EUROSPEECH 2001 Scandinavia
This paper replaces the ordinary output probability with its expected value if the addition of noise is modeled as a stochastic process, which in turn is merged with the HMM in the Viterbi algorithm. The method, which can be seen as a weighted matching algorithm, is applied in combination with spectral subtraction and RASTA to improve the robustness to additive and convolutional noise of a text-dependent speaker verification system. Reductions around 10% or 20% in the error rates and improvements as high as 30% or 50% in the stability of the decision thresholds are reported when the ordinary Viterbi algorithm is replaced with the weighted one. When compared with the baseline system, reductions of 70% or 80% are shown.
Bibliographic reference. Yoma, Nestor Becerra / Fernandez, Miguel Villar (2001): "Additive and convolutional noise canceling in speaker verification using a stochastic weighted viterbi algorithm", In EUROSPEECH-2001, 2845-2848.