EN IEC 60601-2-66:2020

Medical electrical equipment - Part 2-66: Particular requirements for the basic safety and essential performance of hearing aids and hearing aid systems

IEC 60601-2-66:2019 is available as IEC 60601-2-66:2019 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 60601-2-66:2019 applies to the BASIC SAFETY of HEARING AIDS and HEARING AID SYSTEMS, hereafter also referred to as ME EQUIPMENT or ME SYSTEM. IEC 60601-2-66:2019 cancels and replaces the second edition published in 2015. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) revision of the definition about ESSENTIAL PERFORMANCE; b) revision of the application of IEC 60601-1-2:2014 for electromagnetic disturbances; c) correction of the used voltage for HEARING AIDS from 1,6 V to 4,5 V; d) correction of the drop test level from 1,5 m to 1,0 m; e) correction of the wording of IEC 60601-2-66:2015.

Medizinische elektrische Geräte - Teil 2-66: Besondere Festlegungen für die Sicherheit einschließlich der wesentlichen Leistungsmerkmale von Hörgeräten und Hörgerätesystemen

Appareils électromédicaux - Partie 2-66: Exigences particulières pour la sécurité de base et les performances essentielles des appareils de correction auditive et des systèmes de correction auditive

IEC 60601-2-66:2019 est disponible sous forme de IEC 60601-2-66:2019 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.L'IEC 60601-2-66:2019 s'applique à la SECURITE DE BASE des APPAREILS DE CORRECTION AUDITIVE et des SYSTEMES DE CORRECTION AUDITIVE, également appelés ci-après "APPAREILS EM" ou "SYSTEMES EM". L'IEC 60601-2-66:2019 annule et remplace la deuxième édition parue en 2015. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: a) révision de la définition des PERFORMANCES ESSENTIELLES; b) révision de l'application de l'IEC 60601-1-2:2014 pour les perturbations électromagnétiques; c) correction de la tension utilisée pour les APPAREILS DE CORRECTION AUDITIVE de 1,6 V à 4,5 V; d) correction du niveau d'essai de chute de 1,5 m à 1,0 m; e) correction de la formulation de l'IEC 60601-2-66:2015.

Medicinska električna oprema - 2-66. del: Posebne zahteve za osnovno varnost in bistvene lastnosti slušnih pripomočkov in sistemov (IEC 60601-2-66:2019)

General Information

• Status: Published
• Publication Date: 02-Apr-2020
• Withdrawal Date: 18-Feb-2023
• ICS: 11.180.15 - Aids for deaf and hearing impaired people
• ICS: 17.140.50 - Electroacoustics
• Technical Committee: CLC/SR 29 - Electroacoustics
• Drafting Committee: IEC/TC 29 - IEC_TC_29
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 03-Apr-2020
• Completion Date: 03-Apr-2020
• Directive: 93/42/EEC - Council Directive 93/42/EEC of 14 June 1993 concerning medical devices
• Mandate: M/023 - Standardization mandate to CEN/CENELEC concerning the development of European standards relating to medical devices
• Mandate: M/432 - Standardisation Mandate addressed to CEN and CENELEC within the framework of Directive 2007/47/EC amending Directive 90/385/EEC and Directive 93/42/EEC relating to Medical Devices
• Ref Project: SIST EN IEC 60601-2-66:2020 - Medical electrical equipment - Part 2-66: Particular requirements for the basic safety and essential performance of hearing aids and hearing aid systems (IEC 60601-2-66:2019)

Relations

• Replaces: EN 60601-2-66:2015 - Medical electrical equipment - Part 2-66: Particular requirements for the basic safety and essential performance of hearing instruments and hearing instrument systems
• Effective Date: 07-Jun-2022

Overview

EN IEC 60601-2-66:2020 (adoption of IEC 60601-2-66:2019 RLV) is the European adoption of the international collateral standard that sets particular requirements for the basic safety and essential performance of hearing aids and hearing aid systems. It supersedes the 2015 edition and provides updated technical requirements used by manufacturers, test laboratories and regulatory teams for designing, assessing and demonstrating conformity of hearing aids as medical electrical equipment.

Key topics and requirements

• Scope and purpose: Focused on the basic safety and essential performance of hearing aids and hearing aid systems used by people with hearing impairment.
• Essential performance: The 2019/2020 edition revises the definition and application of essential performance, clarifying which functions must be maintained for safety.
• Electromagnetic compatibility (EMC): Aligns with IEC 60601-1-2:2014 application for electromagnetic disturbances and immunity testing relevant to hearing aids.
• Electrical and mechanical corrections: Important corrections include the nominal battery voltage for hearing aids adjusted from 1.6 V to 4.5 V, and the drop test height corrected from 1.5 m to 1.0 m.
• Risk management and documentation: Emphasizes risk analysis, instructions for use, labelling, packaging and maintenance information to support safe operation and compliance.
• Environmental and mechanical testing: Requirements cover mechanical strength, climatic conditions, transport and storage to ensure durability and safe performance.
• Interaction with software and lifecycle requirements: Cross-references to medical device software lifecycle standards (e.g., IEC 62304) where applicable.

Practical applications and who uses this standard

• Manufacturers and design engineers use EN IEC 60601-2-66 to design hearing aids and hearing aid systems that meet safety and performance expectations and to specify electrical, mechanical and EMC tests.
• Regulatory affairs and conformity assessment bodies apply the standard for CE marking and to demonstrate presumption of conformity with EU medical device directives (MDD 93/42/EEC as amended).
• Test laboratories and certification bodies reference the standard for product testing - EMC, drop testing, leakage current and other safety verifications.
• Quality & compliance teams integrate the requirements into risk management files, technical documentation and instructions for use.

Related standards

Common referenced documents include:

• IEC 60601-1 (general requirements for basic safety)
• IEC 60601-1-2:2014 (EMC)
• IEC 60118 series (electroacoustics / hearing aid measurements)
• IEC 62304 (medical device software lifecycle)
• Relevant EMC and test standards cited in the normative references.

EN IEC 60601-2-66 is essential reading for anyone involved in the design, testing or regulatory submission of hearing aids and hearing aid systems seeking compliant, safe and market-ready medical electrical devices.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2020
Nadomešča:
SIST EN 60601-2-66:2016
Medicinska električna oprema - 2-66. del: Posebne zahteve za osnovno varnost in
bistvene lastnosti slušnih pripomočkov in sistemov (IEC 60601-2-66:2019)
Medical electrical equipment - Part 2-66: Particular requirements for the basic safety and
essential performance of hearing aids and hearing aid systems (IEC 60601-2-66:2019)
Medizinische elektrische Geräte - Teil 2-66: Besondere Festlegungen für die Sicherheit
einschließlich der wesentlichen Leistungsmerkmale von Hörgeräten und
Hörgerätesystemen (IEC 60601-2-66:2019)
Appareils électromédicaux - Partie 2-66: Exigences particulières pour la sécurité de base
et les performances essentielles des instruments d'audition et systèmes d'audition (IEC
60601-2-66:2019)
Ta slovenski standard je istoveten z: EN IEC 60601-2-66:2020
ICS:
11.180.15 Pripomočki za gluhe osebe in Aids for deaf and hearing
osebe z okvaro sluha impaired people
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60601-2-66

NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2020
ICS 11.180.15; 17.140.50 Supersedes EN 60601-2-66:2015 and all of its
amendments and corrigenda (if any)
English Version
Medical electrical equipment - Part 2-66: Particular requirements
for the basic safety and essential performance of hearing aids
and hearing aid systems
(IEC 60601-2-66:2019)
Appareils électromédicaux - Partie 2-66: Exigences Medizinische elektrische Geräte - Teil 2-66: Besondere
particulières pour la sécurité de base et les performances Festlegungen für die Sicherheit einschließlich der
essentielles des appareils de correction auditive et des wesentlichen Leistungsmerkmale von Hörgeräten und
systèmes de correction auditive Hörgerätesystemen
(IEC 60601-2-66:2019) (IEC 60601-2-66:2019)
This European Standard was approved by CENELEC on 2020-02-19. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60601-2-66:2020 E

European foreword
The text of document 29/1023/FDIS, future edition 3 of IEC 60601-2-66, prepared by IEC/TC 29
"Electroacoustics" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2020-11-19
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2023-02-19
document have to be withdrawn
This document supersedes EN 60601-2-66:2015 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CENELEC by the European Commission
and the European Free Trade Association, and supports essential requirements of EU Directive(s).
For the relationship with EU Directive(s) see informative Annex ZZ, which is an integral part of this
document.
Endorsement notice
The text of the International Standard IEC 60601-2-66:2019 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 60118-4:2014 NOTE Harmonized as EN 60118-4:2015 (not modified)
IEC 60318-5:2006 NOTE Harmonized as EN 60318-5:2006 (not modified)
IEC 60601-1-9 NOTE Harmonized as EN 60601-1-9
IEC 60601-1-10 NOTE Harmonized as EN 60601-1-10
IEC 60645-1:2017 NOTE Harmonized as EN 60645-1:2017 (not modified)
IEC 61000-4-2 NOTE Harmonized as EN 61000-4-2
IEC 61000-4-8 NOTE Harmonized as EN 61000-4-8
IEC 62489-1:2010 NOTE Harmonized as EN 62489-1:2010 (not modified)
IEC 62489-1:2010/A1:2014 NOTE Harmonized as EN 62489-1:2010/A1:2015 (not modified)
IEC 62489-1:2010/A2:2017 NOTE Harmonized as EN 62489-1:2010/A2:2018 (not modified)
IEC 62366-1:2015 NOTE Harmonized as EN 62366-1:2015 (not modified)
CISPR 11 NOTE Harmonized as EN 55011
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Clause 2 of the general standard applies except as follows:
Replacement:
Publication Year Title EN/HD Year
IEC 60950-1 (mod) 2005 Information technology equipment - Safety EN 60950-1 2006
- Part 1: General requirements
- -  + A11 2009
+ A1 (mod) 2009  + A1 2010
- -  + A12 2011
+ A2 (mod) 2013  + A2 2013
IEC 62368-1 (mod) 2014 Audio/video, information and EN 62368-1 2014
communication technology equipment -
Part 1: Safety requirements
- -  + A11 2017
Addition:
Publication Year Title EN/HD Year
IEC 60118-0 2015 Electroacoustics - Hearing aids - Part 0: EN 60118-0 2015
Measurement of the performance
characteristics of hearing aids
IEC 60118-13 -  Electroacoustics - Hearing aids - Part 13: EN 60118-13 2019
Electromagnetic compatibility (EMC)
IEC 60601-1 2005 Medical electrical equipment - Part 1: EN 60601-1 2006
General requirements for basic safety and
essential performance
+ A1 2012  + A1 2013
- -  + A12 2014
Publication Year Title EN/HD Year
IEC 60601-1-2 2014 Medical electrical equipment - Part 1-2: EN 60601-1-2 2015
General requirements for basic safety and
essential performance - Collateral
Standard: Electromagnetic disturbances -
Requirements and tests
IEC 60601-1-11 2015 Medical electrical equipment - Part 1-11: EN 60601-1-11 2015
General requirements for basic safety and
essential performance - Collateral
Standard: Requirements for medical
electrical equipment and medical electrical
systems used in the home healthcare
environment
IEC 62304 -  Medical device software - Software life EN 62304 2006
cycle processes
+ A1 2015
Annex ZZ
(informative)
Coverage of Essential Requirements of EU Directives
This European standard has been prepared under a Commission’s standardisation request M/023 and
M432 concerning the development of European Standards related to medical devices given to
CENELEC by the European Commission and the European Free Trade Association to provide a
means of conforming to the Essential Requirements given in Annex I of the EU Directives 93/42/EEC
as amended by 2007/47/EC.
General Guidance:
Once this standard will be cited in the Official Journal of the European Union under that Directive,
compliance with the clauses of this standard given in Table ZZ.1 confers, within the limits of the scope
of this standard, a presumption of conformity with the corresponding Essential Requirements (ERs) of
that Directive and associated EFTA regulations.
NOTE 1 This standard is intended to be applied in its entirety only. Selected clauses or
subclauses may be not applicable due to the specific type of equipment under consideration. It is
necessary to understand and apply Clauses 1 to 5. It is also recommended to understand and apply
those clauses which contain general requirements related to a specific subclause. Elements of the
standard that are not cited in Table ZZ.1 may be relevant for the appropriate fulfilment of certain
essential requirements through indirect reference, and for safety and performance aspects of the
device, that are not addressed through essential requirements.
NOTE 2 Where a reference from a clause of this standard to the risk management process is
made, the risk management process needs to be in compliance to the MDD (Directive 93/42/EEC
amended by 2007/47/EC). This means that risks have to be reduced "as far as possible", "to a
minimum", "to the lowest possible level", "minimized" or "removed", according to the wording of the
corresponding essential requirement.
NOTE 3 With respect to Note 4 of 4.2.2 General requirement for risk management, the
manufacturer’s policy for determining acceptable risk must be in compliance with essential
requirements 1, 2, 5, 6, 7, 8, 9, 11 and 12 of the directive.
NOTE 4 References in the Clauses 3 to 17 or in the Annexes of this standard specify whether
the normative references listed in Clause 2 as cited in Annex ZA are to be applied in whole or in part.
NOTE 5 This Annex ZZ is based on Normative References according to Annex ZA, replacing
the references in the core text.
NOTE 6 According to the scope of this standard the coverage in Table ZZ.1 only applies to the
design and construction of HEARING AIDS and HEARING AID SYSTEMS. This European Standard
lists in Table ZZ.1 only the essential requirements covered.
WARNING: Other requirements and other EU Directives and Regulations may be applicable to the
product(s) falling within the scope of this standard.
Table ZZ.1 – Relationship between Essential Requirements of Directive 93/42/EEC
amended by 2007/47/EC, and clauses and subclauses of this standard
Remarks/Notes
Essential Requirements of Clause(s)/sub-
Directive 93/42/EEC clause(s) of this EN
201.7.9.1
1, second indent This document (201.7.9.1, 201.7.9.2.1,
201.7.9.2.1
201.7.9.2.2) covers requirements related to

201.7.9.2.2
instructions for use, including safety
warnings and notices by considering the
technical knowledge, experience, education
and training and where applicable the
medical and physical conditions of intended
users (design for lay, professional, disabled
or other users).
201.7.2.17
5 Covered by requirements to design and
201.7.9.2.2
packaging (201.7.2.17) to withstand

201.15.3
transport and storage with regards of
201.15.3.7
mechanical strength (201.15.3), resistance

to environmental conditions (201.15.3.7) and
the necessary instructions (201.7.9.2.2).
201.7.9.2.1
6 The reduction of unintentional exposure to
201.9.6
excessive acoustic noise is covered in

201.9.6 regarding the design.
201.7.9.2.1 covers information and
instructions for the user related to side
effects.
201.11.1.1
7.1, first indent Covered for risks of fire and high
201.13.1.2
temperatures.
201.11.6.6
7.3 This document covers (201.15.3.7,
201.15.3.7
201.11.6.6) the design of devices in such a

way that they can be used safely with the
materials, substances and gases with which
they enter into contact during their normal
use or during routine procedures.
Requirements for HEARING AIDS that are
intended to be used in explosive and
oxygenenriched atmospheres are not
contained in this standard (see 201.11.2).
7.5, first sentence of first 201.7.9.2.4 Covered for the risk of leakage from the
paragraph only battery in situ.
7.6 201.11.6.5 Covered in 201.11.6.5.
8.1, first sentence only 201.7.9.2.12 Design covered in 201.12.2, 201.11.6.6 and
instruction covered in 201.7.9.2.12.
201.11.6.6
201.12.2
9.1 201.5.5 c)
201.6.2
201.7.9.2.5
201.7.9.2.9
201.8.1
201.8.2.1
201.8.4.2
Remarks/Notes
Essential Requirements of Clause(s)/sub-
Directive 93/42/EEC clause(s) of this EN
9.2, first indent 201.9 Mechanical risks (e.g. ‘entanglement’) are
covered by 201.9.
9.2, second indent 201.5.3 Covered in respect of environmental
temperatures, humidity or variations in
201.5.7
pressure: 201.5.3, 201.5.7, 201.7.2.17,
201.7.2.17
201.7.9.2.1, 201.7.9.2.2, 201.15.3.7 of this
201.7.9.2.1
document provide design and test
201.7.9.2.2 requirements with regards to climatic
environmental conditions which are suitable
201.15.3.7
to remove or minimize as far as possible
these risks.
9.2, third indent 201.7.9.2.2 To fully cover this ER, risks must be
removed or minimised as far as possible.
201.17
Covered for the serviceability of hearing aids
9.2, fourth indent 201.15.2
subject to mechanical wear, electrical

degradation or ageing.
9.3 201.11.1.1 Risks of fire and high temperatures covered
in 201.11.1.1, 201.13.1.2.
201.13.1.2
HEARING AIDS are normally not exposed to
flammable substances or to substances
which could cause combustion.
The requirements for HEARING AIDS that
are intended to be used in explosive and
oxygenenriched atmospheres are not
covered in this document.
12.5 201.17 To fully cover this ER, risks must be
removed or minimised as far as possible.

12.6 201.8 Electrical risks covered in 201.8 for normal
conditions and 201.13 in fault conditions.
201.13
12.7.1 201.15.3.1 Covered by the mechanical requirements in
201.15.3.1.
12.7.3 201.7 The reduction of unintentional exposure to
excessive acoustic noise is covered in
201.9.6
201.9.6 regarding the design, in 201.7
201.13.1.2
regarding correct application 201.13.1.2 in
case of faults.
12.7.4 201.8.1 Covered in respect of the following: Electrical
Risks:
201.8.2.1
201.8.1 Fundamental rule of protection
201.8.7
against electric shock
201.16
201.8.2.1 Connection to power sources

201.16 Limitation of voltage current or
energy 201.8.7 Leakage current. Gas or
hydraulic and pneumatic energy supplies not
applicable to HEARING AIDS.
12.7.5 201.11.1 Covered by 201.11.1 Excessive
temperatures
Remarks/Notes
Essential Requirements of Clause(s)/sub-
Directive 93/42/EEC clause(s) of this EN
12.8.1 201.9.6 Requirements of sufficient accurate
indication of output is covered in 201.9.6.
201.12.4.4
201.12.4.4 covers possible sources of
incorrect output.
12.8.2 201.9.6 The reduction of unintentional exposure to
excessive acoustic noise is covered in

201.9.6
12.9 201.7.9.1 Requirements to specification of function of
controls and indicators on the device or in
201.7.9.2.1
the instructions for use are covered in
201.7.9.2.9
201.7.9.2.1 and 201.7.9.2.9.
13.1 – first and second   201.7.9.2 Covered in respect of the following:
201.7.9.2 Instructions for use. 201.7.9.2.16
paragraph 201.7.9.2.16
Technical description, provided that the

technical description is included in the
instructions for use.
13.1  - first and third paragraph 201.7.2.2 Covered in respect of information on the
packaging in 201.7.2.17. Covered in respect
201.7.2.17
of information in the instruction for use in
201.7.9.2
201.7.9.2.
13.1 - first and fourth paragraph 201.7.9.2 Requirements for instruction for use covered
in 201.7.9.2.
13.2 201.7.8.1 Description of symbols in the documentation
covered in 201.7.9.2.9. Description of
201.7.9.2.9
colours in the documentation covered in

201.7.8.1.
13.3 a) 201.7.2.2 To fully cover this ER, the name and address
of the authorised representative must be

provided, if applicable.
13.3 d) 201.7.2.2 To fully cover this ER the batch number (if
provided) must be preceded by the symbol

LOT.
13.3 i) 201.7.2.17
13.3 j) 201.7.2
13.3 l) 201.7.2.2
13.4 201.7.9.1 Covered for the Instructions for Use.

13.5 201.7.2.2 Serial number required in 201.7.2.2.

Remarks/Notes
Essential Requirements of Clause(s)/sub-
Directive 93/42/EEC clause(s) of this EN
13.6 b) 201.7.9.3 Covered provided the technical description is
included in the instructions for use.

13.6 d) 201.7.9.2.1
201.7.9.2.12
13.6 k) 201.7.9.2.1
13.6 l) 201.7.9.2.1
WARNING 1 — Presumption of conformity stays valid only as long as a reference to this
European Standard is maintained in the list published in the Official Journal of the European
Union. Users of this standard should consult frequently the latest list published in the Official
Journal of the European Union.
WARNING 2 — Other Union legislation may be applicable to the products falling within the
scope of this standard.
IEC 60601-2-66 ®
Edition 3.0 2019-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Medical electrical equipment –

Part 2-66: Particular requirements for the basic safety and essential

performance of hearing aids and hearing aid systems

Appareils électromédicaux –
Partie 2-66: Exigences particulières pour la sécurité de base et les

performances essentielles des appareils de correction auditive et des systèmes

de correction auditive
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 11.180.15; 17.140.50 ISBN 978-2-8322-7350-0

– 2 – IEC 60601-2-66:2019 © IEC 2019
CONTENTS
FOREWORD . 4
INTRODUCTION . 7
201.1 Scope, object and related standards . 8
201.2 Normative references . 10
201.3 Terms and definitions . 11
201.4 General requirements . 12
201.5 General requirements for testing ME EQUIPMENT . 13
201.6 Classification of ME EQUIPMENT and ME SYSTEMS . 15
201.7 ME EQUIPMENT identification, marking and documents . 15
201.8 * Protection against electrical HAZARDS from ME EQUIPMENT . 21
201.9 * Protection against MECHANICAL HAZARDS of ME EQUIPMENT and ME SYSTEMS . 23
201.10 * Protection against unwanted and excessive radiation HAZARDS . 25
201.11 * Protection against excessive temperatures and other HAZARDS . 25
201.12 * Accuracy of controls and instruments and protection against hazardous
outputs. 27
201.13 * HAZARDOUS SITUATIONS and fault conditions for ME EQUIPMENT . 28
201.14 * PROGRAMMABLE ELECTRICAL MEDICAL SYSTEMS (PEMS) . 30
201.15 * Construction of ME EQUIPMENT . 31
201.16 * ME SYSTEMS . 33
201.17 Electromagnetic compatibility of ME EQUIPMENT and ME SYSTEMS . 33
Annexes . 35
Annex E (informative) Examples of the connection of the measuring device (MD) for
measurement of the PATIENT LEAKAGE CURRENT and PATIENT AUXILIARY CURRENT . 36
Annex G (normative) Protection against HAZARDS of ignition of flammable anaesthetic
mixtures . 37
Annex H (informative) PEMS structure, PEMS DEVELOPMENT LIFE-CYCLE and
documentation . 38
Annex I (informative) ME SYSTEMS aspects . 39
Annex J (informative) Survey of insulation paths . 40
Annex K (informative) Simplified PATIENT LEAKAGE CURRENT diagrams . 41
Annex L (normative) Insulated winding wires for use without interleaved insulation . 42
Annex AA (informative) Particular guidance and rationale . 43
Annex BB (informative) Abbreviations . 48
Annex CC (informative) Essential performance . 49
Annex DD (informative) Electromagnetic compatibility of ME EQUIPMENT . 50
Bibliography . 52
Index of defined terms used in this particular standard . 54

Figure 201.101 – Measuring circuit for LEAKAGE CURRENT (see 201.8.7.4.7) . 22

Table 201.101 – MECHANICAL HAZARDS to be considered . 24
Table AA.101 – Summary of the approach of this document . 44

IEC 60601-2-66:2019 © IEC 2019 – 3 –
Table DD.101 – Example of applicable standards for HEARING AID specific setting for
RF radiated emissions . 50
Table DD.102 – Example of applicable tests . 51

– 4 – IEC 60601-2-66:2019 © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MEDICAL ELECTRICAL EQUIPMENT –

Part 2-66: Particular requirements for the basic safety and essential
performance of hearing aids and hearing aid systems

FOREWORD
1) 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.
2) 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.
3) 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.
4) 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.
5) 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.
6) All users should ensure that they have the latest edition of this publication.
7) 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.
8) 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.
9) 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.
International Standard IEC 60601-2-66 has been prepared by IEC technical committee 29:
Electroacoustics.
This third edition cancels and replaces the second edition published in 2015. It constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) revision of the definition about ESSENTIAL PERFORMANCE;
b) revision of the application of IEC 60601-1-2:2014 for electromagnetic disturbances;
c) correction of the used voltage for HEARING AIDS from 1,6 V to 4,5 V;
d) correction of the drop test level from 1,5 m to 1,0 m;
e) correction of the wording of IEC 60601-2-66:2015.

IEC 60601-2-66:2019 © IEC 2019 – 5 –
The text of this International Standard is based on the following documents:
FDIS Report on voting
29/1023/FDIS 29/1030/RVD
Full information on the voting for the approval of this International Standard 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.
In this document, the following print types are used:
– requirements and definitions: roman type;
– test specifications: italic type;
informative material appearing outside of tables, such as notes, examples and references: in smaller type.
–
Normative text of tables is also in a smaller type;
– TERMS DEFINED IN CLAUSE 3 OF THE GENERAL STANDARD, IN THIS PARTICULAR STANDARD OR AS
NOTED: SMALL CAPITALS.
In referring to the structure of this document, the term
– "clause" means one of the seventeen numbered divisions within the table of contents,
inclusive of all subdivisions (e.g. Clause 7 includes subclauses 7.1, 7.2, etc.);
– "subclause" means a numbered subdivision of a clause (e.g. 7.1, 7.2 and 7.2.1 are all
subclauses of Clause 7).
References to clauses within this document are preceded by the term "Clause" followed by the
clause number. References to subclauses within this particular standard are by number only.
In this document, the conjunctive "or" is used as an "inclusive or" so a statement is true if any
combination of the conditions is true.
The verbal forms used in this document conform to usage described in Clause 7 of the ISO/IEC
Directives, Part 2. For the purposes of this document, the auxiliary verb:
– "shall" means that compliance with a requirement or a test is mandatory for compliance with
this document;
– "should" means that compliance with a requirement or a test is recommended but is not
mandatory for compliance with this document;
– "may" is used to describe a permissible way to achieve compliance with a requirement or
test.
An asterisk (*) as the first character of a title or at the beginning of a paragraph or table title
indicates that there is guidance or rationale related to that item in Annex AA.
A list of all parts of the IEC 60601 series, published under the general title Medical electrical
equipment, can be found on the IEC website.

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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.
NOTE The attention of users of this document is drawn to the fact that equipment manufacturers and testing
organizations may need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests. It is the recommendation of the committee that the content of this publication be adopted for
implementation nationally not earlier than 3 years from the date of publication.

IEC 60601-2-66:2019 © IEC 2019 – 7 –
INTRODUCTION
In 1998, the HEARING AID industry represented by the European hearing instrument
manufacturers association (EHIMA) attempted to establish a standard with the main purpose of
providing MANUFACTURERS with a guide to demonstrate conformity with the European Medical
Devices Directive 93/42/EEC.
The draft document prEN 50220 failed CENELEC vote and was published as "EHIMA standard"
in June 1998 with almost identical content. EHIMA concluded in 2009 that the requirements of
that standard were no longer up to date and an internationally accepted standard for HEARING
AID safety published by IEC or ISO to demonstrate compliance with regulatory requirements
should be produced.
This particular standard amends and supplements IEC 60601-1:2005 and
IEC 60601-1:2005/AMD1:2012, hereinafter referred to as the "general standard".
A general guidance and rationale for the requirements of this particular standard are given in
Annex AA. It is considered that knowledge of the reasons for these requirements will not only
facilitate the proper application of this particular standard but will, in due course, expedite any
revision necessitated by changes in clinical practice or as a result of developments in
technology. However, Annex AA does not form part of the requirements of this document.

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MEDICAL ELECTRICAL EQUIPMENT –

Part 2-66: Particular requirements for the basic safety and essential
performance of hearing aids and hearing aid systems

201.1 Scope, object and related standards
Clause 1 of the general standard applies, except as follows:
201.1.1 * Scope
Replacement:
This part of IEC 60601 applies to the BASIC SAFETY of HEARING AIDS and HEARING AID SYSTEMS,
hereafter also referred to as ME EQUIPMENT or ME SYSTEM.
If a clause or subclause is specifically intended to be applicable to HEARING AIDS only, or to
HEARING AID SYSTEMS only, the title and content of that clause or subclause will say so. If that is
not the case, the clause or subclause applies both to HEARING AIDS and to HEARING AID SYSTEMS,
as relevant.
HAZARDS inherent in the intended physiological function of HEARING AIDS or HEARING AID SYSTEMS
within the scope of this document are not covered by specific requirements in this document
except in 201.7.9.2 and 201.9.6.
NOTE See also 4.2 of the general standard.
ACCESSORIES to HEARING AIDS in the HOME HEALTHCARE ENVIRONMENT (e.g. remote control units,
audio streamers, battery chargers, power supplies) can be tested according to the applicable
standard, IEC 60065, IEC 60950-1, IEC 62368-1 or other applicable IEC safety standards.
Alternatively, the general standard may be applied. HEARING AIDS do not have a MAINS PART
intended for connection to AC SUPPLY MAINS. The connection to the SUPPLY MAINS of a HEARING
AID SYSTEM is covered by power supply, charger or other types of ACCESSORIES.
ACCESSORIES with FUNCTIONAL CONNECTION to a HEARING AID may form a HEARING AID SYSTEM.
HEARING AID related ACCESSORIES that are not physically connected to the HEARING AID during
NORMAL USE are not considered to be APPLIED PART, because they do not directly contribute to
the INTENDED USE of the HEARING AID.
Wireless programming interfaces are covered by the applicable standard IEC 60065,
IEC 60950-1, IEC 62368-1 or other applicable IEC safety standards. Alternatively, the general
standard may be applied.
Programming interfaces with wired connection to the HEARING AID are covered by the general
standard.
NOTE Detachable parts of HEARING AIDS, even if supplied separately (e.g. ear hooks, domes, wax guards etc.), are
not considered as ACCESSORIES, but as component parts.
___________
The general standard is IEC 60601-1 and IEC 60601-1:2005/AMD1:2012, Medical electrical equipment – Part 1:
General requirements for basic safety and essential performance.

IEC 60601-2-66:2019 © IEC 2019 – 9 –
This document does not apply to:
– cochlear implants or other implanted HEARING AIDS;
– bone conduction HEARING AIDS;
– educational HEARING AIDS (i.e. group HEARING AIDS, auditory trainers etc.);
– the application of a HEARING AID for the measurement of hearing levels; IEC 60645-1 applies;
– fix installed audio-frequency induction-loop systems or their component parts, as described
in IEC 60118-4 and IEC 62489-1;
– the sound generating function of a tinnitus masker.
This document does not address applicable testing for intentional RF radiation of wireless
equipment (e.g. maximum radiated output power, modulation bandwidth, etc.).
201.1.2 Object
Replacement:
The object of this particular standard is to establish particular BASIC SAFETY requirements for
HEARING AIDS and HEARING AID SYSTEMS as defined in 201.3.202 and 201.3.203.
201.1.3 * Collateral standards
Addition:
This particular standard refers to those applicable collateral standards that are listed in
Clause 2 of the general standard and Clause 201.2 of this particular standard.
IEC 60601-1-3, IEC 60601-1-9 and IEC 60601-1-10 do not apply. All other published collateral
standards in the IEC 60601-1 series apply as published.
201.1.4 Particular standards
Replacement:
In the IEC 60601 series, particular standards may modify, replace or delete requirements
contained in the general standard and collateral standards as appropriate for the particular
ME EQUIPMENT under consideration, and may add other BASIC SAFETY and ESSENTIAL
PERFORMANCE requirements.
A requirement of a particular standard takes priority over the general standard.
For brevity, IEC 60601-1 and IEC 60601-1:2005/AMD1:2012 is referred to in this particular
standard as the general standard. Collateral standards are referred to by their document
number.
The numbering of clauses and subclauses of this particular standard corresponds to that of the
general standard with the prefix "201" (e.g. 201.1 in this document addresses the content of
Clause 1 of the general standard) or applicable collateral standard with the prefix "20x" where
x is the final digit(s) of the collateral standard document number (e.g. 202.4 in this particular
standard addresses the content of Clause 4 of the IEC 60601-1-2 collateral standard, 203.4 in
this particular standard addresses the content of Clause 4 of the IEC 60601-1-3 collateral
standard, etc.). The changes to the text of the general standard are specified by the use of the
following words:
"Replacement" means that the clause or subclause of the general standard or applicable
collateral standard is replaced completely by the text of this particular standard.

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"Addition" means that the text of this particular standard is additional to the requirements of the
general standard or applicable collateral standard.
"Amendment" means that the clause or subclause of the general standard or applicable
collateral standard is amended as indicated by the text of this particular standard.
Subclauses, figures or tables which are additional to those of the general standard are
numbered starting from 201.101. However, due to the fact that definitions in the general
standard are numbered 3.1 through 3.147, additional definitions in this document are numbered
beginning from 201.3.201. Additional annexes are lettered AA, BB, etc., and additional items
aa), bb), etc.
Subclauses, figures or tables which are additional to those of a collateral standard are
numbered starting from 20x, where "x" is the number of the collateral standard, e.g. 202 for
IEC 60601-1-2, 203 for IEC 60601-1-3, etc.
The term "this document" is used to make reference to the general standard, any applicable
collateral standards and this particular standard taken together.
Where there is no corresponding clause or subclause in this particular standard, the clause or
subclause of the general standard or applicable collateral standard, although possibly not
relevant, applies without modification; where it is intended that any part of the general standard
or applicable collateral standard, although possibly relevant, is not to be applied, a statement
to that effect is given in this particular standard.
201.2 Normative references
NOTE Informative references are listed in the Bibliography.
Clause 2 of the general standard applies except as follows:
Replacement:
IEC 60601-1-2:2014, Medical electrical equipment – Part 1-2: General requirements for basic
safety and essential performance – Collateral Standard: Electromagnetic disturbances –
Requirements and tests
IEC 60950-1:2005, Information technology equipment – Safety – Part 1: General requirements
IEC 60950-1:2005/AMD1:2009
IEC 60950-1:2005/AMD2:2013
Addition:
IEC 60118-0:2015, Electroacoustics – Hearing aids – Part 0: Measurement of the performance
characteristics of hearing aids
IEC 60118-13, Electroacoustics – Hearing aids – Part 13: Electromagnetic compatibility (EMC)
IEC 60601-1:2005, Medical electrical equipment – Part 1: General requirements for basic safety
and essential performance
IEC 60601-1:2005/AMD1:2012
IEC 60601-1-11:2015, Medical electrical equipment – Part 1-11: General requirements for basic
safety and essential performance – Collateral Standard: Requirements for medical electrical
equipment and medical electrical systems used in the home healthcare environment

IEC 60601-2-66:2019 © IEC 2019 – 11 –
IEC 62368-1:2018, Audio/video, information and communication technology equipment –
Part 1: Safety requirements
201.3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60601-1 and
IEC 60601-1:2005/AMD1:2012 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
NOTE An index of defined terms is found beginning on page 54.
201.3.73
OPERATOR
Addition:
Note 101 to entry Usually equals to PATIENT for HEARING AIDS in a home healthcare environment.
201.3.76
PATIENT
Replacement:
Note 1 to entry: In this particular standard and in applying the requirements of the general standard, the term
PATIENT has the meaning explained in the second paragraph of 4.1 of the general standard. The PATIENT is also
usually the OPERATOR.
The term PATIENT is being used in this document in line with the general terminology in the medical product field. It
is, however, understood that the user of a HEARING AIDS is typically not an ill person but someone healthy with a
hearing impairment in a HOME HEALTHCARE ENVIRONMENT.
201.3.113
SERVICE PERSONNEL
Replacement:
individuals or entity that assemble, maintain or repair HEARING AIDS or HEARING AID SYSTEMS
201.3.132
TYPE B APPLIED PART
Replacement:
APPLIED PART complying with the specified requirements of this particular standard to provide
protection against electric shock, particularly regarding allowable PATIENT LEAKAGE CURRENT and
PATIENT AUXILIARY CURRENT
Addition:
201.3.201
HEARING AID PROFESSIONAL
audiologically competent person who professionally assesses hearing, selects, fits and delivers
HEARING AID systems and rehabilitation services to persons with hearing impairment
201.3.202
HEARING AID
ME EQUIPMENT which picks up sound and delivers processed sound to the ear canal through air-
conduction
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Note 1 to entry: A HEARING AID includes all detachable parts that are essential for the performance of its INTENDED
USE.
201.3.203
HEARING SYSTEM
HEARING AID SYSTEM
combination, as specified by its MANUFACTURER, of items of equipmen
...