Captions are words displayed on a television, computer, mobile device, or movie screen, providing the speech or sound portion of a program or video via text. Captions allow viewers to follow the dialogue and the action of a program simultaneously. For people with hearing loss who have residual hearing, captions can make the spoken words easier to understand—because hearing, like vision, is influenced by our expectations. (When you have an idea of what someone might be about to say, his or her speech may seem more clear). Captions can also provide information about who is speaking or about sound effects that might be important to understanding a news story, political event, or the plot.

Captions are created from the program’s script or audio file. A caption writer translates the dialogue into captions and makes sure the words appear in sync with the audio. Computer software encodes the captioning information and combines it with the audio and video to create a new master tape or digital file of the program. The captions should appear near the bottom or top of the screen—not in the middle, where misplaced captions can cover the newscaster’s face, a basketball hoop or a quarterback passing the football.

A caption writer (sometimes trained as a court reporter or stenographer) uses a stenotype machine with a phonetic keyboard and special software. A computer translates the phonetic symbols into English captions almost instantaneously. The slight delay is based on the captioner writer’s need to hear and code the word, and on computer processing time. Pre-recorded programming (television shows, movies, documentaries) all should been seen with no errors at all.  Although real-time captioning strives to reach 98 percent accuracy, the audience will see errors. The caption writer may mishear a word, hear an unfamiliar word, or have an error in the software dictionary. In addition, transmission problems can create technical errors that are not under the control of the caption writer. Real-time captioning can be used for programs that have no script; live events, including congressional proceedings; news programs; and non-broadcast meetings, such as the national meetings of professional associations.


CART – Communication Access Realtime Translation

You’ve seen captions on television shows, Netflix, and in movie theaters. CART works in a similar way, transcribing and translating spoken text and sound into words. The text appears in realtime —while the words are spoken or played — on a big screen that everyone can see, on a laptop, or on a mobile device. Remote CART can also be streamed to an Internet browser.

CART helps make your event, speech, courtroom, classroom, workshop, seminar, church service, or meeting compliant with the Americans with Disabilities Act (ADA) and accessible to people who have a hearing loss. Hearing accessible technology and services are crucial to creating an inclusive event so that everyone can participate, regardless of how well they hear. When possible, an audio component should be considered as well: hearing assistive technology such as induction loops, FM, and infrared systems combined with CART provide the highest level of accessibility.

Even people with good hearing sometimes struggle to comprehend completely, especially in loud or noisy environments. CART helps those people, too, as well as people for whom English is a second language. And for people with significant difficulties hearing, CART can mean the difference between staying home and staying engaged.  

The text can be projected onto a screen, displayed on a computer monitor or laptop, or transmitted via the internet. People who need CART, and event and venue managers, should be aware that CART can be combined with PowerPoint or other presentation content—enabling people to view all content on one screen.

We offer the following guidance to help you create and develop the most effective and accurate CART for your event.

Planning for CART and Effective Communication 

Photo of two projection screens with captions.

  1. Select an experienced CART writer. Check to be sure the CART writer is a Certified Realtime Captioner with this certification: CRC. People who pass the CRC skills test provided by the National Court Reporters Association (NCRA) will have the high level of skill and accuracy needed to provide real-time, professional CART writing specifically designed to ensure that people who are deaf or hard of hearing have a full understanding of the event or proceeding. Also, be sure to check the CART writer’s resume to determine whether the individual has a background and experience adequate to match the demands of the job.
  2. Consider audio hearing access technology: hearing loops, FM, or infrared. It can be challenging and fatiguing to read every captioned word; both audio and visual solutions create the ideal.
  3. Send the CART writer copies of presentation materials (Powerpoint presentations, handouts, speeches) as much in advance as possible. This is especially crucial for names and technical terms that need to be correct and spelled properly. Consider sending the caption writer a glossary, bibliography, or staff/attendee list. If you have one, send the room layout chart.
  4. Clarify that you want CART on large screen when viewed by many people. Remember that several people huddled around a laptop is not the ideal solution and may leave out others who would benefit.
  5. Consider the best way to place screens for optimum viewing by the greatest number of people. Think “clear sight lines.”
  6. Make sure the caption writer is admitted to the event without admission fees and with early access to set up.
  7. The caption writer will need a table, reserved space (near the front), an electrical outlet and extension cord, and safety tape to secure the cord.

CART Just Before the Event 

  1. Make sure the display is visible to as much of the audience as possible.
  2. Make sure the font is large enough and stands out from the background.
  3. Make sure at least two lines show on each display, and that the captions remain visible long enough to be read.
  4. Test the display methods from each place in the room that someone may need to read them.
  5. Cover cords with tape so guests don’t trip. 
  6. Coach speakers to speak slowly, pause periodically, and enunciate carefully.
  7. Coach panelists to make sure one person speaks at a time, and to take breaks as needed.
  8. Provide tabletop name cards to presenters or panelists, if possible.

CART During the Event 

Photo of large screen with captions; interpreter standing next to screen.

  1. Monitor caption quality. Be confident in interrupting the speaker to ask that they stay near the microphone, speak more slowly, etc. Watch for repeated “inaudible” instances in the captions.
  2. Use a high quality sound system when possible. Remember that the caption writer must be able to hear clearly. Whenever possible, offer a direct feed to the caption writer via headphones.


See more about CART in action in this YouTube video.