast products^29,30, and Listen's FM manual was revised in November 2025¹⁸. A Bluetooth SIG post, co-written with people from the hearing-aid and loop industries, quotes the International Federation of Hard of Hearing People expecting FM, infrared and loops to function "for the foreseeable future" alongside Auracast, and puts the overlap at "years, maybe even a decade"³¹. A new international standard for all assistive listening systems was published in September 2026, with its requirements in the paid text³².

Where sources disagree

Is 216 MHz reserved? Listen's manual calls 216 MHz a primary band on which "no other types of transmissions are authorized"¹⁸, and a guide describes 216-217 MHz as intended for auditory assistance only². The FCC rules share the band with health care, law enforcement tracking and maritime uses, keeping the channels centred from 216.4525 to 216.4975 MHz for law enforcement tracking only and confining maritime AMTS to 216.750-217.000 MHz⁸, and Canada reserves part of it for law enforcement and gives every user no protection¹⁰. Canada also calls 72-76 MHz exclusive to auditory assistance and wireless microphones while listing model aircraft and remote control frequencies there¹⁰.

How many channels fit in one place. Listen gives six at 72 MHz and three at 216 MHz, at least 300 kHz apart¹⁸; Williams AV gives eight at 72 MHz, some of them 200 kHz apart²¹; Comtek groups up to four at 72 MHz and warns of intermodulation beyond two transmitters⁹. None of the three publishes measurements behind its figure, and Williams AV gives no distance, power or receiver type for its claim²¹.

How much planning is needed. Sennheiser describes 863-865 MHz as a licence-free ISM band usable worldwide "without elaborate frequency planning"¹⁵. CEPT says not every band is available in every country and lists that band as shared with radio microphones⁵, and the European test standard describes an on-site check of DAB reception for installations in 173.965-216 MHz¹³.

Can FM keep speech private? US guidance keeps FM out of jury deliberation rooms because the signal passes through walls^19,4, while the Swiss draft standard allows FM where eavesdropping must be prevented²⁵, and the European study found 10 mW devices more or less confined to their building¹⁴. The devices in that study ran at 10 mW, the CEPT limit in their band, while US 216 MHz systems may use up to 100 mW^5,8.

Range. A maker's 914 m in line of sight at 216 MHz⁴ and the European finding that 10 mW devices stay near their building¹⁴ describe different powers and conditions, and neither is a measurement in an occupied venue.

Analogue or digital. In 2015 European regulators expected these systems to stay analogue¹⁴; by 2018 they had studied a band for digital systems²⁸, and digital products are on sale^17,15.

What would settle it

Independent measurements of FM and digital RF systems in occupied venues, covering reach, interference between neighbouring rooms and venues, and how many channels work together in each band at stated distances and powers; the published figures are makers' own^4,18,21,9. Tests of coexistence with TV channel 13, wireless microphones and white space devices in the US, and with DAB and radio microphones in Europe, where the only measurements found come from one laboratory room in 2014¹⁴. A survey of national rules beyond the US, Canada, Australia and the CEPT recommendation, which says national rules differ⁵. Measurements of telecoil users listening through neckloops with RF receivers in venues^26,27. Evidence that any product uses the 1656.5-1660.5 MHz band²⁸. The receiver requirements of AS 1428.5 and IEC 63087, which are in paid texts^12,32.

Planning while it is open

• Check the national rules where the system will be installed: the CEPT bands are not available in every country, and the US, Canadian and Australian limits differ^5,6,10,11.
• Weigh the two US bands: one maker gives 72 MHz more simultaneous channels and wider audio, and 216 MHz longer range and shorter antennas⁴.
• Before choosing channels, scan both bands with a receiver and survey nearby venues; with the venue's transmitters off, pick the quietest wideband channels and lock them^4,18. At 216 MHz, keep clear of the channels the FCC reserves for law enforcement tracking, centred from 216.4525 to 216.4975 MHz⁸.
• Near an active TV channel 13 station, test with a TV set at the edge of the coverage area and reduce power, use a channel near 217 MHz, or move to 72 MHz^10,18.
• In Europe's 173.965-216 MHz range, identify the local DAB channels, keep at least 300 kHz from occupied ones, check DAB reception at the site boundary, the nearest house and a first-floor window, and expect to retune if DAB use changes^13,14,5.
• For several rooms, take channels from one maker's coordinated set, space them as that maker advises, keep transmitters on different groups well apart, and use the lowest power that covers each room^18,9,21.
• Mount antennas high and vertical, away from metal, and keep coaxial runs short or use lower-loss cable¹⁸.
• Where receivers from other makers may be used, switch off proprietary noise reduction, check the cross-reference tables, and post the frequencies in use^18,22.
• Where speech must stay in the room, do not rely on analogue FM, which US guidance keeps out of jury deliberation rooms; encrypted digital systems exist, and one maker advises against easily guessed PINs on receivers that support them^19,2,17.
• For telecoil users, provide hearing-aid-compatible receivers with neckloops whose frequency response has been tested, and feed the transmitter through an automatic gain control or peak limiter that keeps the signal about 1-3 dB below clipping^23,27,26.
• Outdoors, check for sources of magnetic interference near neckloop users, such as tram lines²⁰.

Sources

1. 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
2. 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
3. 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
4. Should I Use 72 MHz or 216 MHz?. Listen Team (Listen Technologies). Listen Technologies (blog), 24 February 2010. Manufacturer (Listen Technologies, which sells the FM systems compared here as well as infrared, hearing loop, Wi-Fi and Auracast assistive listening products) ↩︎ https://www.listentech.com/should-i-use-72-mhz-or-216-mhz/
5. ERC Recommendation 70-03 relating to the use of Short Range Devices (SRD), Annex 10: radio microphone applications including assistive listening devices. CEPT Electronic Communications Committee (ECC). European Communications Office (ECO Documentation Database), 5 June 2026. Government (CEPT, the European Conference of Postal and Telecommunications Administrations, whose Electronic Communications Committee brings together national spectrum regulators) ↩︎ https://docdb.cept.org/document/845
6. 47 CFR 15.237: operation in the bands 72.0-73.0 MHz, 74.6-74.8 MHz and 75.2-76.0 MHz. US Federal Communications Commission. Electronic Code of Federal Regulations (eCFR), 11 June 2013. Government (US Federal Communications Commission) ↩︎ https://www.ecfr.gov/current/title-47/section-15.237
7. Definition of Auditory Assistance Device (Report and Order, ET Docket No. 10-26, FCC 13-59; final rule). US Federal Communications Commission. Federal Register, vol. 78, no. 112, pp. 34922-34928 (Government Publishing Office), 11 June 2013. Government (US Federal Communications Commission; the proceeding began with a petition from Williams Sound, a maker of auditory assistance devices) ↩︎ https://www.govinfo.gov/content/pkg/FR-2013-06-11/html/2013-13696.htm
8. 47 CFR Part 95, Subpart G: Low Power Radio Service (216-217 MHz). US Federal Communications Commission. Electronic Code of Federal Regulations (eCFR), 10 February 2026. Government (US Federal Communications Commission) ↩︎ https://www.ecfr.gov/current/title-47/part-95/subpart-G
9. BST-75 Synthesized Base Station Transmitter Operator's Manual (72-76 MHz). COMTEK Communications Technology. COMTEK Communications Technology (downloads page), 18 January 2011. Manufacturer (COMTEK Communications Technology, which sells 72-76 MHz and 216 MHz transmitters and receivers for assistive listening, language interpretation and other uses) ↩︎ https://img1.wsimg.com/blobby/go/414496dc-67ac-402c-ac0d-00342b1b241d/downloads/BST-75%20Mmanual.pdf
10. RSS-210, Issue 11: Licence-Exempt Radio Apparatus: Category I Equipment (Annex C: medical telemetry, wireless microphones, auditory assistance, goods tracking and law enforcement devices). Innovation, Science and Economic Development Canada (ISED). Innovation, Science and Economic Development Canada, 25 June 2024. Government (Innovation, Science and Economic Development Canada) ↩︎ https://www.ised-isde.canada.ca/site/spectrum-management-telecommunications/en/devices-and-equipment/radio-equipment-standards/radio-standards-specifications-rss/rss-210-licence-exempt-radio-apparatus-category-i-equipment
11. Radiocommunications (Low Interference Potential Devices) Class Licence 2025. Australian Communications and Media Authority (ACMA). Federal Register of Legislation (Australian Government), F2025L01047, 4 September 2025. Government (Australian Communications and Media Authority) ↩︎ https://www.legislation.gov.au/F2025L01047/asmade/text
12. AS 1428.5:2021 Design for access and mobility, Part 5: Communication for people who are deaf or hearing impaired. Standards Australia. Standards Australia (Standards Store), 3 September 2021. Standards body (Standards Australia) ↩︎ https://store.standards.org.au/product/as-1428-5-2021
13. ETSI EN 300 422-4 V2.1.1: Wireless Microphones; Audio PMSE up to 3 GHz; Part 4: Assistive Listening Devices including personal sound amplifiers and inductive systems up to 3 GHz. ETSI Technical Committee ERM. European Telecommunications Standards Institute, May 2017. Standards body (ETSI; a harmonised standard under the EU Radio Equipment Directive 2014/53/EU) ↩︎ https://www.etsi.org/deliver/etsi_en/300400_300499/30042204/02.01.01_60/en_30042204v020101p.pdf
14. ECC Report 230: Harmonisation possibilities for assistive listening devices in the band 174-216 MHz. CEPT Electronic Communications Committee (ECC), Working Group Frequency Management. European Communications Office (ECO Documentation Database), 22 May 2015. Government (CEPT, the European Conference of Postal and Telecommunications Administrations, whose Electronic Communications Committee brings together national spectrum regulators; the coexistence measurements were made by EHIMA, the European hearing instrument manufacturers' association, at Ofcom's laboratory in the UK) ↩︎ https://docdb.cept.org/document/336
15. Tourguide 2020-D: Information becomes an experience. Quite simply. (product brochure). Sennheiser electronic. Sennheiser electronic GmbH & Co. KG, 2019. Manufacturer (Sennheiser, which sells the Tourguide system described as well as Wi-Fi assistive listening products) ↩︎ https://www.sennheiser.com/globalassets/digizuite/44217-en-tourguide_productbrochure_en.pdf
16. 47 CFR 15.247: operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz. US Federal Communications Commission. Electronic Code of Federal Regulations (eCFR), 1 April 2020. Government (US Federal Communications Commission) ↩︎ https://www.ecfr.gov/current/title-47/section-15.247
17. Digi-Wave 400 Series User Manual (MAN 241N). Williams AV, 2025. Manufacturer (Williams AV, which sells the Digi-Wave system described as well as FM, infrared, hearing loop, Wi-Fi and Auracast assistive listening products) ↩︎ https://williamsav.com/wp-content/uploads/2020/04/Dig-Wave-400-Manual-DLT-400-DW-T410-MAN-241N.pdf
18. User Manual: LT-800-072, LT-803-072 and LT-800-216 Stationary RF Transmitters. Listen Technologies, 3 November 2025. Manufacturer (Listen Technologies, which sells the FM transmitters described as well as infrared, hearing loop, Wi-Fi and Auracast assistive listening products) ↩︎ https://www.listentech.com/wp-content/uploads/2021/01/LT-800_803-User-Manual-2025-11-03-vA4-WEB.pdf
19. 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
20. Auracast practical test outdoors. Pro Audito Schweiz. Pro Audito Schweiz; English reprint by the Center for Hearing Access, 16 September 2026. Independent (Pro Audito Schweiz, Swiss hearing-loss association) ↩︎ https://centerforhearingaccess.org/wp-content/uploads/Pro-Audito-Schweiz-Auracast-practical-test-outdoors.pdf
21. Technical Bulletin: 72 MHz FM Chart (TCH 010G). Williams AV, February 2023. Manufacturer (Williams AV, formerly Williams Sound, which sells the FM systems charted here as well as infrared, hearing loop, Wi-Fi and Auracast assistive listening products) ↩︎ https://williamsav.com/wp-content/uploads/2020/04/TCH-010G-FM-Chart-2020.pdf
22. 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
23. 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/
24. 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
25. 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
26. 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/
27. 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
28. ECC Report 270: Sharing studies between Telecoil Replacement Systems (TRS) and Mobile Satellite Service (MSS) in the frequency range 1656.5-1660.5 MHz. CEPT Electronic Communications Committee (ECC). European Communications Office (ECO Documentation Database), 26 January 2018. Government (CEPT, the European Conference of Postal and Telecommunications Administrations, whose Electronic Communications Committee brings together national spectrum regulators) ↩︎ https://docdb.cept.org/document/1033
29. Auri TX2N / TX2N-D transmitter datasheet. Listen Technologies and Ampetronic (Auri). Ampetronic, July 2025. Manufacturer (Listen Technologies and Ampetronic) ↩︎ https://www.ampetronic.com/wp-content/uploads/UP3B603-2_Auri_TX2N_Transmitter_Datasheet.pdf
30. Infinium system controller and transmitter user manual (MAN 297B). Williams AV, 2026. Manufacturer (Williams AV) ↩︎ https://williamsav.com/wp-content/uploads/2025/08/MAN-297B-Infinium-Controller-Transmitter-BA-CT1.pdf
31. Why Auracast broadcast audio needs to coexist with current assistive listening technologies. Sabin C, Drullman R, Thomas A. Bluetooth SIG (blog), 22 June 2023. Trade body (Bluetooth SIG marketing material; the SIG is an industry association funded by its member companies and owns the Auracast trademark. Written by Chuck Sabin of the SIG's market development staff, Rob Drullman, an independent researcher who is secretary of the technical committee of EHIMA, the European hearing instrument manufacturers' association, and Andrew Thomas of the loop and assistive listening maker Contacta Systems, chairman of the International Hearing Loop Manufacturers Association) ↩︎ https://www.bluetooth.com/blog/why-auracast-broadcast-audio-needs-to-coexist-with-current-assistive-listening-technologies/
32. IEC 63087:2026 Assistive listening devices and systems for active assisted living. IEC TC 100. International Electrotechnical Commission, 18 September 2026. Standards body (International Electrotechnical Commission; the full text is sold, and only a preview is public) ↩︎ https://webstore.iec.ch/en/publication/95094

Change log

• 10 October 2026Published with 32 sources.
• 13 October 2026Clarified survey funding and the scope of school-based radio evidence.
• 13 October 2026Independent audit clarified the survey population and qualified the industry-run school-system measurements.

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