Category: Visual and Media Accessibility

Audio Description

Also known as: AD, Video Description, Described Video, Descriptive Narration

Simply put

Audio description is a spoken narration track that describes important visual information in a video, film, live performance, or other media that a person cannot understand from the audio alone. It helps people who are blind or have low vision follow key visual elements such as actions, scene changes, and on-screen text. These descriptions are commonly inserted into natural pauses in the existing dialogue or soundtrack.

Formal definition

Audio description is a supplementary narration track that verbally conveys meaningful visual content, such as actions, characters, scene changes, settings, and on-screen text, that is not otherwise accessible through the primary audio. In the Web Content Accessibility Guidelines (WCAG), this technique is referred to as 'audio description'; in some regions and documents it is also called 'video description' or 'described video.' Descriptions are typically inserted into existing pauses in dialogue and soundtrack, and audio description is applied across media types including filmed content, television, live performances, and museum experiences.

Why it matters

Audio description bridges a gap that captions and dialogue alone cannot close. For people who are blind or have low vision, a video's spoken audio often omits critical visual information, who is on screen, where a scene takes place, what action is unfolding, or what text appears on the screen. Without a description of these elements, the narrative or instructional value of media can be lost or become confusing. By verbally conveying key visual content, audio description allows these viewers to follow content more fully and independently.

The need for audio description spans a growing range of media. According to the American Council of the Blind's Audio Description Project, audio description is becoming increasingly available across filmed media, live performances, museums, and more. In the United States, the Federal Communications Commission addresses audio description for television programming, describing it as audio-narrated descriptions of a program's key visual elements inserted into natural pauses. This reflects that access to visual media is treated as a meaningful component of accessibility rather than an optional enhancement.

Within technical accessibility guidance, the Web Content Accessibility Guidelines (WCAG) reference this technique as 'audio description,' making it relevant to organizations working toward WCAG conformance for video content. Providing audio description is one part of a broader accessibility effort, and it does not on its own guarantee an accessible experience or legal compliance. Specific obligations vary by jurisdiction, medium, and applicable regulation, for example, television requirements may differ from those affecting web content or physical venues, so organizations should consult current agency rulemaking and qualified legal counsel regarding their particular circumstances. This entry is informational and is not legal advice.

Who it's relevant to

People who are blind or have low vision

Audio description is designed primarily for viewers who cannot perceive key visual content from the audio alone. It helps them follow actions, scene changes, characters, settings, and on-screen text, supporting a more complete and independent experience of the media.

Video producers and media creators

Teams producing filmed content, television, live performances, and museum experiences may need to plan for audio description in their workflows. This includes writing descriptions that fit into natural pauses in the dialogue and soundtrack and adapting the approach to the medium.

Accessibility and compliance professionals

Those working toward WCAG conformance for video content will encounter audio description as a referenced technique in the guidelines. Because conformance requirements evolve and vary by medium and jurisdiction, these professionals should verify current standards and applicable regulations for their context.

Broadcasters and television programmers

In the United States, the Federal Communications Commission addresses audio description for television programming. Broadcasters and distributors of televised content should review current FCC guidance to understand how audio description applies to their programming.

Cultural and public venues

Museums and organizations hosting live performances are increasingly making audio description available. Staff planning exhibits or events can use audio description to convey visual elements to visitors who are blind or have low vision.

Inside AD

Narrated Description of Visual Content

A spoken narration track that conveys important visual information, such as actions, characters, scene changes, on-screen text, and other visual details, that is not otherwise available through the program's dialogue or soundtrack.

Standard (Fitted) Audio Description

Description inserted into the natural pauses between dialogue, without altering the original program timing. This is the most common form but is constrained by the length of available gaps in the audio.

Extended Audio Description

Description in which the video is paused to allow additional narration when natural pauses are too short to convey necessary visual information. This approach is referenced in WCAG under the Extended Audio Description success criterion, which is a higher-level (AAA) requirement.

Relationship to WCAG Success Criteria

Audio description is addressed in WCAG's Time-based Media guidelines. Success criteria commonly cited as targets address audio description or media alternatives for prerecorded synchronized media, with certain criteria at Level A and others at Level AA; extended audio description is addressed at Level AAA. Practitioners should verify the specific criterion and level against the WCAG version they are applying.

Scope: Prerecorded vs. Live

Audio description requirements in WCAG generally focus on prerecorded synchronized media. Live content and audio-only content have different or separate provisions, and audio description is not applicable to media that contains no meaningful visual information.

Common questions

Answers to the questions practitioners most commonly ask about AD.

Is audio description the same as captioning?

No. Captions convey spoken dialogue and important non-speech sounds as on-screen text, primarily serving people who are deaf or hard of hearing. Audio description is a separate track of narration that conveys important visual information, such as actions, settings, characters, and on-screen text, for people who are blind or have low vision. The two address different sensory needs and are generally required independently rather than as substitutes for one another.

Do I need to describe everything happening on screen?

No. Audio description conveys visual information that is important for understanding the content and that is not already available through the existing audio. Narration is typically inserted during natural pauses in dialogue, so it focuses on the elements essential to comprehension rather than describing every visual detail. Over-describing can crowd the audio and reduce usefulness.

How does audio description relate to WCAG success criteria?

WCAG addresses audio description through several success criteria for prerecorded synchronized media. Provisions at Level A and Level AA commonly address audio description for prerecorded video, and there is a higher-level provision addressing extended audio description. Because the specific criteria and their conformance levels differ across WCAG versions, you should consult the applicable version and confirm which criterion and level apply to your content.

When are natural pauses insufficient, and what is extended audio description?

Standard audio description fits narration into the existing pauses in a program's audio. When those pauses are too short to convey the necessary visual information, extended audio description may be used: the media is paused to allow additional narration before playback resumes. This approach is generally associated with a higher WCAG conformance level and is used when standard description cannot adequately convey essential visual content.

Can audio description be automated?

Automated tools may assist parts of the workflow, but determining which visual information is essential, writing concise description, and timing it to natural pauses generally involve human judgment. As with accessibility work broadly, automated processes address only a portion of the task, and human review is commonly needed to produce usable results.

Does providing audio description guarantee compliance or an accessible experience?

No single measure guarantees legal compliance or a fully accessible experience. Providing audio description addresses specific visual-access needs and may help meet relevant WCAG criteria, but overall accessibility depends on many factors, and legal obligations depend on the applicable authority, jurisdiction, and evolving case law and regulation. This entry is not legal advice; consult qualified legal counsel and current agency guidance for your situation.

Common misconceptions

Captions and audio description serve the same purpose, so providing captions is enough.

Captions primarily serve users who are deaf or hard of hearing by conveying spoken dialogue and important sounds as text, while audio description primarily serves users who are blind or have low vision by narrating important visual information. They address different needs and are generally treated as distinct requirements.

Any video with narration or a voiceover already satisfies audio description requirements.

General narration or voiceover that is part of the original program is not the same as audio description. Audio description specifically fills in visual details not conveyed by the existing dialogue or soundtrack, and it must be evaluated against the relevant WCAG success criterion rather than assumed to be present.

Meeting the WCAG audio description criteria guarantees the content is fully accessible and legally compliant.

Meeting a success criterion does not by itself guarantee an accessible experience for all users or immunity from legal claims. Manual review and testing with assistive technology are needed to confirm the description is meaningful, and legal obligations depend on jurisdiction, regulation, and case law, matters for which qualified legal counsel should be consulted.

Best practices

Identify which WCAG version and conformance level you are targeting, then confirm the specific audio description success criterion that applies, noting that AA is commonly cited as a target while extended audio description sits at AAA.

Prioritize conveying essential visual information, actions, scene changes, on-screen text, and character details, that is not already available through dialogue or the existing soundtrack.

Use standard (fitted) description within natural pauses where possible, and consider extended audio description when the available gaps are too short to convey necessary detail.

Do not rely on automated checks alone; verify audio description quality through manual review and testing with users or reviewers who rely on assistive technology.

Distinguish audio description from captions and from ordinary program narration, and provide each as needed rather than treating one as a substitute for the other.

Document your approach and consult qualified legal counsel or current agency guidance for questions about legal obligations, since requirements vary by jurisdiction and evolve through regulation and case law.