In 2012, first responders were left devastated after finding six kids dead as a result of a house fire. But even more alarming to forensic scientists and fire experts was that these kids were still tucked in bed — they had never moved. Although toxicology reports showed that none of the kids were incapacitated and that working fire alarms were in place, it appeared that none of the six kids were alerted to the danger.
Dave Coss, watch manager at Derbyshire Fire and Rescue Service in the UK, explained that if the kids had awoken instead of presumably sleeping through the alarms, they may not have been tragically killed that evening. Since then, investigators with the company have conducted 204 tests on 34 children to see if there is a difference in response between kids and adults to fire alarms. According to the Huffington Post UK, 27 of these kids repeatedly slept through the smoke detector alarms. Of the 20 girls and 14 boys studied, just seven of the girls woke up at least once, while none of the boys were disturbed.
In 2006, the National Fire Protection and Research Foundation (NFPA) studied the effectiveness of alarms for emergency notification of high-risk groups (children, the elderly, and those with hearing impairments) to see if alarm systems met their needs and if high-pitched systems could effectively wake them. They found that "square wave sound with a fundamental frequency in the lower ranges (i.e. 520 Hz) to be more effective than the current high pitched smoke alarm signal across a range of populations (children, older adults, sober young adults, alcohol impaired young adults, and adults with hearing impairments)."
So what does that mean? Based on these results, in 2014, the NFPA updated their provisions to require newly constructed and some renovated commercial sleeping areas to have low-frequency 520 Hz signal alarms. This is a great start, but doesn't protect most children sleeping in their homes.
Even if your children don't have hearing impairments, they could still be at risk of sleeping through high-frequency alarms. There's a difference between being able to hear an alarm and being awoken from a deep sleep by one. Parents should check the frequency of their alarm (you're looking for the Hz number, which should be written on the fire alarm itself), test it out at night with their family, and consider ordering a low-frequency alarm to be extra safe.