Acoustic sensor and home appliance system comprising the same

An acoustic sensor, comprising:

• a communication unit;
• a microphone to collect an acoustic signal;
• a sensor unit to output infrared light and receive light corresponding to the output infrared light;
• a memory to store a failure acoustic signal of a home appliance;
• and
• a processor, wherein in response to the acoustic signal, collected by the microphone, corresponding to the failure acoustic signal of the home appliance, the processor transmits the collected acoustic signal, or data corresponding to the collected acoustic signal, to an external server or a terminal, wherein in response to the acoustic signal, collected by the microphone, being at a reference level or higher, the processor activates the sensor unit which is in an inactive state.