Best-in-Class Captions: Inside InnoCaption’s Benchmarking Process

Captions are only as effective as they are accurate, and accuracy is never one-size-fits-all. That’s why benchmarking sits at the heart of our approach to AI captioning. To truly serve our users, we continuously put competing speech recognition engines to the test, side by side, under real phone call conditions. This rigorous, data-driven, and impartial process is the foundation for captions you can trust when it matters most.

Recently, we sat down with Paul Lee, our Chief Operating Officer, to discuss the unique challenges of captioning phone calls with automated speech recognition (ASR), the details of our testing process, and what continuous benchmarking ultimately means for the people who rely on InnoCaption every day.

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The Unique Challenge of Captioning Phone Calls

When it comes to captioning, not all audio is created equal.

Pre-recorded or rehearsed content, such as TV shows, streaming platforms, or many social videos, typically has clean, consistent audio. These types of media are often scripted or carefully edited and may even begin with a full transcript. The result is clear dialogue, few surprises, and a relatively straightforward task for captioning systems.

Live, unscripted environments like video meetings and live events introduce more unpredictability. People interrupt each other, conversations can shift quickly, and background noise comes in. Even so, these platforms usually deliver high-quality audio, often sampled at 16 kHz or more, which provides speech recognition systems with the detail they need to perform well.

Phone calls, though, present the toughest challenge of all. Traditional phone networks compress voices into a narrow frequency range and use an 8 kHz sampling rate, stripping away much of the information speech engines rely on. It’s like trying to recognize a friend’s face in a blurry photo instead of a sharp one. Add background noise, accents, variable connection quality, and people talking over each other, and phone calls are the most demanding environment for any ASR system.

That is exactly why we focus our benchmarking here. Solving phone call captioning means solving the hardest problem our users face.

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How Our Benchmarking Works

Think of benchmarking as a kind of test drive for captioning technology. We regularly test speech recognition engines from multiple vendors under identical conditions, which lets us directly compare performance on both speed and accuracy. Only the ASR engines that truly excel at phone call captioning make the cut.

Each round of benchmarking includes:

Multi-vendor testing
‍We never set and forget a single engine. Instead, we consistently compare multiple speech recognition systems to ensure we’re always using the strongest option available.

Real-world samples
‍Every engine receives the same diverse set of phone call recordings, featuring background noise, accents, overlapping dialogue, and quick speakers.

Direct comparison
‍By controlling all variables and using identical samples, we ensure fair evaluations. Each system is assessed using two critical measures:

• Speed (Latency): How quickly captions appear after words are spoken. Conversational flow depends on it.
• Accuracy (Word Error Rate): How many words are recognized correctly. Fewer errors mean clearer communication and fewer misunderstandings.
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Crucially, our benchmarking process is not a once-a-year review: it’s ongoing, detailed, and intentional, with new vendors and engines being added to our testing as they emerge. If our current speech recognition engine falls behind, we switch to a better one.

“We don’t assume which engine is best,” says Paul. “We prove it, again and again, by testing every system on the same real phone call audio. That’s how we know we’re giving our users the best captions available right now.”

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What This Means for You

At every step, our decisions are guided by one principle: our users’ needs come first. Benchmarking is not just a technical process. It is our commitment to providing captions you can rely on.

Stay connected in the moment
‍Instant captions keep you right there in the conversation, so you can respond without delay, even during fast-moving calls.

Trust what you read
‍Best-in-class accuracy means clarity on important calls, whether you’re speaking with a healthcare provider or catching up with loved ones.

Confidence, day after day
‍With continuous benchmarking and regular improvements, you can feel confident knowing you always have access to the most advanced AI captioning available.

We understand how vital reliable, timely captions are to communication and independence. That’s why our entire process is dedicated to making every call more accessible, empowering, and worry-free.

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Ready to experience captions you can trust? Try InnoCaption today and see how continuous benchmarking leads to clearer conversations, every time.