The Smart Indoor Siren and the Smart Indoor Camera team up to keep your home extra secure When an unknown face is detected by the Netatmo Smart Camera during your absence, the Siren immediately triggers a powerful 110 dB alarm to scare away the burglar. The Netatmo Smart Camera uses face recognition and people detection to only trigger the Smart Siren when an intrusion occurs: no false alarms caused by a family member, a pet or a harmless movement.