Challenge period
At the end of the anticipation task, the experimenter took the essay back and gave the participant a standard examination paper consisting of 15 questions. Participants were instructed to answer all questions in the 4 min allocated while their autonomic responses were measured. Based on a pilot study of 10 students, we determined that it takes approximately 10 min to answer the 15 questions. As in the anticipation period, the classical music, background TV, and silence groups were exposed to the same background sound interventions during the challenge period.