Understanding Communication Access Real-Time Translation (CART)

Communication Access Real-Time Translation (CART) is a live transcription service that converts spoken language into text instantaneously, making spoken communication accessible to people who are Deaf, hard of hearing, or who have other communication access needs. Used across education, corporate events, broadcasts, and virtual meetings, CART is one of the most accurate and immediate forms of live captioning available. This guide covers what CART is, how it works, the accessibility standards it supports, and how AI-Media’s captioning services can help you deliver it. 

Key Takeaways

• CART stands for Communication Access Real-Time Translation: a live speech-to-text service delivering captions with minimal latency.
• It is primarily used in educational settings, live events, corporate meetings, and virtual conferences.
• CART can be delivered by a human stenographer, an AI-powered ASR system, or a hybrid of both.
• It differs from traditional closed captioning in its emphasis on real-time accuracy, verbatim output, and direct communication access.
• Legal frameworks including the ADA and WCAG 2.1 establish obligations for organisations to provide real-time captioning access in qualifying contexts.
• High-quality CART increases inclusion, engagement, and trust with Deaf and hard-of-hearing audiences.
• AI-Media offers human captioning and AI-powered solutions to support CART delivery across any format or platform.

What is Communication Access Real-Time Translation (CART)?

CART is a real-time speech-to-text transcription service in which spoken words are converted to on-screen text almost simultaneously with speech. Originally developed as a courtroom transcription method using stenography, CART has become a core accessibility tool across education, live events, and professional settings. A trained CART provider, or an AI system, listens to the audio and produces a verbatim transcript that appears on a screen, device, or captioning display for the viewer in near real time.

What distinguishes CART from other forms of live transcription is its verbatim accuracy standard. CART is designed to capture everything that is said, including false starts, filler words, and side comments, because the primary audience relies on the text as their sole access to the spoken content. This makes it distinct from other forms of captioning, which may use different approaches to formatting and presentation depending on the content, audience and delivery environment.

CART is used by a wide range of people. Its most direct beneficiaries are individuals who are Deaf or hard of hearing, but it also supports people with auditory processing disorders, those attending events in a language they are still developing fluency in, and participants in high-noise or acoustically challenging environments. In educational settings, CART has been shown to support broader student comprehension: a study published in the American Annals of the Deaf found that students with hearing loss who received CART services performed significantly better on assessments than those without access to real-time captioning.

Why is CART captioning used?

CART is used wherever spoken communication needs to be made immediately accessible in text form. In classrooms and universities, CART enables Deaf and hard-of-hearing students to follow lectures, discussions, and Q&A sessions without delay. In corporate environments, CART supports accessible meetings, webinars, and town halls for employees and attendees with hearing access needs. In live events and conferences, CART ensures that speakers’ words reach every audience member simultaneously, regardless of hearing ability.

The scale of the need is significant. According to the World Health Organization, over 1.5 billion people worldwide live with some degree of hearing loss, with 430 million experiencing disabling hearing loss. In the US alone, the National Institute on Deafness and Other Communication Disorders estimates that approximately 15% of adults report some trouble hearing. For these individuals, real-time captioning is not a convenience: it is a primary means of communication access in spoken environments.

CART also supports engagement beyond disability inclusion. Events and organisations that provide CART signal a genuine commitment to accessibility, which builds trust with Deaf communities and with broader audiences who value inclusive practice. Accessible events consistently report higher attendee satisfaction scores and stronger return participation from people who have previously been excluded by inaccessible formats.

How does CART transcription work?

CART transcription works by converting spoken audio into text in real time using one of three methods: human stenography, AI-powered automatic speech recognition (ASR), or a hybrid of both.

In a human CART workflow, a trained stenographer uses a specialised stenography machine to capture speech phonetically, at speeds of up to 225 words per minute. The stenography software translates the phonetic strokes into readable text, which is then transmitted to a display screen, laptop, or captioning platform accessible to the viewer. Human CART providers are the benchmark for verbatim accuracy, particularly in complex audio environments with multiple speakers, technical terminology, or strong accents.

AI-powered CART uses ASR technology to process audio in real time and produce a live transcript automatically. Modern ASR platforms have advanced significantly, delivering accuracy levels that are suitable for many live captioning contexts at a fraction of the cost and resource requirement of human stenography. AI-Media’s LEXI technology, for example, delivers broadcast-grade live captions with low latency and multilingual support, making AI-powered CART delivery scalable for organisations with high-volume or recurring captioning needs.

A hybrid model combines AI transcription with human review, where a CART provider monitors the AI output and corrects errors in real time. This approach balances the speed and scalability of AI with the accuracy assurance of human oversight, and is increasingly used for high-stakes live events where both precision and efficiency matter.

Regardless of the delivery method, the CART workflow typically follows this sequence:

• Audio is captured via microphone or direct feed from the event’s audio system.
• The CART provider or ASR engine processes the audio and produces a live text output.
• The text is transmitted to a caption display solution, such as a screen visible to the audience, a personal device, or an integrated platform window.
• The completed transcript is available after the session as an accessible record of proceedings.

Accessibility Requirements for CART Captions

Legal and technical accessibility standards establish clear obligations for organisations providing CART captioning across different contexts.

The Americans with Disabilities Act (ADA) requires that public accommodations and employers provide effective communication access for individuals with hearing disabilities. In practice, this means that educational institutions, event organisers, and employers may be required to provide CART or equivalent live captioning services when requested by a Deaf or hard-of-hearing participant. The ADA does not specify the technology to be used, but courts and regulators have consistently held that real-time captioning is an appropriate auxiliary aid in many contexts. Full ADA guidance on effective communication is available from the US Department of Justice.

WCAG 2.1 (Web Content Accessibility Guidelines) requires that live audio content delivered via web platforms include real-time captions at AA conformance level (Success Criterion 1.2.4). This applies to online meetings, live streams, webinars, and virtual events distributed via websites or apps. For organisations operating digital platforms in the US, EU, or Australia, WCAG 2.1 compliance is typically referenced in national accessibility legislation. View the full WCAG 2.1 guidelines here.

The Rehabilitation Act (Section 508) requires US federal agencies and federally funded organisations to ensure that their electronic and information technology is accessible to people with disabilities, including through the provision of real-time captions for live audio content.

These requirements exist because unequal access to spoken communication has direct consequences for the employment, education, and civic participation of Deaf and hard-of-hearing individuals. CART is one of the most effective tools for meeting these obligations in live and virtual settings, and organisations that proactively provide it reduce legal risk while demonstrating genuine inclusion.

Benefits of CART Captioning

CART delivers a range of practical and strategic benefits for organisations and the audiences they serve.

For Deaf and hard-of-hearing viewers, CART provides immediate, verbatim access to spoken content without the delay or paraphrasing that can accompany other captioning formats. This matters in dynamic settings like Q&A sessions, panel discussions, or classroom exchanges, where the speed and accuracy of the transcript directly affects whether a participant can engage in real time.

For organisations, providing CART demonstrates a concrete commitment to accessibility that goes beyond compliance. Inclusive events attract broader audiences, generate stronger word-of-mouth in Deaf and disability communities, and reduce the risk of accessibility-related complaints or legal exposure. For corporate teams, CART-enabled meetings ensure that colleagues with hearing access needs can contribute fully, improving team cohesion and the quality of decision-making.

CART transcripts also have a practical afterlife. The verbatim record produced during a CART session can be used as meeting minutes, an accessible event record, a searchable archive, or the source file for producing captions for recorded content. This multiplies the return on the initial investment in caption delivery and makes CART a productivity tool as well as an accessibility one.

CART captioning best practices

Delivering CART well requires attention to the factors that directly affect viewer experience and comprehension:

• Visibility and display: Captions should appear in a location that is easy for all viewers to read without needing to look away from the primary content. For in-person events, a dedicated caption display screen is preferable. For virtual settings, captions should be integrated into the platform view rather than displayed in a separate window. Displaying captions in a consistent, prominent position reduces cognitive load for viewers relying on them.
• Font size and contrast: Caption text should be large enough to read comfortably from the viewer’s typical position, with high contrast between text and background. White text on a dark background is generally the most readable combination across varied lighting environments.
• Readability and timing: Caption lines should break at natural speech boundaries and appear in sync with speech, with a maximum latency of three seconds for live content. Excessive latency or mid-phrase line breaks disrupt comprehension and reduce the usability of the captions.
• Compatibility with assistive technology: CART output should be compatible with the viewer’s preferred display method, whether that is a shared screen, a personal device, or an integrated platform caption stream. Testing compatibility before an event reduces the risk of technical access failures during delivery.
• Post-session transcript access: Where possible, provide attendees with a clean, edited transcript after the session. This supports review, note-taking, and archiving, and extends the accessibility value of the CART service beyond the live event itself.

Ready to Enhance Your Content with CART Transcription?

CART captioning is one of the most powerful tools available for making live and virtual communication genuinely accessible to Deaf and hard-of-hearing audiences. Whether you need real-time captions for a university lecture, a corporate all-hands, or a major live event, the quality of your CART delivery determines whether every participant can engage on equal terms.

AI-Media combines human captioning expertise with AI-powered technology to deliver accurate, low-latency CART solutions that scale to any format or audience size. From one-off events to enterprise-wide captioning programmes, AI-Media’s captioning services are built to meet broadcast-grade standards across every context.

Start a conversation with the AI-Media team today to find the right CART solution for your needs.

CART Captioning Frequently Asked Questions

How does CART differ from closed captioning?

CART and closed captioning both convert spoken audio to text, but they serve different primary purposes. Closed captioning is designed for pre-recorded or broadcast video content, where captions can be prepared in advance or generated and reviewed before delivery. CART is designed specifically for live communication access, producing a verbatim, real-time transcript in settings where spoken interaction is happening in the moment. CART prioritises completeness and verbatim accuracy above all else; broadcast captioning often involves some degree of condensing or editing for readability. CART is also typically displayed directly to an individual or small group, rather than embedded in a broadcast signal for a mass audience. 

Is CART transcription done in real-time or is it pre-recorded?

CART is always delivered in real time. It is a live service designed specifically to provide simultaneous text access to spoken communication as it happens. There is no pre-recorded element. After a CART session, the transcript produced during the live event can be edited and made available as a post-session record, but the captioning itself is always generated live, with latency typically measured in seconds.

How accurate is CART captioning?

Accuracy in CART depends on the delivery method. Human CART providers using stenography equipment typically achieve accuracy rates of 98-99% or above, which is the standard required under many accessibility guidelines for effective communication access. AI-powered CART systems have improved significantly and can match or approach these accuracy levels in clear audio conditions with standard vocabulary. Factors that reduce accuracy include heavy background noise, multiple overlapping speakers, strong accents, and highly technical or domain-specific terminology. For critical applications, a hybrid approach combining AI transcription with human oversight delivers the best balance of accuracy, speed, and cost.

How fast is CART transcription in real-time settings?

Professional human CART providers can transcribe at speeds of up to 225 words per minute, which is sufficient to keep pace with most speakers in real-time settings. AI-powered ASR systems process audio and produce text with latency typically ranging from one to three seconds, depending on the platform and audio quality. The three-second threshold is widely accepted as the maximum latency for live captioning to remain functionally useful for viewers, as longer delays break the connection between speech and text and reduce comprehension.

Does CART require a human operator, AI, or both?

CART can be delivered by a trained human stenographer, an AI-powered ASR platform, or a hybrid of the two. Human-delivered CART is the traditional and highest-accuracy approach, particularly suited to complex or high-stakes live settings. AI CART is faster to deploy, more cost-effective at scale, and increasingly accurate across a wide range of conditions. The hybrid model, where AI generates the live transcript and a human operator corrects errors in real time, combines the scalability of AI with the accuracy assurance of human oversight. The right approach depends on the content type, accuracy requirements, budget, and turnaround needs of each use case.

What software or platforms support CART transcription?

CART transcription is supported across a wide range of platforms. Major video conferencing tools including Zoom, Microsoft Teams, and Google Meet all support live caption integration, either natively or via third-party captioning services. For broadcast and live streaming environments, CART output can be delivered via caption encoders and integrated into the broadcast signal or streaming workflow. AI-Media’s live captioning solutions support CART delivery across live events, virtual meetings, and broadcast formats, with caption display options that work across shared screens, personal devices, and integrated platform windows.