Few studies have addressed whether alert parameters for in-vehicle information systems differentially affect annoyance and urgency. This study assesses the influence of the auditory characteristics of alerts on perceived urgency and annoyance and whether these perceptions depend on the context in which the alert is received. Three mixed within/between factorial experiments, with a total of 72 participants, were conducted to investigate 9 alert parameters in 3 driving contexts. These parameters were formant (similar to harmonic series), pulse duration, interpulse interval, alert onset and offset, burst duty cycle, alert duty cycle, interburst period, and sound type. Imagined collision warning, navigation alert, and E-mail notification scenarios defined the driving context. Results showed that all parameters influenced both perceived urgency and annoyance, with pulse duration, interpulse interval, alert duty cycle, and sound type influencing urgency substantially more than annoyance. There was also a strong relationship between perceived urgency and rated appropriateness for high-urgency driving scenarios and a strong relationship between annoyance and rated appropriateness for low-urgency driving scenarios.
Abstract