1.2.4 Captions (Live)
1.2.4 Captions (Live): Captions are provided for all live audio content in synchronized media.
This SC supports the principle of Perceivable because individuals without hearing or with limited hearing cannot “perceive” information presented with the use of sound. The intent of this SC is to provide synchronized (live) captions of broadcasts to people who are without hearing or with limited hearing with a visual alternative to sound while they are watching synchronized media presentations to receive the same information provided through audio.
Impact of Nonconformance with SC 1.2.4 Captions (Live)
| Type of Disability | Description of Impact |
|---|---|
| 302.4 Without Hearing | When ICT provides information, instructions, or cues audibly, users who are deaf will not receive the information. Typically, providing the same information visibly (e.g., providing a warning light or textual dialog to accompany an audible warning sound or captions for audio dialog and other audible information in a video) will enable users who are deaf to get equivalent information. |
| 302.5 With Limited Hearing | Some users cannot hear sounds below certain volumes or at certain frequencies and may not be able hear certain audio outputs from ICT. Background noise can also be problematic for users with limited hearing. Providing modes of operation that enhance audio clarity (e.g., filtering out hisses and pops, blocking sounds at specific frequencies, normalizing voice volumes, removing constant tone patterns), increase the range of volume, increase volume at higher frequencies, and/or give users control over such settings can help users with limited hearing understand, navigate, and operate the ICT. Users with limited hearing may also benefit from some of the same methods used to provide information to users without hearing. |
| 302.9 With Limited Language, Cognitive, and Learning Abilities | Some users require more time than average to process information while others may find complicated instructions difficult to follow. Furthermore, some ICT content can distract or overwhelm users, preventing them from being able to interact with or understand other ICT content. Designers and developers of ICT must consider a broad range of cognitive abilities in order to provide ICT that is simple and easy to use. |
Applicability of Success Criteria 1.2.4 Captions (Live)
| Technology | Applicability of SC 1.2.4 |
|---|---|
| Web | Applies directly; captions must be provided for live audio content in synchronized media and transmitted to the receiver with no more than a broadcast delay. Captions convey not only the content of spoken dialogue, but also equivalents for non-dialogue audio information needed to understand the program content, including sound effects, music, laughter, speaker identification and location. Depending on the format and/or media player, open captions (always visible) in the synchronized media may be used or the media player may allow users to optionally display closed captions. Finally, developers must be aware that the Revised Section 508 Standards require that caption controls in media players must be available at the same menu level as controls for volume and program selection. |
| Software | Applies directly; software developers can provide captions for live audio content in synchronized media with a variety of methods. Such methods may rely on both file format and the media player used to present the synchronized media and the captions. Depending on the format and/or media player, developers may need to provide open captions in the synchronized media or ensure that the selected media player allows users to optionally display closed captions. Finally, developers must be aware that the Revised Section 508 Standards require that caption controls in media players must be available at the same menu level as controls for volume and program selection. |
| Office Documents | Applies directly; depending on the type of document, authors may embed particular types of media files directly in the document and/or stream media from online sources (e.g., YouTube™), assuming a live internet connection. Media embedded directly within a document may rely on a native player or the default Operating System player. In either case, authors may not be able to predict whether the player will provide the ability to display closed captions. In such cases, providing open captions would ensure that all users have access to the captions. |
| PDF Documents | Applies directly; depending on the PDF authoring tool and/or the end user’s PDF viewer, it may be possible to embed media files directly within a PDF document or stream media from an online source, such as YouTube™. For example, Adobe Reader 9 and later can play media files that are H.264-compliant in a native media player. However, the native player does not provide caption controls at the same menu level as the volume and program selection, which does not conform to the Revised Section 508 Standards. When a PDF author cannot predict whether the end user’s media player can display captions, providing open captions would ensure that all users have access to the captions. |
| Mobile Narrative | Applies directly; software developers can provide captions for live video content in synchronized media with a variety of methods. Such methods may rely on both file format and the media player used to present the synchronized media and the captions. Depending on the format and/or media player, developers may need to provide open captions in the synchronized media or ensure that the selected media player allows users to optionally display closed captions. Finally, developers must be aware that the Revised Section 508 Standards require that caption controls in media players must be available at the same menu level as controls for volume and program selection. |