Speaker verification using m-vector extracted from MLLR super-vector

Abstract

In this paper, we propose a speaker verification system called m-vector system, where speakers are represented by uniform segmentation of their Maximum Likelihood Linear Regression (MLLR) super-vectors, denoted m-vectors. The MLLR super-vectors are extracted with respect to Universal Background Model (UBM) with MLLR adaptation using the speakers data. Two criterion are followed to segment the MLLR super-vector: one is disjoint segmentation technique and other one is overlapped windows. Afterward, m-vectors are conditioned by our recently proposed [1] session variability compensation algorithm before calculating score during test phase. However, the proposed method is not based on any total variability space concept and uses simple MLLR transformation for extracting m-vector without considering any transcription of the speech segment. The proposed system shows promising performance compared to the conventional i-vector system. This indicates that session variability compensation plays an important role in speaker verification. Speakers can be represented by simpler way instead of generating i-vector in conventional system and able to achieve performance comparable to the i-vector based system. Experiment results are shown on NIST 2008 SRE core condition.