dr. gary smith says he sees this all the time. >> it would astound you how loud the sounds can get and childrenontinue to sleep through them. >> reporter: why do kids sleep through the alarms? >> they are simply not small adults. they are different biologically. children spend more time in deep sleep than adults do. that's why it is harder for them to awaken in the case of an emergency. >> reporter: that's why he says families need an escape plan. make sure each adult has a designated child to wake up in a real fire. meanwhile researchers are trying to find a sound that works better than the beeping. dr. smith is experimenting with a new alarm prototype. it allows parents to record their own voices as the alarm telling their kids to get up. he says it seems to be working. right now these alarms aren't on the market and it could be at least another year before they are. jeff rossen, nbc news, new york. >>> as we said, this deserves our attention. you can see more of this reporting sunday night on "dateline" 7:00/6:00 p.m. central on this nbc station. >>> we are back in a moment with a look at th

dr. gary smith says he see this is kind of thing all the time. >> it would astound you at how loud the soundso sleep through them. >> reporter: dr. smith is a researcher at ohio's nationwide children's hospital, and has been studying smoke detectors and sleeping children for years. why do kids sleep through these alarms? >> they are simply not small adults. they're different biologically. >> reporter: that means they sleep differently. >> children spend more time in deep sleep than adults do and that's why it's harder for them to awaken in the case of an emergency. >> come on girls, get up. >> reporter: that's why he says families need to map out an escape plan in advance. make sure each adult has a designated child to wake up in a real fire. >> hurry up. >> reporter: that's exactly what the hollanders are doing, after watching their kids sleep right through it. so from now on if you hear that smoke alarm going off? >> i'm running, there's other choice. >> reporter: to wake them up. >> because they're not waking up without me. >> now researchers are taking it to another level trying to figure