Closed captioning is important for deaf so they can actually know what's going on in the show and what people are saying. Even if they can can lip-read, it is really hard and you might miss some words and sometimes the person talking isn't on screen. Also on some shows and movies, you would need descriptions on what's going on. An example would be if you're watching a horror movie and you hear footsteps creaking or a door slamming or ominous music starts playing.

Why Closed Captioning is Important