Day 4 - Making Multimedia accessible

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.

Considering those with hearing impairments

Orange ear symbol with a line through it within a blue box, communicating hearing impairedPeople who are unable to hear audio included in recorded lectures or podcasts require a transcript of the spoken sound. A transcript enables a deaf user to access the audio content, and may be used whilst watching the video. Transcripts are either text or braille, and include the verbatim dialogue along with additional details which help communicate what is being said more fully, e.g. laughter, crying. 

For video content, closed captions are needed provide a more complete full description of what is included in the audio, including both dialogue and other pertinent details, e.g. laughter, door closing. Subtitles are used when the dialogue is needed. If the dialogue stands alone without mention of any additional or background sounds, using only subtitles may be suitable. However, if these incidental sounds will affect how the dialogue is perceived, then closed captions will be needed.  

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

The YouTube website with a video screenshot for adding captions

If you use Microsoft or Apple platforms there are also services available within their suite of products:

Considering those with visual impairments

Orange eye with a line through it, placed in a blue box. Communicating partially sighted userPeople 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.

YouTube Lion King video clip showing the subtitles of verbal description at the bottom of the video clip.

A variety of tools are available for creating audio descriptions, here are two free options you may wish to try:

Audacity Logo


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 Logo

 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.

Considering those with motor skills impairments 

Computer mouse in a blue box communicating a non-mouse userTeaching 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

Screenshot of the OzPlayer Website

Whilst these steps are specifically designed to make presentations accessible to those with hearing, sight and motor skills impairments they can be useful to other users in a variety of situations. For example, transcripts enhance multimedia experiences for those who are unable to listen to sound in a particular social context, have defective computer audio, or are unfamiliar with technical jargon and need to view what is being said alongside a dictionary or translation software.     


Image References:  Icons Creative Commons, from the Designing for Accessibility Posters available as part of this blog series

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