Vocal expression in spontaneous and experimentally induced affective speech: Acoustic correlates of anxiety, irritation and resignation

We present two studies on authentic vocal affect expressions. In Study 1, the speech of social phobics was recorded in an anxiogenic public speaking task both before and after treatment. In Study 2, the speech material was collected from real life human-computer interactions. All speech samples were acoustically analyzed and subjected to listening tests. Results from Study 1 showed that a decrease in experienced state anxiety after treatment was accompanied by corresponding decreases in a) several acoustic parameters (i.e., mean and maximum F0, proportion of high-frequency components in the energy spectrum, and proportion of silent pauses), and b) listeners’ perceived level of nervousness. Both speakers’ self-ratings of state anxiety and listeners’ ratings of perceived nervousness were further correlated with similar acoustic parameters. Results from Study 2 revealed that mean and maximum F0, mean voice intensity and H1-H2 was higher for speech perceived as irritated than for speech perceived as neutral. Also, speech perceived as resigned had lower mean and maximum F0, and mean voice intensity than neutral speech. Listeners’ ratings of irritation, resignation and emotion intensity were further correlated with several acoustic parameters. The results complement earlier studies on vocal affect expression which have been conducted on posed, rather than authentic, emotional speech.