First Direct's new voice biometric log-in is using more than 100 different unique identifiers in order to help make customer sign-in more secure.
The online bank introduced the feature earlier in the summer to its more than one million customers, and has since revealed that more than two thirds of consumers prefer to deal with banking issues over the phone rather than via an app or online.
The bank's voice biometrics system is provided by Nuance Communications and works by cross-checking more than 100 unique identifiers in someone's voice in order to confirm it's them.
Behavioural aspects of speech such as speed, cadence and pronunciation as well as physical characteristics such as the shape of the larynx, vocal tract and nasal passages are also analysed based on your voice.
The system works by asking those who opt-in to record a 'voice print'. Once this is completed, they are no longer required to remember telephone passwords or PIN numbers.
First Direct boss Tracy Garrad said: "Understanding our customers is a big part of why we are the UK's most recommended bank. With the roll out of Voice ID and Touch ID to log on to your account, instead of using a password, it's never been more convenient or secure to access your banking app on the go."
Robert Weideman from Nuance added: "Beyond exceeding consumer expectations and preferences, voice biometrics can materially improve the security of first direct customer banking accounts.
"Unlike PINs and security questions, which can be more easily compromised by fraudsters - on a massive scale - voice biometrics ensures that the person calling first direct is indeed the authorised account holder - with the unique characteristics of their voice."