National foreword

This Published Document is the UK implementation of IEC TR 63079:2017+A2:2020. It supersedes PD IEC TR 63079:2017+A1:2018 and BS 7594:2011, which are withdrawn.

The start and finish of text introduced or altered by amendment is indicated in the text by tags. Tags indicating changes to IEC text carry the number of the IEC amendment. For example, text altered by IEC amendment A1 is indicated by .

The UK participation in its preparation was entrusted to Technical Committee EPL/29, Electroacoustics.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

This publication is not to be regarded as a British Standard.

Compliance with a Published Document cannot confer immunity from legal obligations.

This Published Document was published under the authority of the Standards Policy and Strategy Committee on 30 September 2017.

FOREWORD

The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees.
IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user.
In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies.
All users should ensure that they have the latest edition of this publication.
No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication.
Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

The main task of IEC technical committees is to prepare International Standards. However, a technical committee may propose the publication of a Technical Report when it has collected data of a different kind from that which is normally published as an International Standard, for example “state of the art”.

IEC TR 63079, which is a Technical Report, has been prepared by IEC technical committee 29: Electroacoustics.

The text of this Technical Report is based on the following documents:

Full information on the voting for the approval of this Technical Report can be found in the report on voting indicated in the above table.

This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

The committee has decided that the contents of this document will remain unchanged until the stability date indicated on the IEC website under “http://webstore.iec.ch” in the data related to the specific document. At this date, the document will be

reconfirmed,
withdrawn,
replaced by a revised edition, or
amended.

A bilingual version of this publication may be issued at a later date.

IMPORTANT — The 'colour inside' logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this document using a colour printer.

INTRODUCTION

The performance of induction-loop systems is specified in IEC 60118‑4, whereas IEC TR 63079 gives recommendations and guidance for their design, planning, installation, testing, operation and maintenance. Provisions for components of a system are given in IEC 62489‑1. Methods of calculation and measurement of the magnetic field, in the context of human exposure, are given in IEC 62489‑2.

This document takes the form of guidance and recommendations. It should not be quoted as if it were a specification and particular care should be taken to ensure that claims of compliance are not misleading.

Any user claiming compliance with this document is expected to be able to justify any course of action that deviates from its recommendations.

1 Scope

This document, which is a Technical Report, gives recommendations for and guidance on the design, planning, installation, testing, operation and maintenance of a hearing-loop system (HLS) intended for communicating speech, music and/or other signals. It is mainly concerned with HLS for hearing enhancement, in which the signals are communicated to users of hearing aids equipped with magnetic pick-up coils.

This document does not apply to induction-loop systems which use a carrier frequency, nor to other systems for hearing enhancement purposes which do not use magnetic induction.

2 Normative references

3 Terms, definitions, signs and symbols

3.1 Terms and definitions

3.2 Signs and symbols

4 General

4.1 How to use this document

4.2 Specialist advice

4.3 Safety aspects

4.4 Conforming to existing performance documents

5 Technical advice

5.1 Complying with this document

5.2 Seeking technical advice

5.3 The nature of the advice

5.4 Professional (consultancy) advice

6 Purpose of the system

7 Choosing the system supplier

7.1 General

7.2 Approaching a contractor

7.3 Approaching a manufacturer of HLS equipment

7.4 Approaching a specialist consultant

8 Contractual provisions

8.1 Performance specification

8.2 Verifying that the completed system delivers its intended performance

8.3 Arbitration

9 Classification of systems

10 Design

10.1 General

10.2 Symbols

10.3 Basic theory

10.4 System components

10.5 Objective measurement of intelligibility

10.6 Safety and reliability considerations

10.7 Designing for monitoring and maintenance

10.8 External factors

10.9 Magnetic field overspill

10.10 The role of the system designer in commissioning

11 Responsibility of the installer

12 Installation practices and workmanship

13 Inspection and testing of wiring

14 Commissioning

15 Documentation

16 Certification

17 Acceptance

18 Verification

19 Owner responsibilities

19.1 Signage

19.2 User feedback

19.3 Staff training

20 Operation and maintenance

20.1 General

20.2 Routine testing

20.3 Inspection and servicing

20.4 Non-routine attention

20.5 Special inspection on appointment of a new maintenance organization

20.6 Arrangements for repair of faults or damage

20.7 Modifications to the system

21 User responsibilities

21.1 Responsible person

21.2 Logbook

Bibliography

PD IEC TR 63079:2017+A2:2020

Code of practice for hearing-loop systems (HLS)

Current

Published:

31 Jul 2023