A digital hearing aid has input means for converting an input sound into a digital data for generating an input data, analyzing means for analyzing the input data converted by the input means by a digital conversion and calculating an acoustic pressure at each frequency band, control means for inputting a result of calculation by the analyzing means, acoustic sense characteristics storage means for preliminarily storing acoustic sense characteristics of a deafness and a person having healthy acoustic sense from a fitting means, gain calculation data storage means for preliminarily storing an acoustic pressure range the easiest to hear for the deafness from the fitting means, and acoustic sense compensating means for performing acoustic sense compensation process by amplifying the input data with a given gain. The control means calculates the gain of each frequency range on the basis of the acoustic sense characteristics and an acoustic pressure range stored in the acoustic sense characteristics storage means and the gain calculation data storage means.