During the usual span of life the voice changes from time to time. The first change occurs when one passes from infancy into childhood. The next takes place when the boy and girl move into adolescence. Still another comes when the youth approaches adult life, and the final transpires in old age. These changes are due to physiological modifications which affect the vocal instrument.

Undoubtedly the most interesting phenomena occur at the beginning of youth or adolescence. Until this time voices of boys and girls, as a rule, have presented no great variation in range and quality, both being commonly known as treble or soprano. Early in the teens,- however, the vocal organs undergo marked alterations along with the general physical development. As a result, the voice becomes different in range, power, and quality. Although mutation occurs in both sexes, it is more noticeable in the boys voice than in the girl’s.

To comprehend fully what happens in the vocal mechanism to bring about these modifications would require a study of anatomy which is appropriate only in special cases and for the medical profession. However, a brief description of the larynx, a very important, if not the most important, organ in voice production, may suffice to explain somewhat the causes and effects of change at this time as well as to describe the difference between men’s and women’s vocal instruments.

When not making sound, the larynx, situated in the upper extremity of the trachea, is merely a part of the breathing apparatus. However, when sound is produced, it performs a specific function for which especially adapted structures are necessary. In addition to the vocal cords, these structures, in the main, are cartilages which make up its outer framework and which are joined in such a manner as to insure flexibility as well as firmness. Names of Greek origin describing their shape are applied to them. The largest is the thyroid cartilage, so-called from its resemblance to a shield. Its two main plates meet in front but are open behind and constitute the walls or sides of the voice box. Below the thyroid cartilage, and attached to it, is the cricoid cartilage. In form it looks like a seal ring with the broad part in the back and the narrow in front. Connected with both the cricoid and the thyroid cartilages are the arytenoid cartilages, so named because they somewhat resemble a ladle. Extending across the upper part of the larynx and attached to the thyroid in front and the arytenoids behind are the vocal bands. Thus it is apparent that there is close relationship among all parts. Alteration in size or position in one structure would therefore affect the others.

As a case in point, when the boy grows and develops, the thyroid cartilage pushes out, making what is commonly known as the Adam’s apple. Since the vocal bands are attached to it, they too must extend. Therefore they become considerably longer than the girl’s, whose larynx does not alter in the same manner. Coincident with and as a consequence of the lengthening of the cords, as well as other changes in the boy’s larynx, his voice begins to drop in pitch. In accordance with the growth of the vocal mechanism this descent takes place more or less gradually. Generally in maturity, the man’s voice is about an octave lower than the woman’s.

The voice is high or low in pitch and light or heavy in quality according to the length and thickness of the cords and the shape and size of the larynx and the resonators. As arrule, rule, the man’s larynx is not only larger than the woman’s, but it is also firmer. Consequently the male voice is usually less flexible than the female. Such, in brief, are the causes and effects of the vocal changes that begin in youth and continue until the voice reaches its full development some years later. It should be emphasized that any changing voice is, to a great extent, a new instrument which presents unfamiliar and difficult problems to its owner. This is particularly so at the beginning of adolescence. Vocal authorities differ as to the use of voice at this time. Some advocate that there should be little or no singing, especially in the case of boys. On the contrary, many believe it is psychologically and vocally beneficial for all to sing if voices are produced freely, if periods are brief, and if songs are within a limited range. Experience has shown that, under wise instruction, singing not only conserves and develops voices, but maintains and stimulates interest in music generally. Moreover, it is a wholesome means of self-expression.