A headset including a speaker, a motion sensor, a transceiver, and a processor is provided. The speaker plays audio data. The motion sensor senses a posture of a user to generate first sensing data. The transceiver performs data transmission with an external device. The processor is coupled to the motion sensor and the transceiver. The processor determines whether the posture is correct according to the first sensing data to generate an output result and transmits the output result through the transceiver.
