Assistive Listening Knowledge Base
  • Advocacy presentation (text of a conference talk)

Only quality controlled loops are fit for the future: the new international standard IEC 60118-4 for Audio-Frequency Induction Loop Systems

From https://assistivelisteningknowledgebase.org/evidence/karg-2005-quality-controlled-loops/ · record checked 13 October 2026

  • Karg S
  • European Federation of Hard of Hearing People (text of a talk at the 20th International Congress on the Education of the Deaf, Maastricht)

Nonprofit advocacy (Siegfried Karg, then vice president of the European Federation of Hard of Hearing People and president of Pro Audito Winterthur, a Swiss hearing-loss association; the text is hosted on EFHOH's website)

Summary

A hearing-loss advocate's 2005 talk on why loops should be measured against IEC 60118-4, with the speaker's own estimate of how many installed loops fall short.

Key findings

  • PDF page 2, commentary on slides 8 and 11, names the Casino Theater in Winterthur, Switzerland, renovated in 2002, and describes its frequency-response graph as within ±3 dB from 100 Hz to 5000 Hz. The commentary supplies no measurement date, operator or instrument, and the actual slide graph is absent from this document. The renovation date is not an established measurement date.
  • Lists the four measurements required under the edition then in force, IEC 60118-4:1998: average field strength, maximum field strength, frequency response and magnetic background noise.
  • States: "I would guess that 90% of installed induction loops do not meet this standard", and that the speaker imagines most existing loops have a poor frequency response. No measurements are given for either statement.
  • Shows the loop in a renovated Swiss theatre, with a frequency response within ±3 dB from 100 Hz to 5 kHz, as an example that meets the standard.
  • Reports that a Swiss law in force from 1 January 2004 required assistive listening in new and renovated public buildings and let the national hard of hearing association object to plans, and that the association was "training and certifying professionals" to measure loops to the IEC standard.

Limits

Presentation commentary describing one theatre's frequency-response result, without its graph or raw readings. The separate 90% figure is the speaker's own guess, not a measured survey. Written in 2005 about the 1998 edition, before the 2006 and 2014 editions. The legal points concern Switzerland only.

Read the original

efhoh.org/wp-content/uploads/2017/04/Maastricht-Hearing-Loops-Presentation.pdf

Link checked . We link to the original and do not host copies.

Cited in

Cite this source

Karg S. Only quality controlled loops are fit for the future: the new international standard IEC 60118-4 for Audio-Frequency Induction Loop Systems. European Federation of Hard of Hearing People (text of a talk at the 20th International Congress on the Education of the Deaf, Maastricht). 18 July 2005. https://efhoh.org/wp-content/uploads/2017/04/Maastricht-Hearing-Loops-Presentation.pdf (accessed 13 October 2026).

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