Assistive Listening Knowledge Base
  • Conference paper (in German)

Induktive Höranlagen – internationale Trends und aktuelle Normung (Induction loop systems: international trends and current standards)

From https://assistivelisteningknowledgebase.org/evidence/seidler-2014/ · record checked 13 October 2026

  • Seidler H
  • Fortschritte der Akustik – DAGA 2014 (annual conference of the German Acoustical Society, Oldenburg), pages 294-295

Independent (Hannes Seidler, ENT clinic of the medical faculty, TU Dresden; funding not stated)

Summary

A two-page German conference paper on what the 2014 revision of IEC 60118-4 changed, on the German building rules that call for loops, and on how many hearing aids on the German market have a telecoil.

Key findings

  • Summarises the changes in the new edition of IEC 60118-4: more specific measurement methods and test signals, new requirements for room systems and for local systems, account of metal in the building, and planning to limit overspill.
  • Says magnetic background noise is now to be checked with and without the amplifiers switched on and also with dimmable lighting at half power, and that the speech test signal ISTS and a combined sine and pink-noise signal join the earlier sine, pink noise and simulated speech.
  • Says both RMS and peak meters are allowed for measuring the magnetic field, but peak meters are no longer recommended.
  • For small systems such as alarm call points and counters, reports a required field level within ±6 dB over the defined zone, never more than 8 dB above, and for counters a level of at most -20 dB where other customers wait.
  • Reports the author's updated count of telecoils in the 860 hearing aids available on the German market (status 2013): almost two-thirds have a telecoil or can be fitted with one, so the long-feared decline in telecoils had not, the author writes, taken place. Whether the telecoil is used in a program of the hearing aid is left to the hearing aid acoustician.
  • Says Bluetooth interfaces were then no alternative for public systems: lip-sync cannot be ensured because delays in the standard protocol depend on the transmission path, range is only up to 10 m, at most 10 devices can be coupled to one transmitter, and Bluetooth chips were too power-hungry and too expensive. It reports that at the 2013 Induction Loop Conference a speaker from Widex described the hearing aid industry's aim of replacing loops with a low-cost radio-based Telecoil Replacement System, and adds that no common technical solution was then in sight.
  • Reports that under the accessible-building standard DIN 18040, adopted as a technical building rule in all but four German states (as of 7 March 2014), new service counters with glazing and an intercom must use a loop (at least one where there are several), and assembly, training and seminar rooms with sound systems need an assistive listening system, preferably a loop.
  • The Current standards section says the new requirements are expected to apply to installations in Germany during 2014; reference 1 dates the cited IEC document to 2013. The paper therefore describes anticipated German application of revised requirements, rather than establishing the text of the final December 2014 IEC edition.

Limits

The small-system paragraph on page 295 does not state the reference level for its dB figures, including the waiting-area maximum of -20 dB. The paper precedes the December 2014 IEC publication and cites a 2013 version in reference [1]. A short conference summary written before the 2014 edition was adopted in Germany. It gives the tolerances for small systems but not the room-system figures, and it has not been checked here against the paywalled standard. The building rules are German. The 2013 hearing aid count is the author's own, with no method given; it counts models available, not devices sold or in use, and its breakdown is shown only in a chart. The conference was held on 10 to 13 March 2014.

Read the original

pub.dega-akustik.de/DAGA_2014/data/articles/000138.pdf

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Cited in

Cite this source

Seidler H. Induktive Höranlagen – internationale Trends und aktuelle Normung (Induction loop systems: international trends and current standards). Fortschritte der Akustik – DAGA 2014 (annual conference of the German Acoustical Society, Oldenburg), pages 294-295. March 2014. https://pub.dega-akustik.de/DAGA_2014/data/articles/000138.pdf (accessed 13 October 2026).

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