PURPOSE: To turn the sound of vibration into a clear tone and at the same time to recognize a sound source at the front of an auricle, by forming a pierced hole to the walls of the left and right ear cups or the wall of a sound tube.

CONSTITUTION: A diaphragm 1 is stuck to the inside at an end of a sound tube 2, and the opening at the other end of the tube 2 is led to the front of an auricle. The pierced holes 6 and 6' are provided to the wall of an ear cup 5 which can be fixed at the front of the auricle. As a result, the sound of vibration is not closed in the ear cup but turned into a clear tone. When the holes 6 and 6' are formed at the front of the auricle, a vibrating source is substantially obtained at the front of the auricle. Thus a sound source is virtually positioned in front of the auricle. In case the size of the cup 5 is extremely reduced, a pierced hole 6''' is provided to the wall of the tube 2. Then the same effect is obtained by controlling the position of the hole 6'''.