Input data are analyzed by FFT, etc. in an analyzing section and power every frequency band is calculated and sent to a control section. In a gain control section, changing characteristics of a gain used in the control section are calculated on the basis of hearing ability characteristics of a user obtained from a memory section and a gain setting memory section, a sound pressure for starting a reduction in gain, and a sound pressure for setting the gain to be equal to or greater than 0 dB. The calculated changing characteristics are sent to the control section. In the control section, the gain every frequency band required in a hearing sense compensating section is determined on the basis of analyzed results obtained from the analyzing section, the hearing ability characteristics of the user obtained from the memory section, and the changing characteristics of the gain obtained from the gain control section. The control section sends data of the gain to the hearing sense compensating section. The hearing sense compensating section obtaining the input data and the gain data performs hearing sense compensation processing with respect to the input data and sends the processed input data to an output section.