The 21st Century Communications and Video Accessibility Act was passed by Congress to update our nation’s telecommunications protections for people with disabilities. The CVAA follows a string of laws, passed in the 1980s and 1990s that were designed to ensure that telephone and television services would be accessible to all Americans with disabilities. The 'Audible Crawl Rule' requires that emergency information is available in an audible format as well as the traditional crawl that is often scrolled across the viewer’s TV screen. This information is available on the SAP (secondary audio program) of your television or set top box.
Below are instructions on activating this feature:
1.) The "Spanish" channel (second audio) is used to pass the audio for the visually impaired viewers called Text To Speech (TTS).
2.) If you do not hear audio, check to make sure your TV or set top box has the audio set to ENGLISH.
3.) The TTS audio on the second audio channel will have an aural version of any crawl information put onto it. During NBC programming it will have the "Video descriptor" audio that NBC provides.
4.) During non-NBC programming that audio channel will be silent.
Below are several links to TV assistance, for changing from Spanish to English on TVs and set top boxes.