Effect of spectral parameters on the elderly’s urgency perception of auditory warning signals

Abstract

This study aims at revealing the effects of spectral features of warning sounds on elderly people’s urgency perception and how it differs from the young group. A serial of experiments was conducted to investigate the independent variables including the sound pressure level and frequency of pure tone, with or without harmonics, fundamental frequency, spectral shape and irregularity of harmonics on the objective reaction time and subjective urgency evaluation. The results showed that SPL and frequency had significant effects on the elderly’s reaction time to pure tones. The elderly people tended to evaluate the lower frequency domain to be the most urgent one than young group. Elderly people were also likely to perceive sounds without harmonic components to be more urgent. Considering the spectral features of harmonics, the lower fundamental frequency of harmonics, spectral shape with great proportion of energy on low frequency domain and certain level of irregular components would be beneficial for elderly people’s urgency perception. These findings indicated that the warning sounds of the elderly need to be carefully designed.