A hearing aid includes: a first microphone configured to generate a first input signal from an input sound; a second microphone configured to generate a second input signal from the input sound; a signal processing unit configured to generate an output signal from the first input signal and the second input signal; and a receiver configured to play an output sound from the output signal. The signal processing unit determines time responses of the first input signal and the second input signal based on a contact sound generated when the hearing aid is contacted in a predetermined time period, and distinguishes a plurality of settings of the hearing aid and changes the setting based on the time responses.