For a full five minutes, Tracy Mehan watched in disbelief as her 12-year-old slept through a smoke alarm blaring in the same room as him — not stirring once.
Mehan had brought her son to a Columbus, Ohio, sleep lab to take part in an experiment pitting traditional high-pitched smoke alarms against various models that played recordings of moms’ voices to see which did a better job of rousing kids from deep sleep.
Mehan’s son was old enough to understand how deadly fires can be, and was not a particularly heavy sleeper, so she was pretty confident about what would happen.
“I thought, ‘Oh, he’ll wake up. He’s not going to be a good test case, because he’ll wake up to all of the alarms,’” Mehan told RR-Magazine, adding that she and her family had practiced a fire escape plan in their own home many times.
Mehan and her family are more prepared than most, because she works in communications for the Center for Injury Research and Policy at Nationwide Children’s Hospital in Columbus, where the study was performed. In other words, she was not involved in the research itself, but she was familiar with the kind of work the center does.
So she was stunned when her son slept straight through the loud, traditional alarm.
“It shook me, because as a parent I was assuming that a smoke alarm going off in his room was going to wake him up,” she said, chuckling at the memory of watching her son sleep right through the beeping.
She was equally surprised when he awoke almost immediately to the alarm that played a recording of her voice, telling him to wake up and leave the room.
Results from that experiment, published this week in The Journal of Pediatrics, suggest Mehan’s son is hardly an outlier. Nearly 180 kids took part in the study, and they were almost three times more likely to be awakened by alarms that used their mothers’ voices than by traditional smoke alarms.
Only about half of the 5- to 12-year-olds in the study woke up to the sound of a typical smoke alarm.
They also had much quicker response times — a potentially lifesaving difference given that most people only have about three to four minutes to escape a house fire. The median time it took for kids to escape their bedroom with a traditional high-pitched alarm was roughly five minutes. For the voice alarms, it was more like 20 to 30 seconds.
“Clearly, under residential conditions, we were able to demonstrate that these voice alarms are much more effective than the typical high-pitch alarm,” study author Gary Smith, director of the Center for Injury Research and Policy at Nationwide Children’s Hospital, told RR-Magazine.
As many as half of all residential fire deaths happen when people are asleep, and Smith and his team were aware of research suggesting that children are, as they wrote in the study, “remarkably resistant” to waking up with traditional alarms.
And yet starting around age 5, children are able to perform self-rescue — basically, to get themselves out of the house when there is a fire — which is why Smith and his team focused on 5- to 12-year-olds, he said. Late childhood has been called the “golden age” of sleep, because it is a time when kids’ sleep cycles and patterns are well-established, but they’re young enough that other sleep disturbances like later bedtimes and stress have not yet begun.
According to the most recent National Fire Protection Association figures, 77 percent of all fire deaths occur at home. There isn’t data on how many deaths occur as a result of sleeping through alarms, but at least one other preliminary study has suggested it is common for children in that general age range to remain fast asleep.
Experts in childhood injuries pay close attention to mitigating the risks associated with fires and burns, which are the third leading cause of accidental injury-related death in kids age 14 and younger.
“I have not really seen anything in the published literature on this before, and there hasn’t been anything on the radar saying that current alarms don’t wake children,” said Gina Duchossois, Injury Prevention Program manager for Children’s Hospital of Philadelphia, who was not involved in the study. “But as a mom, when I think about how my own children would react, it doesn’t necessarily surprise me.”
Smith and his team tested several different versions of voice alarms, some of which played recordings in which moms specifically said their kids’ names — a factor that did not appear to influence awakening or escape times. The voice alarms used in the study are not commercially available, and moms were told to speak as though it was an emergency — in other words, with some emotion — but not necessarily to yell.
In 2006, Smith and his team performed a much smaller study involving personalized voice alarms that included just 24 children and yielded similar results. Because it was so small, however, and involved alarms played at levels about four times louder than those in most homes, Smith described it to RR-Magazine as simply a basic test of concept.
There are no alarms that use parent voices available on the market, but one small company tried it around the time of Smith’s preliminary study. KidSmart offered a vocal alarm that allowed parents to record their own voices urging kids to leave, selling at the time for around $65. (By comparison, basic smoke alarms cost $10 or less.) But the company went out of business.
Smith said the next step in this line of research is to determine whether it’s essential to have the child’s mother record the message — or if it could be their father or another caregiver, perhaps even a generic recorded voice telling kids to get up and get out of the room.
“There are a lot of questions that we’re answering with this series of studies along the way,” Smith said. “Wouldn’t it be nice if we didn’t have to include the part where you record your own voice?”
“It would bring down the cost,” he added, “and that’s important for being competitive on the market, but also [in terms of] bringing down the cost for low-income families, who we know are at greater risk for residential fire injuries.”
He emphasized, however, that the message for parents and families is not that fire alarms are not worth it.
Nationally, 3 out of every 5 home fire deaths occur in homes with no alarms or with alarms that are not working properly. The death rate from home fires is nearly twice as high in households with no smoke alarms as it is in those with working smoke alarms.
“Just having one of the current alarms in your home provides a huge survival advantage, and we absolutely do not want to give the message that the current alarms are not working,” Smith said. “What we’re trying to do is to focus on that 5- to 12-year age group that does not always respond to the high pitch alarm — that will just sleep right through it.”