Provided are an acoustic sensor and a home appliance system comprising the same. The acoustic sensor comprises a communication unit, a microphone to collect an acoustic signal, 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. Accordingly, failure of the home appliance may be easily diagnosed.