The sense of Hearing.
The sense of hearing lies in the ear, the organs of which are contrived with admirable skill and ingenuity. The air is capable of being moved so as to produce a rapid shaking or vibration. Such a movement of the air is made by the explosion of a gun, by the human voice, &c. Thus vibration of the air with the perception of it, is what we call sound.
Now at the bottom of a winding cavity in the ear is a delicate organ called the drum, which is affected by every motion of the air, however slight; and which, by means of nerves, conveys to the brain the perception of such motion. It is by this means that we hear distant as well as near sounds, and often know what is going on even beyond the reach of sight. Hearing, then, is only perceiving vibrations or quick motions of the air, and sound is only such vibration, with the perception of it.
The delicacy and perfection of the mechanism of the ear are so great, that by its power we not only are able to distinguish the vibrations of the air, caused by the voice of one person, from those produced by that of another, but even to distinguish the vibrations, produced by one string of a musical instrument from those of another. It is owing to the perfection of this mechanism that we are able to distinguish musical notes, to judge of the distance of sounds, to discriminate between the several songs of the orchard and the grove.
Most quadrupeds have long ears, which they can move forward and back with great ease, so as to distinguish with quickness and accuracy the species of sounds, and the nature and situation of the animals or objects which produce them. If you notice a cat or dog, or even a horse, you will observe that the ear is very active, seeking to gather information as to what is going on around. The ears of the hare and rabbit are peculiarly fitted to the use of such timid creatures.
We observe that children seem often inattentive to sounds, and that they are very fond of noise. The reason is this: the bones of their ears are soft, and therefore not sonorous; accordingly, their sense of hearing is dull. When they appear inattentive, they do not hear; yet the exercise of the sense is pleasant, and therefore loud noises delight them. For this reason it is that they usually speak loud, and, when several of them are together, they seem to be much gratified with making an uproar.
The sense of hearing is not only of the greatest use to us in the serious business or life, but it is the source of an infinite number of pleasures. What gratification we sometimes enjoy at hearing the voice of a dear friend! What enjoyment we derive from music! Beside all this, language, which is the great vehicle of thought, is communicated by the ear. It is true that after they are formed we commit words to paper; but these are only signs of sounds previously formed. Without hearing we could have no speech, and all would be dumb; without speech there could be no writing, no books. How vastly, then, is the circle of our knowledge and our pleasures enlarged by this sense, and how does the goodness and the wisdom of the Creator appear in bestowing upon his creatures such a wonderful and beneficent gift!