Patent ID: 8762149

Claim:
A method for verifying the identity of a speaker based on the speaker's voice, comprising the steps of: a) receiving, at a computer, a voice utterance; b) verifying, using the computer, that the speaker's voice corresponds to the speaker the identity of which is to be verified based on the received voice utterance, using biometric voice data; c) verifying, using the computer, that the received voice utterance is not falsified, preferably after having verified the speaker's voice in step b) and without requesting any additional voice utterance from the speaker, using the following procedures: determining a speech modulation index or a ratio between signal intensity in two different frequency bands, or both, of the received voice utterance preferably to determine a far field recording of a voice; evaluating the prosody of the received voice utterance; and detecting discontinuities in the background noise; and d) accepting the speaker' s identity to be verified when both verification steps give a positive result and not accepting the speaker' s identity to be verified if any verification steps give a negative result.