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 I'information - Accessibilité du composant interface utilisateur Partie 23:Présentation visuelled'informations sonores Reference number IEC IS0/IEC 20071-23:2018(E) ISO @ IS0/IEC 2018 IS0/IEC20071-23:2018(E) COPYRIGHTPROTECTEDDOCUMENT @IS0/IEC2018 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 below orIso'smemberbody inthe country ofthe requester. ISO copyright office CP 401 · Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +4122 749 01 11 Fax:+41227490947 Email:[email protected] Website: www.iso.org Published in Switzerland ii IS0/IEC2018-Allrightsreserved IS0/IEC20071-23:2018(E) 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 55 4.6 Modes of display 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 content.... .6 5.2 Unpredictableaudiocontents 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 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 Fontsize 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 IS0/IEC2018-Allrightsreserved ii