Strobe lights versus auditory smoke alarm signals: Effectiveness for waking up selected populations

Strobe lights are recommended in the USA and elsewhere as a suitable emergency notification signal for waking the deafor hard ofhearing (NFPA 72, 2002 standard). This paper reviews the relevant literature, and reports on the waking effectiveness of strobe lights (177 candela or more) in comparison to the current high pitched smoke alarm and a low frequency square wave tone (520 Hz dominant frequency). The signals were activated at increasing intensity levels during slow wave (deep) sleep in two groups: (i) 38 adults aged 18–77 years with mild to moderately severe hearing loss in the range of 25–70dBA in both ears, and (ii) 32 young adults aged 18–26 years impaired with alcohol at 0.05 blood alcohol content. It was found that three quarters ofthe participants slept through the strobe light activated at above the recommended intensity of the standard. Further, adding a strobe light to a current smoke alarm signal is likely to be less effective at waking participants than sounding a low frequency square wave...