Closed Captions
A Closed Caption is a textual video overlay that is not always visible on the display. It is instead, an optional feature that can be used to get textual representation of audio. This is suitable for the hearing impaired as it displays not only the dialog, but also describes other sounds to be heard from the audio track. The NTSC Closed Caption standard requires that any TV set larger than 13 inches must be capable of decoding and displaying Captions.