Emotion recognition from speech: WOC-NN and class-interaction

This study represents an extension work of the Weighted Ordered Classes-Nearest Neighbors (WOC-NN), a class-similarity based method introduced in our previous work [1]. WOC-NN computes similarities between a test instance and a class pattern of each emotion class in the likelihood space. An emotion class pattern is a representation of its ranked neighboring classes weighted according to their discrimination capability. In this study the class ranks weights are normalized inside each class pattern. We have also studied a new model of distance pattern based on a double class ranks introduced in order to take into account the interaction between the rank variables. The performance of the system based on double class ranks exceeds those based on a single class rank. Furthermore, using likelihood score rank of all class models in the decision rule of WOC-NN adds valuable information for data discrimination. The experiments on FAU AIBO corpus show that WOC-NN approach enhances the relative performance with 5.1% compared to Bayes decision rule. Also, the obtained result outperforms the state-of-the art ones.