PROBLEM TO BE SOLVED: To provide a hearing aid capable of adjusting hearing aiding based on degradation in selectivity of frequency of a hearing aid wearer (hearing impaired person).
SOLUTION: A hearing aid 1 processes for hearing aiding with acoustic signal inputted from a microphone 2, and outputs the acoustic signal through an earphone 4. It comprises a signal processor 5, auditory nerve excitation pattern calculators 6 and 7, auditory filter form memories 8 and 9, comparator 10, correction processor 11, or the like. The auditory nerve excitation pattern calculators 6 and 7 calculate auditory nerve excitation pattern of hearing impaired person and hearing normal person based on the output signal of the signal processor 5 and the auditory filter form of the hearing impaired person and hearing normal person stored in the auditory filter form memories 8 and 9. The comparator 10 compares the auditory nerve excitation patterns of them, and the correction processor 11 corrects the input acoustic signal to provide an output acoustic signal so that the auditory nerve excitation pattern of the hearing impaired person comes to be equal to that of the hearing normal person.