The Effect of Vocal Alarms on Operator Mistrust

Abstract

The use of alarms has increased in many operational areas because of increased reliance on automation and the duty to warn about system anomalies. Past research has supported the use of verbal alarms for relaying complex information. However, researchers have not considered the impact of vocal alarms on operator trust. In this research, 56 participants reacted to auditory alarms while performing a complex primary task. Half of the participants experienced vocal alarms, and the others experienced nonvocal alarms. Contrary to expectations, we noted that participants reacted to nonverbal alarms more quickly than verbal alarms. Furthermore, participants responded to verbal alarms more often than verbal alarms. We also noted that verbal alarms interfered with the primary task more than nonverbal alarms. We suggest that alarm designers alter verbal alarm onset algorithms during high operator workload.