Captioning and accessibility glossary

A public document on a website or event page describing what accessibility provisions are available — captions, ASL on request, accessible registration, etc.

The Americans with Disabilities Act — US federal civil rights law prohibiting disability discrimination, increasingly applied to digital experiences including virtual events.

American Sign Language — the primary sign language of Deaf communities in the US and parts of Canada, distinct from English in grammar and vocabulary.

Automatic Speech Recognition — the technology that converts spoken audio into text, used by all automated captioning systems.

A separate narration track describing visual content for blind and low-vision audiences — for video content where visuals carry information not conveyed in dialogue.

A general term for someone who produces captions — encompassing stenographers, voice-writers, and editors of automated captions.

Communication Access Realtime Translation — human-driven live captioning produced by a trained captioner using a stenography system.

Captions that the viewer can toggle on or off — typically rendered as overlay text on video, controlled by the playback environment.

A per-event list of domain-specific terms (product names, technical jargon, speaker names) supplied to an ASR system to improve transcription accuracy on those terms.

The process of identifying which speaker is talking at any given moment — answering 'who said what' in a multi-speaker recording.

The legal standard under the ADA requiring that communications with people with disabilities be 'as effective as' communications with non-disabled people.

European harmonized accessibility standard for ICT (information and communication technology), incorporating WCAG 2.1 AA and additional functional requirements.

An event with both in-person and remote attendees sharing the same speakers and program.

The delay between a word being spoken and the corresponding caption appearing on the audience's screen.

Real-time text rendering of spoken audio, displayed alongside an event as it happens.

Captions that are permanently embedded in the video frame — visible to all viewers, not toggleable.

A synonym for live captioning — captions produced and displayed during the event, not afterwards.

Subtitles for the Deaf and Hard of Hearing — same-language captions that include non-dialogue audio cues like [APPLAUSE] or [DOOR SLAMS].

A section of the US Rehabilitation Act requiring federal agencies' information technology to be accessible — typically benchmarked against WCAG 2.0 AA or higher.

Labels in a transcript indicating who is speaking at each segment — often displayed as 'Speaker 1:' or replaced with actual names in post-processing.

SubRip Subtitle — the most common subtitle file format, plain-text with sequential entries containing timing and text.

A trained professional who produces verbatim text of spoken content using a stenography machine — the traditional human captioner role.

Speech-to-Text — alternative name for Automatic Speech Recognition (ASR), used interchangeably in most contexts.

Text rendering of dialogue, traditionally for translation rather than accessibility — though usage has blurred in recent years.

A complete text record of spoken content from an event, typically with timestamps and speaker labels.

Producing captions in a different language from the speaker's source language — typically built on top of source captions in modern captioning systems.

Captioning that captures every spoken word exactly, including filler words, false starts, and disfluencies — as opposed to clean-read captioning that smooths the speech.

Web Content Accessibility Guidelines, version 2.2 — the accessibility standard that underlies most institutional and regulatory accessibility requirements for digital content.

Web Video Text Tracks — the W3C-standardized subtitle/caption format for the web, supporting styling and positioning that SRT lacks.

Word Error Rate — the standard accuracy metric for speech recognition, measuring the percentage of words incorrectly transcribed.