Kidde smoke alarms make a few different sounds: loud continuous alarms, periodic chirping and consistent chirping. The loud alarm typically indicates combustion. However, false alarms occasionally cause this noise.
False alarms occur due to an improperly fitted battery, a dirty smoke alarm sensing chamber, high humidity in the environment, electrical power interruption or a worn-out device. In some cases, these conditions cause intermittent chirping instead. Chirping every 30 to 60 seconds usually means that the owner should replace the battery. However, it sometimes signifies a device malfunction or interference from another system. In addition, a Kidde smoke alarm also chirps continually when the Hush feature is activated or a sealed battery model needs replacing.