What is voice authentication? (pros, cons, FAQs)

by Time Doctor
voice authentication

Voice authentication is an identity authentication technology that verifies a user based on their unique biometric characteristics. 

It’s secure, fast, and can be applied across several fields like mobile applications, IoT devices, and call centers. 

Moreover, the advancement in neural networks over the past few years has enabled the development of faster and more accurate voice authentication systems.

In this article, we’ll cover everything you need to know about voice authentication — what it is, how it works, and its practical use cases. We’ll also highlight its major benefits and challenges.

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Let’s get started.

What is voice authentication?

Voice authentication or voice recognition is a biometric authentication technology that enables users to access online services using speech. 

In other words, voice biometrics is the science of using a person’s voice as a unique identifying biological characteristic.

Often, voice characteristics are measured using liveness detection or prompting the user to speak a unique phrase for the current transaction. It can also be measured passively — the user doesn’t have to speak a required phrase knowingly. 

2 Types of voice authentication

Here are two key types of voice authentication methods:

A. Text-dependent

As the name suggests, text-dependent authentication depends on the words a person is speaking. This sequence of words is often system-generated and referred to as a “voice passphrase.”

Typically, a voice passphrase is three or four words long and takes 1.5 seconds to speak the words. However, you can choose randomized numbers too.

Text-dependent authentication is an active authentication method, which means the speaker must knowingly perform the enrollment or speak the required system-generated phrase. 

Such authentication mechanisms are built for fraud prevention as the probability of a potential imposter to record the victim’s voice speaking the exact passphrase is low.

Voice-based mobile or web login or verifying customer identity through IVR authentication are some great examples of text-dependent authentication. 

B. Text-independent

This voice biometric authentication method performs voice verification without the constraint on the speech content.

Compared to the text-dependent method, text-independent authentication is more convenient as the user can speak freely to the system. However, it will require longer training and testing utterance samples to achieve more accurate performance.

Text-independent verification can be used in call centers where the customer could say anything while interacting with an agent or IVR (Interactive Voice Response), enabling speaker identification in the background.

Let’s now take a detailed look at the mechanism behind speaker verification.

How does voice authentication work?

Voice recognition systems enroll a person by creating an initial template. It’s often the result of merging several templates from samples of that person’s speech for greater accuracy.  

The initial template is called the enrollment template or enrollment voiceprint. The authentication tool stores these templates in secure databases.

So how does it authenticate an enrolled user?

Depending on the method of authentication (text-dependent or text-independent), a voice biometrics tool collects a user’s voice template. 

However, it doesn’t authenticate what the person is speaking — it only checks who is speaking.

It extracts the characteristics that distinguish a person’s speech from other people. The result is a voiceprint or voice template, analogous to a fingerprint.  

Does this mean a person with a similar tone can bypass the system?

A person’s voice is extremely difficult to forge for biometric comparison purposes because of its inherent uniqueness like dialect, speaking style, and pitch. 

This simply means that even if a voice impersonation sounds similar to the human ear, a detailed analysis of the voiceprint done through computer algorithms can help distinguish it from the sample.


Over 70 body parts, each with a unique size and shape, contribute to how a person speaks. 

Voice biometrics relies on voice characteristics that strongly correlate to the physiological qualities of how a person creates speech.  

Now that you know all about voice authentication and how it works, let’s check out some of its real-world applications..

4 practical use cases for voice authentication

From contact centers and mobile applications to messenger apps and smart home devices, voice biometrics can work across various use cases. 

Here’s a detailed look at them: 

1. Mobile applications

Voice authentication’s primary consumer-facing use case is hands-free mobile authentication. All you need to do is provide a voice command to log in or authorize purchases, eliminating the need to memorize logins and passwords.

This is ideal for mobile phones or other settings where face recognition and other forms of biometric authentication can be inconvenient.

Additionally, voice authentication can also be useful for virtual assistant solutions such as Google Home, Amazon’s Alexa, and Siri. You can use it to place orders and perform other functions that require some authentication.

2. Calls centers and IVR systems

Outdated security methods like traditional passwords or questions are no longer secure enough. 

Voice biometrics systems offer resistance against voice mimicking through intrinsic algorithms used for biometric analysis and offer a blocklist. This makes the technology especially helpful in the call support industry. 

You can also use speaker recognition as an authenticator during customer support calls. Callers may find this more convenient and secure than sharing personal data such as their license or credit card number for identity verification.

3. Web applications

You can add voice verification systems to web pages or applications in the banking and e-commerce sectors. Voice authentication in web applications can be helpful in the remote identification of users. 

Additionally, passive enrollment or text-independent authentication makes it easy to onboard new users for your service without any registration. Customers are automatically verified in real-time while interacting with an IVR or contact center agent.

4. Internet of things (IoT)

IoT applications offer new and innovative ways for communication and interaction between humans and machines. 

Proper implementation of voice authentication can provide a more flexible user experience than traditional methods like touch screens.

And as voice authentication can provide an added layer of security, you can easily access your IoT home device without any concerns. 

Clearly, voice biometric authentication seems to make things a lot easier. 

However, before you decide to use voice authentication for your business, let’s take a look at its benefits and challenges.

3 key advantages of using voice authentication

voice authentication advantages

Here are three excellent benefits of using voice biometric authentication:

1. Reduced costs

A voice biometrics solution not only reduces the operational cost but increases the efficiency of your security process. 


It helps you save tons of money by eliminating traditional customer authentication techniques like security questions. Instead, the solution recognizes the speaker’s voiceprint to verify their identity. 

For call centers, this ultimately reduces the average handle time (AHT), which otherwise the agent would’ve spent on authenticating customers — translating to reduced operational costs.

2. Increased security

Unlike PINs and security questions, voice biometrics ensures that the person calling is indeed who they say they are. 

And with the growing number of identity fraud attacks, the need for strong and secure methods like multi factor authentication (MFA) has increased. 

What’s MFA?

MFA is a method of login verification that combines at least two different factors of proof. 

Voice recognition is considered a Type 3 authentication factor, also called Something You Are.

This authentication factor uses any part of the human body that can be offered for verification, like palm scanning, facial recognition, or voice verification.

3. Improved customer experience

With speaker recognition technology, callers no longer need to provide passwords or PINs or answer security questions to verify their identity. 

This makes voice biometrics ideal for multichannel deployments. Once a customer is enrolled, you can use their voiceprint across all of your company’s support channels. 

It makes the workflow easier and more efficient for your legitimate customers, which in turn can lead to improved CSAT, NPS, and Customer Effort Scores

Additionally, depending on the reason for the call, voice biometrics can reduce the time it takes for identity verification. This can help you enhance call personalization as well as customer experiences.

Check out these 10 easy steps to improve customer experience.

2 major challenges of voice authentication

Here are two common challenges of voice authentication: 

1. Authentication through audio deep fakes

The recent advancement in artificial media technology has allowed people to create deep fakes. These are synthetically produced fake voices of a person, identical to their original voice.

Deep fakes are becoming more common and may make an AI program believe in its authenticity.

So how do you prevent unauthorized users from entering the database?
You can create an allowlist of voiceprints and store them in an active directory. During this process, the voice recognition system enrolls the user into a list of allowed members.

So, each time a user tries to access the system, their voiceprint is compared against both the allowlist and a blocklist of fraudster voiceprints.

And while the authentication is underway, passive fraud detection can send alerts if the voiceprint matches against the blocklist database.

2. Lack of accuracy

Background noise is one of the major factors that affect automatic speech recognition. It can impact the quality of the speaker’s voice template and, in turn, decrease the accuracy level of the authentication process.

A voice authentication system may not be able to differentiate between your speech, other people talking, and ambient noise — leading to transcription mix-ups and errors.

This means it can be challenging to use voice authentication in noisy environments like busy offices or public spaces.

For seamless authentication, you can use close-talking microphones or noise-canceling headsets that enable the software to focus on your speech. And while you can ensure this in a business setting, not every customer can have access to such gadgets or a quiet environment.

Additionally, you should also keep in mind to take your initial recording in a quiet place. 

Still have some doubts about voice authentication?

Let’s check out some frequently asked queries.

Voice authentication FAQs

Here are four frequently asked questions about voice authentication:

1. Will voice authentication work if the user has a cold?

Even if the user has a cold, a good voice recognition algorithm will continue to work as expected and with high accuracy. 

However, if the voice sounds entirely different, then by design, the person would not be recognized as a match with the enrollee. 

For such extreme cases, the user may be required to verify their identity through another biometric modality or means of authentication like fingerprint or iris scanner.

2. How does a voice biometric system adjust to changes in a person’s voice over time?

Voice biometric systems support model enrichment.

This means new voice templates are merged into previous templates to adapt to changes in a user’s voice over time. And as the change is slow, it can require several years for material change. 

This allows continued verification of the user’s voice that changes over time due to disease or age.

3. Does a voice biometric system understand what a user is saying?

Voice biometrics and speech recognition are two different biometric modalities.
However, as both are dependent on the human voice, you can notice some synergy.

Voice biometrics identify the unique characteristics of the user’s speech, whereas knowing what is said is the domain of speech recognition. 

4. Is voice authentication prone to spoofing?


That is why voice biometric systems should be deployed with voice anti-spoofing, also known as “liveness detection,” to prevent fraudsters from impersonating a real user. 

Modalities like speech conversion and TTS (Text-to-Speech) create certain signal artifacts (errors) that sometimes a human ear cannot detect. Anti-spoofing algorithms find and identify these artifacts to determine voice liveness accurately.

Wrapping up

Clearly, voice authentication offers many benefits like cost savings, increased security, and enhanced customer experience.

However, it comes with its own set of challenges. For instance, you need to use noise cancellation headphones or operate in a quiet environment for a seamless experience.

Go through this article to gain an in-depth understanding of voice authentication and how it can help your business.

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