Automatic speaker recognition has long been an interesting and challenging problem to speech researchers.1−10 The problem, depending on the nature of the final task, can be classified into two different categories: speaker verification and speaker identification. In a speaker verification task, the recognizer is asked to verify an identity claim made by an unknown speaker and a decision to reject or accept the identity claim is made. In a speaker identification task, the recognizer is asked to decide which out of a population of N speakers is best classified as the unknown speaker. The decision may include a choice of “no classification” (i.e., a choice that the specific speaker is not in a given closed set of speakers). The input speech material used for speaker recognition can be either text dependent (constrained text) or text independent (free text).