5th International Conference on Spoken Language Processing
This paper presents a HMM-based speaker verification system which was implemented for a field trial. One of the challenges for moving HMM from speech recognition to speaker verification is to understand the HMM score variation and to define a proper measurement which is comparable across speech samples. In this paper we define two basic verification measurements, a qualifier-based measurement and a competition-based measurement, and examine score normalisation approaches using these two measurements. This leads to some useful theoretical differentiation between cohort model and world model approaches used for HMM score normalisation. We adopted a world model method for score normalisation in the system. The adaptive variance flooring technique is also implemented in the system. The paper presents evaluation results of the implementation.
Bibliographic reference. Gu, Yong / Thomas, Trevor (1998): "An implementation and evaluation of an on-line speaker verification system for field trials", In ICSLP-1998, paper 0070.