oSIST prEN ISO 21388-1:2025
(Main)Acoustics - Hearing aid fitting management (HAFM) - Part 1: General process (ISO/DIS 21388-1:2025)
Acoustics - Hearing aid fitting management (HAFM) - Part 1: General process (ISO/DIS 21388-1:2025)
This document applies to hearing aid fitting management (HAFM) services offered by hearing aid professionals (HAP) when providing benefit for their clients. The provision of hearing aids relies on the knowledge and practices of a hearing aid professional, to ensure the proper fitting and adequate service in the interest of the client with hearing loss.
This document specifies general processes of HAFM from the client profile to the follow-up through administering, organising and controlling hearing aid fitting through all stages. It also specifies important preconditions such as education, facilities and systems that are required to ensure proper services.
The focus of this document is the services offered to the majority of adult clients with hearing impairment. It is recognized that certain populations with hearing loss such as children, persons with other disabilities or persons with implantable devices can require services outside the scope of this document. This document generally applies to air conduction hearing aids and for the most part also to bone conduction devices.
Hearing loss can be a consequence of serious medical conditions. Hearing aid professionals are not in a position to diagnose or treat such conditions. When assisting clients seeking hearing rehabilitation without prior medical examination, hearing aid professionals are expected to be observant of symptoms of such conditions and refer to proper medical care.
Further to the main body of the document, which specifies the HAFM requirements and processes, several informative annexes are provided. Appropriate education of hearing aid professionals is vital for exercising HAFM. Annex A defines the competencies required for the HAFM processes. Annex B offers a recommended curriculum for the education of hearing aid professionals. Annex C is an example of an appropriate fitting room. Annex D gives guidance on the referral of clients for medical or other specialist examination and treatment. Annex E is a recommendation for important information to be exchanged with the client during the process of HAFM. Annex F is a comprehensive terminology list offering definitions of the most current terms related to HAFM.
It is the intention that these annexes be helpful to those who wish to deliver HAFM of the highest quality.
Hörgeräteanpassungsmanagement (HAFM) - Teil 1: Allgemeiner Prozess
Dieses Dokument ist anwendbar für Dienstleistungen des Hörsystemanpassungsmanagements (HAFM), die von Hörakustikern (HAP, en: hearing aid professionals) angeboten werden, wenn sie Leistungen für ihre Kunden erbringen. Die Versorgung mit Hörgeräten beruht auf den praktischen Erfahrungen des Hörakustikers, um eine angemessene Anpassung und einen adäquaten Service im Interesse des Kunden mit Hörverlust sicherzustellen.
Dieses Dokument legt allgemeine Prozesse des HAFM von der Erstellung des Kundenprofils bis hin zur Nachsorge durch die Administration, Organisation und Kontrolle der Hörsystemanpassung über alle Stufen fest. Es legt darüber hinaus wichtige Voraussetzungen, wie z. B. die zur vorschriftsmäßigen Bereitstellung der betreffenden Dienste erforderlichen Ausbildungen, Einrichtungen und Anlagen, fest.
Dieses Dokument konzentriert sich auf die für die Mehrheit an erwachsenen Kunden mit eingeschränktem Hörvermögen angebotenen Dienstleistungen. Es bleibt anzumerken, dass für bestimmte Gruppen von Menschen mit Hörverlust, wie z. B. Kinder, Personen mit anderen Behinderungen oder Personen mit implantierbaren Systemen, Dienste erforderlich sein können, die außerhalb des Anwendungsbereichs dieses Dokuments liegen. Dieses Dokument gilt im Allgemeinen für Luftleitungshörgeräte und größtenteils auch für Knochenleitungshörgeräte.
Ein Hörverlust kann die Folge ernstzunehmender Krankheiten sein. Hörakustiker sind nicht dafür zuständig, derartige Krankheiten zu diagnostizieren oder zu behandeln. Wenn Hörakustiker Kunden betreuen, die die Rehabilitation ihres Hörvermögens wünschen, ohne sich vorher medizinisch untersuchen zu lassen, müssen sie auf Symptome derartiger Krankheiten achten und auf angemessene ärztliche Betreuung verweisen.
In Ergänzung zum Hauptteil dieses Dokuments, der die Anforderungen an das HAFM und die HAFM-Prozesse festlegt, enthält es mehrere informative Anhänge. Um das HAFM ausführen zu können, ist eine entsprechende Ausbildung zum Hörakustiker unerlässlich. Anhang A legt die für die HAFM-Prozesse erforderlichen Kompetenzen fest. Anhang B enthält die für die Ausbildung von Hörakustikern empfohlenen Lehrinhalte. Anhang C enthält ein Beispiel für einen geeigneten Anpassungsraum. Anhang D enthält einen Leitfaden für die Verweisung von Kunden an einen Arzt oder an sonstige Spezialisten zwecks entsprechender Untersuchung und Behandlung. Anhang E enthält Empfehlungen zu wichtigen, mit dem Kunden im Verlauf des HAFM auszutauschenden Informationen. Anhang F enthält eine umfassende Liste der maßgeblichen Terminologie mit Definitionen der meisten gegenwärtig im Zusammenhang mit HAFM verwendeten Begriffe.
Mit diesen Anhängen ist vorgesehen, Personen dabei zu unterstützen, ein HAFM mit höchster Qualität zu etablieren.
Acoustique - Gestion des appareils d'aide auditive (HAFM) - Partie 1: Processus général (ISO/DIS 21388-1:2025)
Le présent document s’applique aux services offerts par les audioprothésistes lorsqu’ils prennent en charge leurs clients. La délivrance des aides auditives s’appuie sur les connaissances et les pratiques d’un audioprothésiste afin d’assurer une bonne adaptation prothétique et un service adéquat dans l’intérêt du déficient auditif.
Le présent document spécifie les processus généraux de l’adaptation des aides auditives, depuis le profil du client jusqu’au suivi, en passant par toutes les étapes d’administration, d’organisation et de contrôle de l’adaptation des aides auditives. Il présente également les conditions préalables importantes telles que la formation, les installations, les équipements et les systèmes qui sont exigés pour assurer des services appropriés.
Le présent document concerne les services offerts à la majorité des clients adultes souffrant de troubles de l’audition. Il est reconnu que certaines populations de déficients auditifs, comme les enfants, les personnes souffrant d’autres handicaps ou les personnes porteuses d’implants, peuvent nécessiter d’autres services que ceux couverts par le domaine d’application du présent document. Le présent document s’applique généralement aux aides auditives en conduction aérienne et, pour la plupart, également aux aides auditives en conduction osseuse.
La déficience auditive peut être la conséquence de pathologies graves que les audioprothésistes ne sont pas en mesure de diagnostiquer ou de traiter. Lorsqu’ils aident des clients en quête d’une réhabilitation auditive sans examen médical préalable, les audioprothésistes sont censés identifier les symptômes de ces pathologies et orienter les malades vers les professionnels de santé appropriés.
Outre le corps principal du document, qui spécifie les exigences et processus d’adaptation des aides auditives, plusieurs annexes informatives sont fournies. Une formation appropriée des audioprothésistes est fondamentale pour assurer l’adaptation des aides auditives. L’Annexe A définit les compétences requises pour le processus d’adaptation des aides auditives. L’Annexe B propose un programme recommandé pour la formation des audioprothésistes. L’Annexe C montre un exemple de salle d’appareillage appropriée. L’Annexe D fournit des recommandations relatives à l’orientation des clients vers un autre spécialiste en vue d’un traitement et d’examens médicaux complémentaires. L’Annexe E présente les informations importantes qu’il est recommandé d’échanger avec le client pendant le processus d’adaptation des aides auditives. L’Annexe F est une liste terminologique complète offrant des définitions des termes les plus courants liés à l’adaptation des aides auditives.
L’objectif est que ces annexes soient utiles aux personnes désireuses d’assurer une gestion optimale du processus d’adaptation des aides auditives.
Akustika - Vodenje ustreznosti slušnih pripomočkov - 1. del: Splošni postopek (ISO/DIS 21388-1:2025)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2025
Akustika - Vodenje ustreznosti slušnih pripomočkov - 1. del: Splošni postopek
(ISO/DIS 21388-1:2025)
Acoustics - Hearing aid fitting management (HAFM) - Part 1: General process (ISO/DIS
21388-1:2025)
Acoustique - Gestion des appareils d'aide auditive (HAFM) - Partie 1: Processus général
(ISO/DIS 21388-1:2025)
Ta slovenski standard je istoveten z: prEN ISO 21388-1
ICS:
11.180.15 Pripomočki za gluhe osebe in Aids for deaf and hearing
osebe z okvaro sluha impaired people
17.140.01 Akustična merjenja in Acoustic measurements and
blaženje hrupa na splošno noise abatement in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
International
Standard
ISO/DIS 21388-1
ISO/TC 43
Acoustics — Hearing aid fitting
Secretariat: DIN
management (HAFM) —
Voting begins on:
Part 1: 2025-06-25
General process
Voting terminates on:
2025-09-17
ICS: 17.140.01; 11.020.10; 11.180.15
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
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This document is circulated as received from the committee secretariat.
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Reference number
ISO/DIS 21388-1:2025(en)
DRAFT
ISO/DIS 21388-1:2025(en)
International
Standard
ISO/DIS 21388-1
ISO/TC 43
Acoustics — Hearing aid fitting
Secretariat: DIN
management (HAFM) —
Voting begins on:
Part 1:
General process
Voting terminates on:
ICS: 17.140.01; 11.020.10; 11.180.15
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland Reference number
ISO/DIS 21388-1:2025(en)
ii
ISO/DIS 21388-1:2025(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Service preconditions . 4
4.1 General .4
4.2 Educational requirements .4
4.2.1 General .4
4.2.2 Requirements for hearing aid professionals .4
4.2.3 Maintenence of competencies and skills of hearing aid professionals .4
4.3 Facility requirements .5
4.3.1 General .5
4.3.2 Room requirements .5
4.4 Equipment requirements .5
4.4.1 General .5
4.4.2 Audiometric equipment .5
4.4.3 Equipment for otoscopy and earmould impressions .6
4.4.4 Hearing aid programming equipment .6
4.4.5 Electroacoustic measurement equipment .6
4.4.6 Maintenance tools .6
4.4.7 Demonstration samples .7
4.5 Ethical requirements .7
4.5.1 General .7
4.5.2 Professional competence .7
4.5.3 Relationship with clients .7
4.5.4 Conflict of interest .7
4.5.5 Relationship with medical and other health practitioners .7
4.5.6 Relationship with colleagues .8
4.5.7 Advertising .8
5 General stages of HAFM . 8
5.1 General .8
5.2 Client profile .9
5.2.1 General .9
5.2.2 General assessment.9
5.2.3 Audiological assessment.10
5.2.4 Medical referral .11
5.3 Counselling.11
5.3.1 General .11
5.3.2 Selection of hearing aid system .11
5.4 Hearing aid fitting .11
5.4.1 Ear coupling elements .11
5.4.2 Pre-setting of hearing aids . 12
5.4.3 Setting and fine-tuning of hearing aids . 12
5.5 Verification and validation . 12
5.6 Post-fitting counselling . 13
5.7 Follow-up . 13
6 Quality of service . 14
6.1 General .14
6.2 Documentation .14
6.3 Client evaluation of services . . 15
6.4 Customer complaint handling . 15
6.5 Corrective actions . . 15
iii
ISO/DIS 21388-1:2025(en)
Annex A (informative) Minimum competencies of the hearing aid professional (HAP) .16
Annex B (informative) Recommendation for organisation of education and training for hearing
aid professionals (ISCED level 5) . 19
Annex C (informative) Fitting room example .21
Annex D (informative) Recommendation on the referral of clients for medical
or other specialist examination and treatment .23
Annex E (informative) Informational counselling to support hearing aid fitting management .24
Annex F (informative) Terminology .27
Bibliography .40
iv
ISO/DIS 21388-1:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent
rights identified during the development of the document will be in the Introduction and/or on the ISO list of
patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 43, Acoustics.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO/DIS 21388-1:2025(en)
Introduction
The World Health Organisation (WHO) estimates that there are 360 million people with hearing
[22]
impairment, approximately 5,3 % of the world population. Hearing aids (HAs) are one of the most widely-
[39][40]
used treatment options for people with a hearing loss. For the proper use of HAs, hearing aid fitting
management (HAFM) is a crucial issue for manufacturers, practitioners, hearing aid professionals and
[39][42][43]
especially for HA users. Individually optimized outcome of HA use is supported by comprehensive
[42] [43]
HA fitting protocols and the impact of “poor fit and comfort” can lead to non-compliance, HA return
and additional hearing loss with over-amplification. Accordingly, the whole process of HA fitting should be
optimized to achieve functional benefits, user satisfaction and cost-effectiveness.
Two observations are important to take into account when developing an HAFM standard. Firstly, the term
[16][44]–[46]
"hearing aid fitting" is widely used among service providers and industry sectors. Secondly, it
has potentially conflicting interpretations: while guidelines for HA fitting have been written to tackle these
[17][18][23]–[32][34]–[37][47][48]
issues by various national and professional bodies, many jurisdictions are still
not covered worldwide and there is a need to promote a more common understanding of the HA fitting
process. It is likely that different understanding of fitting has led to non-uniform care, outcome variability
and, in many cases, dissatisfaction with the use of HAs.
The main purpose of this document is thus to provide a general framework for HAFM including the pre- and
post-fitting stages to make it more explicit and transparent so that all related tasks, including professional
services, administration and financial aspects can be systematized. The overall objective is to achieve the
best possible hearing rehabilitation, which can only be accomplished through adequate knowledge, training
and skills of the professional and a systematic approach to HA fitting in close collaboration with the client.
The general framework of HAFM in this document is divided into six stages (client profile, counselling,
hearing aid fitting, verification and validation, post-fitting counseling, and follow-up) based on the common
practices of hearing aid professionals, and as recommended by various pre-existing guidelines.
By dividing the hearing aid fitting process into stages, HAFM service providers can systematically identify
and administer the service components needed for high service quality, user satisfaction, client-centered
services, client self-efficacy and compliance rates with HAs (e.g. consistently using HAs and attending follow-
up appointments). The stages focus on the components of the framework to achieve high rehabilitation
outcomes such as communication skills, speech intelligibility, perception of the acoustic environment,
comfort for the HA users and sound quality. In addition, this document can be a basis for making cost
assessments for each stage or component, which can help improve public health funding systems. Another
possible application is to use this document as a minimum basis for the development of professional training
programs in HAFM.
vi
DRAFT International Standard ISO/DIS 21388-1:2025(en)
Acoustics — Hearing aid fitting management (HAFM) —
Part 1:
General process
1 Scope
This document applies to hearing aid fitting management (HAFM) services offered by hearing aid
professionals (HAP) when providing benefit for their clients. The provision of hearing aids relies on the
knowledge and practices of a hearing aid professional, to ensure the proper fitting and adequate service in
the interest of the client with hearing loss.
This document specifies general processes of HAFM from the client profile to the follow-up through
administering, organising and controlling hearing aid fitting through all stages. It also specifies important
preconditions such as education, facilities and systems that are required to ensure proper services.
The focus of this document is the services offered to the majority of adult clients with hearing impairment.
It is recognized that certain populations with hearing loss such as children, persons with other disabilities
or persons with implantable devices can require services outside the scope of this document. This document
generally applies to air conduction hearing aids and for the most part also to bone conduction devices.
Hearing loss can be a consequence of serious medical conditions. Hearing aid professionals are not in a
position to diagnose or treat such conditions. When assisting clients seeking hearing rehabilitation without
prior medical examination, hearing aid professionals are expected to be observant of symptoms of such
conditions and refer to proper medical care.
Further to the main body of the document, which specifies the HAFM requirements and processes, several
informative annexes are provided. Appropriate education of hearing aid professionals is vital for exercising
HAFM. Annex A defines the competencies required for the HAFM processes. Annex B offers a recommended
curriculum for the education of hearing aid professionals. Annex C is an example of an appropriate fitting
room. Annex D gives guidance on the referral of clients for medical or other specialist examination and
treatment. Annex E is a recommendation for important information to be exchanged with the client during
the process of HAFM. Annex F is a comprehensive terminology list offering definitions of the most current
terms related to HAFM.
It is the intention that these annexes be helpful to those who wish to deliver HAFM of the highest quality.
2 Normative references
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.
ISO 8253-1, Acoustics — Audiometric test methods — Part 1: Pure-tone air and bone conduction audiometry
ISO 8253-2, Acoustics — Audiometric test methods — Part 2: Sound field audiometry with pure-tone and
narrow-band test signals
ISO 8253-3, Acoustics — Audiometric test methods — Part 3: Speech audiometry
IEC 60118-7, Electroacoustics — Hearing aids — Part 7: Measurement of the performance characteristics of
hearing aids for production, supply and delivery quality assurance purposes
ISO/DIS 21388-1:2025(en)
IEC 60645-1:2017, Electroacoustics — Audiometric equipment — Part 1: Equipment for pure-tone and speech
audiometry
IEC 60645-5, Electroacoustics — Audiometric equipment — Part 5: Instruments for the measurement of aural
acoustic impedance/admittance
IEC 61669, Electroacoustics — Measurement of real-ear acoustic performance characteristics of hearing aids
International Standard Classification of Education, ISCED. United Nations Educational, Scientific and Cutural
Oganization, 2011, ISBN 978-92-9189-123-8, https:// uis .unesco .org/ sites/ default/ files/ documents/
international -standard -classification -of -education -isced -2011 -en .pdf
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
auditory dynamic range
difference between the hearing (3.7) threshold and the uncomfortable loudness level (UCL)
3.2
client
person with hearing loss (3.8) being serviced by a HAP (3.13)
3.3
client profile
comprehensive record of a client's (3.2) auditory functionality, social situation, activity opportunities, needs
and expectations as well as a client’s audiological and medical history
3.4
ear impression
representation of the three-dimensional geometry of the relevant part of the concha and ear canal
3.5
fine-tuning
adjustment of the hearing aid system (3.10) to best match the needs and preferences of the client (3.2)
3.6
fitting system
set of devices typically comprising a computer, fitting software and a programming interface used to adjust
hearing aids (3.9)
3.7
hearing
manner in which a person detects, discriminates, identifies and cognitively processes sounds
3.8
hearing loss
reduction of the hearing (3.7) ability
3.9
hearing aid
wearable electroacoustic instrument intended to process sounds in order to compensate for hearing loss (3.8)
Note 1 to entry: Hearing aids are medical devices and comply with the requirements of IEC 60601-2-66.
ISO/DIS 21388-1:2025(en)
3.10
hearing aid system
customized structure consisting of one or two hearing aids (3.9), earmoulds and related components such as
a remote control or interfaces to other information or communication systems
3.11
hearing aid fitting
systematic procedure for individualizing and optimizing a hearing aid system (3.10) to compensate for
hearing loss (3.8)
3.12
hearing aid fitting management
HAFM
systematic process to administer, organise and control hearing aid fitting (3.11) through all stages
3.13
hearing aid professional
HAP
person who is appropriately trained and has proven competency in professionally assessing hearing,
selecting, fitting and delivering hearing aid systems (3.10) and rehabilitation services to persons with
hearing loss (3.8)
3.14
hearing rehabilitation
systematic process for improving functional hearing abilities and communication skills through hearing aid
fitting (3.11), counselling, instruction, education, training and developing listening skills
Note 1 to entry: The term “habilitation” includes all rehabilitation processes with additional interventions to develop
listening, speech and language skills for prelingually deafened individuals such as children which are outside the
scope of this document.
3.15
maximum output
maximum sound pressure level at the output of a hearing aid (3.9) as adjusted by the HAP (3.13)
3.16
pre-setting of hearing aids
configuration and adjustment of a hearing aid (3.9) using a prescriptive rule and relevant audiological data
3.17
verification
provision of objective evidence that a given item fulfils specified requirements
Note 1 to entry: In the field of hearing aid fitting (3.11), the verification usually means evaluating physical,
electroacoustic and psycho-acoustic aspects of a hearing aid fitting by presenting signals to hearing aids (3.9) in a
hearing aid test box or a real-ear or by using functional gain measurement in accordance with ISO 8253-2.
[SOURCE: ISO/IEC Guide 99:2007, 2.44, modified - Examples removed, original Notes to entry replaced with
Note 1 to entry.]
3.18
validation
verification (3.17), where the specified requirements are adequate for an intended use
Note 1 to entry: In the field of hearing aid fitting (3.11), the verification usually means a comprehensive evaluation
of the user benefits of a hearing aid fitting using methods which include speech audiometry and subjective response
questionnaires.
[SOURCE: ISO/IEC Guide 99:2007, 2.45, modified - Example removed, Note 1 to entry added.]
ISO/DIS 21388-1:2025(en)
4 Service preconditions
4.1 General
For quality service provision, the following preconditions shall be fulfilled:
— educational requirements;
— facility requirements;
— equipment requirements;
— ethical requirements.
Further preconditions are given by local applicable laws and regulations.
4.2 Educational requirements
4.2.1 General
The competencies of persons delivering the service are essential to the quality of service and should be
rooted in appropriate education from recognized educational institutions and organisations as well as
relevant practical skills obtained in a structured process. Ongoing education is required as it is vital to
maintaining the competencies, skill levels and knowledge needed for best practice.
In general, delegation of tasks to staff without the required education should not be permitted. More than
one type of staff can perform certain tasks in accordance with their specific educational background
following national or regional regulations. The overall responsibility of the service provision shall rest with
a HAP with the education specified in 4.2.2.
In order to facilitate the acquisition of practical skills, practices may include trainees from educational
programs in their staff. Services performed by trainees shall take place under the supervision of a qualified
HAP who shall be present at the facilities and who remains responsible for all activities carried out by the
trainee.
4.2.2 Requirements for hearing aid professionals
A minimum education level 5 according to the International Standard Classification of Education, ISCED, or
equivalent is required in order to perform all stages of hearing aid fitting management. A level 6 education
is recommended.
It is recommended that the educational program includes the following academic topics: basic mathematics
and science including acoustics, anatomy and physiology, psychology and linguistics, audiology, hearing aid
technology, hearing rehabilitation processes, hearing aid fitting.
The following practical skills should be obtained through training: client interaction, audiometric
measurements, earmould management, hearing aid programming, fitting verification and validation,
hearing aid modification and repair.
Suggestions for minimum competencies of the HAP and a suitable education program are given in Annexes A
and B, respectively.
Any HAP shall have proven minimal competencies through testing in order to practice independently.
NOTE It is recognized that developing countries sometimes do not readily have access to this level of education.
4.2.3 Maintenence of competencies and skills of hearing aid professionals
Hearing aid professionals shall receive ongoing education to maintain the competencies and increase skill
levels. Ten hours annually is the minimum, 20 hours or more is recommended.
ISO/DIS 21388-1:2025(en)
Ongoing education can be acquired in multiple ways such as: in-class training, conferences, manufacturer’s
courses, e-learning, webinars and other recognized sources.
4.3 Facility requirements
4.3.1 General
Facilities for hearing aid provision should be of sufficient size to facilitate reception of clients, hearing
assessment, hearing aid provision, and maintenance of hearing devices. The facilities shall have a size that
can accommodate the clinician, the client and at least one accompanying person. Facilities shall be clean,
safe and readily accessible for persons with disabilities. Facilities should also have access to running water
and toilets. The practice should be clearly identifiable and provide access to contact via telephone, SMS, fax,
website or email. Hours of operation should be publicly accessible.
Facilities for the cleaning and disinfection of equipment shall be available. Moreover, hand washing facilities
and containers for the disposal of single use (and potentially contaminated) items should also be provided.
4.3.2 Room requirements
Any consultation area shall be sufficiently private so that any other persons within the facility are not able
to overhear conversations taking place. In addition, an appropriate ventilation and temperature control
sould be considered, since sound treated rooms can become warm and unpleasant.
Audiometric testing rooms/areas shall comply with maximum ambient noise levels in accordance with
ISO 8253-1, and ISO 8253-3, to allow threshold levels to be measurable down to 20 dB HL for air conduction,
and 30 dB HL for bone conduction. If it is desired to do sound field audiometry, the ambient noise levels
shall be in accordance with ISO 8253-2 for measurable threshold levels down to 20 dB HL. Fitting areas also
require a controlled acoustic environment where:
— the reverberation time should be less than 0,5 s at 500 Hz;
— the equivalent A-weighted sound pressure level of the ambient noise shall be less than 45 dB under usual
operating conditions averaged over at least 30 s;
The 30 s measurement period shall be representative of the steady-state ambient noise in the fitting
area. If a longer measurement period leads to a different result, the averaging time shall be increased.
— no dominant pure-tone components are in the ambient noise;
2 3
— the minimum floor surface area is 10 m and the minimum volume is 25 m .
An example of a fitting room is shown in Annex C.
4.4 Equipment requirements
4.4.1 General
In order to provide quality services, a range of equipment is required. The equipment cited below is
considered the minimum requirement. All equipment shall be specific to the functions required and fit for
purpose.
4.4.2 Audiometric equipment
For pure-tone audiometry, an audiometer shall be used for testing of air-conduction and bone-conduction
thresholds using masking when required. The audiometer can be part of an integrated system with multiple
functional modes. A pure-tone audiometer can also be used for measurement of the most comfortable
loudness level (MCL) and uncomfortable loudness level (UCL).
The audiometer shall be a pure-tone audiometer of Type 1 or Type 2 as specified in IEC 60645-1:2017.
ISO/DIS 21388-1:2025(en)
The performance of this equipment shall be checked and calibrated according to ISO 8253-1.
For speech audiometry, equipment fulfilling the requirements of IEC 60645-1 shall be available. Power
amplifier and loudspeaker shall be available if sound field speech audiometry is performed. The performance
of this equipment shall be checked and calibrated according to ISO 8253-3.
The maximum interval between objective periodical checks of the audiometric equipment shall not exceed
12 months. National or regional legislation can call for more frequent checks.
A tympanometer is recommended for impedance measurements to identify possible causes of conductive
hearing loss and possible reasons for referral. The performance of this equipment shall be checked and
calibrated according to IEC 60645-5.
4.4.3 Equipment for otoscopy and earmould impressions
For inspection of the ear-canal and tympanic membrane, an otoscope with ear specula of different sizes shall
be available. Equipment for taking ear impressions shall also be available. For impression taking by moulding
techniques the following shall be available: moulding syringes or moulding gun with suitable compounds
for making earmould impressions; otoblock/cotton dam; hygiene products for hands and equipment. Ear
impressions can also be taken by means of ear scanning systems.
4.4.4 Hearing aid programming equipment
A computer system with suitable hardware and software for hearing aid programming and storing of
relevant client and fitting data shall be available.
4.4.5 Electroacoustic measurement equipment
Electroacoustic equipment for measuring hearing aid characteristics on an acoustic coupler or ear simulator
(gain, output level, distortion, induction pick-up coil sensitivity, etc.) in accordance with IEC 60118-7 shall be
available.
Equipment for in-situ measurement of real-ear acoustical characteristics of hearing aids fulfilling the
requirements of IEC 61669 shall be available. The International Speech Test Signal (ISTS) as defined by
IEC 60118-15 should be available for in-situ measurements.
A sound calibrator can be useful for in-practice calibration and checks of acoustic equipment.
It is recommended that the intervals between calibrations of electroacoustic measurement equipment do
not exceed twelve months.
4.4.6 Maintenance tools
Tools and accessories required depend on the services offered. The following equipment is recommended
for maintenance of hearing aid systems:
— tools for drilling and polishing;
— ultrasonic bath;
— set of screwdrivers, pliers and scalpel;
— scissors, forceps, disinfectant, sound tubes;
— picks and brushes;
— stethoscopic listening device;
— binocular magnifying glass or illuminated magnifying glass;
— vacuum pump, compressor or aerosol.
ISO/DIS 21388-1:2025(en)
4.4.7 Demonstration samples
For demonstration of products, a selection of hearing aids, accessories and other assistive hearing devices
should be available. Wireless connectivity devices such as wireless remote microphone systems (WRMS),
TV-streamers, etc. should be part of the selection of accessories. An induction loop can also be useful for
demonstration of telecoils.
4.5 Ethical requirements
4.5.1 General
The HAP shall always work with the goal of achieving the best possible solution for the client.
4.5.2 Professional competence
HAPs shall practice only within their scope of training, experience and competence. They should engage in
the provision of hearing health care that represents the prevailing standard of practice and shall participate
in a regular program of ongoing education.
Annex A gives a detailed suggestion for minimum competencies of the HAP.
4.5.3 Relationship with clients
In all dealings with clients, the HAP shall be respectful and keep all personal information gathered private
and confidential.
The HAP shall treat clients with respect, honesty and not abuse or exploit the client psychologically, sexually,
physically or financially.
4.5.4 Conflict of interest
The HAP is entitled to reasonable compensation for services to or on behalf of clients. The HAP shall not
engage in practices and financial arrangements influencing decisions in the best interest of the clients. The
HAP shall receive compensation only for services actually rendered to the client and not receive or pay a fee
for making a referral. The HAP shall refrain from competition adverse arrangements that infringe the ethics
of the profession. This includes collusion with medical practitioners, hearing aid manufacturers or other
third-party health care professionals resulting in circumvention of normal competitive conditions.
When a HAP makes a written or oral public statement concerning a product of a company from which they
receive compensation, or a company which holds a significant equity position in the practice or a company
which they hold a significant equity position in, the HAP shall disclose the financial relationship with that
company.
4.5.5 Relationship with medical and other health practitioners
Hearing aid professionals shall represent themselves and their credentials to the public in a truthful and
honest fashion. A HAP should cooperate and communicate with other health care professionals in order to
provide the best care possible to clients.
When a HAP recognises that communication and/or hearing problems can be caused by medical conditions
that require medical treatment, they shall refer to an appropriate medical practitioner. Annex D gives
guidance on indications that lead to a medical referral and how to interact with clients in these situations.
The HAP shall undertake to make available to the physician and other involved service providers all
necessary and relevant documentation with consent of the client.
ISO/DIS 21388-1:2025(en)
4.5.6 Relationship with colleagues
A HAP shall refrain from unjustifiable criticism of colleagues' judgement, training, knowledge or skills.
A HAP shall not knowingly ignore professional misconduct or incompetence and shall report it to their
superior, professional college or applicable authority.
4.5.7 Advertising
A HAP often advertises their services. The requirements related to such advertising are given in applicable
national or regional directives and legislation.
5 General stages of HAFM
5.1 General
The stages of HAFM shall be performed by a hearing aid professional, to ensure the best possible outcome
and adequate service in the interest of the client. These stages cover assessment of the client's needs and
degree of hearing loss followed by the selection and fitting of suitable hearing aids, rehabilitation and short
and long-term monitoring and support.
Hearing aid fitting shall consist of the delivery of the hearing aids, the fitting process and the related care.
The efficacy of the hearing aid system depends on the type of device chosen, its fitting, the counselling and
the follow-up.
Initially, the general process of HAFM shall be explained to the client, including the financial aspects. During
the entire fitting process, decisions shall be made in a close dialogue with the client after counselling by the
HAP (informed consent).
Annex E gives a comprehensive set of suggestions for how to communicate with the client in accordance
with the principles of person centered care.
The HAP shall pay particular attention to clients with no previous experience in using hearing aids.
The general framework of HAFM consists of six stages, as depicted in Figure 1: client profile, counselling,
hearing aid fitting, verification and validation, post-fitting counselling and follow-up. This general framework
includes all the necessary activities for best practice HAFM. The stages are listed in non-chronological order.
The client may pass through these stages in a different order, with an overlapping with other stages, or
multiple times due to an iterative approach.
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