ANATOMY ; LARYNC;OSCOPE, the instrument used for examining the glottis and larynx.
The voices of children are high-pitched or treble. When the boy attains puberty, there is a change in the larynx, and he sounds lower, usually bass notes. The lower, middle and upper registers of the voice involve a shifting of the laryngeal positions, and this is why a slight conscious effort is required .of a singer in going from the natural voice to the fal setto. In regard to the highest development of the human voice in song, the action of the three hollow spaces, nasal, oral and laryngeal, has much to do with the modification and modulation of the singer's voice. These spaces are to the vocal bands what the violin is to the strings; and for every tone and vowel the mucous membrane of the spaces named thust be drawn into a special position (including the position of the larynx) before the air in the spaces can be brought into vibration by the ac tion of the vocal bands. But the vibration of the cords alone is never the tone. The sur faces of the mucous membranes are drawn into different shapes, particularly fit to pro duce tone waves or to disturb them, and to pro duce in such tone-waves not only fundamental tones, but overtones. The tongue is a large
and direct agent in formation, in the middle or oral space, as it is connected with the upper part of the larynx, its derangement in action being alone sufficient to utterly destroy tone, or, on the contrary, when well adjusted and hang ing normally in relation to the other voice parts, to give what is termed the silvery quality to the voice. These spaces are as important in producing the modification and modulations of the singing voice as are the vocal cords and intrinsic muscles of the larynx; there being no doubt, that the movements of the larytut de pend upon and are controlled by the muscles and movements outside that organ. The con trol of the motive power, the breath, is of the utmost importance in maintaining the fixa tion and cord stretching of the vocal mechan ism. Consult (Sound and Speech Waves as Revealed by the Phonograph' (Proceedings, Royal Society, Etinburgh 1897) Scripture, E. W.,