Incremental adaptation using active learning for acoustic emotion recognition

The performance of speech emotion classifiers greatly degrade when the training conditions do not match the testing conditions. This problem is observed in cross-corpora evaluations, even when the corpora are similar. The lack of generalization is particularly problematic when the emotion classifiers are used in real applications. This study addresses this problem by combining active learning (AL) and supervised domain adaptation (DA) using an elegant approach for support vector machine (SVM). Active learning selects samples in the new domain that are used to adapt the speech classification models using domain adaptation. This paper demonstrates that we can increase the performance of the speech recognition system by incrementally adapting the models using carefully selected samples available after active learning. We propose a novel iterative fast converging incremental adaptation algorithm that only uses correctly classified samples at each iteration. This conservative framework creates sequences of smooth changes in the decision hyperplane, resulting in statistically significant improvements over conventional schemes that adapt the models at once using all the available data.