In each larynx different parts or regions of the scale are produced by different laryngeal mechanisms. Laryngoscopic observations show that for each region o• system there is a particu lar 'setting' of the larynx, which is maintained throughout each register, the chief change being an increasing tension of the cords as the notes rise in pitch; at the 'break' or change of register there is a sudden shifting of the. setting. In most voices the ear recognizes three registers, the lower. middle, and upper, also termed the thick, thin, and small registers. In the first the cords vibrate as thick masses, in the second only their thin edges vibrate, and in the last the vibrating chink of the glottis is much reduced in length. Ease and smoothness of transition from one register to another is one of the prin cipal objects in training the singing voice. The lower and middle registers are sometimes called the chest voice, and the upper the head voice. In the male the thin register is called the /Ws, lVomen use mostly the upper part of the idlest register and the lower part of the falsetto. Young children use the falsetto en tirely. The middle voice, that is the upper part of the chest register, is used in speaking, on account of its flexibility, reach, and the ease with which it is sustained. Besides the musical tones formed in the larynx a large number of other sounds CUD be produced in the vocal tubes. Speech consists in the modification of the laryn geal tones by other organs superior and anterior to the larynx (as the tongue, the cavity of the lances, the lips, teeth, and palate, with its velum and the uvula acting as a valve between the throat and nostrils), so as to produce those ar ticulate sounds of which language is formed.
I cniriluguism appears to consist merely in the varied mothfication of the sounds produced in the larynx in imitation of the modifications which distance imposes upon the voice. The es sential mechanism of ventriloquism consists in taking a full breath, then keeping the muscles of the chest and neck fixed, and speaking with the month almost closed and the lips and lower jaw as motionless as possible, while air is very slowly expired through a narrow glottis. Care is also taken that none of the expired air is allowed to escape through the nose. Much of the ventrilo quist's skill, however, in imitating sounds com ing from particular directions depends on deceiv ing other senses than hearing. The direction from which sounds reach the ear is never very clearly distinguished, and when the attention is directed to a particular point, the imagination is apt to refer to that point whatever sounds we may hear. :?ee PALATE; ACOUSTICS. Consult: Helmholtz, Die Lehr(' von den Tonu»lpfindungen (Brunswick. I S77) : 111'01V/10 and Behnke. Voice. Song and Speech. (New York, 1S87) ; The hygiene of the Vocal Organs (London, ISS7) ; Durant, Hygiene of the Voice (New York, 1S79) ; and Foster, Textbook of Physiology (New York, IS9S).