  The performances of the automatic speaker verification (ASV) systems degrade
due to the reduction in the amount of speech used for enrollment and
verification. Combining multiple systems based on different features and
classifiers considerably reduces speaker verification error rate with short
utterances. This work attempts to incorporate supplementary information during
the system combination process. We use quality of the estimated model
parameters as supplementary information. We introduce a class of novel quality
measures formulated using the zero-order sufficient statistics used during the
i-vector extraction process. We have used the proposed quality measures as side
information for combining ASV systems based on Gaussian mixture model-universal
background model (GMM-UBM) and i-vector. The proposed methods demonstrate
considerable improvement in speaker recognition performance on NIST SRE
corpora, especially in short duration conditions. We have also observed
improvement over existing systems based on different duration-based quality
measures.
