Public Speaking in Front of a Virtual Audience: The Influence of Listeners’ Attitude on Voice, Speech, and Anxiety

Background: Public speaking (PS) is a complex and multidimensional activity that enables the transmission of a message from a sender to several receivers. Understanding PS mechanisms is of paramount importance as our PS proficiency can have repercussions in our daily lives. Various situational variables, such as audience attitude, appear to influence PS performance by modulating anxiety. An audience displaying negative and disengaged behavior (i.e.: averted gaze, shaking head, backward posture) has been found to increase anxiety compared to a positive and engaged audience (i.e.: mutual gaze, nodding, smiling, forward-leaning posture). However, little is known about which aspects of oral communication are impacted by audience attitude. Objective: To determine the influence virtual audience’s attitude on voice, speech, and anxiety parameters.
Methods: We conducted acoustic analyses on the speech productions of 64 university students in front of two types of audience : (1) a positive and engaged audience (2) a negative and disengaged audience. We analyzed multiple parameters related to anxiety (self-reported, heart rate), voice (F0 median and IPR) and speech (percentage of filled pauses, silence duration). Results: The linear mixed model showed that self-reported anxiety was higher during and after the negative condition, whereas physiological anxiety was greater throughout the positive condition. Regarding vocal parameters, a decrease in median f0 and its variation was observed at the beginning of the positive condition. In terms of speech, participants produced a higher number of filled pauses at the start of the positive condition, as well as more silent pauses at the end of the PS, particularly in the negative condition. Conclusions: Contrary to our expectations, the positive condition appears to elicit higher physiological anxiety than the negative condition. Behavioral manifestations of anxiety (voice and speech) also seem to be more closely related to physiological anxiety. Given that anxiety levels remained relatively low across conditions, it can be hypothesized that the induced anxiety may have led to an optimization of PS performance rather than its deterioration. Further research is needed to examine the influence of situational variables in PS, in order to better understand and train this critical skill.