Gender and Vocal Stress Differences During Truthful and Deceptive Information Sequences

The focus of this study was to determine the efficacy of the Mark II Voice Stress Analyzer as a means of discriminating between truthful and deceptive communications. A simulated job interview was manipulated so that participants in the deceptive condition told the truth on all questions except two, producing two types of deception: prepared and spontaneous lies. Participants in the truthful condition were truthful throughout the interview. Gender was introduced as a predictor variable. Results indicate that the Mark II can objectively and unobtrusively detect vocal stress indicative of deception for the prepared lie, but not for the spontaneous lie. Truthful participants demonstrated no significant differences for any of the information sequences, indicating that the Mark II avoids the problems of falsely identifying innocent subjects. Females exhibited elevated levels of vocal stress during the prepared deception, whereas males did not. Implications of this study and recommendations for future research were noted.