What is captioning?
Captioning is the process of converting the audio content of a video into text and displaying the text on a screen or monitor. Captions not only display words as the textual equivalent of spoken dialogue or narration, but they also include non-dialogue information needed to understand the content, including speaker identification, sound effects, and music description. MIT and NAD have agreed to the following definition of captioning, which is based on captioning standards included in the WCAG 2.0 and 2.1 guidelines.
I. to overlay or externally embed synchronized visual text for speech and provide non-dialogue audio information needed to understand the program content, including speaker identification, sound effects, and music description, on a digital media file at an accuracy rate equal to that offered by a vendor captioning service such as 3PlayMedia and in a manner consistent with industry standards regarding synchronicity, completeness, and proper placement; and
II. in the case of “audio-only” files or video files for which overlaid or externally embedded captioning is not technically feasible to prepare and provide a text-only transcript or link to such transcript.