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Enhancing accessibility of video and audio

Table of Contents

Introduction

  • Video and audio plays an essential role in teaching and learning. For example:
    • Instructors upload pre-recorded video and/or podcast online for students to access at their own pace to access the learning content under asynchronous teaching mode.
    • Instructors adopting the flipped classroom instruction model make heavy use of video as pre-class learning materials.
    • Screen recording for tutorial and step-by-step demonstration of certain topics and skills.
    • Recording of classes, workshops, seminars, and conferences.
    • Videos showcasing research findings and public education.
    • Animation video is commonly used to illustrate abstract concepts or models.
    • Podcast has become more and more popular method of delivery of educational materials.
  • If the video and audio is inaccessible, it is possible that some students may be unable to access the content and participate in the learning activities. It hinders equal opportunities of participation in learning activities.
  • Besides the content, it is equally important to consider the accessibility of the media players and channels. It is always good to consider the contexts as well as the diverse characteristics and needs of the target audience. Modify the content design and media player in response to their needs accordingly.
  • There are many media editing tools, media players and channels. Their accessibility-related functions may vary across the programme versions, operating systems, and/or hardware, such as computer screens, mobile phone, tablets, and types of screen readers.
  • In this section, there are some recommended practices of creating accessible video and audio. These practices are not exhaustive or definitive. The practices are mainly about creating new video and audio files yourself. If you are using existing media, you may make use of the recommended practices to check and enhance the accessibility of these existing video and audio to better cater for diverse access needs of the audience. The principles would still apply.
  • It is important to note that software and computer programmes are constantly and rapidly developing along with changing accessibility functions. Refer to the specific media editing tools and media players for the latest status of accessibility-related functions.
  • Production process
    1. Consider accessibility throughout the whole production stage.
  • Media players
    1. Select media players with accessibility functions.
    2. Refer to player-specific accessibility support updates.
    3. Be aware of restricted access to certain platforms.
  • Content (“Storyboard”)
    1. Be mindful of inclusive language and disability representation.
    2. Write descriptive script and avoid vague narration.
    3. Avoid too much flashing content.
  • Shooting
    1. Avoid shaky video.
    2. Ensure front view of the speakers and sufficient lighting.
  • Editing
    1. Avoid extreme differences in sound effects.
    2. Put text overlay on plain background.
  • Alternative presentations
    1. Provide captions and use auto-captioning effectively.
    2. Provide transcripts and timestamps.
    3. Provide sign language interpretation.
    4. Provide audio description for video.
  • Playing of media
    1. Avoid default autoplay of media.

Production process

Media players

  • Select media players that support a wider range of accessibility-related functions whenever possible.
  • The playing mode of the media players would affect the accessibility of the video or audio to the users. A general underlying principle is to select media players that allow users to choose options they are comfortable with and that match their access needs. The following are six examples of recommended options.
    • Allow users to adjust the video speed so they can watch the video at their own pace. Different people are comfortable with different watching speed. Some users may find the original speed too fast that they miss out lots of important information when watching. Conversely, some users may be running out of time and would need to finish watching the video in shorter time.
    • Provide timestamps of any meaningful segments or video chapters to facilitate users to find and re-watch certain parts of the video more easily.
    • Allow users to freely set how captions are displayed, such as text style, text size, colours and position. It would make the captions more readable to more specific groups of people.
    • Support the use of interactive transcripts for audience to access the transcript and media file at the same time. They can select and click-on a particular part within the transcript text and go to the corresponding part in the media file directly.
    • Allow users to access the media players on different devices and/or browsers.
    • Allow users to access alternative formats of the media within the same player, such as sign language interpretation.
  • An example of media player that supports the abovementioned six accessible player settings is the “Able Player”.
  • References:
  • There might be varying extent of restricted access to online media player platforms and applications at some geographical locations. Be aware that some users may not be able to access the online media player platforms due to such restriction in access.
  • It is always important to consider the contexts and the characteristics and needs of the target audience of the video and audio. Modify the choice of the online media player platforms, and/or provide alternative means to access the video and audio in response to their needs accordingly.

Content ("Storyboard")

  • Use inclusive language in the storyboard and scripts. Avoid biased language.
  • Consider disability representation and diversity in mind when drafting the storyboard and scripts.
  • Portray disabled people as ordinary people in society as they are. Do not create an impression of separateness, specialness, and dependence. Avoid focusing on their medical conditions.
  • Avoid portraying disabled people as a passive recipient of help from others.
    • For example, a student with visual impairment being helped to cross the road or the wheelchair of a wheelchair-using student being pushed by a fellow classmate.
  • Portray diversity. Show people with disabilities in everyday social situations and campus environment.
    • For example, a group of students walking around the campus including students with diverse characteristics to represent the inherent diversity, e.g., disability and skin colour.
  • Avoid emphasizing too much on some people with disabilities who have “remarkable achievements” as role models through storytelling or first-person sharing in the storyboard and scripts.
    • Storytelling approach is often used to “inspire” others by conveying the idea of “see how these people with disabilities can overcome barriers with a never-give-up attitude and complete this and that” to motivate people without disabilities to try harder.
    • The hidden agenda is that if people with disabilities can achieve their goals, then surely can people without disabilities. It might also put much pressure on students with disabilities to think that they have to be an “inspiration” to matter. Mind the issues of possibly manifesting “inspiration porn”.
    • Inspiration porn is the stereotypical portrayal of people with disabilities doing something ordinary as “inspirational” solely or in part on the basis of their disabilities (Stella Young, 2014).
    • After all, the accomplishments of people with disabilities are worth celebrating on the basis of their competency (instead of their disability status) just as it is to celebrate the accomplishments of people without disabilities.
  • It is becoming more and more common to create screen recording for tutorial and step-by-step demonstration of certain topics and skills, such as the use of computer programmes.
  • Narration of screen recordings typically involves large amount of verbal description of the step-by-step demonstration or explanation that are synchronized with the contents being shown on screen.
  • When drafting the script and narrating the screen recording, avoid using vague descriptions such as “Click here”, “This”, “There”, “This button”, or “That slide”. It is suggested to use more descriptive and precise phrases such as “Go to the Insert Tab and click the Insert Table subtab”, “the text box at the top right of the screen”, “the Submit button at bottom right of the screen”, or “the slide number 19”. Verbalize the contents concerned that are being shown on screen clearly, such as the location, direction, label, and/or name of the target objects and destination.
    • It is recommended that the narration would work as if the screen recording were “audio only”.
  • Do not assume that all audience can see what is being shown on screen, use a mouse for system control, or follow the narration at your pace. It may take some time for some audience to familiarize themselves with the contents being shown on screen.
  • References:
  • Creative use of animation or flashing content in video may promote user engagement. However, be aware of the overuse of animations or flashing objects in the media.
  • Content that flashes more than three times per second may trigger unpleasant feelings, dizziness, nausea, or seizures in some people, such as people who are photosensitive.
  • Animation or flashing content may distract some users from the main content, especially people who have difficulties in reading or concentrating.
  • Users of assistive technologies such as screen readers and magnifier may not be able to interpret the rapidly changing animated content in time before the content goes away.
  • Provide an option (e.g., “On Click”) to allow users to play, pause, or stop the autoplay of the flashing content, if possible. It allows users to read the content at their own pace or as they want to.
  • Do not convey important information solely by animation or flashing content.

Shooting

  • Shaky video may cause motion sickness, and/or distract viewers.
  • Try using different tools or methods to keep the camera steady during filming.
  • Some audience may use lip-reading and speakers’ facial expression to facilitate the interpretation and understanding of the content.
  • Ensure the front view of the speakers is visible and under sufficient lighting. It facilitates lip-reading and observation of facial expressions or any other nonverbal expression.

Editing

  • Keep the volume level at consistent level whenever it is possible. Unexpected sound or extreme differences in sound effects within the same video or audio may be shocking or distracting to some audience.
  • If there will be sudden loud noise or any potentially triggering sound in the media, provide users with a warning message and/or mention this information in the media timestamps to alert the audience. For example, audience may want to turn down the volume of their earphones before playing the media file.
  • Put text overlay on plain background to make the text more readable. It will be less likely that the audience would miss the text.
  • Avoid overlay text on a busy background of a wide range of colours. It could be difficult to ensure sufficient contrast between the colours in the background image and the text. It is difficult to read the overlaid text.
  • Check and ensure sufficient colour contrast between the background and the text overlay.
  • To increase the accessibility of the text overlay:
    • Method 1: Insert the text over the plain section of the screen. Ensure sufficient colour contrast between that section and the text.
    • Method 2: Insert a solid background behind the text. Ensure sufficient colour contrast between the solid background and the text.
    • Method 3: Insert a darker overlay to the screen to increase the colour contrast between the background and the text.

Images comparing the not-recommended way of overlaying texts over a busy background, and the three more accessible methods to increase the accessibility of text overlay.

Alternative presentations

  • Provide captions of video and audio.
  • Captions are the text description of the dialogue and background sound of the media content. The information conveyed by the caption and the associated media should be synchronized and equivalent. Audience should be able to receive the same information if they access either the media or captions alone.
    • Subtitles and captions are similar but different. Subtitles are translations of the dialogue in the media. Captions are the text descriptions of the dialogue in the same language spoken in the media, instead of translations.
  • Captions could enhance the accessibility to deaf and hard-of-hearing users. It could facilitate their understanding of the media. It would also be useful when the media content involves many specialized topics and jargons, and some audience under the following two examples of situations.
    • Audience being in a sound-sensitive environment in which playing out the audio loud is not allowed, or noisy environments.
    • Audience are not familiar with the language used in the media. The speakers in the media have strong or multiple accents that are difficult to understand.
  • If the media with captions are uploaded online, the captions would improve the search engine optimization of the media content. The media may reach more potential audience.
  • There are two types of captions, namely closed captions, and open captions. Closed captions can be toggled on or off by the audiences while the media is being played. Open captions cannot be toggled on or off by the audiences while the media is being played. The provision of open or closed captions would be partly dependent on the specifications of the media player. Some media players may or may not provide the options of toggling on and off the captions.
  • Avoid using pre-rendered (or “burned-in” captions) unless the selected media players do not support alternative display modes of captions (such as “closed captions”). If you embed the captions in the video file directly, make sure the font, font size, and colour contrast of the text and background are accessible and easy to read.
    • Be aware that whether the burned-in captions may block some part of the video contents.
    • If burned-in captions are needed, it is suggested to use “under video captions”. The captions are displayed below the media screen, so the captions would not overlap the media content.

Two illustrations showing a video with captions overlapping the screen and a video with under video captions.

  • Provide transcripts and timestamps of video and audio.
  • Transcripts are the text version of the content conveyed by the video and audio. The information conveyed by the transcripts and the associated video and audio should be equivalent. Audience should be able to receive the same information if they access either the video and audio or transcripts alone.
  • Transcripts could enhance the accessibility to deaf and hard-of-hearing users. It could facilitate their understanding of the media. It would also be useful under the following seven examples of situations.
    • Audience being in a sound-sensitive environment in which playing out the audio loud is not allowed, or noisy environments.
    • Audience are not familiar with the language used in the media. The speakers in the media have strong or multiple accents that are difficult to understand.
    • Audience encounter low bandwidth or unstable Internet connection, and/or unlimited data plans on mobile phones to load the media. Transcripts may be particularly preferred under such situation because users do not need to struggle to load the whole media to access the media content and captions.
    • The media content involves many specialized topics and jargons.
    • The sound system of the media players and/or the devices are not working. The sound quality is poor.
    • Transcripts allow users to search for keywords, jump to specific sections, and navigate more extended clips or information.
    • Transcripts can be converted to alternative formats (such as Braille) and/or translated to other languages to cater for the diverse needs of different users.
  • If the media with transcripts are uploaded online, the transcripts would improve the search engine optimization for the media content. The media may reach more potential users.
  • Put the transcript in logical paragraphs, instead of a large piece of text, to facilitate readability and understanding.
    • For dialogue, when there is more than one speaker, indicate the speaker who is talking in the transcript. Include the description of the tone of voice. This could help the audience to identify who is speaking that line and understand the content more logically.
    • If the media has background music, you may exclude it from the transcript unless it is a key element that is required for the understanding of the media content. Another method is to indicate the presence and a brief description of the background music at the beginning of the transcript.
    • The non-speech elements, like meaningful sound effects, whistle, or sound of footsteps, should also be included in the transcript. This kind of information could help the audience to understand the context more comprehensively.
    • Examples of the use of different indicators to express different situations:
      • Italics may be used to indicate the speech of speakers who are off-screen. For example, “Amy: Open the door, please” could be used when Amy is not seen in the video and only her voice appears.
      • Capitalized letters may be used to indicate that a speaker is yelling. For example, “Amy: STOP” could be used to indicate that Amy in the video is shouting this line.
      • Parentheses, lowercase, italics and with a space before and after could be used to indicate non-speech sounds. For example, [Amy laughing] could be used for Amy’s laughing sound.
      • [silence] could be used when there are people in that scene are talking but the audio is muted on purpose.
      • [unintelligible] could be used when you hear something being said but cannot make out the words.
  • Provide the transcript in accessible ways. There can be different methods of posting the transcript, partly depending on the media hosting method, media player functions, and/or the delivery method of the media file.
    • The transcript may be available as a separate text file for downloading, as a separate webpage, or embedded in the media player.
    • Some media players can support the use of interactive transcripts. Audience can access the transcript and media file at the same time. They can select and click-on a particular part within the transcript text and go to the corresponding part in the media file directly. Here is an example of interactive transcripts.
  • If you really cannot provide transcripts of the video or audio, notify the audience, and provide contact methods for audience to ask for alternative formats.
  • Timestamps for different sub-sections of the video or audio can facilitate easy navigation through the media.
    • Sometimes, timestamps are included in auto-generated transcription. However, these timestamps could potentially create burden to some audience when they go through the transcript. It might be better to include timestamps in the transcript only when the timestamps can present useful information.
  • Examples of programmes for creating and delivering transcripts and timestamps:
  • Further guidelines of creating transcripts:
  • Other references:
  • Provide sign language interpretation of the video and audio to cater for the access needs of deaf or hard-of-hearing audience and those in need.
  • There are different methods to displaying sign language interpretation in video and audio.
    • Example 1: As an overlay window at the bottom right corner of the video.
    • Example 2: Split the original video screen into two parts side-by-side: with the speaker’s video screen on the left and the window showing the sign language interpretation on the right.
    • Example 3: As a separate video showing mainly the sign language interpretation and caption.

Three illustrations showing the video layouts of example 1, 2, and 3.

Playing of media

  • Avoid autoplay of media such as video and audio by default.
  • Unexpected content and default autoplay may be inaccessible to some users of assistive technologies such as screen readers.
  • Unexpected sound or flashing content may trigger seizures or discomfort in some people.
  • Unexpected sound may be shocking or distracting to some users.
  • If there will be sudden loud noise or any potentially triggering scenes in the media, mention this information in the webpage to alert the users. For example, users may want to turn down the volume of their earphones before playing the media file.
  • Allow users to control playback of the media at the own pace whenever it is possible. Users may want to re-visit certain parts of the media content at their own pace.