Page:Popular Science Monthly Volume 45.djvu/92

80 this case it will be observed that the original sound and the jangle both came from the same place, so that it was not so difficult to locate.

There was no mistake about it, as the old lady sang through each verse, and at every verse the jangle appeared. She, however, seemed totally unconscious of any discordant effect in her vocal effort, and I have no doubt did not notice it at all.

The difficulty of locating sounds correctly may be illustrated in one way by the advantage the ventriloquist takes of this peculiarity, for in the exercise of his art he can speak in such manner that his voice appears to come from an image beside him, or from some distant place. Analogous to optical delusion, the ventriloquist might be well termed an exponent of sound delusion; and, again, the attempt to deceive an audience as to the source of sound by a supposed performer on the stage going through the motions of playing upon a cornet or other musical instrument while the real performer is behind the scenes is often successfully practiced. I was once present at a practical test made before an audience which will further illustrate how difficult it is to determine whence a sound comes. A gentleman took his seat in a chair upon the platform and was blindfolded. Another party held a snapper sounder in one hand and would produce the snap now directly over his head, now to one side, behind his back, etc. At each sound of the snapper the blindfolded party was requested to point in the direction from which he thought the sound proceeded. In almost every attempt he pointed in the wrong direction.

As a result of observations which I have made among animals, there is a wide difference between them as to the ability of distinguishing and correctly locating sound; for instance, men and women have not such an acute sense of quickly locating a sound as some of the four-footed animals, such as the rabbit, mule, the cat, and some species of dogs. It is quite probable that the ability these animals have to move their ears about, and long ears at that, accounts for the quickness they have for determining the direction of a sound. I have often tried the experiment of testing this sense of correctly locating sound with a cat by imitating the squeak of a mouse by whistling through the teeth. The first squeak or two would result in the cat springing up and, with ears erect and moving about, listen for the next sound; at the second attempt the cat would as a rule look directly into my face, as much as to say, "You can't fool me that way," would settle down again to its nap, and no further imitation squeaks would start it up again.

The not infrequent result of any unusual sound behind a mule illustrates how well his sense of hearing serves him in this