Video captions and transcripts

• Why use captions?
• Captions, subtitles or transcripts?
• How to create captions
• Help and support

Why use captions?

Captions benefit everyone, but they’re imperative for making video content accessible to people who are deaf or hard of hearing.

UCL has a legal duty to make its digital content perceivable, operable, understandable and robust. The regulations aim to make online public services accessible for everyone, including those with disabilities.

More information on the regulations can be found on the Government Digital Accessibility website.

It’s also worth referring to UCL’s Digital Accessibility Policy, particularly Section 4: Multimedia Policy and Section 5: Teaching Content Policy.

Accessibility

When you make your content accessible, you allow people who might be deaf or hard of hearing to have access to the videos you produce. More than 5% of the world's population has some form of hearing loss; by adding captions there is an opportunity to serve and reach this group. 

Helping people with English as a Second Language (ESL)

Captions make it easier for non-native English speakers to understand. Viewing videos with captions over the spoken audio allows learners to develop an ear for the more nuanced features of the English language, especially when idioms and slang terms are used. 

Improve average video watch time

Captions tend to grab and hold an audience’s attention; people are more likely to watch a video to its completion if they have the option to turn on captions. 

Search engine optimisation (SEO)

Search engines can’t crawl video. However, they can crawl the text on websites. Adding captions and a transcript to your video will help your video rank higher on search results.

User Experience

80% of people who use captions are not deaf or hard of hearing. Captions make videos accessible in noisy environments, assist with focus on speech, and clarify hard-to-understand dialogue. They give viewers flexibility to watch anytime, anywhere, in a way that suits their needs.

Captions, subtitles or transcripts?

Captions, subtitles and transcripts are distinct but overlap in many ways. While all display text on the screen, the purpose for using each is quite different.

Captions

Captions are a text version of the spoken part of a television, movie, or computer presentation. They are in the language of the medium rather than a translation to another language. These can either be manually generated by a human or by using a form of AI called Automatic Speech Recognition (ASR).

Captions can either be closed or open:

We suggest using closed captions where possible (Mediacentral, Panopto, Micosoft Stream, Teams and Zoom all support this functionality). Only use open captions when closed captions is not supported.

The most common types of closed captioning files are SRT (SubRip) and VTT (Video Text Tracks).

Subtitles

Subtitles are translations for people who don’t speak the language being spoken in the video e.g. for foreign language films. These may simply provide a translation of the dialogue, or they could additionally include audio description of background sounds and music or an indication of who is speaking when.

Transcripts

Transcripts provide a complete written version of all spoken content in a video or audio recording. Unlike captions or subtitles, transcripts are not time-synchronized with the media; they exist as a standalone text document.

Audio description

Audio description is a form of narration used to provide information about key visual elements in multimedia. This is primarily targeted at people who are blind or have reduced vision.

How to create captions

There are a number of different options for captioning your content, some provided by UCL and a few approved external services.

There a few things to check before you decide on a captioning service to use:

• Refer to UCL’s Digital Accessibility Policy for what you need to do to ensure your content is accessible. Depending on the type of content you’re creating, you may be required to create captions, transcripts or both.
• Is your content pre-recorded or live streamed?
• Do you have budget to spend on captioning?
  • Whilst there are both free and paid for captioning services, free options tend to be Automatic Speech Recognition (ASR) only and therefore require more checking and manual corrections. Paid for services usually also use ASR but this is normally done in conjunction with a person checking the output which leads to a more accurate final product.
  • If you’re providing captions for a student with Reasonable Academic Adjustments, a high degree of accuracy is essential.

Optimise audio quality 

The better the quality of audio in your media, the more accurate the captions will be. Some tips to improve your audio quality are:

• Use an external microphone, as opposed to the inbuilt one in your computer or laptop.
• Do a test recording before the session to check the quality. 
• A microphone too close to your mouth will pick up more speech distortion. Try lowering or raising from mouth. Keep it at an even distance. 
• Minimise background noise.
• Use the full version of abbreviations and acronyms, as Automatic Speech Recognition   (ASR) often struggles with these (e.g. say University College London rather than UCL).
• Speak at a steady pace. 
• Repeat audience questions back to them, as your audio quality will probably be better than the room audio.

JISC has put together some information on this subject.

Captioning services

Pre-recorded content

UCL’s video portal Mediacentral does not have ASR captioning in-built, so captions have to be created using a different platform and then uploaded to the video.

Pre-recorded captions often require editing, so please check your captions before making your video available to staff and students.

Live streaming

Some operating systems have a live captioning feature that can be used across all apps on the device. For more information, please refer to the guidance from your manufacturer:

• Windows 11: Use live captions to better understand audio
• macOS: Get live captions of spoken audio on Mac
• iOS: Get live captions of spoken audio on iPhone
• Android: Caption media and calls on your device
• Samsung: Use Live Caption and Live Transcribe on your Galaxy device

Editing tools

If you already have a captioning file, you can use one of the below tools to carry out any edits you may need:

• Notepad: Can read .VTT and .SRT files. Good for quick edits.
• Subtitle Edit: Free downloadable caption editor.
• Subtitle Horse: Free web-based caption editor.
• Subtitle Tools: Online tools for syncing, fixing and converting subtitles.
• CADET: Free software download which allows users to create and edit their own captions. 

Help and support

If you’re unsure on what solution is right for you or you need assistance with a Reasonable Academic Adjustment, please get in touch with the Digital Accessibility team who will be happy to assist.

For enquires on how to use the systems listed, please get in touch with the relevant support team via MyServices.