Abstract: The sound wave and temperature sensor of the present disclosure can be used for detecting whether a fire accident occurs within a specific area without risking altering or damaging existing sensors, and can be a part of an intelligent home security system. One aspect is to provide an integrated sound wave and temperature sensor that can efficiently work together with the existing sensors. An example apparatus can include a sound sensor, a temperature sensor, a communication circuit, and a microcontroller. The microcontroller can be configured to, responsive to the sound sensor detecting an audible alarm emitted from an environmental detector, determine whether an ambient temperature exceeds a threshold value. Further, the microcontroller can, responsive to both the sound sensor detecting the audible alarm and the ambient temperature exceeding a threshold value, cause the communication circuit to transmit an alert to a recipient.