prEN ISO 17651-4

SLOVENSKI STANDARD
01-februar-2026
Simultano tolmačenje - Delovno okolje tolmačev - 4. del: Zahteve in priporočila za
tolmačenje znakovnega jezika (ISO/DIS 17651-4:2025)
Simultaneous interpreting - Interpreters’ working environment - Part 4: Requirements and
recommendations for signed language interpreting (ISO/DIS 17651-4:2025)
Simultandolmetschen - Arbeitsumfeld des Dolmetschers - Teil 4: Anforderungen an und
Empfehlungen für das Gebärdensprachdolmetschen (ISO/DIS 17651-4:2025)
Interprétation simultanée - Environnement de travail des interprètes - Partie 4: Exigences
et recommandations pour l’interprétation en langue des signes (ISO/DIS 17651-4:2025)
Ta slovenski standard je istoveten z: prEN ISO 17651-4
ICS:
91.040.10 Javne stavbe Public buildings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 17651-4
ISO/TC 37/SC 5
Simultaneous interpreting —
Secretariat: DIN
Interpreters’ working
Voting begins on:
environment —
2026-01-01
Part 4:
Voting terminates on:
2026-03-26
Requirements and
recommendations for signed
language interpreting
ICS: 91.040.10
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Reference number
ISO/DIS 17651-4:2026(en)
DRAFT
ISO/DIS 17651-4:2026(en)
International
Standard
ISO/DIS 17651-4
ISO/TC 37/SC 5
Simultaneous interpreting —
Secretariat: DIN
Interpreters’ working
Voting begins on:
environment —
Part 4:
Voting terminates on:
Requirements and
recommendations for signed
language interpreting
ICS: 91.040.10
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 2026
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 17651-4:2025(en)
ii
ISO/DIS 17651-4:2025(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 General requirements . 3
4.1 Workspaces.3
4.2 Siting & visibility .4
4.3 Accessibility .4
4.4 Technical control and technical support staff .5
4.5 Support services . .5
4.6 Fire safety and evacuation .5
5 Equipment for all workspaces . 6
5.1 Lighting .6
5.2 Backdrop .6
5.3 Visual display .6
5.4 Camera and pre-sets .7
5.5 Incoming sound .7
5.6 Whiteboard . .8
6 On the floor . 8
6.1 Allocation of workspaces .8
6.2 Meeting hall .8
6.2.1 Interpreters' view .8
6.2.2 Placement .8
6.2.3 Equipment .8
6.3 Conference hall .8
6.3.1 General requirements .8
6.3.2 Interpreters' view .9
6.3.3 Placement .9
6.3.4 Workspace facing the audience . 13
6.3.5 Workspace facing the rostrum . 13
6.3.6 Equipment . 13
7 Signed language interpreting booth . 14
7.1 General requirements .14
7.2 Dimensions . 15
7.3 Interpreter's view and placement .17
7.4 Booth interior .18
7.4.1 Temperature control .18
7.4.2 Equipment .18
7.4.3 Electricity supply .19
7.4.4 Internet access .19
8 From a hub . 19
8.1 General requirements .19
8.2 Interpreter's view . 20
9 Amenities for interpreters .20
9.1 Toilets . 20
9.2 Interpreters' room . 20
Annex A (informative) Simplified checklists .21
Annex B (informative) Flowchart .22
Annex C (informative) Workspace placements in meeting halls .23

iii
ISO/DIS 17651-4:2025(en)
Annex D (informative) Workspace placements in conference halls .24
Annex E (informative) Layout of visual displays .28
Annex F (informative) Broadcast image .32
Bibliography .35

iv
ISO/DIS 17651-4:2025(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 on 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 the following URL: www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 37, Language and terminology, Subcommittee
SC 5, Translation, Interpreting and related technology. The ISO/IEC Guide 71:2014 is used to develop an
accessible standard in consultation with key stakeholders.
A list of all parts in the ISO 17651 series can be found on the ISO website.
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 17651-4:2025(en)
Introduction
This document concerns the logistical and technical equipment requirements and recommendations for the
working environment of signed language interpreters.
Interpreting services can be provided at a communicative event where the interpreter is at the same
or a different location as speakers, signers, participants, the audience, or other interpreters. In both
cases technical support is needed. Signed and spoken language interpreters interpreting at the same
communicative event interact and collaborate with each other. As signed languages are expressed and
perceived in the visual-manual modality, interpreting into and from a signed language requires a working
environment that facilitates this. Measures need to be taken to provide the signed language interpreter with
the required audio-visual input, and an unobstructed view of the communicative event, depending on the
location of the interpreter in relation to the speaker or signer, participant, audience and other interpreters.
Signed language interpreters interpret in various workspaces, depending on:
[1]
— the type of setting such as conference interpreting (ISO 23155 ), community interpreting (ISO 13611
[2] [3] [4]
), healthcare interpreting (ISO 21998 ), legal interpreting (ISO 20228 );
— the layout of the room where the communicative event takes place, such as
— either a dedicated signed language interpreting booth, a dedicated workspace for signed language
interpreting on the floor, or both
— or at a distance from a signed language interpreting booth in an interpreting hub.
This document addresses the following:
a) workspace requirements specific to signed language interpreters;
b) visual communication between interpreters and participants at an event;
c) teamwork among interpreters and among interpreters and technical support staff;
d) technical requirements and dedicated technical support;
e) dimensions and design of a dedicated signed language interpreting booth;
f) a working environment that minimises factors contributing to cognitive load, recognising that
interpreting demands sustained high levels of concentration.
This document complements the existing Parts (1-3) of the ISO 17651 series; these set out the essential
requirements for simultaneous interpreting: Part 1: Requirements and recommendations for permanent booths,
Part 2: Requirements and recommendations for mobile booths, Part 3: Requirements and recommendations for
interpreting hubs and this fourth part details comprehensively the relevant requirements for the workspaces
of signed language interpreters.

vi
DRAFT International Standard ISO/DIS 17651-4:2025(en)
Simultaneous interpreting — Interpreters’ working
environment —
Part 4:
Requirements and recommendations for signed language
interpreting
1 Scope
This document specifies the logistical and technical equipment requirements and recommendations for
the working environments of signed language interpreters. This document also ensures the usability and
accessibility of workspaces of signed language interpreters.
It draws from, and adds to, the existing standards on interpreters’ working environment, interpreting
[5]
equipment, simultaneous interpreting delivery platforms and conference equipment ISO 17651-1 ,
[6] [7] [8] [9] [10]
ISO 17651-2 , ISO/FDIS 17651-3 , ISO 20109 , ISO 24019 and ISO 22259 .
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 9241-20, Ergonomics of human-system interaction — Part 20: An ergonomic approach to accessibility within
the ISO 9241 series
ISO 9241-303, Ergonomics of human-system interaction — Part 303: Requirements for electronic visual displays
ISO 9241-303:2011, Ergonomics of human-system interaction — Part 303: Requirements for electronic visual
displays
ISO 17069:2020, Accessible design — Consideration and assistive products for accessible meeting
ISO 17069, Accessible design — Consideration and assistive products for accessible meeting
ISO 17651-1, Simultaneous interpreting — Interpreters’ working environment — Part 1: Requirements and
recommendations for permanent booths
ISO 17651-1:2024, Simultaneous interpreting — Interpreters’ working environment — Part 1: Requirements
and recommendations for permanent booths
ISO/FDIS 17651-3, Simultaneous interpreting — Interpreters’ working environment — Part 3: Requirements
and recommendations for interpreting hubs
ISO 20109:2025, Simultaneous interpreting — Equipment — Requirements
ISO 20109, Simultaneous interpreting — Equipment — Requirements
ISO 21542:2021, Building construction — Accessibility and usability of the built environment
ISO 21542, Building construction — Accessibility and usability of the built environment
ISO 22259:2019, Conference systems — Equipment — Requirements

ISO/DIS 17651-4:2025(en)
ISO 24019, Simultaneous interpreting delivery platforms — Requirements and recommendations
ISO 24019:2022, Simultaneous interpreting delivery platforms — Requirements and recommendations
ISO 24019:2022, Simultaneous interpreting delivery platforms — Requirements and recommendations
IEC 60118-4, Electroacoustics - Hearing aids - Part 4: Induction-loop systems for hearing aid purposes - System
performance requirements
IEC 60268-4:2018, Sound system equipment - Part 4: Microphones
IEC 62489-1, Electroacoustics - Audio-frequency induction loop systems for assisted hearing - Part 1: Methods of
measuring and specifying the performance of system components
EN ISO 22259:2021, Conference systems - Equipment - Requirements (ISO 22259:2019)
EN 1335-1, Office furniture - Office work chair - Part 1: Dimensions - Determination of dimensions
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 http:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
interpreter
person who interprets
[11]
[SOURCE: ISO 20539:2023 , 3.1.13]
3.2
interpreting
interpretation
rendering spoken or signed information from a source language into a target language in spoken or signed
form, conveying both the meaning and language register of the source language content
[11]
[SOURCE: ISO 20539:2023 , 3.1.11]
3.3
signed language
language which uses a combination of hand shapes, orientation and movement of the hands, arms or body,
and facial expressions
[11]
[SOURCE: ISO 20539:2023 , 3.1.7]
3.4
signed language interpreting
interpreting (3.2) between two signed languages (3.3) or between a signed language and a spoken language
[11]
[SOURCE: ISO 20539:2023 , 3.4.3]
3.5
simultaneous interpreting
mode of interpreting (3.2) performed while a speaker or signer is still speaking or signing
[11]
[SOURCE: ISO 20539:2023 , 3.4.12]

ISO/DIS 17651-4:2025(en)
3.6
booth
simultaneous interpreting booth
self-contained unit enclosing the interpreter’s (3.1) workspace
Note 1 to entry: One of the purposes of booths is to provide insulation, both from the noise transmitted from the
booth's external environment into the booth itself and vice versa, and from noise passing from one booth to another.
[11]
[SOURCE: ISO 20539:2023 , 3.5.2.1]
3.7
video display
electronic device which represents information in a visual form
[11]
[SOURCE: ISO 20539:2023 , 3.5.2.43]
3.8
overlay
substitution of part of an image by another image
[11]
[SOURCE: ISO 20539:2023 , 3.5.2.44]
3.9
accessibility
extent to which products, systems, services, environments and facilities can be used by people from a
population with the widest range
[12]
[SOURCE: ISO 9241-112:2025 , 3.11, modified - "of user needs, characteristics and capabilities to achieve
identified goals in identified contexts of use" deleted at the end of the definition; Note 1 to entry deleted]
3.10
communicative event
encounter between two or more parties during which information is transmitted
[11]
[SOURCE: ISO 20539:2023 , 3.4.32]
4 General requirements
4.1 Workspaces
Signed language interpreters interpret in diverse settings based on the nature and configuration of each
communicative event. All workspaces shall provide adequate conditions, including:
— uninterrupted incoming sound;
— clear lighting;
— unobstructed view of the room and the visual resources;
— physical comfort.
Appropriate logistical and technical arrangements shall be made to meet the above requirements.
Workspaces for signed language interpreters can be:
— a dedicated space on the floor where the communicative event is held;
— a signed language interpreting booth at the venue where the communicative event is held;
— a signed language interpreting booth in an interpreting hub.

ISO/DIS 17651-4:2025(en)
When providing signed language interpreting services at a communicative event, organisers and service
providers shall ensure accessibility support in accordance with ISO 17069.
The logistical and technical setup shall enable all signed and spoken language interpreters at the same
communicative event to collaborate with each other from their respective workspaces.
When designing new rooms or renovating existing ones, workspaces for interpreters — either a booth, a
workspace on the floor, or both — shall be integrated into the structure so that the room itself and the
workspaces and interpreting booths constitute a well-balanced unit in terms of layout, people flow within
buildings, accessibility and usability in accordance with ISO 21542.
Workspaces for interpreters in a shared physical space with participants shall be clearly visible, free of
visual obstructions (see 4.2) and located away from extraneous sources of disturbance, such as kitchens,
public corridors and passageways. The workspaces shall not be placed in front of a window or an area that
produces a bright backlight.
In order to facilitate speech intelligibility, the room should not cause reverberation or echoes exceeding the
[13]
values recommended for the type of room in accordance with AS/NZS 2107 .
[13]
NOTE AS/NZS 2107 also specifies methods of measuring the background sound level and the reverberation
time in unoccupied spaces.
Technical advisors and spoken or signed language interpreters with expert knowledge of workspaces for
interpreters and related equipment, qualified technicians or suppliers shall be consulted for the design and
operation.
4.2 Siting & visibility
Signed language interpretation involves visual interaction with signing participants. When signers are
present, signed to spoken language interpretation shall be provided from the interpreter workspace on
the floor where the communicative event is held (4.1). Additionally, a second signed language interpreting
team can provide interpretation into a signed language from a dedicated sign language interpreting booth
(Clause 7). The signed language interpretation can be broadcast to either screens in the same hall and venue,
or publicly, or both.
Visual cooperation between the interpreters in the signed language interpreting team(s) is essential for
teamwork; therefore there shall be no visual obstructions between the lines of sight of the interpreters,
speakers, signers, participants, the audience, or other interpreters, nor between the workspaces of the
interpreting teams.
4.3 Accessibility
It shall be possible to quickly, easily and safely access:
— the dedicated signed language interpreting workspaces on the floor;
— one booth from another booth;
— all booths from inside or outside the room.
A minimum of 10 % of the booths, rounded up to the next whole number, shall be accessible to persons with
a disability, in accordance with ISO 21542.
An individual induction loop shall be installed in the room and the dedicated signed language interpreting
booth, and shall comply with IEC 60118-4 and IEC 62489-1.
Live captions provide access to the spoken language in text format and should be provided when requested
by the interpreters.
ISO/DIS 17651-4:2025(en)
4.4 Technical control and technical support staff
In settings where technical equipment for signed language interpreters is used, specifically trained technical
[14]
support staff shall assist and monitor the interpreter's work system (see ISO 6385 ) to:
— check the set-up of the dedicated interpreting workspaces, including the required equipment such as
cameras, lighting, backdrop, audio and audio receivers (see 7.4);
— align the dedicated lighting on the interpreter to the light in the room (see 5.1 and 7.4.2.2);
— demarcate and block off the dedicated interpreting workspace on the floor, for example with the use of a
stanchion;
— adjust or pre-set the height, zoom and framing of the camera for each of the interpreting team members;
— demonstrate and explain to the interpreting team the use of a pre-set camera control panel, if provided
(see 7.4.2.5);
— send the input to the broadcasters to display the broadcast image of the signed language interpreter,
such as on television, webcast and app streaming.
The technical controls shall be placed close to the interpreting workspaces so that:
— technical support staff can access them easily;
— visual communication between the technical support staff and the interpreters is possible;
— technical support staff have a clear view of the entire room, including the rostrum, speakers, signers and
all visual aids such as projection screens and displays.
The technical control should be installed:
— on a table;
— in a rack;
— or in a booth that conforms to the requirements and recommendations for a permanent booth or a mobile
[5] [6]
booth for simultaneous interpreting in accordance with ISO 17651-1 or ISO 17651-2 .
If not present in the room, a central technical control shall be available in the venue.
Interpreters shall be able to communicate directly with the technical support staff, who shall have safe,
quick, and easy access to the interpreter workspaces and the room.
NOTE In technically complex settings it has proven to be useful to have the presence of dedicated technical
support staff for the signed language interpreting team.
4.5 Support services
Signed language interpreters are unable to hold and handle documents whilst interpreting into a signed
language. Consequently, to conduct the required preparation, the event organizers shall provide signed
language interpreters with all relevant documentation prior to the start of the event.
4.6 Fire safety and evacuation
Fire safety evacuation maps and plans shall be available on the workspaces on the floor (see Clause 6), inside
the dedicated booth (see Clause 7) and inside the interpreters' room (see 9.2).

ISO/DIS 17651-4:2025(en)
5 Equipment for all workspaces
5.1 Lighting
[15]
To protect the interpreter from disability glare (see ISO 9241-303:2011 , 5.4.11), indirect lighting, or a
lamp reflector shall be used. Each lighting source projected on the interpreter shall be individually and
manually adjustable for:
— beam angle;
— light intensity.
5.2 Backdrop
The backdrop behind the signed language interpreter shall cover the vertical space from the floor up. The
horizontal space shall comfortably cover the signing space of the interpreter. The following minimum
dimensions shall apply:
— width: 2,00 m;
— height: 2,30 m.
The location where the interpreter will be positioned shall be marked on the floor. The distance between the
interpreter and the backdrop shall be at least 1 metre.
The backdrop shall have a uniform colour, so that the image of the interpreter can be seen without any visual
distraction. The backdrop colour value shall be mid-range. The backdrop material shall be flat without any
unevenness, non-glaring, and cause no reflections.
NOTE Viewers who identify as deafblind or with a visual impairment should be consulted to determine if a specific
colour backdrop is preferred; interpreters should wear plain clothes in a colour that contrasts with their skin colour.
5.3 Visual display
A video display in the direct line-of-sight of the interpreter shall provide the incoming images as seen by the
audience on the main screen. The video display shall be positioned at a convenient ergonomic angle, i.e. with
a gaze angle from 0° to 40° and a head-tilt angle from 0° to 25° in accordance with ISO 9241-303.
For interpreters who are working directly from captions, a second video display shall provide the live text
and shall be positioned underneath or next to the camera to avoid eye strain. The video display shall be
positioned at a convenient ergonomic angle for the interpreter to read the text without the need to tilt or
move their head.
The incoming signal of the video displays shall be displayed without distorting their original aspect ratio.
Video displays shall be flat and flicker-free. They should be anti-glare and easily cleanable. The video display
shall not obstruct visibility into and from the room in which the communicative event takes place.
Screen sizes shall be in proportion to the viewing distance to ensure the interpreter can comfortably read
any displayed text. There shall be sufficient contrast between the text and the background. Both the symbols
[16]
and the screen background should have different luminance or colour, in accordance with ISO 9241-303 .
The incoming image shall follow the requirements in accordance with ISO 20109:2025, 5.2. Video displays
shall conform to ISO 20109:2025, 7.3.
The image size and quality shall be such that the visual content is readable and the speaker’s face is clearly
visible. The image of the signer shall transmit their detailed facial expression, lip and hand movements. The
image of the signer shall be framed from one hand span above their head to just below their hips so that the
hands of the signer are never out of frame. Examples of different configurations on the visual display are
provided in Annex E.
NOTE 1 Good results have been achieved with:

ISO/DIS 17651-4:2025(en)
— dual video displays with a diagonal dimension between 140 cm (55 inches) and 165 cm (65 inches) at a viewing
distance of between 170 cm and 200 cm;
— single video displays with a diagonal dimension between 165 cm (65 inches) and 216 cm (85 inches) with multi-
view of the different video signals at a viewing distance of between 170 cm and 200 cm.
NOTE 2 It is good practice that technical support staff and interpreters coordinate the configuration of the content
to be displayed to interpreters.
5.4 Camera and pre-sets
The camera shall be positioned at the eye level of the interpreter at a convenient ergonomic angle, i.e. with a
gaze angle from 0° to 40° and a head-tilt angle from 0° to 25° in accordance with ISO 9241-303.
The camera height shall be adjustable via a control panel automatically adapting the pre-set height of the
camera to the height of the interpreter. Specifically trained technical support staff shall be available to set
the camera and program any pre-sets (see 4.4).
The broadcast image of the interpreter shall:
— position the interpreter within the frame with sufficient space on either side to fully capture arm
movements;
— transmit the interpreter's detailed facial expression, lip movements, and hand movements;
— be framed at least 15 centimetres above the interpreter's head to just below their hips so that the
interpreter’s hands are never out of frame;
— cover at least 1/3 of the horizontal plane of the display on the main screen in the room;
— not be overlayed by any other images or text.
Examples of broadcast images are provided in Annex F.
The camera shall have a frame rate of 30 (FPS) or higher to capture the fluid movements in signed language
communication, including facial expressions and mouth movements. For viewers, a lower resolution with
adequate bitrate provides better signed language comprehension than a higher resolution with insufficient
[17][18]
bitrate .
The minimum bitrates for various resolutions are:
3840×2160 (4K): 16 Mbps
1920×1080 (Full HD): 8 Mbps
1280×720 (HD): 4 Mbps
In case of bandwidth constraints, the encoder shall maintain an adequate bitrate, reducing spatial resolution
as necessary, and the compression quality shall take precedence over high spatial resolution.
5.5 Incoming sound
Incoming sound shall be provided through a wireless receiver in accordance with ISO 20109:2025, 10.3, and
shall be connected to each interpreter’s headphones, allowing for uninterrupted sound input.
NOTE Good results have been achieved with Radio Frequency (RF) receivers. Infrared (IR) receivers are not
suitable as the interpreters' signing movements disrupt the infrared signal.
The receiver shall allow the interpreters to select either the audio from the floor or a minimum of three pre-
set interpreted languages.
The interpreters' headphones shall conform to ISO 20109:2025, 8.3.1.

ISO/DIS 17651-4:2025(en)
5.6 Whiteboard
A whiteboard of A4 size with markers and wiper shall be provided for the interpreters to write information on.
6 On the floor
6.1 Allocation of workspaces
The allocation of the interpreters' workspace depends on the layout of the meeting hall or conference hall
[10]
and the seating arrangement of the various parties in the communicative event (see ISO 22259 ).
NOTE It is good practice that event organizers consult with the signing participants and interpreters on the
location of the interpreters’ workspace and the participants’ seating arrangements.
6.2 Meeting hall
6.2.1 Interpreters' view
The interpreters' workspace(s) shall be placed in such a way that the interpreters have a direct view of the
entire room, the speakers, signers and all visual resources, such as projection screens and displays.
6.2.2 Placement
In a meeting hall where all parties are physically present there are various possible workspaces. Examples
of workspaces in meeting halls are provided in Annex C. The workspace shall be allocated across from the
signing audience members at a maximum distance of 3 metres.
6.2.3 Equipment
In case the workspace does not provide the visibility, lighting or sound levels for interpreters to interpret,
the following shall be provided:
— lighting in accordance with 5.1;
— incoming sound in accordance with 6.3.6.5;
— a microphone in accordance with 6.3.6.7;
— visual displays in accordance with 5.3.
In a small meeting hall where all audience members are seated, the interpreters shall also be seated on
comfortable chairs in accordance with EN 1335-1 with the following characteristics:
— easily movable;
— adjustable height;
— adjustable or removable armrests.
6.3 Conference hall
6.3.1 General requirements
Signed language interpretation involves visual interaction with signing participants. When signers are
present, signed to spoken language interpretation shall be provided from the interpreters' workspace on
the floor (Clause 6). Additionally, a second signed language interpreting team can provide interpretation
into a signed language from a dedicated signed language interpreting booth (Clause 7). The signed language
interpretation can be broadcast to either screens in the same hall and venue, or publicly, or both.

ISO/DIS 17651-4:2025(en)
6.3.2 Interpreters' view
The interpreters' workspaces shall be placed in such a way that the interpreters have a direct view of the
entire room, including the rostrum, speakers, signers and all visual aids, such as projection screen and
displays (see Annex D). The interpreting workspaces shall be situated in such a way that the interpreters’
view is without any visual obstruction. The sign language interpreters’ workspaces shall not hinder the
view of the spoken language interpreters' booths into the room. In large rooms video displays shall be used
to facilitate the interpreters' view of speakers and signers, in accordance with ISO 20109.
6.3.3 Placement
In a hall with a theatre-style seating arrangement, there are two dedicated workspaces for signed language
interpreters:
— on the floor, next to the rostrum, facing the audience (see 6.3.4);
— on the floor, facing the rostrum (see 6.3.5).
A designated area next to the rostrum facing the rostrum shall be allocated for signed language interpreters,
within view of all participants in the audience and without any visual obstructions (Figure 1).
A second space at the front of the room, facing the rostrum, shall be allocated for the team of interpreters
providing interpreting services between a signed and a spoken language or between two signed languages
(Figure 2).
In a communicative event, both workspaces can be used at the same time to provide interpreting services:
the workspace on the conference hall floor next to the rostrum facing the audience for signing audience
members and the workspace on the conference floor facing the rostrum for signers on the rostrum.
When signing participants are physically present at the communicative event, the dedicated interpreting
workspace on the conference hall floor facing the rostrum shall be used to provide interpretation into a
spoken language for signers on the rostrum (Figure 2).
Additionally, in case the conference hall has a dedicated booth (Clause 7) a second team can provide
interpretation into a signed lang
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