Summary
The consultation draft of the Swiss standard for obstacle-free buildings, intended to replace SIA 500:2009. Its section 7.8 sets requirements for assistive listening systems, including Auracast.
Key findings
- Requires assistive listening systems to use Auracast transmitters as well as inductive transmission, preferably a fixed loop to EN 60118-4 and otherwise receivers with neckloops. Infrared and FM may be used where eavesdropping must be prevented.
- Sets a minimum STI of 0.7, and asks that all seats lie within the reception area where possible. If not, as many seats as possible and at least 20% (also 20% of each seat category) must be covered, placed near the stage with a view of it.
- States that the time difference between speech signals of similar level, such as room sound and the assistive signal, should where possible not exceed 30 ms and must not exceed 40 ms. Near the stage, or with a video image of the talker, the lip-to-audio difference should preferably stay within 50 ms.
- For FM, infrared and Auracast, operators must provide receivers with neckloops (guide value at least 4, or 5% of seats from 100 seats), simple headphones should be available, and field strength and frequency response measured through the neckloop must meet EN 60118-4.
- Requires an acceptance report showing that the system works and meets the requirements, and a receiver with headphones for the operator's own checks.
- Proposed sections 7.8.2 and 7.8.5 require use information at every visitor entrance. If reception is partial, visitors must be told which seats are suitable, using an entrance plan or seat pictograms; loop seats exceeding the referenced magnetic-noise recommendation do not count as covered.
- Proposed section 7.8.7 makes receiver quantity depend on building use and requires allowance for a high expected number of hearing-aid users, alongside its guide values of four receivers or 5% of visitor seats from 100 seats.
Limits
A consultation draft (comments closed 3 October 2025). The draft states that it has no validity and must not be applied, and the final standard may differ. Swiss scope only. The linked copy carries Pro Audito's highlighting.
Read the original
pro-audito.ch/wp-content/uploads/prSIA500_Vernehmlassungsentwurf-mit-Hervorhebungen.pdf
Cited in
- Should the Auracast stream be delayed to line up with the loudspeakers?Open
- Which systems satisfy the ADA and building codes, and does a listener's own phone count?Disputed
- Auracast, hearing loop, infrared, RF or Wi-Fi: which suits which room?Disputed
- How many receivers and neckloops does each code require, and how should a loan pool be run?Partly answered
- What commissioning tests and pass limits will the standards require?Open
- Open or protected: when should a venue broadcast need a code?Open
- How is an installed hearing loop checked against IEC 60118-4, and how often does it pass?Partly answered
- Where does infrared assistive listening work, and where does it fall short?Partly answered
- Which radio bands can venue FM and RF systems use, and what limits them?Partly answered
- Should a venue keep its hearing loop when it adds Auracast, and can one system serve both?Partly answered
- What works in places of worship, and what do the rules ask of them?Partly answered
- Do neckloops give telecoil users good sound from FM, infrared, Wi-Fi and Auracast receivers?Not reliable yet
- What works in courtrooms, council chambers and other meeting rooms where speech must be heard by all and kept in the room?Partly answered
- What works in theatres and cinemas, and what do the rules ask of them?Partly answered
Cite this source
SIA (Swiss Society of Engineers and Architects). prSIA 500:2025-07 Hindernisfreie Bauten (obstacle-free buildings), consultation draft. SIA; consultation copy with highlights published by Pro Audito Schweiz (in German). July 2025. https://pro-audito.ch/wp-content/uploads/prSIA500_Vernehmlassungsentwurf-mit-Hervorhebungen.pdf (accessed 13 October 2026).
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