None of these movements are elegant--they scarcely put one in an artistic light; but they are highly effective in strengthening parts every voice-user must employ.
To furnish adequate support for the diaphragm and chest in a very vigorous use of the voice, as in the most trying pa.s.sages a tragic actor has to speak or a vocalist to sing, the abdominal muscles must remain more or less tense, and to do so effectually they must have strength beyond that possessed by the corresponding muscles in ordinary persons; hence the desirability of employing special exercises to increase their vigor. Hill climbing and bicycling also tend to this end, but the latter is for many reasons not a form of exercise to be recommended to one who wishes to attain the highest results with the voice. Wind, dust, a stooping position, excessive heat of the body, etc., are all among the many factors of risk for the delicate vocal mechanism.
As the expiratory blast is so important in voice-production, the exercises above recommended should be followed by others in which this principle is specially recognized.
1. Inspire so as to fill the chest to the fullest with considerable rapidity; then allow the breath-stream to pa.s.s out with the utmost slowness.
2. Fill the chest with special reference to its lower or its upper part, as desired, and very rapidly, letting the breath flow out slowly.
SUMMARY.
The primary purpose of respiration in all animals is the same--namely, to furnish oxygen and remove carbon dioxide (carbonic acid). The lowest animals, as the amoeba, breathe by the whole surface of the body. In all vertebrates the anatomical mechanism is essentially the same: a membrane (covered with flat cells) in which the blood is distributed in the minutest blood-vessels (capillaries). Respiration is finally effected in the tissues (cells) of the body. The more active the animal, or the higher in the scale, the more need of frequent interchange between the air, the blood, and the tissues.
The respiratory organs in mammals are the mouth, nose, larynx, trachea, bronchial tubes, and lung-tissue or air-cells proper. The windpipe is made up of cartilaginous rings completed by membrane, muscle, etc. (behind). The bronchial tubes are the continuation of the windpipe, and branch tree-like until they become very fine. The air-cells are built round these latter. The lung-tissue is highly elastic. The lungs are made up of an elastic membrane, covered with flat cells, and very abundantly supplied with a mesh-work of the finest blood-vessels. The whole of the respiratory tract as far as the air-cells is lined by mucous membrane.
The air consists essentially of 21 parts of oxygen and 79 parts of nitrogen, with a variable quant.i.ty of watery vapor. Only a small portion of the total oxygen of the air is removed before it is exhaled. The respiratory act consists of (1) inspiration, and (2) expiration; the latter is of a little longer duration than the former.
The rate of breathing in man is from 14 to 18 per minute, in the resting state, or about one respiration to three or four heart-beats.
The quant.i.ty of air inspired depends on (1) the size of the thorax, and (2) the extent of its movements. These are effected solely by muscular contractions, and give rise to an increase in all the diameters of the thorax. The lungs are closely applied (but not attached) to the inside of the chest wall, and remain so under all circ.u.mstances. When the chest cavity is enlarged by inspiration, the air, pressing down into the elastic lungs, expands them as much as possible, that is, as much as the chest walls will allow; but the lungs are never at any time either filled with or emptied of air to their utmost capacity. At most, the amount of expansion is very moderate.
_The Quant.i.ty of Air in the Lungs._
1. The quant.i.ty of air inspired in quiet breathing is about 20-30 cubic inches.
2. The quant.i.ty that can be added to this by a deep inspiration is about 100 cubic inches.
3. The quant.i.ty that can be expelled by a forcible expiration is about 100 cubic inches.
4. The quant.i.ty that cannot be expelled at all is about 100 cubic inches.
The above are named: (1) The tidal air; (2) complemental air; (3) supplemental air; (4) residual air. The quant.i.ty that can be expelled by the most forcible expiration after the most forcible inspiration, that is, the air that can be moved, indicating the "vital capacity,"
is about 225-250 inches.
The chest is enlarged by the muscles of inspiration, the princ.i.p.al of which is the diaphragm or midriff. This muscle (tendinous in the centre) is attached to the spinal column (behind) and to the last six or seven ribs. When it contracts it becomes less domed upward, and is pressed down more or less on the contents of the abdomen; hence the walls of the latter move outward. During ordinary inspiration the lower ribs are steadied by other muscles, so that no indrawing of these ribs takes place, but a very forcible expiration makes such indrawing very noticeable. In addition to the enlargement of the chest by the descent of the diaphragm, the ribs are elevated and everted by the muscles attached to them, with the total result that the chest cavity is enlarged in all its three diameters during inspiration. The first rib is fixed by muscles from above. During extremely forced inspiration a large proportion of all the muscles of the body may act.
Ordinary expiration is the result largely of the elastic recoil of the chest walls, only a few muscles taking part. The diaphragm ascends and becomes more domed. During forced expiration many other muscles are called into action. It is of importance for the singer and speaker to note: (1) That the chest cavity should be increased in all its directions; (2) that the muscular action should be easy and under perfect control, but also vigorous when required; (3) that the breath be taken through the nostrils when the individual is not actually vocalizing or about to do so; (4) that the breath be kept in or let out in the proportion required.
Breathing is a reflex or involuntary act. The respiratory centre, consisting of an expiratory and inspiratory division, is situated in the bulb, or medulla oblongata, the portion of the brain just above the spinal cord. All the ingoing nervous impulses affect respiration through the outgoing impulses that pa.s.s along the nerves to the muscles; that is, the ingoing impulses pa.s.s up by the nerves from the lungs to the centre, and thence along other nerves to the respiratory muscles. The condition of the blood determines the activity of the respiratory centre, but the incoming impulses regulate this activity.
The respiratory centre can be approached from every part of the body.
_Hygiene._
Every thing that favors the full and free expansion of the chest in a pure atmosphere is favorable, and the reverse unfavorable. Corsets are against the laws of beauty, are unnecessary for support, and may by compression injure and displace important organs, as the liver, stomach, etc.; and must interfere with the fullest expansion of the chest. They have militated against the physical, and indirectly the moral and mental advancement of the race.
_Practical Exercises._
I. Measurements of the chest.
II. Exercises to strengthen muscles, promote complete expansion, regulate inflow and outflow of air, etc.
1. (_a_) Inspiring slowly, with counting.
(_b_) Holding.
(_c_) Expiring slowly, with counting.
2. The same, holding longer.
3. The same, with shorter inspiration and longer expiration. Gradually diminish first and lengthen last.
4. Breathing through open lips.
5. Exercises to strengthen diaphragm.
6. Exercises to improve shape of chest and strengthen muscles.
7. Exercises to strengthen abdominal muscles.
CHAPTER VI.
THE SPECIAL VOICE-PRODUCING MECHANISM, THE LARYNX.
The larynx, or voice-box, is not the sole voice-producing apparatus, as is often supposed, but it is of great, possibly the greatest, importance. In describing the parts of this portion of the vocal mechanism the author deems it wiser to use the terms commonly employed by anatomists and physiologists, as others are awkward and inadequate.
Moreover, there is this great advantage in learning the technical names of structures, that should the reader desire to consult a special work on anatomy in reference to this or other important organs, he will find in use the same terms as he has himself already learned. Such are, as a matter of fact, not difficult to learn or remember if one knows their derivation or other reason for their employment. All the muscles of the larynx have names which are not arbitrary but based on the names of the structures to which they are attached, so that one has but to know their connections and the names of the solid structures, which are few, to have a key to the whole nomenclature.
When one is not using the voice the larynx is simply a part of the respiratory apparatus, but when one phonates this organ a.s.sumes a special function for which specific structures are essential. As sound is caused by vibrations of the air, and these may be set up by vibrations of the vocal cords, it may with absolute correctness be said that the whole larynx exists for the vocal bands so far as voice-production is concerned. Such a view renders the study of the larynx much more interesting and rational; one is then engaged in working out that solution of a problem which Nature has accomplished.
The vocal cords, we can conceive, might be either relaxed or tightened, and lengthened or shortened, or both, and beyond that we can scarcely understand how they might have been modified so as to be effective in the production of sounds of different pitch. As a matter of fact, these are the methods Nature has employed to accomplish her purpose. For each vocal cord one fixed point, and only one, is required. We know of only one method in use by Nature to cause movement in living structures--viz., contraction, and muscle is the tissue which above all others has that property; hence the movements of the vocal cords are brought about by muscles. But both for the attachment of the muscles and the vocal cords themselves solid, relatively hard structures are required. Bone would prove too unyielding, but cartilage, or gristle, meets the case exactly. The entire framework of the larynx--its skeleton, so to speak--is made up of a series of cartilages united together so as to ensure sufficient firmness with pliability.
The cartilages have been named from their shape, as that appealed to the original observers, and the terms employed are of Greek origin.
The largest and strongest is the _thyroid_ (_thureos_, a shield) cartilage, which resembles somewhat two shields put together in front without any visible joint, and open behind but presenting a strongly convex surface externally, in front and laterally. "Front" (anterior) and "back" (posterior) always refer in anatomy to the subject described, and not to the observer"s position. In observing another"s larynx the subject observed and the observer naturally stand front to front, and it is impossible to see or touch the back of the larynx as it is covered behind by the other structures of the neck.
This thyroid, the largest of the cartilages, is attached to the hyoid or tongue bone above by a membrane, so that the whole larynx hangs suspended from this bone by a membrane, though not by it alone, for muscles are attached to it which also serve for its support. It is of practical importance to remember that the larynx is free to a very considerable extent, otherwise it would go ill with the voice-producer in the vigorous use of the voice, not to mention the advantages of mobility as well as pliability in the movements of the neck generally.
[Ill.u.s.tration: FIG. 20 (Spalteholz). Shows the thyroid cartilage above and the cricoid below both viewed from the side. The anterior surface is turned toward the right.]
[Ill.u.s.tration: FIG. 21 (Spalteholz). A front view of FIG. 20.]
[Ill.u.s.tration: FIG. 22 (Spalteholz). The back or signet surface of the cricoid or ring cartilage, to which several muscles are attached.]
[Ill.u.s.tration: FIG. 23 (Spalteholz). The cricoid cartilage, seen from the side, and showing behind and laterally the articular or joint surfaces by which it connects with the thyroid below and the arytenoid cartilage above.]
[Ill.u.s.tration: FIG. 24 (Spalteholz). Shows the arytenoid cartilages, the most important of all the cartilages of the larynx, inasmuch as to the part termed "vocal process" the vocal band is attached on each side. The movements of the vocal bands are nearly all determined by the movements of these cartilages, which have a swivel-like action. In the above the front surfaces are turned toward each other.]
The _cricoid_ (_krikos_, a signet-ring) is the cartilage next in size.