Robust emotion recognition by spectro-temporal modulation statistic features

Most speech emotion recognition studies consider clean speech. In this study, statistics of joint spectro-temporal modulation features are extracted from an auditory perceptual model and are used to detect the emotion status of speech under noisy conditions. Speech samples were extracted from the Berlin Emotional Speech database and corrupted with white and babble noise under various SNR levels. This study investigates a clean train/noisy test scenario to simulate practical conditions with unknown noisy sources. Simulations demonstrate the redundancy of the proposed spectro-temporal modulation features and further consider the dimensionality reduction. The proposed modulation features achieve higher recognition rates of speech emotions under noisy conditions than (1) conventional mel-frequency cepstral coefficients combined with prosodic features; (2) official acoustic features adopted in the INTERSPEECH 2009 Emotion Challenge. Adding modulation features increased the recognition rates of INTERSPEECH proposed features by approximately 7% for all tested SNR conditions (20-0 dB).