ISO/IEC 20071-23:2018
(Main)Information technology — User interface component accessibility — Part 23: Visual presentation of audio information (including captions and subtitles)
Information technology — User interface component accessibility — Part 23: Visual presentation of audio information (including captions and subtitles)
This document provides guidance for producers, exhibitors, and distributors on the visual presentation of alternatives to audio information in audiovisual content, such as captions/subtitles. This document provides requirements and recommendations that are intended to support users who are not able to use the audio information, prefer to use a visual representation of audio information, or prefer both audio and visual presentations. NOTE Many users do not have a choice, for instance, when in a noisy environment (e.g. bar, restaurant, etc.). In these situations, the user does not select a visual presentation of audio information but is offered the content with captions/subtitles. This document acknowledges the various needs and preferences of viewers (end users) as well as the different approaches to visual presentation of audio information. It applies to all presentations of visual alternatives to audio information intended to be presented as captions/subtitles. This document does not apply to the presentation devices or transmission mechanisms used to deliver the content or visual presentations of audio information. These devices could include, but are not limited to: televisions, computers, wireless devices, projection equipment, DVD and home cinema equipment, video game consoles, and other forms of user interfaces technology. This document does not apply to transcoding files and formats for the various video outputs. This document gives guidance on visual presentations which are delivered in the same language as in the audio (i.e., intra-lingual captions/subtitles) and visual presentations which are translated into a different language (i.e., inter-lingual captions/subtitles). This document does not apply to the specific process of language translation. This document helps to improve accessibility. This document does not establish requirements on specific industries (e.g. television broadcasting, motion pictures) nor is it intended to supersede specific international standards within their domain.
Technologies de l'information — Accessibilité du composant interface utilisateur — Partie 23: Présentation visuelle d’informations sonores
General Information
Standards Content (Sample)
INTERNATIONAL ISO/IEC
STANDARD 20071-23
First edition
2018-09
Information technology — User
interface component accessibility —
Part 23:
Visual presentation of audio
information (including captions and
subtitles)
Technologies de l'information — Accessibilité du composant interface
utilisateur —
Partie 23: Présentation visuelle d’informations sonores
Reference number
©
ISO/IEC 2018
© ISO/IEC 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
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below or ISO’s member body in the country of the requester.
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Published in Switzerland
ii © ISO/IEC 2018 – All rights reserved
Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Framework for the visual presentation of audio information . 3
4.1 Purpose . 3
4.2 Motivation . 4
4.3 Locations of presentations . 4
4.4 Modes of presentations . 4
4.5 Modes of access . 5
4.6 Modes of display . 5
4.7 Levels of importance . 5
4.7.1 General. 5
4.7.2 Essential information. 5
4.7.3 Significant information . . 6
4.7.4 Helpful information . 6
4.7.5 Unhelpful information . 6
5 Applicability of requirements and recommendations . 6
5.1 Predictable audio contents . 6
5.2 Unpredictable audio contents . 6
6 Production of visual presentations of audio information . 7
6.1 Consideration to match the intended meaning . 7
6.2 Ease of understanding of visual presentations of audio information . 7
6.3 Consideration of output devices . 7
6.4 Verification of visual presentations of audio information with the intended output
devices . 7
6.5 Connecting visual presentations of audio information data with content data . 7
6.6 Combining multiple visual presentations of audio information . 8
6.7 Update of visual presentations of audio information data . 8
6.8 Evaluation . 8
6.9 Evaluations including contribution of typical users . 8
7 Visual design . 8
7.1 General . 8
7.2 Personalization . 8
7.3 Engagement . 8
7.4 Synchronization of presentations . 9
7.5 Avoidance of information obstruction . 9
7.6 Font size . 9
7.7 Font type .10
7.8 Font face .10
7.9 Upper, lower, and mixed case letters .10
7.10 Contrast and use of colour .10
7.11 Speed .11
7.12 Number of lines .11
7.13 Spacing between characters and lines (kerning and leading) .11
7.14 Correct punctuation.11
7.15 Spacing between words and phrases .12
7.16 Transitions between presentations .12
7.17 Sentence segmentation .12
7.18 Indication of sentence breaks over multiple visual presentations .12
7.19 Additional duration for location change .13
© ISO/IEC 2018 – All rights reserved iii
7.20 Modes of display .13
8 Visual alternative container (VAC) .13
8.1 General .13
8.2 VAC position and area .13
9 Describing speech .13
9.1 Describing verbal content .13
9.2 Grammar .14
9.3 Vulgar verbal content and slang .14
9.4 Language variation .14
9.5 Foreign accents .14
9.6 Indiscernible audio content .14
9.7 Spelling .14
9.8 Abbreviations .15
9.9 Homophones, homonyms, homographs, heteronyms, and heterographs .15
9.10 Long speech .15
9.11 Describing multiple simultaneous information .15
9.12 Confirmation by content producers when producing visual presentations of speech .15
9.13 Sources of information .15
10 Non-speech information (NSI) .16
10.1 General .16
10.2 Describing NSI .
...
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