Abstract: A system and method for the detection and alerting of the presence of carbon monoxide having a system 50 including, a CO detector component 51, a processing component 52, and a power supply component 53 for powering the CO detector and processing components 51, 52; the CO detector component supplies an electrical output signal 53 proportional to a measured level of CO; the processing component performs analog to digital conversion of the electrical output signal 53, generates a first digital audio signal by performing analog to digital conversion of a first analog audio signal 54, generates a second digital audio signal relative to the electrical output signal 53; generates a third digital audio signal by combining the first and second digital audio signals; and generates a second analog audio signal 55 by performing digital to analog conversion of the third digital audio signal.