[kaisersozei]

I concur with the dog suggestion.

Also, I haven't seen it mentioned, but most of the professional home alarm systems have "panic buttons" that can be activated in emergencies, if things get really out of hand. Some of them even have direct in-home audio monitoring which links to a dispatch center so that the alarm company can silently listen in and send whatever help (fire, ambulance, police) is needed at the time.