PURPOSE: To eliminate harmful acoustic waves to resolve displeasure and pain of the user, by providing a means, which attenuates rapidly or cuts a sound band higher than a prescribed frequency, in or among respective main bodies of a mike, an amplifier, and an earphone.

CONSTITUTION: A means which attenuates rapidly or cuts a high sound band part higher than several 100∼several 1,000Hz out of sounds reaching earholes in accordance with a desire of the user is provided in or among respective main bodies of a mike 1, an amplfier 3, and an earphone 8 which constitute a hearing aid. That is, a felt or cloth is arranged on the outside of the mike 1, and a channel driver 4, a trap 5, etc. are inserted to the intermediate stage of the amplifier 3, thereby attenuating a prescribed frequency region. Further, a network 7 is connected to the output stage of the amplifier 3 to attenuate rapidly frequencies higher than a prescribed frequency, and the diaphragm of the earphone 8 is made from paper or the like to make the tone quality soft. Thus, harmful ultrasonic waves and the high sound band which is unnecessary practically are eliminated to resolve displeasure and pain such as earache and headache.