Visual speech: A physiological or behavioural biometric?

Abstract

This paper addresses an issue concerning the current classification of biometrics into either physiological or behavioural. We offer clarification on this issue and propose additional qualifications for a biometric to be classedas behavioural. It is observedth at dynamics play a key role in the qualification of these terminologies. These are illustrated by practical experiments baseda round visual speech. Two sets of speaker recognition experiments are considered: the first uses lip profiles as both a physiological anda behavioural biometric, the second uses the inherent dynamics of visual speech to locate key facial features. Experimental results using short, consistent test andt raining segments from video recordings give recognition error rates as: physiological - lips 2% and face circles 11%; behavioural - lips 15% and voice 11%. © Springer-Verlag 2001.