Captioning and accessibility glossary
Definitions for terms used in live captioning, accessibility, and event production. 30 entries — covering ASR, CART, WCAG 2.2, ADA, SDH, SRT, and more.
A
Accessibility statement
A public document on a website or event page describing what accessibility provisions are available — captions, ASL on request, accessible registration, etc.
ADA
also: Americans with Disabilities ActThe Americans with Disabilities Act — US federal civil rights law prohibiting disability discrimination, increasingly applied to digital experiences including virtual events.
ASL
also: American Sign LanguageAmerican Sign Language — the primary sign language of Deaf communities in the US and parts of Canada, distinct from English in grammar and vocabulary.
ASR
also: Automatic Speech Recognition, speech recognition, STT, speech-to-textAutomatic Speech Recognition — the technology that converts spoken audio into text, used by all automated captioning systems.
Audio description
also: AD, described videoA separate narration track describing visual content for blind and low-vision audiences — for video content where visuals carry information not conveyed in dialogue.
C
Captioner
A general term for someone who produces captions — encompassing stenographers, voice-writers, and editors of automated captions.
CART
also: Communication Access Realtime TranslationCommunication Access Realtime Translation — human-driven live captioning produced by a trained captioner using a stenography system.
Closed captions
also: CCCaptions that the viewer can toggle on or off — typically rendered as overlay text on video, controlled by the playback environment.
Custom vocabulary
also: custom dictionary, vocabulary boostA 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.
D
E
Effective communication
The legal standard under the ADA requiring that communications with people with disabilities be 'as effective as' communications with non-disabled people.
EN 301 549
European harmonized accessibility standard for ICT (information and communication technology), incorporating WCAG 2.1 AA and additional functional requirements.
H
L
O
R
S
SDH
also: Subtitles for the Deaf and Hard of HearingSubtitles for the Deaf and Hard of Hearing — same-language captions that include non-dialogue audio cues like [APPLAUSE] or [DOOR SLAMS].
Section 508
A section of the US Rehabilitation Act requiring federal agencies' information technology to be accessible — typically benchmarked against WCAG 2.0 AA or higher.
Speaker labels
also: speaker identificationLabels in a transcript indicating who is speaking at each segment — often displayed as 'Speaker 1:' or replaced with actual names in post-processing.
SRT
also: SubRip Subtitle, .srtSubRip Subtitle — the most common subtitle file format, plain-text with sequential entries containing timing and text.
Stenographer
also: court reporter, steno captionerA trained professional who produces verbatim text of spoken content using a stenography machine — the traditional human captioner role.
STT
also: speech-to-text, ASRSpeech-to-Text — alternative name for Automatic Speech Recognition (ASR), used interchangeably in most contexts.
Subtitles
Text rendering of dialogue, traditionally for translation rather than accessibility — though usage has blurred in recent years.
T
Transcript
A complete text record of spoken content from an event, typically with timestamps and speaker labels.
Translation
also: live translation, real-time translationProducing captions in a different language from the speaker's source language — typically built on top of source captions in modern captioning systems.
V
W
WCAG 2.2
also: Web Content Accessibility Guidelines 2.2Web Content Accessibility Guidelines, version 2.2 — the accessibility standard that underlies most institutional and regulatory accessibility requirements for digital content.
WebVTT
also: VTT, .vtt, Web Video Text TracksWeb Video Text Tracks — the W3C-standardized subtitle/caption format for the web, supporting styling and positioning that SRT lacks.
WER
also: word error rateWord Error Rate — the standard accuracy metric for speech recognition, measuring the percentage of words incorrectly transcribed.