Don't know if it fits your needs/setup, but I have one of these and it works with my Kidde smoke detectors (these)
Basically just a widget listens for a standard smoke/CO2 alarm sounds, so it doesn't have to be "in the loop" with your detectors.
That said, my smoke detectors do have the wireless interconnect, so if one goes off, they all go off, so I didn't have to worry about where to put the audio detector, just stuck it next to one of the smoke detectors.
Don't know if it fits your needs/setup, but I have one of these and it works with my Kidde smoke detectors (these)
Basically just a widget listens for a standard smoke/CO2 alarm sounds, so it doesn't have to be "in the loop" with your detectors.
That said, my smoke detectors do have the wireless interconnect, so if one goes off, they all go off, so I didn't have to worry about where to put the audio detector, just stuck it next to one of the smoke detectors.