Glossary

Searchable terminology from accessibility, web standards, and related fields.

17 results found in Media Accessibility.

Chroma Key (Green Screen, Blue Screen, Chroma Keying)
A video-post-production technique in which a solid, uniformly coloured background (often green or blue) is replaced with another image, video, or transparency using colour-matching software. In access…
Educational Video (Instructional Video, Video Lecture)
Video content created to teach - including talking-head lectures, screencasts, animations, hand-drawn (Khan-style) explanations, recorded classroom sessions, programming/coding demonstrations, intervi…
Interpretive Alt Text
Alt text that goes beyond objective, functional description to convey interpretive dimensions of an image such as mood, symbolism, narrative, and aesthetic effect. It is most relevant for images where…
Mimetic Language (Sound Symbolism, Phonomimes, Ideophones)
Words or vocalizations whose sounds imitate or evoke the sensory qualities of what they describe, such as the rustle of leaves, the thud of a drum, or the hiss of escaping air. Mimetic language sits a…
Non-diegetic Sound (Non-diegetic Audio, Extradiegetic Sound)
Sound in film, television, or games that does not originate from any source within the story world and cannot be heard by the characters - for example, orchestral score, voice-over narration, or added…
Object-Based Audio (OBA, Object-Based Broadcasting)
An audio production and delivery paradigm in which speech, music, effects, and ambience are transmitted as discrete objects with metadata describing their role and relationships, rather than as a sing…
Participatory Captioning
A framework proposed by Nguyen et al. (2026) that characterises social media video captioning as a collaborative, community-sustained infrastructure co-produced by viewers, creators, and platforms — r…
Playhead (Play Head, Cursor Position)
The visual indicator on a video or audio timeline that shows the current playback position, typically a vertical line or triangle marker that moves in time with the media. Playheads are a core primiti…
Podcast (Podcasting)
An episodic, on-demand audio programme distributed over the internet, typically via RSS or proprietary platforms such as Spotify, Apple Podcasts, and BBC Sounds. Podcasts are a dominant form of long-f…
Read-Along (Read Along, Synchronised Highlighting, Karaoke-style Highlighting)
An accessibility pattern in which on-screen text is highlighted word-by-word or phrase-by-phrase in synchronisation with spoken audio. Used in children's reading apps, language-learning tools, accessi…
Scrubbing (Video Scrubbing, Timeline Scrubbing)
The interaction of dragging a playhead across a video or audio timeline to preview content at arbitrary positions, typically with real-time visual or audio feedback. Scrubbing is ubiquitous in video e…
Social Media Video Captions (SMVC)
An umbrella term for the textual or symbolic elements — platform-generated captions, creator-edited captions, user-generated captions, and non-speech information such as sound effects, music cues, or …
Sound Design (Audio Design)
The craft of creating, selecting, and arranging audio elements - dialogue, music, ambient sound, foley, and effects - to shape the experience of a film, game, broadcast, or interactive product. For ac…
Speaker Diarisation (Speaker Diarization, Speaker Segmentation)
The automatic process of segmenting an audio recording by speaker identity — answering "who spoke when" — and labelling each segment. A critical pre-requisite for accessible transcripts of multi-voice…
Subtitle (Subtitles, Open captions (video), Movie subtitles)
On-screen text that reproduces the spoken dialogue of a video, most commonly rendered in a "movie subtitle" style (white text with a black outline, one or two lines at the bottom of the frame). Subtit…
Talking-Head Video (Talking Head)
A common educational video format in which a presenter speaks directly to the camera, typically filling the frame, with no or few accompanying visuals. For d/Deaf and Hard-of-Hearing learners, talking…
YouDescribe
A free web platform operated by the Smith-Kettlewell Eye Research Institute that enables volunteers to crowdsource audio descriptions for YouTube videos. Viewers can request a video be described and s…