Abstract: An intrusion alarm and emergency illumination apparatus includes an audible alarm and lighting device which are activated by sounds associated with human intrusion into a physical structure. The sounds of intrusion may be differentiated from other sounds by a bandpass digital amplifier and rate of rise detector which receive audio-electrical waveforms from a microphone. A monostable multivibrator and variable resistance element may be employed to select the duration of activation of the lightning device and alarm and may be employed to provide a preselected exit delay permitting an operator to arm the system and leave the premises without having the sounds of his exiting activate the lighting device and alarm. Emergency illumination may be provided by a reserve power system used to energize the lighting device and alarm system during power outages.