Abstract
Automatic recognition of human emotions in a continuous dia-log model remains challenging where a speaker's utterance includes several sentences that may not always carry a single emotion. Limited work with stan-dalone speech emotion recognition (SER) systems proposed for continuous speech only has been reported. In the recent decade, various effective SER systems have been proposed for discrete speech, i.e., short speech phrases. It would be more helpful if these systems could also recognize emotions from continuous speech. However, if these systems are applied directly to test emotions from continuous speech, emotion recognition performance would not be similar to that achieved for discrete speech due to the mismatch between training data (from training speech) and testing data (from continuous speech). The problem may possibly be resolved if an existing SER system for discrete speech is enhanced. Thus, in this work the author's existing effective SER system for multilingual and mixed-lingual discrete speech is enhanced by enriching the cepstral speech feature set with bi-spectral speech features and a unique functional set of Mel frequency cepstral coefficient features derived from a sine filter bank. Data augmentation is applied to combat skewness of the SER system toward certain emotions. Classification using random forest is performed. This enhanced SER system is used to predict emotions from continuous speech with a uniform segmentation method. Due to data scarcity, several audio samples of discrete speech from the SAVEE database that has recordings in a universal language, i.e., English, are concatenated resulting in multi-emotional speech samples. Anger, fear, sad, and neutral emotions, which are vital during the initial investigation of mentally disordered individuals, are selected to build six categories of multi-emotional samples. Experimental results demonstrate the suitability of the proposed method for recognizing emotions from continuous speech as well as from discrete speech.