Customers can use their voice as verification on the customer service voice portal – technology by Nuance, the global market leader in speech recognition, in action

In mid-2018, Deutsche Telekom became the first telecommunications provider in Germany to successfully introduce voice biometrics as part of its customer service voice portal. In the future, our customers will be able to provide verification without having to give long customer or booking numbers. After completing a one-time personal training phase (enrolment), they will be able to provide verification by simply saying “At Deutsche Telekom, my voice is my password.” (in German).

We – a highly motivated, committed project team made up of members from various departments within Deutsche Telekom (e.g. Customer Service, IT, Technology) and vendors (Nuance, Unisys, mVISE) – were able to make voice biometrics available to our customers in the shortest time possible. To do so we are using voice biometrics technology by U.S. company Nuance– a global market leader in voice-recognition software. You might already have heard of a well-known product by the company – “Siri”, the speech recognition technology found on many smartphones nowadays, is also from Nuance.

Biometric authentication from the customer’s perspective

What makes customers happy? Getting straight to the point without first having to spend a lot of effort proving who they are. Introducing voice biometrics removes the need for time-consuming verification with advisers. In order to provide their voice print, the customer does a voice-controlled recording of their contractual data. After successful verification of contractual data, they will then be required to record a voice print by repeating the predefined passphrase, “At Deutsche Telekom, my voice is my password.” (in German). Once the voice print is recorded, they will no longer have to painstakingly provide contractual data when they call.

The technology

Voice biometrics are used to compare a person’s voice with a stored voice print. Using complex algorithms an encoded sequence is generated from what is said, which must conform exactly to the text requirements. Voice biometrics are therefore not a form of voice recording, but rather the digitalization of a person’s various voice characteristics derived from the anatomical and physiological dimensions of the mouth, nose and throat, as well as their patterns of behavior. The analysis takes place on the basis of over 140 individual factors. This calculation also involves individual voice characteristics, such as pitch, style of speaking, pace, intonation, and frequency spectrum. The voice print is then saved in the system. This serves as a reference for verification when the customer next calls, saving them from having to spend a lot of time entering their customer number and other data.

Security and resistance to deception

Voice biometrics are more secure than standard password prompting, since voice prints cannot be guessed or imitated by others. Even attempts at deception using recorded or computer generated voices are safely recognized. In addition, voice prints, which are already established in the banking sector, are more secure against forgery than fingerprints or eye recognition: speech cannot be reproduced from a voice print. It is also linked to the system’s architecture and may only be used within the system. Since a customer’s voice print is a type of personal data that is to be protected, data protection and security were always in mind. Nuance’s technology recognizes, among other things, attempts at deception by replaying recorded statements by the customer (e.g. with smartphone) or even by means of text-to-speech (TTS) technology, which requires spending a great deal of time and effort creating a personalized, computer generated voice. If misuse has been recognized or if verification was unsuccessful, the customer will have to provide authentication using contractual data as before. Although verification may occasionally be refused, the solution is secure, protects personal data, and reduces talk time between customer and adviser as authentication questions are no longer necessary. The solution has also successfully been certified by IT-TÜV Austria.

Official launch of voice biometrics at the International Broadcast Exhibition Berlin

The voice biometrics solution was officially presented to our customers and the press at the International Broadcast Exhibition Berlin on August 28, 2018. At the Deutsche Telekom booth, interested customers were given the opportunity to have a random statement symbolically engraved on a keychain.

Figure 1: Deutsche Telekom’s voice biometrics booth at the International Broadcast Exhibition Berlin

Deutsche Telekom as a pioneer of voice technology – new use cases planned

As a company, we have introduced voice biometrics in Germany. This application provides support for call center agents and is significantly more convenient for customers. Speech is still the most commonly used medium in customer service, even if digital media are gaining more and more attention. Voice biometrics can always be used in situations in which the user must be verified. By providing this solution on the voice portal, we can open up many other business cases – e.g. authentication in the Telekom app or for “Hallo Magenta (Deutsche Telekom’s Alexa)

Our team

We are a highly motivated, committed project team of more than 70 employees from various departments within Deutsche Telekom and from external vendors. Despite the enormous time pressure, it was important for us to continually reflect on our collaboration (what was going well, what could have been better). There were certainly project phases in which we didn’t make the progress we had hoped for, so we made the decision to adapt our approach so we would be able to react more flexibly to the new challenges we were continually facing.

The results of these lessons learned attest to our positive team spirit. We have spoken very openly, honestly and confidentially as a team regarding our perceptions and observations. Both the collaboration within the departments and between ourselves and the vendors was highlighted by all as being invaluable – the team members’ unrestrained, respectful approach to one another was also praised. The team also benefited from the extensive specialist knowledge of the individual members.

Have we sparked your interest in working on new technologies together as part of a highly motivated team? You can find more information on development methods, software development tools, our work approach, etc., at our trade fair booth.  Our colleagues Thomas (Kromik), Jörg (Schröder), and Detlef (Hardt) will be happy to answer all questions.  #takepart!

In addition, exciting workshops on the following topics are waiting for you on June 7th.:

  • Teach a machine in understanding Human Language
  • How to build solutions for blind people
  • [email protected] feat. iOS Live Hacking and New Agile Coding Culture

And Reghu Ram Thanumalayan, Vice President Software Engineering Deutsche Telekom, will give a keynote speech “What is your leading code?” at the “Coding Society” stage.

Would you like to take part?

Is IT part of your DNA? Are you lateral thinking, creative, innovative, and fascinated by the development of digital growth areas? Are you interested in collaborating internationally to develop tailor-made IT solutions for the Deutsche Telekom Group? Then work with us to drive digitalization of Magenta IT forward to be the best in customer satisfaction and direct the technological transformation towards things such as all IP, cloud services, over-the-top services, NG OSS and e-company. Our motto: technology leadership and innovative IT services all in one.

Videos (in German)

Job search:


Thomas Kromik (DT IT, E-CSO-MC)

Jörg Schröder (DT IT, E-CSO-MC0101)

Dr. Detlef Hardt (DT IT, E-CSO-MC0101)

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