By January 1, 2014, new internet websites and web content on those sites must conform with WCAG 2.0 Level A.
As of January 1, 2021, all internet websites and web content must conform with WCAG 2.0 Level AA, other than, success criteria 1.2.4 Captions (Live), and success criteria 1.2.5 Audio Descriptions (Pre-recorded).
Making mulitmedia (video, podcasts, and other audio files) accessible means adding a text equivalent of spoken words through captions, transcripts, or description of the audio. In order to be fully accessible to the maximum number of users, web multimedia should include both synchronized captions AND a descriptive transcript.
Captions provide a text equivalent of the audio presented within multimedia. Captions allow the content of web audio and video to be accessible to those who cannot hear the audio. Captioning not ensures accessibility to individuals who have a hearing impairment but they also improve access to those indiviudals for whom an additional textual representation of the verbal and auditory is an important learning support. For example, individuals for whom English is not a first language.
Captions are either open or closed. Open Captions are always in view and cannot be turned off. Open Capitons look and display the same information as closed captions except they cannot be turned off. They are a permanent part of the video and are always displayed much like subtitles in a foreign language film. Closed Captions can be turned on and off by the viewer.
Captions not only display words as the textual equivalent of spoken dialogue or narration, but they also include speaker identification, sound effects, and music description.
Web accessibility guidelines indicate that captions should be synchronized at approximately the same time that audio is available. Captioning a video on the Internet involves embedding a file that contains time synchronized text along with the video. The primary multimedia technologies on the Internet are Microsoft's Windows Media Player, Apple's Quicktime, RealNetwork's RealPlayer, and Macromedia Flash. Each media player handles captions differently.
Please note that for materials not created by you, or that you do not hold the copyright for, you first need to obtain permission to create a captioned copy of the video or audio file.
For most web videos, both captions and a text transcript should be provided. Transcripts also provide an important part of making web multimedia content accessible. Transcripts allow anyone that cannot access content from web audio or video to read a text transcript instead. Transcripts do not have to be verbatim accounts of the spoken word in a video. They can contain additional descriptions, explanations, or comments that may be beneficial.
Screen reader users may also prefer the transcript over listening to the audio of the web multimedia.
Transcripts can be created by using speech recognition software such as Dragon Naturally Speaking or speech-to-text built into Windows or Mac OSX Lion. The results should be reviewed for errors, especially when the audio is low-quality or when unusual words are used.
For Audio Resources:
For Video Resources: