On voicing activity under the control of emotion and loudness

Abstract

For a parametric study of interplay between loudness control and emotional modulation in voicing activity, electroglottography (EGG) data collected from two male and two female subjects are examined. The subjects read emotionally neutral sentences in a self-controlled manner with four different emotional states (neutral, angry, sad, happy) and three levels of loudness (soft, normal, loud). The analysis focused on the timing and shape-related EGG waveform parameters of the vowel /a/ in the data as a function of emotional state and loudness level. Specifically, open quotient (OQ), speed quotient (SQ), and noise-to-harmonic ratio (NHR) of EGG waveform are investigated. Pitch, root-mean-square (RMS) energy, and duration of speech waveform are also analyzed. Despite inter-subject differences, some general tendencies of the EGG parameters can be observed. It is found that angry emotion shows the lowest OQ in a given loudness level, and happy emotion exhibits significantly higher OQ than angry emotion. SQ mainly varies along the loudness dimension, smaller SQ in louder voice. NHR is the highest in soft voice and shows no clear emotion-dependent pattern. The results suggest that OQ is the main EGG parameter that is controlled by speakers for emotion expression, in addition to its role in loudness control.