II. Direction.—The direction whence a sound comes seems to be judged of by the right or left ear receiving the stronger impression, which however can only take place when the sound's source is in a plane, or nearly so, with a line passing through both ears. It is familiarly known that a person in a house cannot by the noise of an approaching carriage judge with certainty whether it is coming from the right or left. He accurately judges it to be approaching, passing, or receding, as the case may be, by the gradations of loudness, but is unable to decide with certainty whether its approach or recession is from up or down the street. Common experience shows the judgment to be more fallible concerning the direction than the distance of sounds. Professor Muller of Berlin states, in his 'Physiology,' that Venturini's experiments, detailed in Voles Mag.,' bd. ii., demonstrate the impos sibility under certain circumstances of estimating whence a sound comes to the ear. Now, without entering upon the merits of those valuable experiments, enough has been above stated to show that we do not hear, but that we judge, the direction a sound has travelled from its source on reaching the ear.
It has been remarked, and the writer of this article confirms its truth from observations made both in public and in private ventriloquy, that the ventriloquist indicates either directly or indirectly the direction which he wishes his audience to believe the sound is coming. Thus they directly indicate it by words, such as—" Are you up there ? " "He is up the chimney;" He is in the cellar," "Are you down there ?" &c. And they indirectly indicate it by some suggestive circumstance, as an action or gesture which is so skilfully unobtrusive and natural as to effect its object without being discovered. Thus, when the ventrilo quist looks or listens in any direction, or even simply turns towards any point, as if he expected sound to come thence, the attention of an audience is by that means instantly directed also to the same place. Thus, before a sound is produced, the audience expect it to come in the suggested direction. And the ventriloquist has merely, by his
adjustment of vocal loudness, to indicate the necessary distance, when a misjudgment of the audience will complete the illusion which he has begun.
The effect which is produced on sound by its travelling from a distance is observed to be 1. That its loudness is reduced in proportion to the distance.
2. That its pitch remains unaltered.
3. That its quality or tone is somewhat softened.
4. That its duration remains unaltered.
5. That human speechis somewhat obscured, chiefly in the consonant sounds.
Now, the ventriloquist imitates the sound, not as it is heard at its source, but as it is heard after travelling from a distance. A skilful ventriloquist can effect his imitations without much movement of his lips and features. Now, it has been observed that ventriloquists, during their efforts, turn the front face away from the audience and scarcely even show the profile. The author of this article confirms this observa tion, as far as regards moderste-sized rooms, but he has seen the front face in a:theatre.
It is quite easy to speak without moving the jaw, and it is the jaw's movements which disturb the features in utterance. Now the labial sounds, such as a, r, at, when the jaw is thus fixed, can be made with a slight movement of the lips. The lips and jaws bring always mine.
what open during veutrlio pray, a sii lake' movement remains unnoticed. unless special attention be directed to it; and all the modi fications of voice can be produced without at all distorting the features or moving the The preceding outline of the philosophy of ventriloquism is sufficient to exhibit the nature of the Art. 'ro enter upon the consideration of all the vocal menus adopted to accomplish the various ituitations would fill a volume The mode of counterfeiting variations in loud ness by changes of pitch, and also by changes from the natural to the falsetto register of voice, are amongst the wonders of vocal science, and are capable of extensive application by the seientifle ventriloquist.