Your Voice is Your Password at
Turk Telekom Mobile

Vocal Passphrase Case Study


“Significantly reduced call duration, improved customer satisfaction and $400,000.00 savings”

All Thanks to Sestek Vocal Passphrase


“We implemented Vocal Passphrase technology at Turk Telekom Contact Center to allow our customers securely and easily complete various transactions without losing time with traditional security questions. When we decided to carry out this project, Vocal Passphrase was a new technology and choosing the right technology provider was an important decision to make. Sestek’s expertise in the speech technology field and continuous R&D efforts played an important part in our decision. Rapid increase in the number of registered voice prints and positive feedback we get from our customers prove that we made the right decision.”

Eniz AkdağTurk Telekom Call Center Operations Director
The Need

Leading telecommunications operator in Central & Eastern Europe, Middle East and Asia; Turk Telekom Mobile used manual security methods in their contact center to verify the identity of a caller, which eventually resulted in longer call duration and customer dissatisfaction.

The Decision

Aimed to improve customer experience and overall satisfaction, Turk Telekom Mobile decided to replace their conventional identity verification procedure with an eficient biometric system and selected Sestek Vocal Passphrase as the most suitable solution to their needs.

The Implementation

Sestek Vocal Passphrase was implemented at Turk Telekom Mobile call center in 2011. Thanks to biometric verification system the customer gets enrolled by creating a vocal password. Once enrolled, caller is verified by vocalizing the same passphrase once for each call.

The Results

Sestek Vocal Passphrase solution made a valuable contribution to Turk Telekom Mobile’s call center in terms of customer satisfaction, agent motivation, and business efficiency. Customers can access the system upon enunciating their passphrase, which means that time is not lost answering security questions.

Moreover, call center agents benefit from the automated verification process, which has replaced the time-consuming manual security processes. As a result, within first two years the number of registered voice prints reached approximately 2 million at Turk Telekom Mobile’s customer call center, and is over 3 million as of today. 1 in every 5 calls made by the vocal password procedure. Following the implementation, the average call duration was shortened by 15 seconds, resulting in savings of USD $400,000.00

Sestek Vocal Passphrase

  • Biometric speaker authentication system
  • Language and accent-independent structure
  • Verifies speaker’s identity while also enabling protection against fraud and identity theft
  • Answers to security needs by providing high-level security measures and reducing call center costs

turk telekom logo

  • Turk Telekom is the first integrated telecommunications operator in Turkey.
  • The company has 14.1 million fixed access lines, 10.3 million broadband and 20.2 million mobile subscribers as of June 30, 2018.
  • Turk Telekom provides mobile, internet phone, TV products and services.