Abstract
In order to study features of auditory alarms suitable for both young adults and the elderly, the following four auditory alarms were designed and tested: (1) a 2kHz pure tone; (2) an amplitude-modulated tone composed of the product of 2kHz and 2.5kHz sinusoidal signals; (3) a frequency sweep tone from 3kHz to 0.5kHz; (4) a frequency sweep tone from 0.2kHz to 2.7kHz. The audibility of these alarms was examined in terms of the reaction time. Impressions of the urgency of these alarms were also evaluated. There were significant differences in impressions of urgency for alarms (3) and (4) between male and female subjects, and between young and elderly subjects. In view of the overall evaluation of reaction time and impression analysis, alarm (2) is considered the best. The experimental results suggest that a complex, frequency-changing sound would be most effective in creating auditory alarms suitable for both young adults and the elderly.
