A headphone, having a sleep mode and a full-power operation mode, includes a sensor set to detect a state of a wearer in a sleep state or an awake state, Active Noise Cancellation (ANC) earphones, and a controller coupled to the sensor set and the earphones, which can control the headphone to switch between the sleep and the full-power operation modes based on the detected state of the wearer. Once the controller determines the wearer falling into the sleep state, the controller will switch the headphone from the full-power operation mode to the sleep mode, turn off the earphones, and increase the wearer state detection interval used while the headphone being in the sleep mode. This may reduce power consumption of the headphone and help improve the sleep quality of the wearer.