| 摘要 |
PROBLEM TO BE SOLVED: To provide a hearing aid with extremely simple handling and without using a battery, which is easy to receive a sound desired to listen, can hear the sound naturally, and is easy to receive only a sound from the front.SOLUTION: A concave-type sound collecting hearing aid mounted to an auricle of a human body and having high directivity to a selective sound desired to listen is a structure whose size is 10-20 cm in a vertical direction of a human head, 10-15 cm in a front direction and 5-15 cm in a horizontal direction, and which has a focal point with a concave surface at an ear hole. By detaching from or attaching to the auricle, the shape of a music instrument resonance box becomes a three-dimensional noncontiguous aspheric surface structure, and the concave-type sound collecting hearing aid amplifies the sound desired to listen by removing howling of a high sound area. |
