If the speaker claims to be of a certain identity and the voice is used to verify this claim, this is called verification or authentication. On the other hand, identification is the task of determining an unknown speaker’s identity. In a sense speaker verification is a 1:1 match where one speaker’s voice is matched to one template (also called a “voice print” or “voice model”) whereas speaker identification is a 1:N match where the voice is compared against N templates.

From a security perspective, identification is different from verification. For example, presenting your passport at border control is a verification process: the agent compares your face to the picture in the document. Conversely, a police officer comparing a sketch of an assailant against a database of previously documented criminals to find the closest match(es) is an identification process.

Speaker verification is usually employed as a “gatekeeper” in order to provide access to a secure system (e.g. telephone banking). These systems operate with the users’ knowledge and typically require their cooperation. Speaker identification systems can also be implemented covertly without the user’s knowledge to identify talkers in a discussion, alert automated systems of speaker changes, check if a user is already enrolled in a system, etc.

In forensic applications, it is common to first perform a speaker identification process to create a list of “best matches” and then perform a series of verification processes to determine a conclusive match.