*Follow the links below for examples.
For accessibility purposes videos can be defined as moving visual images with or without synchronized sound. Examples include YouTube videos, motion pictures, and cartoon shows.
Common video file types include MP4, MOV, WMV and AVI.
Videos with sound must contain closed captions and videos without sound should have audio description.
Captions are the text format equivalent of the spoken audio from within a video. Captions address the need of users who cannot access audio. By providing content information via a textual format, all users, including your deaf users, stand to benefit.
Audio description is required when important information is visually shown on the screen that cannot be observed by a blind or vision-impaired individual.
For accessibility purposes audio files can be defined as multimedia content that uses sound only. Examples include podcasts and songs.
Common file formats include MP3, M4A, WAV, and WMA.
Text transcripts are a way for deaf and deaf-blind users to know the content of an audio podcast.
Transcripts include the verbatim dialogue (words spoken) and additional details, for example when there is laughter sound, the same should be mentioned in the transcript.
Resources
Deque University Multimedia Accessibility: Is it Important?