The Child-Voice in Singing | Page 3

of vocal registers is as vexing to-day as ever.
While, then, we may confidently expect further and more complete elucidation of the physiology of the voice, there is yet sufficient data to guide us safely in vocal training, if we neglect not the empirical rules which the accumulated experience of the past has established.
The organ by which the singing-voice is produced is the larynx. It forms the upper extremity of the windpipe, which again is the upper portion and beginning of the bronchial tubes, which, extending downward, branch off from its lower part to either side of the chest and continually subdivide until they become like little twigs, around which cluster the constituent parts of the lungs, which form the bellows for the supply of air necessary to the performance of vocal functions. Above, the larynx opens into the throat and the cavities of the pharynx, mouth, nose, and its accessory cavities, which constitute the resonator for vocal vibrations set up within the larynx.
The larynx itself consists of a framework of cartilages joined by elastic membranes or ligaments, and joints. These cartilages move freely toward and upon each other by means of attached muscles. Also the larynx as a whole can be moved in various directions by means of extrinsic muscles joined to points above and below.
The vocal bands are two ligaments or folds of mucous membrane attached in front to the largest cartilage of the larynx, called the thyroid, and which forms in man the protuberance commonly called Adam's apple; and, extending horizontally backward, are inserted posteriorly into the arytenoid cartilages, the right vocal band into the right arytenoid cartilage and the left band into the left cartilage. These arytenoid cartilages, by means of an articulation or joint, move freely upon the cricoid, the second large cartilage of the larynx, forming its base, and sometimes called the ring cartilage, from its resemblance in shape to a seal ring. The vocal bands are composed of numberless elastic fibres running in part parallel to each other, and in part interwoven in various directions with each other. The fibres also vary in length; some are inserted into the extending projections, called processes of the arytenoid cartilages, and some extend further back and are inserted into the body of the cartilages. The vocal bands, then, lie opposite each other, on a level, raised a little in front, and with a narrow slit between, called the glottis.
The muscles controlling the action of the vocal bands, and which regulate the mechanism producing sound, are of three groups, viz., abductors (drawing-apart muscles), adductors (drawing-together muscles), and tensors.
The abductors act to keep the bands apart during respiration, while the function of the adductors and tensors is to bring the bands into position for speech or singing. They are, since phonation is at will, voluntary muscles; but it is an interesting fact that the laryngeal muscles of either side invariably act together. It has been shown that it is not possible to move one vocal cord without the other at the same time executing the same movement. It is thus shown that the laryngeal muscles are, to a less extent, under the control of the will than are those of either hand or eye. The rational training of the singing-voice cannot, therefore, proceed upon any theory based upon the voluntary training of the muscles controlling the movements of the vocal cords.
The mucous membrane which lines the larynx is liberally supplied with secreting glands, whose function is to keep the parts moist. Above the vocal bands, another pair of membranous ligaments are stretched across the larynx forming, with its sides and the vocal bands, a pouch or pocket. The upper ligaments are sometimes called the false vocal cords, but are more properly termed ventricular bands. Their function has occasioned much speculation, but whatever modification of tone they may be supposed to produce, they no doubt protect the true vocal bands and permit their free vibration. The larynx, in the production of sound, may be compared to an organ-pipe. The two vocal cords which act simultaneously and are anatomically alike, when set in vibration by the blast of air coming from the lungs, correspond to the reed of the organ-pipe; the vibration of the cords, producing sound, which is communicated to the air enclosed in the cavities of the chest and head. Pitch of tone is determined by the rapidity of vibrations of the bands, according to acoustical law, and the length, size, and tension of the cords will determine the number of vibrations per second, i.e., their rapidity.
Strength or loudness of tone is determined primarily by the width or amplitude of the vibrations of the vocal membrane, and quality or timbre is determined by the form of the vibration.
The infinitely varying anatomical divergencies in the form and structure of the