The sense of Hearing is a more complex one than in the case of Taste, Touch and Smell. In the latter three the objects to be sensed must be brought in close contact with the sense-organs, while in Hearing the object may be far removed, the impressions being carried by the vibrations of the air, which are caught up and reported upon by the nervous organism of the sense of Hearing.
The internal mechanism of the ear is most wonderfully intricate and complex, and excites to wonder the person examining it. It cannot be described here for want of space, but the student is advised to inquire into it if he has access to any library containing books on the subject. It is a wonderful illustration of the work of the mind in building up for itself instruments with which to work–to acquire knowledge.
The ear records vibrations in the air from 20 or 32 per second, the rate of the lowest audible note, to those of 38,000 per second, the rate of the highest audible note. There is a great difference in individuals in regard to the fineness of the sense of Hearing. But all may develop this sense by the application of Attention. The animals and savages have wonderfully acute senses of Hearing developed only along the lines of distinctness, however–on the other hand musicians have developed the sense along different lines.