Categorical and Dimensional Ratings of Emotional Speech: Behavioral Findings From the Morgan Emotional Speech Set

Purpose: Emotion classification for auditory stimuli typically employs 1 of 2 approaches (discrete categories or emotional dimensions). This work presents a new emotional speech set, compares these 2 classification methods for emotional speech stimuli, and emphasizes the need to consider the entire communication model (i.e., the talker, message, and listener) when studying auditory emotion portrayal and perception. Method: Emotional speech from male and female talkers was evaluated using both categorical and dimensional rating methods. Ten young adult listeners (ages 19-28 years) evaluated stimuli recorded in 4 emotional speaking styles (Angry, Calm, Happy, and Sad). Talker and listener factors were examined for potential influences on emotional ratings using categorical and dimensional rating methods. Listeners rated stimuli by selecting an emotion category, rating the activation and pleasantness, and indicating goodness of category fit. Results: Discrete ratings were generally consistent with dimensional ratings for speech, with accuracy for emotion recognition well above chance. As stimuli approached dimensional extremes of activation and pleasantness, listeners were more confident in their category selection, indicative of a hybrid approach to emotion classification. Female talkers were rated as more activated than male talkers, and female listeners gave higher ratings of activation compared to male listeners, confirming gender differences in emotion perception. Conclusion: A hybrid model for auditory emotion classification is supported by the data. Talker and listener factors, such as gender, were found to impact the ratings of emotional speech and must be considered alongside stimulus factors in the design of future studies of emotion.