The KidSmart Vocal Smoke Detector relies on the ‘cocktail party effect,’ where a person’s own name or a familiar voice is more easily discernable even against a great deal of background noise. Allowing the user to record their voice onto the device, the KidSmart plays back the recording and a standard warning tone when it detects fire.
There are some interesting echoes of the early days of audio recording here. I can't quite put my finger on it, but having my house speak to me in my own voice...haunted or soon-to-be-normal?