Nest smoke detector

Nest Gives the Lowly Smoke Detector a Brain — And a Voice

The $129 Nest Protect, launching this fall, is a handsome white square with rounded corners and an op-arty sunflower pattern. When smoke or carbon monoxide reaches a government-specified level of peril, the device performs like every other alarm. But what sets Nest Protect apart is its vocal warning before things get that bad. This feature has the potential to save lives: Millions of people intentionally disable smoke alarms because they’re fed up when the alert blares at the slightest hint of charred bacon. Nest’s verbal alert gives owners a chance to head off a heart-palpitating klaxon call when none is warranted, making it less likely they’ll rip out the batteries in disgust. And the Nest Protect will never wake you at 3 a.m. to inform you that the battery is low—instead, when the lights go down at bedtime, its gentle ring of light provides a status report. A green glow means all is fine; a yellow circle tells you that it’s time to replace the battery.