Duration compensation of i‐vectors for short duration speaker verification
Jianbo Ma, Vidhyasaharan Sethu, Eliathamby Ambikairajah, Kong Aik Lee · Electronics Letters · 2017
The standard i‐vector/Gaussian probabilistic linear discriminant analysis (G‐PLDA) system does not compensate for duration mismatch, which is a significant confounding factor in short duration speaker verification. A novel duration compensation technique to normalise the distribution mismatch caused by duration variation in the i‐vector space is proposed. The proposed technique involves the use of two factor analysers that are tied together to share latent variables for a given speaker as the underlying generative model of the i‐vector space. This leads to a transform which maps the original i‐vectors onto a latent subspace that is expected to be duration invariant. The proposed method has the advantages that it normalises distribution mismatch while taking into consideration both inter‐ and intra‐speaker variability. Experiments conducted on NIST SRE 2010 database shows that the proposed method leads to 18.54, 15.48 and 8.77% relative improvements when tested on utterances of 10, 5 and 3 s durations, respectively, compared with the best results obtained by either standard i‐vector/G‐PLDA or the previously proposed twin model G‐PLDA.