Abstract: A dual powered flashlight responsive to an audible smoke detector alarm includes a sound sensor for sensing an audible smoke detector alarm and producing an electrical alarm signal in response; a frequency-sensitive amplifier amplifying the electrical alarm signal but not other signals; an integrator for integrating the electrical alarm signal amplified by the frequency-sensitive amplifier and for generating a trigger signal only when the integrated signal exceeds a threshold; a lamp; a battery connector for receiving a battery for providing current for illuminating the lamp; a power supply including a mains connector connectable to electrical power lines and powering the frequency-sensitive amplifier and the integrator; and a switch receiving the trigger signal and a power supply signal from the power supply for connecting the lamp to the battery in response to at least one of a trigger signal and absence of application of electrical power to the mains connector.