Patent ID: 8622147

Claim:
A sound based fire alarm, the system comprising: a self contained automatic stovetop fire extinguisher which emits a audible signal upon activation; a sound burst sensor which detects audible signals and outputs a sense signal to a sensor circuitry; wherein, the sensory circuitry processes received sensed signals and outputs processed sensed signals to a control circuitry; wherein, the control circuitry receives processed sensed signals from the sensor circuitry, determines activation of the self contained automatic stovetop fire extinguisher, and outputs a trigger signal to an alarm system when activation of the self contained automatic stovetop fire extinguisher is determined; and wherein, the alarm system comprises an alarm circuitry and an alarm device, and wherein, when the alarm circuitry receives the trigger signal from the control circuitry, the alarm device provides a continuous fire alarm; wherein, the sensory circuitry filters received sensed signal with a 2.5 kHz to 5.0 kHz band pass filter and outputs filtered sensed signals to the control circuitry; wherein, the control circuitry comprises: a digital signal processor which calculates a power spectral density via a fast fourier transform on a received sensed sound burst signal; and an integrator which integrates the power spectral density signal over 3.0 kHz to 4.0 kHz; and wherein the control circuitry compares the integrated signal to a 120 decibel value and outputs a trigger signal to the alarm circuitry when the integrated signal exceeds 120 decibels.