Elderly less likely to wake to smoke alarm
(Reuters)
Updated: 2006-08-25 08:58 NEW YORK - The high-pitched
signal typically used in smoke alarms may not wake older adults, according to a
study conducted by the Fire Protection Research Foundation. In comparative tests
on various alarm sounds, adults aged 65 years and older were much more likely to
wake to a mixed-frequency signal than a pure high-frequency signal used in
standard US smoke alarms.
Household smoke alarms reduce the chances of dying in a fire by up to 50
percent when present and working properly. However, studies have shown that the
elderly do not fully benefit from smoke alarms, particularly during the
overnight hours when they are asleep.
According to the National Fire Protection Association, older adults are more
than twice as likely to die in a home fire as the average person.
The current study investigated arousal from sleep in 42 adults aged 65 to 85
years in response to various signals including the high-frequency signal used in
most US smoke alarms, a mixed-frequency signal, and a male voice saying "Danger,
Fire, Wake Up."
The high-pitched smoke alarm signal was least likely to wake the study
subjects, Dorothy Bruck from Victoria University, Australia and the study team
reports. The male voice also performed poorly.
The mixed signal was most effective in waking sleeping elderly.
The study also found that the volume needed to wake up to the high-frequency
signal was significantly higher than that needed to wake up to the
mixed-frequency signal.
"The high frequency alarm signal currently found in smoke alarms should be
replaced by an alternative signal that performs significantly better in
awakening most of the adult population, once the nature of the best signal has
been determined," the authors recommend.
In the meantime, they encourage the use of interconnected smoke alarms that
include an alarm in each bedroom to increase the chance of sleeping individuals
being woken by an alarm.
The study also tested the performance abilities of older adults upon
awakening suddenly to a smoke alarm. The results suggest a decrease in physical
functioning of around 10 percent to 17 percent may be expected during the first
five minutes after waking up. There were, however, "no important" effects on
simple or complex cognitive functioning.
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