ESCA Workshop on Automatic Speaker Recognition, Identification, and Verification

Martigny, Switzerland
April 7-9, 1994

Analysis of Type-II Errors for VQ-Distortion Based Speaker Verification

Michael Wagner, Fangxin Chen, Iain Macleod, Bruce Millar, Shuping Ran, Andrew Tridgell, Xiaoyuan Zhu

TRUST (Technology for Robust User-Conscious Secure Transactions) Project, Australian National University, Canberra, Australia

This paper investigates the distribution of inter-speaker distances for the "training" speakers of the TIMIT speech database. The analysis is based on a speaker verification paradigm with 8 speakers serving as customers and the remaining speakers serving as impostors. The distance measure used is an average variance-weighted vector quantisation (VQ) distortion. It is found that the interspeaker distances correlate significantly with the differences of fundamental frequency (FO) between the speakers. Moreover, the shape of the distribution of impostor distances is largely determined by the customer's FO. A distinct asymmetry of VQ distances is observed between low-FO customers and high-FO impostors on the one hand and high-FO customers and low-FO impostors on the other. The type-II error function is estimated from a sample of impostors with similar FO to the customer. Dialect difference within TIMIT is not found to contribute significantly to VQ distance.

Full Paper

Bibliographic reference.  Wagner, Michael / Chen, Fangxin / Macleod, Iain / Millar, Bruce / Ran, Shuping / Tridgell, Andrew / Zhu, Xiaoyuan (1994): "Analysis of type-II errors for VQ-distortion based speaker verification", In ASRIV-1994, 83-86.