Optimizing Emergency Awakening to Audible Smoke Alarms: An Update

Abstract

Objective: This review examines research on arousal from sleep in an emergency. It considers whether the current smoke alarm signal is optimal for waking those most at risk of dying in a fire and, if not, how it may be improved. Background: The fire fatality rate during the sleeping period is approximately three times greater than at other times. Method: Four key areas are reviewed: (a) the characteristics of four signals (high-frequency beeping, Temporal 3, voice, and naturalistic sounds); (b) how human characteristics alter arousal to different signals; (c) research comparing the effectiveness of different alarms in different sleeping populations; and (d) acoustical, methodological, and theoretical implications. Results: Significant risk factors for staying asleep include high levels of background noise, being a heavy sleeper, sleep deprivation, being a child, hypnotics, alcohol intoxication, and hearing impairment. The high-frequency beeping signal was significantly less effective than either a voice alarm or mixed-frequency beeping in waking selected at-risk groups. Conclusion: The alternative signals were more effective in arousing various groups of sleepers than was the high-frequency signal currently used in smoke alarms. Application: Replacement of the current smoke alarm signal with one of a lower frequency is likely to wake more people more quickly and save lives.