Deutsche Telekom has launched its voice identification feature SpeechID, removing the need for verification data or passwords.
The operator commercially launched the function at this year's IFA consumer show in Berlin, which ends tomorrow.
In order to take advantage of the solution, consumers must register their voice on a Deutsche Telekom hotline.
From that point onwards, consumers can identify themselves with their voice when making calls to Deutsche Telekom's call centres.
The operator said a unique set of data is created from the voice imprint and stored by the operator. Once a customer makes the call, the voice is checked against the data and verified if they tally.
The operator described the service as "forgery-proof" and claimed it was sophisticated enough to tell if a consumer is tired or has a cold. Even if the data was to be obtained, Deutsche Telekom said there was no way a voice could be reverse engineered from the information.
Caroline Clemens, Senior Expert for Voice User Interface Design at Deutsche Telekom, said: "The procedure is simple and safe, and as unique as a fingerprint."
It is the second voice service the operator has launched in the past week.
It opened beta testing for its smart speaker at IFA, asking 1,000 consumers to apply for the chance to test its "Hello Magenta" voice interface.
It developed the software in partnership with Orange. The French operator is set to launch its own djingo smart speaker by the end of this year.