Phonexia Voice Verify Achieves Over 96% Accuracy Out of the Box

Phonexia Voice Verify Achieves Over 96% Accuracy Out of the Box

November 25, 2021

By in Blog

As the world’s first vendor to introduce voice biometrics technology powered entirely by deep neural networks, Phonexia has been involved in perfecting machine learning concepts for speaker recognition for quite some time.

In 2020, we developed a commercial solution, Phonexia Voice Verify, designed specifically for passive voice biometric authentication of clients reaching out to contact centers. The main promise of Phonexia Voice Verify is the ability to verify a speaker over the phone with extreme accuracy after only three seconds of free speech.

Its free speech authentication capability means that a person can start talking to a contact center agent about anything straight away and be verified instantly as they speak. This passive voice biometrics approach is a genius way to enhance both authentication security and the customer experience at the same time. And all that without introducing additional passwords for clients to remember.

It is the most seamless way to strengthen your contact center’s ability to minimize the exposure of your clients to voice phishing and identity theft attacks while improving client experience and promoting self-service over the phone at the same time. It is one of those perfect win/win situations for businesses and clients.

As already hinted earlier, the accuracy of voice biometrics plays a vital role for its deployment in contact centers. The question is, how do you measure it?

Phonexia Voice Verify’s Accuracy After 3 Seconds of Free Speech

When we created Phonexia Voice Verify, we measured its accuracy on one of the world’s top scientific test sets – the NIST Speech Recognition Evaluation 2016 test set to be specific. The NIST is the scientist’s place to go for testing innovative concepts and pressure these systems as much as possible. And this is absolutely fine. There has to be a way to test your systems to their limits.

Based on these measurements, Phonexia Voice Verify was able to verify speakers with over 92% accuracy after three seconds of free speech. Although this is an excellent result in itself, it may not always reflect the conditions of the real world.

Especially, if you can fine-tune the voice verification solution further based on the unique environment of each contact center and its conversational data to improve the accuracy further.

That said, we wanted to find out how Phonexia Voice Verify would perform when tested on a real contact center’s data without any calibrations.

Therefore, when we got an opportunity to test the solution against a real bank’s contact center data without any adjustments, we happily accepted.

How Did Phonexia Voice Verify Perform on a Real Bank’s Contact Center Data Out of the Box?

Below, you can see a graph that represents the accuracy of Phonexia’s voice biometrics technology released over the past few years, including the latest “out-of-the-box” test of Phonexia Voice Verify performed on the bank’s contact center data:

Phonexia Speaker Identification Accuracy History - Years 2015-2021

As you can see, the Phonexia voice biometrics’ accuracy has been constantly improving over the years, with the biggest improvement achieved between 2015 and 2019 when we, as the first voice biometrics vendor in the world, went full on with state-of-the-art deep neural networks.

Then, in 2020, we developed Phonexia Voice Verify that used further improved deep neural networks which were able to identify a speaker based on voice in just three seconds of free speech.

And finally, when we tested our out-of-the-box, uncalibrated Phonexia Voice Verify on the real bank’s contact center data, we achieved outstanding verification accuracy of 96% after three seconds of free speech.


Phonexia Voice Verify offers incredibly robust 96% voice verification accuracy, achievable out of the box, after only three seconds of free speech.

The accuracy doesn’t stop there, however, but increases further with the speech length, exceeding 97% accuracy after five seconds of free speech.

Therefore, it is entirely possible for businesses to strengthen their authentication processes with passive voice biometrics right after the deployment of Phonexia Voice Verify and focus on further fine-tuning later on.

Even though every contact center’s circumstances and infrastructure are unique in many ways and the final uncalibrated performance may differ, the cutting-edge performance of Phonexia Voice Verify can provide organizations with ultimate value right from the outset. And even greater value after calibration.

Would you like to try voice verification for yourself? Check out our free online demo of Phonexia Voice Verify.

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