What is Live Captioning: Making Content Accessible to Everyone

Captioning is essential for making your video content accessible to the public. Although most believe that only 15% of Americans who are hard of hearing or deaf require captions, this is far from the case. For many, watching a video with the sound off is a preferred way to consume content.

But what happens when you’re streaming a live event? You cannot traditionally add captions while the event occurs. For this, there is real-time captioning.

This article will cover “What is live captioning?” and how the process works.

What is Live Captioning?

Creating real-time captions has only become possible with the advancement of technology. With 69% of consumers watching video content with the sound off, there’s an actual commercial demand for bringing the capabilities of closed captioning to the live sphere.

At the heart of live captioning is Automatic Speech Recognition (ASR) technology and the role of the professional live captioner. So, what is a live captioner? These professional captioners receive access to media alongside the viewer to deliver highly accurate captions in seconds.

Due to the diminished ability to produce captions, reaching the same 99% accuracy of traditional captioning isn’t yet possible. However, with the advent of AI live captioning, products like Sonix AI can still hit a stunning 96-97% accuracy rate.

Live Caption vs. Closed Caption

Now that you know what is a live caption, how does it differ from closed captioning?

The primary difference is closed captions are designed for pre-recorded content, and live captions are intended for real-time use. Specifically, live captions are designed for live-streamed content like webinars.

Technically speaking, live captions remain a sub-category of closed captions because the viewer can still turn them on and off.

How Does Live Captioning Work?

Creating AI captioning live relies on a Real-Time Messaging Protocol (RTMP) to connect the stream with the captioning service. If this isn’t possible, the workaround involves sending the stream directly to a professional captioner who can use the same technology to provide captions.

Delivering captions relies on using either ASR technology or a professional captioner. Naturally, the former is the more affordable and preferable option because as technology advances, it becomes more accessible than ever to match the proficiency of even the most experienced captioner.


Typically, most people using this technology will also include a back up stream linked between the encoder and the video player to prevent unexpected interruptions to the primary stream. These days, most of the captioning happens automatically, making creating captions with the right product as simple as clicking a button.

Valuable Applications of Real-Time Captioning 

Live captions are vital for any event in an era where live-streamed events are becoming more common. To illustrate the rise of live streaming today, an estimated 163.4 million Americans will watch live videos by the end of 2023.

So, where can real-time captioning become useful?

  • Lectures – Make educational events more accessible by adding live captions to your sessions. They can make it easier to grasp complicated topics and expand your knowledge to non-native English speakers.
  • Conferences – Open up your landmark event to more people by adding captioning in real time.
  • Product Demonstrations – Transform your product tutorials and enhance your audience’s understanding of your product and its features.
  • Q&A – Increase your engagement by letting your audience ask their questions in a live setting. That is one of the best ways to make your audience feel involved.
  • Interviews – Do you conduct live interviews with special guests? Make the most of the experience with live captions.

These five applications are a small selection of environments where live captions are exceptionally useful for increasing the accessibility and understanding of your content. But any live video or audio content can benefit from captioning in real time.

How to Create Live Captioning with Sonix

Are you ready to unleash the power of real-time transcription and captioning? Sonix’s latest innovation is now open for early bird access to users who want to add this unique AI-powered feature to their arsenals.

Get started by following this straightforward step-by-step guide.

Step One – Connect Your Stream

The first step is to establish an RTMP stream. By using Sonix, you already have a target to where you can send your stream so that our platform can generate your captions in real time. No technical experience is required to do this because we’ll provide you with detailed instructions for how to do it.

Step Two – Let the Captioning Begin

With our AI-powered ASR technology, your captions will begin when we detect audio from your stream. These live captions will appear automatically, and a secondary stream ensures that interruptions won’t affect your captions.

Step Three – Delivery

The final step is to deliver your captions to your audience. That can happen however you prefer. For example, these captions can be embedded in a web page, sent to a second screen, or delivered to an API. Crucially, you can save your captions for later and apply them to downloadable media for attendees who want to rewatch your content.

Harness the Power of Live Captioning with Sonix

Content continues to evolve, and so does captioning. Understanding what is live captioning is vital to create high-quality broadcasts in real-time that everybody can enjoy.

To meet the needs of content creators and companies competing in the live streaming environment, we have developed real-time live caption solutions to make delivering highly accurate captioning a breeze.
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