Data
Glossary
Assistive listening terms with English and German definitions, German terms and links to the evidence behind each definition.
Reading the results
Definitions concern systems provided by venues and their shared receiving paths. German terms and definitions are editorial translations. The German definitions are also shown on the German summaries page. Protocol classes and timing parameters describe mechanisms; they do not establish current device availability or measured venue performance. The 72 MHz and 216 MHz entries concern US bands. (Bluetooth SIG Audio 2025; Bluetooth SIG Generic Audio Working… 2026; US Federal Communications Commission 2013; US Federal Communications Commission 2026)
Column definitions · Compilation and interpretation · Change log
Scroll horizontally to read all columns. Empty cells mean no value was recorded; read each row’s notes and limits with its results.
| Term | Short definition | German term | German definition | Source ID | Source locator | Funding | Limitations |
|---|---|---|---|---|---|---|---|
| 72 MHz | A common label for US assistive listening systems using frequencies in the 72–76 MHz range. The FCC rule permits operation in 72.0–73.0, 74.6–74.8 and 75.2–76.0 MHz, subject to its conditions. | 72-MHz-Bereich | Gebräuchliche Bezeichnung für Höranlagen in den USA, die Frequenzen im Bereich von 72 bis 76 MHz nutzen. Die FCC-Vorschrift erlaubt den Betrieb in den Bereichen 72,0 bis 73,0 MHz, 74,6 bis 74,8 MHz und 75,2 bis 76,0 MHz unter den darin festgelegten Bedingungen. | fcc-15-237; compton-conley-2015 | fcc-15-237: Section 15.237, heading and paragraphs (a)–(b) | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Government [fcc-15-237]; Nonprofit advocacy [compton-conley-2015] | fcc-15-237: A legal limit on the transmitter only: it sets no audio quality, range or receiver requirement. Because the definition includes language translation, interpretation systems use the same channels, and Part 15's general conditions (15.5) require these devices to cause no harmful interference and to accept interference from others. Date is the Federal Register publication of the section's latest amendment (78 FR 34927), as given in the eCFR source note; the text read was current to 6 October 2026. compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| 216 MHz | A common label for US assistive listening systems using the 216–217 MHz Low Power Radio Service band. That service also includes health-care communication, law-enforcement tracking and other specified uses. | 216-MHz-Bereich | Gebräuchliche Bezeichnung für Höranlagen in den USA, die das Frequenzband von 216 bis 217 MHz des Low Power Radio Service nutzen. Dieser Funkdienst umfasst auch Kommunikation im Gesundheitswesen, Ortung durch Strafverfolgungsbehörden und weitere festgelegte Nutzungen. | fcc-95-lprs; compton-conley-2015 | fcc-95-lprs: Sections 95.2103, 95.2131 and 95.2163 | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Government [fcc-95-lprs]; Nonprofit advocacy [compton-conley-2015] | fcc-95-lprs: Transmitter rules only: nothing on audio quality, coverage or receivers. The band is shared with health care, law enforcement tracking and maritime uses. Date is the subpart's latest amendment shown by eCFR (10 February 2026); most sections summarised here date from the 2017 reorganisation of Part 95, and the antenna section was amended in 2024. Text read as current to 6 October 2026. compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| Access point (AP) | The network device that provides the Wi-Fi link to connected wireless devices and sends network traffic to them. | WLAN-Zugangspunkt (AP) | Netzwerkgerät, das die WLAN-Verbindung zu angeschlossenen drahtlosen Geräten bereitstellt und den Netzwerkverkehr an diese Geräte überträgt. | ietf-2021-rfc9119 | ietf-2021-rfc9119: Sections 2, 3.1.1, 3.1.2, 3.1.4, 3.2, 4.3 and 4.6 | Standards body | ietf-2021-rfc9119: A general technical document on Wi-Fi multicast, not about audio or assistive listening; it reports no measurements of its own, and the 5% loss figure is given without a study behind it. Wi-Fi equipment and standards have changed since October 2021. |
| Assistive listening system (ALS) | A system that carries sound from its source to listeners through receivers or compatible hearing devices, reducing the effects of distance, room noise and reverberation. | Höranlage | Anlage, die Schall von seiner Quelle über Empfänger oder geeignete Hörsysteme zu den Zuhörenden überträgt und dabei die Auswirkungen von Entfernung, Raumgeräuschen und Nachhall verringert. | compton-conley-2015 | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Nonprofit advocacy | compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| Auracast | The Bluetooth SIG's brand for interoperable broadcast audio using Bluetooth LE Audio. A transmitter sends audio that compatible receivers within range can receive. | Auracast | Marke der Bluetooth SIG für interoperable Audioübertragung per Broadcast mit Bluetooth LE Audio. Ein Sender überträgt Audio, das geeignete Empfänger innerhalb der Reichweite empfangen können. | hunn-2024-le-audio-book | hunn-2024-le-audio-book: Sections 2.2.8, 3.3 and 4.4; chapter 12 introduction | Independent | hunn-2024-le-audio-book: The author's explanations, not a specification. The Broadcast Audio URI specification (2024) lists the author under GN Hearing A/S. |
| Auracast Assistant | A device or application that helps a listener discover and select a broadcast and supplies the information the receiving device needs to join it. | Auracast-Assistent | Gerät oder Anwendung, das beziehungsweise die beim Finden und Auswählen einer Audioübertragung hilft und dem empfangenden Gerät die zum Empfang nötigen Informationen bereitstellt. | hunn-2024-le-audio-book; bluetooth-sig-2026-bap | hunn-2024-le-audio-book: Sections 2.2.8, 3.3 and 4.4; chapter 12 introduction | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Independent [hunn-2024-le-audio-book]; Standards body [bluetooth-sig-2026-bap] | hunn-2024-le-audio-book: The author's explanations, not a specification. The Broadcast Audio URI specification (2024) lists the author under GN Hearing A/S. bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| BASE | Broadcast Audio Source Endpoint, the announcement data structure describing an LE Audio broadcast group, its subgroups and streams. It provides parameters that receiving devices need to interpret the broadcast. | Broadcast-Audio-Konfigurationsstruktur (BASE) | Broadcast Audio Source Endpoint: Datenstruktur zur Ankündigung einer LE-Audio-Broadcast-Gruppe, die deren Untergruppen und Datenströme beschreibt. Sie enthält Parameter, die empfangende Geräte zur Interpretation der Übertragung benötigen. | bluetooth-sig-2026-bap | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Standards body | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| Basic Audio Profile (BAP) | The Bluetooth profile that defines how LE Audio devices distribute and receive audio, including device roles, audio configurations and timing. | Basic Audio Profile (BAP) | Bluetooth-Profil, das festlegt, wie LE-Audio-Geräte Audio verteilen und empfangen, einschließlich Geräterollen, Audiokonfigurationen und zeitlicher Abläufe. | bluetooth-sig-2026-bap | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Standards body | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| BIG | Broadcast Isochronous Group, a group of one or more broadcast isochronous streams with related timing. The streams can carry audio intended to play together, such as left and right stereo channels. | Isochrone Broadcast-Gruppe (BIG) | Broadcast Isochronous Group: Gruppe aus einem oder mehreren isochronen Broadcast-Datenströmen mit aufeinander abgestimmten zeitlichen Abläufen. Die Datenströme können Audio enthalten, das gemeinsam wiedergegeben werden soll, etwa den linken und rechten Stereokanal. | bluetooth-sig-2026-bap; hunn-2024-le-audio-book | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | hunn-2024-le-audio-book: Sections 2.2.8, 3.3 and 4.4; chapter 12 introduction | Standards body [bluetooth-sig-2026-bap]; Independent [hunn-2024-le-audio-book] | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. hunn-2024-le-audio-book: The author's explanations, not a specification. The Broadcast Audio URI specification (2024) lists the author under GN Hearing A/S. |
| Broadcast isochronous stream (BIS) | A one-way Bluetooth LE stream that carries broadcast data on a timed schedule without acknowledgements from receiving devices. | Isochroner Broadcast-Datenstrom (BIS) | Bluetooth-LE-Datenstrom in einer Richtung, der Broadcast-Daten nach einem festen Zeitplan ohne Empfangsbestätigungen der empfangenden Geräte überträgt. | hunn-2024-le-audio-book | hunn-2024-le-audio-book: Sections 2.2.8, 3.3 and 4.4; chapter 12 introduction | Independent | hunn-2024-le-audio-book: The author's explanations, not a specification. The Broadcast Audio URI specification (2024) lists the author under GN Hearing A/S. |
| Broadcast Sink | The Bluetooth LE Audio role that discovers and receives broadcast audio streams. | Broadcast-Empfänger | Rolle in Bluetooth LE Audio, die Broadcast-Audiodatenströme findet und empfängt. | bluetooth-sig-2026-bap | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Standards body | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| Broadcast Source | The Bluetooth LE Audio role that sends broadcast audio and advertises the information needed to discover and receive it. | Broadcast-Quelle | Rolle in Bluetooth LE Audio, die Broadcast-Audio sendet und die zum Finden und Empfangen nötigen Informationen bekannt gibt. | bluetooth-sig-2026-bap | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Standards body | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| Broadcast_Code | The code needed to decrypt an encrypted Bluetooth audio broadcast. Within a broadcast group, all streams use the same code or all are unencrypted. | Broadcast-Code | Code, der zum Entschlüsseln einer verschlüsselten Bluetooth-Audioübertragung benötigt wird. Innerhalb einer Broadcast-Gruppe verwenden alle Datenströme denselben Code oder sind alle unverschlüsselt. | bluetooth-sig-2026-bap; bluetooth-sig-2025-pbp | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | bluetooth-sig-2025-pbp: Sections 1, 4.1–4.3 and 5.1 | Standards body [bluetooth-sig-2026-bap]; Standards body [bluetooth-sig-2025-pbp] | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. bluetooth-sig-2025-pbp: A product specification for interoperability, not an installation or venue standard. Rules for public transmitters, such as defaulting to Standard Quality, come from the SIG's separate transmitter guide. |
| Broadcast_ID | A three-byte identifier advertised by a Bluetooth broadcast source to help scanning devices find a broadcast group. It remains unchanged for the lifetime of that group. | Broadcast-Kennung | Drei Byte lange Kennung, die eine Bluetooth-Broadcast-Quelle bekannt gibt, damit suchende Geräte eine Broadcast-Gruppe finden können. Sie bleibt während der gesamten Lebensdauer dieser Gruppe unverändert. | bluetooth-sig-2026-bap | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Standards body | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| Broadcast_Name | The human-readable name advertised for a Bluetooth broadcast group, which a scanning device can show in its list of broadcasts. Several transmitters carrying the same audio may use the same name. | Broadcast-Name | Für Menschen lesbarer Name einer Bluetooth-Broadcast-Gruppe, den ein suchendes Gerät in seiner Liste der Audioübertragungen anzeigen kann. Mehrere Sender, die dasselbe Audio übertragen, dürfen denselben Namen verwenden. | bluetooth-sig-2025-pbp | bluetooth-sig-2025-pbp: Sections 1, 4.1–4.3 and 5.1 | Standards body | bluetooth-sig-2025-pbp: A product specification for interoperability, not an installation or venue standard. Rules for public transmitters, such as defaulting to Standard Quality, come from the SIG's separate transmitter guide. |
| Client isolation | A network setting that restricts communication between wireless clients and other local devices. Manufacturer Listen Technologies warns that it can prevent phones from reaching its venue audio server. | Client-Isolierung | Netzwerkeinstellung, die die Kommunikation zwischen drahtlosen Clients und anderen lokalen Geräten einschränkt. Der Hersteller Listen Technologies warnt, dass sie verhindern kann, dass Smartphones den Audioserver des Veranstaltungsorts erreichen. | listen-2024-listen-everywhere-network-guide | listen-2024-listen-everywhere-network-guide: “How It Works”, p. 1; “Connection Method #1: Venue Scan (mDNS)”, p. 4; “Guest Networks and VLANs”, p. 5 | Manufacturer | listen-2024-listen-everywhere-network-guide: A maker's configuration note with no measurements. The bandwidth figure and the 20% guideline are the maker's own, and the note gives no number of listeners per access point. The date is the revision printed on the note (15 August 2024). The previous revision (V3, 28 April 2022) said that audio is streamed to each phone by unicast, and recommended an open network without encryption because encryption can lower the number of users per access point and add latency; the 2024 revision leaves out both statements. The maker now sells the system as ListenWIFI. |
| Cochlear implant | An electronic hearing device that stimulates the auditory nerve through electrodes in the cochlea, enabling some people with severe hearing loss to perceive sound. | Cochlea-Implantat | Elektronisches Hörsystem, das den Hörnerv über Elektroden in der Cochlea stimuliert und dadurch manchen Menschen mit hochgradigem Hörverlust die Wahrnehmung von Schall ermöglicht. | etsi-2022-tr-103-614 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | Standards body | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| Counter loop | A small hearing loop intended for communication with a listener close to a service or ticket counter, including through a screen. | Induktive Höranlage am Schalter | Kleine induktive Höranlage für die Kommunikation mit einer Person in der Nähe eines Service- oder Ticketschalters, auch durch eine Trennscheibe hindurch. | iec-60118-4-2014; etsi-2022-tr-103-614 | iec-60118-4-2014: Archived consolidated edition 3.1 preview, Introduction and Scope, printed pp. 8–9 | etsi-2022-tr-103-614: Clause 5.1.0, printed p. 9 | Standards body [iec-60118-4-2014]; Standards body [etsi-2022-tr-103-614] | iec-60118-4-2014: Read from the IEC webstore abstract and from the public preview of the consolidated edition 3.1 (2017) published by the German standards publisher VDE Verlag (https://www.vde-verlag.de/iec-normen/preview-pdf/info_iec60118-4%7Bed3.1%7Db.pdf), which shows the cover, the contents, the introduction and the scope; the rest of the 109-page text is paywalled. Neither states the numeric targets (reference field strength, tolerances, frequency limits, maximum background noise), so any figure quoted for them comes from secondary summaries, such as manufacturers' commissioning guides, and has not been checked here against the standard. etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| Direct audio input (DAI) | A wired connection that carries audio from a separate receiver into a hearing aid equipped to accept it. | Direkter Audioeingang (DAI) | Kabelverbindung, die Audio von einem separaten Empfänger in ein Hörgerät überträgt, das über einen entsprechenden Eingang verfügt. | bakke-1999 | bakke-1999: Sections 2.1.3–2.1.4, pp. 7–8; 2.2.3, pp. 13–14; 2.3, p. 16 | Government | bakke-1999: Analogue-era systems and listening tests from 1999; the criteria rest on ratings of recorded sentences, not venue measurements. These are recommendations to the Access Board, not an enforceable standard, and the report predates Bluetooth streaming. |
| DTIM | Delivery Traffic Indication Message, a Wi-Fi indication associated with delivery of buffered multicast or broadcast traffic to devices using power saving. Waiting for the next DTIM beacon can delay multicast audio. | DTIM (Meldung zu gepufferten Gruppendaten) | Delivery Traffic Indication Message: WLAN-Meldung im Zusammenhang mit der Zustellung gepufferter Multicast- oder Broadcast-Daten an Geräte im Energiesparbetrieb. Das Warten auf das nächste DTIM-Beacon kann Multicast-Audio verzögern. | ietf-2021-rfc9119 | ietf-2021-rfc9119: Sections 2, 3.1.1, 3.1.2, 3.1.4, 3.2, 4.3 and 4.6 | Standards body | ietf-2021-rfc9119: A general technical document on Wi-Fi multicast, not about audio or assistive listening; it reports no measurements of its own, and the 5% loss figure is given without a study behind it. Wi-Fi equipment and standards have changed since October 2021. |
| Emitter | The part of an infrared listening system that turns the transmitter signal into infrared light directed into the listening area. | Infrarotstrahler | Teil einer Infrarot-Höranlage, der das Sendersignal in Infrarotlicht umwandelt und in den Hörbereich abstrahlt. | compton-conley-2015 | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Nonprofit advocacy | compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| Field strength | In hearing-loop work, the strength of the magnetic signal at a listening position. It is commonly expressed in mA/m or as a level in decibels relative to a stated reference. | Feldstärke | Bei induktiven Höranlagen die Stärke des magnetischen Signals an einem Hörplatz. Sie wird üblicherweise in mA/m oder als Pegel in Dezibel bezogen auf einen angegebenen Referenzwert ausgedrückt. | etsi-2022-tr-103-614 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | Standards body | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| Field strength meter | An instrument that measures the strength of the audio-frequency magnetic field produced by a hearing loop. | Feldstärkemessgerät | Messgerät für die Stärke des Magnetfelds im Tonfrequenzbereich, das eine induktive Höranlage erzeugt. | etsi-2022-tr-103-614 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | Standards body | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| FM | Frequency modulation, the radio transmission method used by traditional venue FM listening systems. A listener uses a receiver tuned to the same channel as the transmitter. | Funk (FM); Frequenzmodulation | Frequenzmodulation: das Funkübertragungsverfahren herkömmlicher FM-Höranlagen an Veranstaltungsorten. Zum Hören wird ein Empfänger verwendet, der auf denselben Kanal wie der Sender eingestellt ist. | compton-conley-2015 | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Nonprofit advocacy | compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| Frequency response | How the level delivered by a system varies with audio frequency. For a hearing loop, this describes the magnetic field level across the audio-frequency range. | Frequenzgang | Abhängigkeit des von einem System abgegebenen Pegels von der Tonfrequenz. Bei einer induktiven Höranlage beschreibt der Frequenzgang den Magnetfeldpegel über den Tonfrequenzbereich. | etsi-2022-tr-103-614 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | Standards body | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| Hearing aid | A personal amplification device worn by a listener to help with hearing loss. | Hörgerät | Persönliches Verstärkungsgerät, das getragen wird, um bei Hörverlust das Hören zu unterstützen. | etsi-2022-tr-103-614 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | Standards body | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| Hearing instrument | A collective term for a hearing aid or cochlear implant. | Hörsystem | Sammelbegriff für ein Hörgerät oder ein Cochlea-Implantat. | etsi-2022-tr-103-614 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | Standards body | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| Hearing loop | An assistive listening system that sends audio-frequency current through a loop of wire to create a magnetic signal received by telecoils. | Induktive Höranlage; Ringschleife | Höranlage, die einen Strom im Tonfrequenzbereich durch eine Drahtschleife leitet und dadurch ein magnetisches Signal erzeugt, das von T-Spulen empfangen wird. | etsi-2022-tr-103-614 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | Standards body | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| High Quality | A Public Broadcast Profile stream class using specified 48 kHz audio settings. Support for those settings is optional for Basic Audio Profile broadcast receivers. | Hohe Qualität | Klasse von Datenströmen im Public Broadcast Profile mit festgelegten Audioeinstellungen für 48 kHz. Die Unterstützung dieser Einstellungen ist für Broadcast-Empfänger nach dem Basic Audio Profile optional. | bluetooth-sig-2025-pbp; bluetooth-sig-2026-bap | bluetooth-sig-2025-pbp: Sections 1, 4.1–4.3 and 5.1 | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Standards body [bluetooth-sig-2025-pbp]; Standards body [bluetooth-sig-2026-bap] | bluetooth-sig-2025-pbp: A product specification for interoperability, not an installation or venue standard. Rules for public transmitters, such as defaulting to Standard Quality, come from the SIG's separate transmitter guide. bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| IEC 60118-4 | The international standard specifying hearing-loop system performance, including magnetic field strength, frequency response and measurement methods. | IEC 60118-4 (Norm für induktive Höranlagen) | Internationale Norm, die Anforderungen an die Leistung induktiver Höranlagen festlegt, einschließlich magnetischer Feldstärke, Frequenzgang und Messverfahren. | iec-60118-4-2014 | iec-60118-4-2014: Archived consolidated edition 3.1 preview, Introduction and Scope, printed pp. 8–9 | Standards body | iec-60118-4-2014: Read from the IEC webstore abstract and from the public preview of the consolidated edition 3.1 (2017) published by the German standards publisher VDE Verlag (https://www.vde-verlag.de/iec-normen/preview-pdf/info_iec60118-4%7Bed3.1%7Db.pdf), which shows the cover, the contents, the introduction and the scope; the rest of the 109-page text is paywalled. Neither states the numeric targets (reference field strength, tolerances, frequency limits, maximum background noise), so any figure quoted for them comes from secondary summaries, such as manufacturers' commissioning guides, and has not been checked here against the standard. |
| Infrared (IR) | An assistive listening method that carries audio using invisible infrared light from emitters to compatible receivers. | Infrarot (IR) | Verfahren zur Hörunterstützung, bei dem Audio mit unsichtbarem Infrarotlicht von Strahlern zu geeigneten Empfängern übertragen wird. | compton-conley-2015 | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Nonprofit advocacy | compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| IR subcarrier | In an analogue infrared system, an electrical carrier modulated by the audio signal, which in turn modulates the emitted infrared light. Its frequency identifies an audio channel rather than the frequency of the light itself. | Infrarot-Unterträger | In einem analogen Infrarotsystem ein elektrischer Träger, der vom Audiosignal moduliert wird und seinerseits das ausgesendete Infrarotlicht moduliert. Seine Frequenz kennzeichnet einen Audiokanal und bezeichnet nicht die Frequenz des Lichts selbst. | bakke-1999 | bakke-1999: Sections 2.1.3–2.1.4, pp. 7–8; 2.2.3, pp. 13–14; 2.3, p. 16 | Government | bakke-1999: Analogue-era systems and listening tests from 1999; the criteria rest on ratings of recorded sentences, not venue measurements. These are recommendations to the Access Board, not an enforceable standard, and the report predates Bluetooth streaming. |
| Latency | The time a signal takes to pass through a stated part or all of an audio system. For an LE Audio broadcast, total delay includes transmitter processing, transport latency and receiver presentation delay. | Verzögerung | Zeit, die ein Signal benötigt, um einen angegebenen Teil eines Audiosystems oder das gesamte System zu durchlaufen. Bei einer LE-Audio-Broadcast-Übertragung umfasst die Gesamtverzögerung die Verarbeitung im Sender, die Transportverzögerung und die Wiedergabeverzögerung im Empfänger. | bluetooth-sig-2026-bap | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Standards body | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| LC3 | Low Complexity Communications Codec, the audio encoding and decoding method that Bluetooth LE Audio devices must support. | LC3 (Audiocodec) | Low Complexity Communications Codec: Verfahren zum Codieren und Decodieren von Audio, das Bluetooth-LE-Audio-Geräte unterstützen müssen. | hunn-2024-le-audio-book | hunn-2024-le-audio-book: Sections 2.2.8, 3.3 and 4.4; chapter 12 introduction | Independent | hunn-2024-le-audio-book: The author's explanations, not a specification. The Broadcast Audio URI specification (2024) lists the author under GN Hearing A/S. |
| LE Audio | Bluetooth audio using the Bluetooth Low Energy transport, with support for connected and broadcast audio. Its specifications require support for the LC3 audio codec. | Bluetooth LE Audio | Bluetooth-Audio über Bluetooth Low Energy, mit Unterstützung für verbindungsorientierte Audioübertragung und Broadcast-Audio. Die Spezifikationen verlangen die Unterstützung des Audiocodecs LC3. | bluetooth-sig-2026-bap; hunn-2024-le-audio-book | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | hunn-2024-le-audio-book: Sections 2.2.8, 3.3 and 4.4; chapter 12 introduction | Standards body [bluetooth-sig-2026-bap]; Independent [hunn-2024-le-audio-book] | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. hunn-2024-le-audio-book: The author's explanations, not a specification. The Broadcast Audio URI specification (2024) lists the author under GN Hearing A/S. |
| Line of sight | An unobstructed path between an infrared emitter and the light-sensitive part of a receiver. Objects in that path can create shadows in the system's coverage. | Sichtverbindung | Ungehinderter Übertragungsweg zwischen einem Infrarotstrahler und dem lichtempfindlichen Teil eines Empfängers. Gegenstände auf diesem Weg können Abschattungen im Versorgungsbereich des Systems verursachen. | compton-conley-2015 | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Nonprofit advocacy | compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| Loop driver | The amplifier that supplies audio-frequency current to a hearing-loop cable. | Schleifenverstärker | Verstärker, der das Kabel einer Ringschleife mit Strom im Tonfrequenzbereich versorgt. | etsi-2022-tr-103-614 | etsi-2022-tr-103-614: Clause 5.1.0, printed p. 9 | Standards body | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| Loop listener | A portable receiver that makes a hearing-loop signal audible, allowing a person without a telecoil hearing device to listen to it. | Ringschleifenempfänger | Tragbarer Empfänger, der das Signal einer induktiven Höranlage hörbar macht, sodass auch eine Person ohne Hörsystem mit T-Spule zuhören kann. | etsi-2022-tr-103-614; compton-conley-2015 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Standards body [etsi-2022-tr-103-614]; Nonprofit advocacy [compton-conley-2015] | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| M/T setting | A hearing-aid setting that uses the microphone and telecoil together, allowing room sound and the loop signal to be heard at the same time. | M/T-Programm | Einstellung eines Hörgeräts, bei der Mikrofon und T-Spule gemeinsam genutzt werden, sodass Schall aus der Umgebung und das Ringschleifensignal gleichzeitig hörbar sind. | bakke-1999 | bakke-1999: Sections 2.1.3–2.1.4, pp. 7–8; 2.2.3, pp. 13–14; 2.3, p. 16 | Government | bakke-1999: Analogue-era systems and listening tests from 1999; the criteria rest on ratings of recorded sentences, not venue measurements. These are recommendations to the Access Board, not an enforceable standard, and the report predates Bluetooth streaming. |
| mA/m | Milliamperes per metre, a unit of magnetic field strength used for hearing loops. ETSI uses 400 mA/m as the reference for a magnetic field level of 0 dB. | Milliampere pro Meter (mA/m) | Milliampere pro Meter: Einheit der magnetischen Feldstärke, die bei induktiven Höranlagen verwendet wird. ETSI verwendet 400 mA/m als Referenzwert für einen Magnetfeldpegel von 0 dB. | etsi-2022-tr-103-614 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | Standards body | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| Magnetic background noise | Unwanted audio-frequency magnetic fields from electrical cables or equipment that can interfere with reception of a hearing-loop signal. | Magnetisches Störfeld | Unerwünschte Magnetfelder im Tonfrequenzbereich von elektrischen Leitungen oder Geräten, die den Empfang des Signals einer induktiven Höranlage stören können. | iec-60118-4-2014 | iec-60118-4-2014: Archived consolidated edition 3.1 preview, Introduction and Scope, printed pp. 8–9 | Standards body | iec-60118-4-2014: Read from the IEC webstore abstract and from the public preview of the consolidated edition 3.1 (2017) published by the German standards publisher VDE Verlag (https://www.vde-verlag.de/iec-normen/preview-pdf/info_iec60118-4%7Bed3.1%7Db.pdf), which shows the cover, the contents, the introduction and the scope; the rest of the 109-page text is paywalled. Neither states the numeric targets (reference field strength, tolerances, frequency limits, maximum background noise), so any figure quoted for them comes from secondary summaries, such as manufacturers' commissioning guides, and has not been checked here against the standard. |
| mDNS | Multicast DNS, a mechanism used to discover services on a local network. Manufacturer Listen Technologies uses it as one way for its listening app to find the venue audio server. | Multicast-DNS (mDNS) | Multicast DNS: Verfahren zum Finden von Diensten in einem lokalen Netzwerk. Der Hersteller Listen Technologies nutzt es als eine Möglichkeit, mit der seine Höranlagen-App den Audioserver des Veranstaltungsorts findet. | ietf-2021-rfc9119; listen-2024-listen-everywhere-network-guide | ietf-2021-rfc9119: Sections 2, 3.1.1, 3.1.2, 3.1.4, 3.2, 4.3 and 4.6 | listen-2024-listen-everywhere-network-guide: “How It Works”, p. 1; “Connection Method #1: Venue Scan (mDNS)”, p. 4; “Guest Networks and VLANs”, p. 5 | Standards body [ietf-2021-rfc9119]; Manufacturer [listen-2024-listen-everywhere-network-guide] | ietf-2021-rfc9119: A general technical document on Wi-Fi multicast, not about audio or assistive listening; it reports no measurements of its own, and the 5% loss figure is given without a study behind it. Wi-Fi equipment and standards have changed since October 2021. listen-2024-listen-everywhere-network-guide: A maker's configuration note with no measurements. The bandwidth figure and the 20% guideline are the maker's own, and the note gives no number of listeners per access point. The date is the revision printed on the note (15 August 2024). The previous revision (V3, 28 April 2022) said that audio is streamed to each phone by unicast, and recommended an open network without encryption because encryption can lower the number of users per access point and add latency; the 2024 revision leaves out both statements. The maker now sells the system as ListenWIFI. |
| Metal loss | Weakening of a hearing-loop signal caused by metal in the building structure. The loss depends on frequency and can reduce higher audio frequencies more strongly. | Metallverlust | Abschwächung des Signals einer induktiven Höranlage durch Metall in der Gebäudestruktur. Der Verlust ist frequenzabhängig und kann höhere Tonfrequenzen stärker abschwächen. | bavaria-2019-loop-planning | bavaria-2019-loop-planning: Sections 1.5–1.6, pp. 7–8; section 2.4, p. 14 | Government | bavaria-2019-loop-planning: Planning guidance for Bavarian state buildings, not a study (its cost factors match the German hard-of-hearing association's table, which the association itself calls qualitative; see dsb-2013-warum-induktive-hoeranlagen): the metal loss example is a simulation, and the 1,000 m² to 80 m² example and cost factors are given without data. One of the authors represents a hearing-loss organisation that advocates loops, and the guidance calls loops the best technical aid. It cites DIN EN IEC 60118-4 and German building standards. Its list of problems with 2.4 GHz, Bluetooth and WLAN systems reflects its 2019 status and gives no sources or measurements. The date is the edition's stated status date (Stand 01.01.2019); the file was created in December 2018 and last modified in December 2019. |
| Multicast | Network delivery of data to a group of receivers. On Wi-Fi, ordinary multicast frames do not receive individual acknowledgements from each listener device. | Multicast | Übertragung von Daten über ein Netzwerk an eine Gruppe von Empfängern. Bei WLAN erhalten gewöhnliche Multicast-Frames keine einzelnen Empfangsbestätigungen von den jeweiligen Empfangsgeräten. | ietf-2021-rfc9119 | ietf-2021-rfc9119: Sections 2, 3.1.1, 3.1.2, 3.1.4, 3.2, 4.3 and 4.6 | Standards body | ietf-2021-rfc9119: A general technical document on Wi-Fi multicast, not about audio or assistive listening; it reports no measurements of its own, and the 5% loss figure is given without a study behind it. Wi-Fi equipment and standards have changed since October 2021. |
| Neckloop | A small loop of wire worn around the neck and connected to an audio receiver. It turns the receiver's output into a magnetic signal for a hearing-device telecoil. | Halsringschleife | Kleine Drahtschleife, die um den Hals getragen und an einen Audioempfänger angeschlossen wird. Sie wandelt das Ausgangssignal des Empfängers in ein magnetisches Signal für die T-Spule eines Hörsystems um. | compton-conley-2015 | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Nonprofit advocacy | compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| Overspill | The part of a hearing-loop magnetic signal that extends beyond the intended listening area and may be received in nearby spaces. | Übersprechen | Teil des magnetischen Signals einer induktiven Höranlage, der über den vorgesehenen Hörbereich hinausreicht und in benachbarten Bereichen empfangen werden kann. | etsi-2022-tr-103-614 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | Standards body | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| Perimeter loop | A hearing-loop cable laid horizontally around the boundary of the area to be covered, with one or more turns. | Perimeterschleife | Kabel einer Ringschleife, das mit einer oder mehreren Windungen horizontal entlang der Grenze des zu versorgenden Bereichs verlegt ist. | etsi-2022-tr-103-614 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | Standards body | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| Phased array | Overlapping hearing loops driven by currents with different phases. This arrangement can make coverage more even and reduce spill compared with a perimeter loop of the same size. | Mehrsegmentschleifensystem mit Phasenschieber | Überlappende Ringschleifen, die mit Strömen unterschiedlicher Phasenlage betrieben werden. Diese Anordnung kann gegenüber einer gleich großen Perimeterschleife eine gleichmäßigere Versorgung erreichen und das Übersprechen verringern. | etsi-2022-tr-103-614; bavaria-2019-loop-planning | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | bavaria-2019-loop-planning: Sections 1.5–1.6, pp. 7–8; sections 2.4–2.5, pp. 14–15 | Standards body [etsi-2022-tr-103-614]; Government [bavaria-2019-loop-planning] | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. bavaria-2019-loop-planning: Planning guidance for Bavarian state buildings, not a study (its cost factors match the German hard-of-hearing association's table, which the association itself calls qualitative; see dsb-2013-warum-induktive-hoeranlagen): the metal loss example is a simulation, and the 1,000 m² to 80 m² example and cost factors are given without data. One of the authors represents a hearing-loss organisation that advocates loops, and the guidance calls loops the best technical aid. It cites DIN EN IEC 60118-4 and German building standards. Its list of problems with 2.4 GHz, Bluetooth and WLAN systems reflects its 2019 status and gives no sources or measurements. The date is the edition's stated status date (Stand 01.01.2019); the file was created in December 2018 and last modified in December 2019. |
| Presentation delay | For an LE Audio broadcast receiver, the interval from a frame's synchronization reference to the start of its playback or output. It includes receiver processing and is one part of total system delay. | Wiedergabeverzögerung | Bei einem LE-Audio-Broadcast-Empfänger die Zeitspanne vom Synchronisationsreferenzpunkt eines Frames bis zum Beginn seiner Wiedergabe oder Ausgabe. Sie umfasst die Verarbeitung im Empfänger und ist ein Teil der Gesamtverzögerung des Systems. | bluetooth-sig-2026-bap | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Standards body | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| Public Broadcast Profile (PBP) | The Bluetooth profile defining announcements that help devices discover public audio broadcasts and identify their supported audio configurations. | Public Broadcast Profile (PBP) | Bluetooth-Profil, das Ankündigungen festlegt, mit deren Hilfe Geräte öffentliche Audioübertragungen finden und deren unterstützte Audiokonfigurationen erkennen können. | bluetooth-sig-2025-pbp | bluetooth-sig-2025-pbp: Sections 1, 4.1–4.3 and 5.1 | Standards body | bluetooth-sig-2025-pbp: A product specification for interoperability, not an installation or venue standard. Rules for public transmitters, such as defaulting to Standard Quality, come from the SIG's separate transmitter guide. |
| Receiver | The device that picks up an assistive listening signal and provides audio through headphones or a connection to a hearing device. It may be built into a hearing device or be a separate unit. | Empfänger | Gerät, das ein Höranlagensignal empfängt und Audio über Kopfhörer oder eine Verbindung zu einem Hörsystem bereitstellt. Es kann in ein Hörsystem eingebaut oder ein separates Gerät sein. | compton-conley-2015 | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Nonprofit advocacy | compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| Silhouette | An inductive coupler that turns a receiver's audio into a magnetic signal for a hearing-device telecoil. It is an alternative coupling accessory to a neckloop. | Induktionsplättchen | Induktiver Koppler, der das Audiosignal eines Empfängers in ein magnetisches Signal für die T-Spule eines Hörsystems umwandelt. Er ist eine Alternative zur Halsringschleife als Kopplungszubehör. | kim-kim-2014; bakke-1999 | kim-kim-2014: Assistive Listening Device section, “FM sound systems” and “Infra-red sound systems” subsections | bakke-1999: Sections 2.1.3–2.1.4, pp. 7–8; 2.2.3, pp. 13–14; 2.3, p. 16 | Independent [kim-kim-2014]; Government [bakke-1999] | kim-kim-2014: A short narrative review without new data; its statements on infrared cite no measurements. The journal records five days between receipt and acceptance. Written before Auracast. bakke-1999: Analogue-era systems and listening tests from 1999; the criteria rest on ratings of recorded sentences, not venue measurements. These are recommendations to the Access Board, not an enforceable standard, and the report predates Bluetooth streaming. |
| Standard Quality | A Public Broadcast Profile stream class using audio settings every Basic Audio Profile broadcast receiver must be able to decode. The mandatory settings use 16 or 24 kHz sampling. | Standardqualität | Klasse von Datenströmen im Public Broadcast Profile mit Audioeinstellungen, die jeder Broadcast-Empfänger nach dem Basic Audio Profile decodieren können muss. Die vorgeschriebenen Einstellungen verwenden eine Abtastrate von 16 oder 24 kHz. | bluetooth-sig-2025-pbp; bluetooth-sig-2026-bap | bluetooth-sig-2025-pbp: Sections 1, 4.1–4.3 and 5.1 | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Standards body [bluetooth-sig-2025-pbp]; Standards body [bluetooth-sig-2026-bap] | bluetooth-sig-2025-pbp: A product specification for interoperability, not an installation or venue standard. Rules for public transmitters, such as defaulting to Standard Quality, come from the SIG's separate transmitter guide. bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| Subgroup | Within an LE Audio broadcast group, one or more streams intended to be decoded and played together. Separate subgroups can offer different programmes or alternative mixes of the same programme. | Untergruppe | Innerhalb einer LE-Audio-Broadcast-Gruppe ein oder mehrere Datenströme, die gemeinsam decodiert und wiedergegeben werden sollen. Getrennte Untergruppen können unterschiedliche Programme oder alternative Mischungen desselben Programms anbieten. | bluetooth-sig-2026-bap | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Standards body | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| T-switch | A control or listening-programme setting that selects a hearing device's telecoil input for listening to a loop. | T-Schalter; T-Programm | Bedienelement oder Hörprogrammeinstellung, mit dem beziehungsweise der der T-Spulen-Eingang eines Hörsystems zum Empfang einer induktiven Höranlage ausgewählt wird. | bakke-1999; etsi-2022-tr-103-614 | bakke-1999: Sections 2.1.3–2.1.4, pp. 7–8; 2.2.3, pp. 13–14; 2.3, p. 16 | etsi-2022-tr-103-614: Clause 5.1.0, printed p. 9 | Government [bakke-1999]; Standards body [etsi-2022-tr-103-614] | bakke-1999: Analogue-era systems and listening tests from 1999; the criteria rest on ratings of recorded sentences, not venue measurements. These are recommendations to the Access Board, not an enforceable standard, and the report predates Bluetooth streaming. etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. |
| Telecoil | A small magnetic pickup coil that receives the signal from a hearing loop or neckloop. It can be built into a hearing aid, cochlear-implant processor or separate receiver. | T-Spule | Kleine magnetische Empfangsspule, die das Signal einer Ringschleife oder Halsringschleife aufnimmt. Sie kann in ein Hörgerät, einen Cochlea-Implantat-Prozessor oder einen separaten Empfänger eingebaut sein. | etsi-2022-tr-103-614; compton-conley-2015 | etsi-2022-tr-103-614: Clause 3.1, pp. 6–7; clauses 5.1.1–5.1.4, pp. 9–11 | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Standards body [etsi-2022-tr-103-614]; Nonprofit advocacy [compton-conley-2015] | etsi-2022-tr-103-614: A spectrum-planning document rather than a performance study: its spill figures come from one illustrative plot without stated loop size or measurement method, and its market figures are estimates without sources. Its statement on Bluetooth Low Energy gives no evidence and dates from January 2022 or earlier. It records that no comments were received at enquiry. The document shows January 2022 as its publication month. compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| Transmitter | The part of a wireless listening system that sends the audio signal to receivers, such as the FM unit connected to a venue sound system. | Sender | Teil einer drahtlosen Höranlage, der das Audiosignal an Empfänger sendet, etwa das FM-Gerät, das an die Beschallungsanlage eines Veranstaltungsorts angeschlossen ist. | compton-conley-2015 | compton-conley-2015: Opening explanation, printed pp. 1–2; loop section pp. 2–3; FM section pp. 4–5; infrared section pp. 6–8 | Nonprofit advocacy | compton-conley-2015: Expert guidance, not a study: no measurements or references are given. First written in 2006 and revised by the author in 2015; this copy is HLAA's reprint dated 28 October 2021, so it predates Auracast and says no large-area systems broadcast over Bluetooth. It is distributed by HLAA's hearing loop program. Its description of 216-217 MHz as for auditory assistance only is narrower than the FCC rules, which share the band with other uses. |
| Transport latency | The actual time taken to transfer audio data between the transmitting and receiving devices. In LE Audio this is one component of total system delay. | Transportverzögerung | Tatsächlich benötigte Zeit zur Übertragung von Audiodaten zwischen sendendem und empfangendem Gerät. Bei LE Audio ist sie ein Bestandteil der Gesamtverzögerung des Systems. | bluetooth-sig-2026-bap | bluetooth-sig-2026-bap: Sections 1, 1.6, 2.2.2, 3.7.2, 6.5, 7.1.1 and 7.2; Table 6.4 and codec configuration entries | Standards body | bluetooth-sig-2026-bap: Defines what devices must support, not how a venue system is set up or measured. |
| Unicast | Network delivery addressed to an individual receiving device. Manufacturer Williams AV explains that unicast audio creates a separate copy of the stream for each listener. | Unicast | Übertragung über ein Netzwerk, die an ein einzelnes empfangendes Gerät adressiert ist. Der Hersteller Williams AV erklärt, dass bei Unicast-Audio für jede zuhörende Person eine eigene Kopie des Datenstroms erzeugt wird. | williams-av-2024-wavecast-network-guide; ietf-2021-rfc9119 | williams-av-2024-wavecast-network-guide: “Description”, “How it Works” and “Unicast vs Multicast”, p. 3 | ietf-2021-rfc9119: Sections 2, 3.1.1, 3.1.2, 3.1.4, 3.2, 4.3 and 4.6 | Manufacturer [williams-av-2024-wavecast-network-guide]; Standards body [ietf-2021-rfc9119] | williams-av-2024-wavecast-network-guide: A maker's network guide: the user limits are the maker's own, given without test conditions, and it gives no latency figures. No date is printed; the revision code is TCH 040I-1223, and the year comes from the PDF's creation date (15 January 2024). The maker's WaveCAST C product page linked this revision on 9 October 2026. ietf-2021-rfc9119: A general technical document on Wi-Fi multicast, not about audio or assistive listening; it reports no measurements of its own, and the 5% loss figure is given without a study behind it. Wi-Fi equipment and standards have changed since October 2021. |
| Wi-Fi streaming | Delivery of venue audio through a local Wi-Fi network to listeners' phones or Wi-Fi receivers. Manufacturer Williams AV describes this route for its WaveCAST system. | Audioübertragung über WLAN | Übertragung des Audiosignals eines Veranstaltungsorts über ein lokales WLAN an Smartphones oder WLAN-Empfänger der Zuhörenden. Der Hersteller Williams AV beschreibt diesen Übertragungsweg für sein WaveCAST-System. | williams-av-2024-wavecast-network-guide | williams-av-2024-wavecast-network-guide: “Description”, “How it Works” and “Unicast vs Multicast”, p. 3 | Manufacturer | williams-av-2024-wavecast-network-guide: A maker's network guide: the user limits are the maker's own, given without test conditions, and it gives no latency figures. No date is printed; the revision code is TCH 040I-1223, and the year comes from the PDF's creation date (15 January 2024). The maker's WaveCAST C product page linked this revision on 9 October 2026. |
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Codebook
termEnglish term or identifier, with an expanded name or abbreviation where useful. Protocol identifiers retain their spelling.
short_definitionOne or two sentences explaining the term in the context of venue-provided assistive listening.
german_termGerman equivalent or explanatory label. Semicolons separate alternatives; established protocol names and identifiers may remain in English. These translations are editorial equivalents, not official translated specification titles.
german_definitionGerman translation of short_definition, preserving its scope, qualifications and manufacturer attributions. Both definitions share the row’s source citations; translations are editorial, not official specification wording.
source_idLibrary source identifiers supporting the row, separated by semicolons. Feature-specific and supporting-source columns retain their more precise roles.
source_locatorOriginal page, section, table or model entry supporting the row; source names identify locations when several originals are used.
fundingSource-record funding labels. With multiple primary sources, each label is followed by its source id in brackets. Funding detail remains in funding_detail where supplied by the earlier compilation.
limitationsRow-specific interpretation limits and source-record reading limits. Missing information is not reported, never an inferred zero.
Compilation and interpretation
glossary.csv contains 60 terms used in the questions, with English and German definitions, German terms and definition citations to 14 existing library records. Source-record limitations also refer to one contextual record. The English definitions and German terms were compiled and independently audited against the private archived originals on 2026-10-13. German definitions were translated from the English on 2026-10-14, retaining the same source citations and qualifications, and independently checked against the records and archived originals on that date. The audit is recorded in docs/research-notes/codex-d7-glossary-german.md.
The file is UTF-8 CSV, with one header row and standard quoting, sorted by English term with numeric labels first. Values are text. Source ids refer to the whole definition, including any qualification in its second sentence. The research report, docs/research-notes/codex-q24-glossary.md, maps terms to the original sections used.
Definitions describe mechanisms and vocabulary, not present device availability or measured performance. In particular, Standard Quality and High Quality are profile configuration classes, presentation delay is one component of total delay, and the 72 MHz and 216 MHz entries describe US bands. Manufacturer examples are identified in their definitions. RFC 9119 supplies general network-path evidence rather than a test of venue audio (Bluetooth SIG Audio 2025; Bluetooth SIG Generic Audio Working… 2026; US Federal Communications Commission 2013; US Federal Communications Commission 2026; Perkins et al. 2021).
Change log
- 2026-10-14: Audited all 60 German definitions against the records and archived originals; clarified surrounding sound in the M/T definition and added the phased-array spill locator.
- 2026-10-14: Added German definitions for all 60 terms, shown on the glossary page and the German summaries page.
- 2026-10-14: Corrected ETSI locators for counter loop, loop driver and T-switch definitions.
- 2026-10-13: Migrated 60 rows with codebook and source provenance into the data section.
Cite this page
Equal Access Audio. “Glossary” Assistive Listening Knowledge Base. Version 2.1. Compiled 13 October 2026; updated 14 October 2026. https://assistivelisteningknowledgebase.org/data/glossary/ (accessed the date you read it).