Best practices for text alternatives for audio and video

• Film studies: students analyzing film techniques, camera angles, or editing styles may benefit from focusing solely on visual elements.
• Language learning: observing mouth movements and facial expressions can aid in understanding spoken languages.
• Non-verbal communication: studying body language and gestures without audio distractions can enhance comprehension of non-verbal cues.

While watching videos without sound may seem unusual, it reflects the diversity of human preferences and learning styles. As media consumption continues to evolve, it’s likely that silent viewing will remain a popular choice for many individuals.

Essential text alternatives

Transcripts

Transcripts provide a complete text-based version of material that was originally produced in audio or video format and allow individuals who are deaf or hard of hearing to read the text equivalent.

Unlike captions and subtitles, transcripts do not appear on-screen during playback but can be displayed below the original media or used as separate resources.

Transcripts can also be translated into multiple languages and serve various purposes beyond accessibility. They can be useful for research, accessibility, and SEO purposes.

The standard WCAG 2.1 AA requires an alternative for audio content and an alternative for video content, but a transcript covers both and is 100% recommended.

All audio content should provide a full-text transcript, which should also include any audio content used as a part of a video. Transcripts are typically available on a separate webpage or as a downloadable file.

Best practices for audio and video transcripts

• Audio content: for audio-only media, provide a text transcript that includes dialogue and any significant non-spoken audio elements. This is sufficient for podcasts and similar formats.
• Video content: for videos, a descriptive transcript should accompany the video, detailing both the audio and visual elements, such as character movements and on-screen text. Timed transcripts are beneficial, allowing users to navigate the content easily.

Captions

Captions are on-screen text descriptions of a video’s dialogue, identifying speakers and describing other relevant sounds, like descriptions of video action, background noise, and speaker identification. They can be open or closed and are often required by law for videos to be accessible to people with hearing impairments.

Captions are typically synchronised and provided in the language native to the original video rather than being translated into another language.

Captions reach a wider audience beyond the deaf and hard-of-hearing, as 80% of captions users are not deaf or hard-of-hearing.

In fact, every single one of us has used captions. Everyone can have temporary or situational hearing difficulties. A person suffering from an ear infection or cold may be unable to hear properly. Talking while wearing a mask might also have an impact on the sound.

You may be in a public place where listening to audio is either impossible due to noise or you are in a place where playing audio is inadvisable.

Types of captions

• Closed captions: these can be toggled on or off by users and should include spoken dialogue, non-verbal sounds, and relevant audio cues to enhance understanding.
• Open captions: these are always visible and should be placed carefully to avoid obscuring important visual content.
• Live captions: while not mandated by the EU Web Accessibility Directive, providing live captions is highly recommended for real-time audio content.

Subtitles

Subtitles serve a different purpose than captions. They translate the spoken dialogue of a video into another language. Like captions, subtitles appear on-screen during playback but do not include non-speech elements such as sound effects or background music. This makes subtitles particularly useful for audiences who do not understand the language being spoken in the video. For instance, English-speaking viewers can enjoy Spanish-language films with English subtitles.

Example subtitle format:

00:01:23 --> 00:01:25 Speaker 1
Hello, everyone! Today we'll be discussing web accessibility standards.

Descriptive text

For visual elements without audio descriptions, provide descriptive text that conveys important visual information.

• Describe key visuals, such as graphs, charts, or images.
• Include any relevant color coding or other visual cues.
• Provide alternative formats like braille or tactile graphics when appropriate.

Audio descriptions

For video content, consider adding audio descriptions. Audio descriptions are narrated descriptions of the visual elements in a video, such as actions, scene changes, and on-screen text. They provide individuals who are blind or have low vision with a comprehensive understanding of the video content.

Example of good alt text for audio

When it comes to providing alternative text (alt text) for audio content, there isn’t a direct visual equivalent like we have for images. However, we can still create meaningful descriptions that convey the essential information or purpose of the audio file.

Here are some examples of good alt text for various types of audio:

Podcast episode

For a podcast episode, the alt text could be:

This concise description provides:

• The episode number.
• A brief title or topic.
• Key speaker.

Music track

For a music track, consider:

This includes:

• Song title.
• Genre or style.
• Artist name.

Audio tutorial

For an educational audio tutorial:

This alt text gives users an idea of what they can expect to learn from the audio.

News report

For a news report audio clip:

This provides:

• Type of content (news report).
• General topic.
• Timeliness indicator (breaking).

Interview clip

For a short interview excerpt:

This includes:

• Source (NPR).
• Interviewee name.
• Main topic.

Tips for audio descriptions

When crafting alt text for audio, keep these tips in mind:

1. Be concise yet informative.
2. Include key names, titles, or topics.
3. Indicate the type of audio content.
4. Provide context if necessary.
5. Avoid unnecessary words like audio or file.

Remember, the goal is to give users who cannot hear the audio a clear idea of its purpose and content. By following these guidelines, you can ensure that your audio content remains accessible and informative for all users.

Metadata

Proper metadata helps assistive technologies understand the nature and purpose of audio and video content.

• Include relevant keywords in HTML5 track elements for captions and subtitles.
• Use structured data markup (e.g., JSON-LD) to provide machine-readable information about audio and video content.

Example HTML5 track element:

<track kind="captions" label="English Captions" src="english.vtt" srclang="en">

Additional tips

• Consider using automated transcription tools to generate text alternatives, but always review and edit the output to ensure accuracy and quality.
• Provide a clear indication of when the text alternative is being updated or revised.
• Consider providing a feedback mechanism for users to report errors or suggest improvements to the text alternative.

Captions vs. subtitles for videos

Captions and subtitles are essential for individuals who are deaf or hard of hearing.

The main difference between captions and subtitles lies in their purpose. Captions are a text version of the spoken part of a video, primarily used to help viewers who cannot hear the audio and also describe other sounds like music, sound effects, and speaker identification.

Subtitles provide a translation, typically including dialogue, for viewers who don’t understand the language being spoken.

All videos with audio components should have accurate, synchronized captions. Users should ideally be able to turn captions on or off based on their needs and preferences.

In summary, subtitles are intended for people who are deaf or hard of hearing and in situations where the audio cannot be played, while subtitles are intended for people who do not understand the language in which the video is spoken.

Enhancing accessibility and SEO

Benefit from search engine optimization

Integrating video captions and audio transcriptions into your content strategy offers significant SEO benefits, enhancing both visibility and user engagement.

Enhanced search engine indexing and ranking

Search engines primarily rely on text to understand and index multimedia content. By providing captions and transcriptions, you create additional text for search engines to crawl, which improves the indexing of your videos. This allows search engines to better comprehend the context and themes of your content, leading to higher visibility in search results.

Important to remember is that closed captions are indexable by search engines, unlike open captions encoded into the video file.

Impact on AI search engines indexing

The text alternatives for audio and video, such as transcriptions or captions, can significantly improve video page indexing by AI search engines. This is because AI search engines use natural language processing to understand and analyze text-based content more accurately. By providing text alternatives, you help these search engines to better comprehend the context and relevance of the audio or video content, making it more discoverable for users.

For instance, when a video includes a transcript that accurately reflects its spoken content, search engines can extract keywords and phrases from this text. This allows them to understand what the video is about more comprehensively than if they were relying solely on metadata (like titles and descriptions) or visual cues alone.

Structured data

Implementing structured data for videos, including information about transcripts and captions, can further enhance indexing. This structured data helps search engines categorize and display your video content more effectively.

Video indexing reports

Google Search Console provides reports on video indexing, which can show how well your video pages are indexed. Pages with comprehensive text alternatives are more likely to be indexed successfully, as they provide valuable content that search engines can crawl.

Better keyword strategy alignment

Transcriptions and captions serve as a rich source of keyword data. By including relevant keywords naturally within the text, you signal to search engines what your video is about. This can help your content rank for a wider variety of search terms, increasing the likelihood of attracting targeted traffic.

Increased engagement and retention

Captions enhance the user experience by making videos accessible to a broader audience, including those who are deaf or hard of hearing, as well as viewers in sound-sensitive environments. Meta studies have shown that videos with captions see increased engagement, as they cater to users who may prefer watching without sound. For instance, videos with captions can experience a significant boost in view time, contributing to better SEO outcomes.

Greater accessibility

Closed captions not only improve SEO but also ensure that content is accessible to all users, including non-native speakers and those with hearing impairments. This inclusivity can foster positive brand perception and loyalty, as consumers increasingly value socially responsible practices.

Opportunities for content repurposing

Transcriptions provide a textual format that can be repurposed for various content types, such as blog posts or social media snippets. This not only enhances your SEO strategy by creating more content for indexing but also helps in building internal links, which can further improve site navigation and authority.

Incorporating video captions and audio transcriptions is a strategic move that enhances SEO by improving search engine indexing, keyword optimization, and user engagement. Additionally, it promotes accessibility, making your content more inclusive and appealing to a wider audience. By leveraging these tools, content creators can significantly boost their online visibility and engagement metrics.

Ensuring media accessibility

Ensure accessibility of media players

When using media players, ensure they support accessibility features such as captions, audio descriptions, and keyboard navigation. This ensures that everyone, including individuals with disabilities, can fully interact with and understand the audio and video content.

When implementing audio or video players, prefer native, built-in players in the browsers.

Follow WCAG guidelines

Adhere to the Web Content Accessibility Guidelines (WCAG), specifically WCAG Success Criteria 1.2.1 for audio-only and video-only content and WCAG Success Criteria 1.2.2 for captions. These guidelines provide a framework for making audio and video content accessible.

Legal considerations

Many countries have laws requiring captioning for certain types of content:

• ADA compliance in the United States.
• European Accessibility Act in Europe and other places that adopted EAA.
• Canadian Radio-television and Telecommunications Commission (CRTC) requirements.

Code examples

Video example

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Video with captions, subtitles, and transcript</title>
</head>
<body>
    <h1>Video title: exploring nature</h1>

    <video width="640" height="480" controls>
        <source src="nature_video.mp4" type="video/mp4">
        <track kind="captions" src="nature_captions.vtt" srclang="en" label="English">
        <track kind="captions" src="nature_captions.es.vtt" srclang="es" label="Spanish">
        <track kind="subtitles" src="nature_subtitles.vtt" srclang="en" label="English">
        <track kind="subtitles" src="nature_subtitles.es.vtt" srclang="es" label="Spanish">
        <p>Your browser does not support the HTML video element.</p>
    </video>

    <h2>Transcript</h2>
    <pre>
        [00:00] Introduction to nature exploration
        [00:30] Walking through the forest
        [01:15] Observing wildlife
        [02:00] Discussing environmental impact
        [03:00] Conclusion
    </pre>

    <h3>Alternative text description</h3>
    <p>This video features a person walking through a lush forest, observing various plants and animals. The camera pans across trees, showing leaves rustling in the wind. The speaker discusses the importance of preserving natural habitats and the interconnectedness of ecosystems.</p>
</body>
</html>

Audio example

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Audio with captions, subtitles, and transcript</title>
</head>
<body>
    <h1>Audio title: environmental impact lecture</h1>

    <audio controls>
        <source src="environmental_impact_audio.mp3" type="audio/mpeg">
        <track kind="captions" src="environmental_impact_captions.vtt" srclang="en" label="English">
        <track kind="captions" src="environmental_impact_captions.es.vtt" srclang="es" label="Spanish">
        <track kind="subtitles" src="environmental_impact_subtitles.vtt" srclang="en" label="English">
        <track kind="subtitles" src="environmental_impact_subtitles.es.vtt" srclang="es" label="Spanish">
        <p>Your browser does not support the HTML audio tag.</p>
    </audio>

    <h2>Transcript</h2>
    <pre>
        [00:00] Introduction to environmental impact
        [00:45] Effects of pollution on ecosystems
        [02:20] Climate change and its consequences
        [04:05] Renewable energy solutions
        [06:00] Conclusion and call to action
    </pre>

    <h3>Alternative text description</h3>
    <p>This audio lecture discusses the effects of human activity on the environment. The speaker explains how pollution harms ecosystems, describes the impacts of climate change, and suggests renewable energy alternatives. The talk concludes with a call to action for listeners to reduce their carbon footprint.</p>
</body>
</html>