Spot's sound detection algorithm is programmed to detect the pattern of standard smoke and carbon monoxide alarm signals.
For smoke alarms, Spot listens for the Temporal-Three (T3) alarm signal, which produces 3 long beeps followed by a pause.
For carbon monoxide alarms, Spot listens for the T4 alarm signal, which produces 4 long beeps followed by a pause.
Smoke and carbon monoxide alarms manufactured starting in 1996 have followed this standard set by the American National Standards Institute and National Fire Protection Association. The majority of alarms installed prior to 1996 produced a steady continuous sound.
Spot is only programmed to detect the T3 and T4 alarm signals. If you're still using an alarm that produces a continuous pattern, you're due for a change! Smoke detectors only last up to a maximum of 10 years.