BACKGROUND. Conventional residential tone smoke alarms fail to awaken the majority of children during slow wave sleep. With the objective of identifying a more effective smoke alarm for children, we compared a personalized parent voice smoke alarm with a conventional residential tone smoke alarm, both presented at 100 dB, with respect to their ability to awaken children 6- to 12-years-old from stage 4 sleep and prompt their performance of a simulated self-rescue escape procedure.
METHODS. Using a randomized, nonblinded, clinical research design, a volunteer sample of healthy children 6- to 12-years-old was enrolled in the study. Children were trained how to perform a simulated self-rescue escape procedure when they heard a smoke alarm. Each child's mother recorded a voice alarm message, “First name! First name! Wake up! Get out of bed! Leave the room!” For each child, either the voice or tone smoke alarm was randomly selected and triggered during the first cycle of stage 4 sleep, and then the other alarm was triggered during the second cycle of stage 4 sleep. Children's sleep stage was monitored by electroencephalography, electro-oculography, and chin electromyography. The 4 main outcome measures included the number of children who awakened, the number of children who escaped, the time to awakening, and the time to escape.
RESULTS. Twenty-four children were enrolled. The median age was 9 years, and 11 (46%) were boys. One half of the children received the parent voice alarm first, and one half received the tone alarm first; however, the order that the alarm stimuli were presented was not statistically associated with awakening or escaping. Twenty-three (96%) of the 24 subjects awakened to the parent voice alarm compared with 14 (58%) to the tone alarm. One child did not awaken to either stimulus. Nine children awakened to their parent's voice but not to the tone, whereas none awakened to only the tone and not the voice. Twenty (83%) of the subjects in the parent voice alarm group successfully performed the escape procedure within 5 minutes of alarm onset compared with 9 (38%) in the tone alarm group. The median time to awaken was 20 seconds in the voice alarm group compared with 3 minutes in the tone alarm group. The median time to escape was 38 seconds in the voice alarm group compared with the maximum allowed 5 minutes in the tone alarm group. When exposed to the tone alarm, older children were more likely to awaken and were more likely to escape than younger children. There was no association between child's age and awakening or escaping for children exposed to the parent voice alarm. There was no association between child's gender and awakening or escaping for either alarm type.
CONCLUSIONS. To our knowledge, this study is the first to compare the ability of different types of smoke alarms to awaken children while monitoring sleep stage. The personalized parent voice smoke alarm at 100 dB successfully awakened 96% of children 6- to 12-years-old from stage 4 sleep with 83% successfully performing a simulated self-rescue escape procedure, significantly outperforming the 100-dB conventional residential tone smoke alarm. These findings suggest a clear direction for future research, as well as important fundamental changes in smoke alarm design, that address the unique developmental needs of children. The development of a more effective smoke alarm for use in homes and other locations where children sleep provides an opportunity to reduce fire-related morbidity and mortality among children.