Probabilistic Approach Using Joint Long and Short Session i-Vectors Modeling to Deal with Short Utterances for Speaker Recognition

Speaker recognition with short utterance is highly challenging. The use of i-vectors in SR systems became a standard in the last years and many algorithms were developed to deal with the short utterances problem. We present in this paper a new technique based on modeling jointly the i-vectors corresponding to short utterances and those of long utterances. The joint distribution is estimated using a large number of i-vectors pairs (coming from short and long utterances) corresponding to the same session. The obtained distribution is then integrated in an MMSE estimator in the test phase to compute an “improved” version of short utterance i-vectors. We show that this technique can be used to deal with duration mismatch and that it achieves up to 40% of relative improvement in EER(%) when used on NIST data. We also apply this technique on the recently published SITW database and show that it yields 25% of EER(%) improvement compared to a regular PLDA scoring.