Using sound and video can greatly enhance the presentation of information, and it is now commonplace to add video clips to teaching presentations in particular to illustrate the concepts described and provide material for discussion. However, as with all resources, consideration needs to be given to those who are potentially unable to access the content. Below are just a few things you should consider to improve the experience for all users and reach a larger audience.
The three main criteria that need to be considered for captions and subtitles are:
1. Synchronized – captions and subtitles must be available at the same time as the video and audio, so the information from the multimedia is received in the same way by all members of the audience.
2. Accessible – captions must be accessible with good colour contrast, font and background, which makes it easy to read the text.
3. Textual equivalent – captions must present the same content that is available from the multimedia format, so that the same message is communicated with and without sound.
There are a variety of captioning and subtitling services available to help you add these features to video. Some examples are listed below:
Free Video Captioning Tools
If you use Microsoft or Apple platforms there are also services available within their suite of products:
People who are unable to view video require the visual experience to be carefully scripted in a way that ensures all important content is accessible through audio.
A narration sound file can be provided to support the content if information is displayed in a visual format only.
Audio description can also be included in the media file, as used in this YouTube Lion King example clip.
A variety of tools are available for creating audio descriptions, here are two free options you may wish to try:
Audacity is a free open source tool for creating sound files and can be used to create a narration file and uploaded to streaming services such as YouTube.
YouDescribe – audio description for YouTube Videos. A free accessibility tool to add audio description to YouTube videos. It allows anyone, anywhere to contribute description of an existing video and let a viewer who is visually impaired check it out right away.
Teaching materials are typically made available to the audience after the lecture or tutorial, so that attendees can review and revise what has been presented. In this scenario, care needs to be taken to ensure the presentation remains accessible to those with motor-skills impairments which mean they are unable to use a mouse, as they who would otherwise have difficulty in navigating the presentation.
People who are unable to use a mouse require a multimedia player that:
• works with a keyboard alone
• responds to verbal commands using speech input
• is not set to auto play on display
The first full accessible video player is called OzPlayer, and is free for not-for-profit use. For a full list of accessible players and specifications, visit the Digital Accessibility Matters Website
Image References: Icons Creative Commons, from the Designing for Accessibility Posters available as part of this blog series
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