Glossary · Accessibility term
CART
Also called: Communication Access Realtime Translation, realtime captioning
CART is live captioning written by a person rather than a machine, and the letters stand for Communication Access Realtime Translation. A trained captioner writes on a steno machine into realtime software, and the words land on a screen, a laptop, a tablet or a phone a second or two behind the speaker. What you are buying is accuracy. The service is word for word by definition and it carries environmental sound as well as speech, because a caption that drops the fire alarm has not described the room. The credential to ask a supplier for is Certified Realtime Captioner, which is passed by writing at 180 words a minute at 96% accuracy. That pair of numbers is the thing to hold a quote against, and it is why automatic speech recognition is a different purchase rather than a cheaper version of the same one. Most CART now arrives remotely, so the captioner does not have to be in the room.
In practice
Book it the way you would book an interpreter, which means early and with material sent ahead. A captioner writing your product names, your executives' names and your acronyms for the first time will get them wrong at speed, and every one of those errors lands on screen in front of the room. Send a glossary, the running order and any slides. Ask how the text will be displayed, because the answer changes the room. A projected screen serves everybody, a second monitor serves one person, and a private link on somebody's own phone serves them without announcing to the room that they need it.
Understand what you are choosing between. Automatic speech recognition is instant, cheap and unattended, and it degrades exactly where a live event is hardest, on accents, crosstalk, background noise and any word it has never met. CART is a person, so it costs more and it holds up under all four. WCAG sets an outcome rather than a method, so nothing forbids automatic captions. What decides it is whether the captions on the day carry the meaning, and on a high-stakes event that is not a gamble worth taking.
CART and a sign language interpreter are two accommodations for two groups, not two ways of doing one thing. Somebody whose first language is a signed language is reading a second language on that screen. Somebody who lost their hearing later in life may not sign at all. Ask what people need rather than picking one and calling the event covered.
Why it matters
Live captioning is one of the accessibility jobs where the standard is easy to state and the buying is where it goes wrong. The criterion at Level AA asks for captions on live synchronised media and says nothing about how good they have to be, so a purchasing decision made on price alone can technically produce captions and still leave the audience it was bought for unable to follow. The 180 words a minute at 96% accuracy behind the professional credential gives you something to hold a supplier to, and it is the number nobody quotes at you when they are selling automatic captions instead.
What word for word actually includes
A speaker breaks off mid-sentence and the room laughs. The fire alarm sounds during the closing question. Somebody's phone rings twice. A CART transcript carries all three, because the definition covers environmental sound as well as speech. A caption track that reports only the words has told a deaf attendee what was said and left them the only person in the room who does not know why everybody stood up.
Where this shows up on the site
Related terms
- CaptionsCaptions are a synchronized text version of everything you would hear in a video, covering speech and the non-speech sound that matters as well.
- TranscriptA transcript is the text version of audio or video, and two different things go by that one word.
- Real-time textReal-time text is a conversation in text where what you type reaches the other person as you type it, rather than when you press enter.
- Sign language interpretationSign language interpretation is a signed version of spoken content, usually a video track running alongside the main one.
Knowing the word is the easy part.
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