A speaker authentication system includes a data fuser operable to fuse voiceprint match attempt results with additional information to assist in authenticating a speaker providing audio input. In other aspects, the system includes a data store of speaker voiceprints and a voiceprint matching module adapted to receive an audio input and operable to attempt to assist in authenticating a speaker by matching the audio input to at least one of the speaker voiceprints. The voiceprint matching module adjusts a confidence of voiceprint match attempt results by at least one of: (a) a number of utterance repetitions upon which a matching speaker voiceprint has been trained; or (b) a passage of time since a training occurrence associated with a matching speaker voiceprint.