We had to replace all of the fire alarms in the house with the new types
mandated in 2006. All *16* of them were replaced with combination
smoke/carbon monoxide hardwired types that not only beep
but also have voice announcements of "Fire, Fire, Evacuate, Evacuate".

When one goes off, they all go off. With 16 of them blaring, it's like
hearing a fire alert in 7.1 surround sound.