The Voice in Singing Part 9

[19] Although our recitative is formed after the recitative of the ancient drama, yet the latter, according to all accounts, appears to have been very different from our opera recitative, and to have had greater resemblance to the monotonous recitation of the Romish Liturgy, which seems to be a relic of ancient art.

APPENDIX

STRUCTURE OF THE VOCAL ORGANS

The larynx is a sound-giving organ belonging to that cla.s.s of wind instruments called reed instruments, although it differs in various respects from all artificial arrangements of the kind.

The sound or tone-generating apparatus of the larynx consists of tense, elastic _membranes_, the so-called _chordae vocales_, which are enclosed in a sounding case composed of movable cartilaginous plates, and may be stretched by a certain apparatus of muscles in very different and exactly measurable degrees. They are made to vibrate audibly by a current of air impelled with various degrees of force and at will by the lungs in expiration through the narrow c.h.i.n.k (glottis) formed by the fine edges of the chords.

Thus the lungs correspond to the bellows of the organ; the trachea, at the top of which the vocal instrument is placed, answers to the conduit (_Windrohr_), and the cavity of the throat in front of the instrument with its two avenues, the mouth and the nostrils, to the resonance pipe (_Ansatzrohr_).

THE LUNGS

The lungs are two cellular, sponge-like elastic organs, largely made up of little cavities of conical shape, which, in the regular alternations of two opposite respiratory movements of air, are at one time expanded, and then again compressed. The two lungs are not of equal size; the right lung is one-tenth larger in volume than the left.

THE TRACHEA, OR WINDPIPE,

Through which the air of the lungs enters and pa.s.ses out, consists of from sixteen to twenty-six cartilaginous rings, posteriorly incomplete, lying horizontally one above the other.

These rings are connected by a membrane covering them externally and internally. As they enter the cavity of the chest, they divide into two branches, likewise composed of rings, one entering the right, the other the left lung. Before they join the lungs they divide again into several smaller branches, which again subdivide fork-like in the lungs, and terminate in numberless little grape-like cl.u.s.ters of hollow vesicles. The diameter of the trachea in adults is from one-half to three-fourths of an inch when at rest.

THE LARYNX

The larynx may be regarded as the funnel-shaped termination of the trachea. It enlarges upward and is composed of various cartilages more or less mobile, connected by ligaments and moved by muscles. The exterior of the larynx is formed by the

I. Thyroid cartilage.

II. Cricoid cartilage.

The cartilages in the interior are:

I. The Arytenoid cartilages.

II. Cartilages of Wrisberg.

III. Cartilages of Santorini.

IV. Cuneiform cartilages.

To the cartilages of the larynx must be further added the Epiglottis, with the little cartilage at the centre of its inner side.

1. The _thyroid cartilage_ is the largest cartilage of the larynx, and consists of two four-cornered cartilaginous plates held together in front and diverging behind; the anterior borders are convex, and consequently where the two plates meet in front they form an upper and a lower notch or slit. The posterior angles of this cartilage extend into the so-called horns of the _thyroid cartilage_. At the upper horns are ligaments attached, which form the connection between the hyoid bone and the larynx, while the lower horns serve to join the thyroid to the cricoid cartilage. In females and boys the angle formed by the two plates of the _thyroid cartilage_ is obtuse. In the male s.e.x at a certain period the larynx changes its shape, and the plates of the _thyroid cartilage_ then form an acute angle, which is visible on the outside of the throat, and is popularly known as the _Adam's apple_. At this time the diameter of the male larynx becomes a third larger than that of the female larynx, and in consequence the voice is lower, and its different registers are more enlarged in compa.s.s.

2. The _cricoid cartilage_ resembles in shape a seal ring; its broader side is situated posteriorly between the lower horns of the _thyroid cartilage_, and it is connected by its lower edges immediately with the upper edge of the first ring of the trachea. From its side at the back part project two rounded surfaces, which give attachment to the _arytenoid cartilages_.

3. The _arytenoid cartilages_ are two small but very mobile bodies in the form of three-cornered pyramids. The base of the pyramid rests upon the before-mentioned rounded surface at the back of the upper border of the _cricoid cartilage_; one of its sides turns to the front, the two others to the back and outwards. The surfaces between the anterior and postero-interior corners are accordingly turned towards one another. The surface posteriorly is concave, and affords s.p.a.ce for a part of the _arytenoid muscle_; the inner surface is smooth, and forms, during quiet breathing, a part of the lateral wall of the larynx; the anterior surface is rough and irregular, and to it adhere the _vocal chords_, the _thyro-arytenoid muscle_, the _lateral and posterior crico-arytenoid muscles_, and upon these the bases of the _cuneiform cartilages_. The _arytenoid cartilages_ are lengthened at their summits by two little pear-shaped elevations, the _cartilages of Santorini_ (called _apophyses_ in Garcia's observations), which are connected with them by ligamentous fibres, and extend with them some distance into the larynx.

4. The _cartilages of Wrisberg_ are described by Hyrtl as slight elevations upon the front or anterior edge of the _arytenoid cartilages_, inclining towards the interior, and, like all parts of the larynx, covered by the mucous membrane.

5. The _cuneiform cartilages_ (as Wilson names them) are two long, slender cartilaginous laminae which become somewhat broader at both ends. These cartilages, with their base, rest in the middle of the anterior surface of the _arytenoid cartilages_, and reach to the middle of the vocal chords, by which they are enveloped. The action of these cartilages renders possible the production of the head tones, but they are not found in every larynx. The fact that they are oftener found in the female larynx than in that of the male, and that the male larynx is mostly used in scientific investigations, as it is larger and more easily dissected, may be the reason why up to the present time no mention is made of them either in German or French manuals. They are sometimes referred to as cuneiform cartilages, or confounded with the cartilages of Wrisberg, probably because it seemed unaccountable that these important bodies should so long have escaped the attention of anatomists.

From the anterior surface of the _arytenoid cartilages_, extending towards the centre of the inner wall of the _thyroid cartilage_, running diagonally through the cavity of the larynx, are stretched the two pairs of chords already more than once mentioned--the vocal chords, consisting of folds of the mucous membrane which envelopes the whole larynx. The two lower of these chords, the vocal chords strictly so called, into which the _cuneiform cartilages_ project and through which the interior thyro-arytenoid muscles run, have their points of attachment at the _arytenoid cartilages_, somewhat lower than the upper pair. Each of these parallel pairs of chords form between their lips a slit running antero-posteriorly. The slit of the upper pair is opened in the shape of an ellipse; that of the lower pair, the glottis, is very narrow. As the upper chords have their point of attachment posteriorly and higher, they form with the lower chords two lateral cavities, the ventricles.

The two pairs of chords, therefore, are the free interior edges of the membrane, covering the whole larynx and extending into it to the right and the left. Only the lower vocal chords serve directly for the generation of tones. More or less stretched and presenting resistance to the air forcibly expired from the lungs through the trachea, they are thus made to vibrate. The upper or false vocal chords do not co-operate with them to generate tone, but like all the remaining parts of the mouth and throat belong to the resonance apparatus of the voice, to which also appertains the back part of the mouth, the _pharynx_, over the sophagus, the throat, or gullet. This is separated from the anterior cavity of the mouth by the palate, which is a curtain formed by the mucous membranes of the cavity of the mouth, and the centre of which forms the pendent uvula.

Above the sophagus, immediately over the palate, lie close together, and separated only by a very thin osseous part.i.tion, the two posterior nasal orifices. These serve as pa.s.sages for the air during inspiration and expiration; they are likewise considered as belonging to the resonance apparatus.

Upon both sides of the cavity of the mouth, between the two wings of the palate, lie the tonsils, two glandular bodies, which separate the sides of the cavity of the mouth from the _pharynx_. The anterior cavity of the mouth, which is separated from the nasal cavities by the palate, requires no description, as every one can acquaint himself with its structure in his own person and in others. Upon its formation, as well as upon the position of its different parts and upon the character of those parts of the larynx and of the cavity of the mouth which have been described as the resonance apparatus, the difference in the fulness and timbre of tones depends.

The _epiglottis_ is fixed at the anterior portion of the larynx, at the root of the tongue, within the angle formed by the two surfaces of the thyroid cartilage. It is a very elastic fibro-cartilage, freely moving in a posterior direction. Its color is yellowish and its general form that of a spoon; its upper surface is covered with a mult.i.tude of little mucous glands set in shallow cavities. In the downward pa.s.sage of food the _epiglottis_ covers the upper orifice of the larynx like a valve, over which the food pa.s.ses into the sophagus or gullet, without being able to enter the larynx and the trachea.

In the centre of its interior side there is a little rounded cartilage, movable in every direction, which has as yet no name. Czermak mentions it first in his observations with the laryngoscope. In the male larynx, after the voice has altered, the cartilages become more or less ossified and gradually harden with increasing age. The cartilages of the female larynx, with rare exceptions, usually continue with little or no change. The muscles, by which the movements of the larynx are effected, are:

I. The posterior crico-arytenoid.

II. The lateral crico-arytenoid.

III. The crico-arytenoid.

IV. The thyro-arytenoid.

V. The arytenoid.

VI. The internal thyro-arytenoid.

In late works upon laryngoscopy the different muscles of the larynx are variously designated and divided. Bataille terms the first three of the above-named muscles the exterior muscles of the larynx; the three others he comprehends under the name of thyro-arytenoid or vocal muscle, which divides into three slips in the interior of the larynx. This, however, as well as the description of the character and action of the different muscles, belongs to the department of science. What I have already stated seems to me to be sufficient for an understanding of the action of these organs in the production of sound in the different registers. The reader is referred to any good manual of anatomy for a full description of the muscles, ligaments, nerves, vessels and membranes.

THE END.