水中における聴覚の伝達メカニズムに関する実験的考察

抄録

To clarify the propagation mechanism of underwater hearing, threshold levels were carefully measured as a function of submerged skull and ear canals by means of a tank with low background noise level. From several experimental results, it is concluded that the mechanism of underwater hearing is primarily due to bone conduction but the external ear canals also play an important role in total sensation as listed below. (1) At frequencies above about 1 kHz, underwater hearing is primarily bone conduction via skull and more sensitive around the ear than at top of head. (2) Water in the ear canal acts as a loss to bone conduction. (3) At frequencies below about 1 kHz, the ear canal conduction gradually makes greater contribution to the auditory sensation and total characteristics slightly vary depending on the ear canal conditions.