The Mechanism of the Human Voice Part 5

I am aware that the very opposite is taught by some. There are those who maintain that nasal tone arises from the air _not_ being able to get through the nose. I am even informed that in some parts of England where nasal tone seems to be a general affliction, it is the practice of teachers of singing to cause their pupils to bathe their noses in hot water in order to relax the muscles which are supposed by their contraction to produce nasal tone. I would, however, in support of my statement, draw attention to the following indisputable facts:--(1) It is quite possible to completely close the nostrils, and yet to produce pure vocal tone.

(2) Persons who are either partly or entirely without the soft palate can _under no circ.u.mstances_ utter a single sound without the most p.r.o.nounced nasal quality. It seems to me that these facts sufficiently speak for themselves; but if any of my readers are not convinced by them, let them try this experiment: Take a thin mirror and hold it flat against the upper lip, with the gla.s.s upwards. Now sing a pure vocal tone, and the mirror will remain perfectly bright. Sing, on the contrary, with nasal quality, and the mirror will at once be completely dimmed. This shows conclusively that nasal sound is produced by singing _through_ the nose, and this cannot be done without lowering the soft palate. Teachers of singing know well enough that guttural tone is caused by the obstinate arching up of the tongue, and if they understand their business they eventually succeed in teaching a pupil labouring under this disadvantage to get perfect control over his tongue. But n.o.body thinks of the soft palate, though that can be brought under subjection just as well as the tongue. Let singing masters see to it, and young ladies will no longer be laughed at for having to put their noses into hot water before charming their friends with a song.

It now only remains to be added that the interior of the windpipe and of the voicebox, as well as that of the throat, the mouth, and the nose, is lined with a thin mucous membrane of a pinkish colour. This concludes my description of the Vocal Organ as a musical instrument.

DIFFERENCES OF THE VOICEBOX, OR LARYNX, IN CHILDREN, WOMEN, AND MEN.

The voicebox of a newly-born baby is about one-third the size of that of a grown woman. It is therefore rather large in proportion to other parts of the body, with the exception of the head, which comparatively is larger still. The horizontal outline of the shield cartilage is a very gentle curve, and the upper horns are short, in consequence of which the voicebox is close to the tongue. The wedges, according to Merkel, are strongly developed; the vocal ligaments are short and thick, and the pockets deep. Up to the third year the voicebox grows very considerably, but no particular alterations take place from that time to the period of p.u.b.erty, which generally occurs at the age of 14 or 15, rather earlier in girls than in boys. This period of change lasts from six to twelve months, or sometimes even two or three years. During this time the vocal organs undergo a marked change. In boys, the angle at which the two plates of the shield meet becomes more and more acute, and the length of the vocal ligaments increases only in the proportion of five to ten. In girls, on the other hand, the horizontal outline of the shield does not lose its evenness, and the length of the vocal ligaments increases only in the proportion of five to seven. The cartilages would seem, especially in boys, to grow more rapidly than the muscles, so that the slowly-growing muscles do not, at first, control the newly-developed cartilages. This accounts for the unmanageable state of the voice at this period. The changes which take place in the female voicebox are very imperceptible, so that they do not materially affect the character of the voice. In the male voicebox, on the contrary, the alterations are very marked, and the result is that the high voice of the boy is changed into the tenor or the ba.s.s of the man. While, therefore, before the period of p.u.b.erty the voicebox is materially the same in both s.e.xes, there are, afterwards, considerable differences noticeable, not only with regard to size, but also with regard to shape. This seems, indeed, sufficiently obvious, and any one can see it by simply comparing the outside of the throat of a man with that of a woman.

Nevertheless we are told by Mr. Lunn[L] that "Anatomy teaches us that there is no difference between the male and female larynx save in size;" and by Dr. Garrett (on page 13 of the book quoted before) that "The male larynx does not differ anatomically in the least from that of the female, except in size."

My readers may judge for themselves whether these statements are borne out by facts or not.

It must further be observed that the whole upper part of the shield in the female voicebox is less developed than in the male. The upper horns are short, so that the voicebox is more closely attached to the tongue-bone, and its position in the throat is altogether higher in woman than in man. To show more clearly still the difference in the proportions of the male and the female voicebox, I give below some average measurements (taken from Luschka's great work on the Larynx) which I have, for the convenience of English readers, reduced, as nearly as possible, from centimetres and millimetres to inches.

MALE. FEMALE.

Height of the voicebox in } 2-4/5in. 1-9/10in.

front, with the lid raised } (7 cent.) (4.8 cent.)

Greatest width between the } 1-3/5in. 1-2/5in.

plates of the shield cartilage} (4 cent.) (3.5 cent.)

Depth between the lower } border of the shield cartilage, } 1-1/5in. 1 in.

and the opposite point } (3 cent.) (2.4 cent.) of the ring cartilage. }

Length of the vocal c.h.i.n.k ... 1 in. 3/5 in.

(25 mm.) (15 mm.)

According to this eminent anatomist, therefore, the differences between male and female larynges are as follows: In height, 9/10; in width, 1/5; in depth, 1/5; in the length of the vocal c.h.i.n.k, 2/5 of an inch. As it is plain that if there were "no difference between the male and the female larynx save in size," all their proportions would be alike, I think I may safely a.s.sume that I have proved my point, which is a rather important one, as the reader will see when the registers in the male and female voice come up for discussion.

We will now consider the question how the various cla.s.ses of voice--_i.e._, Sopranos, Contraltos, Tenors, and Ba.s.ses--are to be accounted for by corresponding differences in the voicebox. We know that tone is produced by the vibrations of the vocal ligaments. It is clear, therefore, that a voice will be high or low according to the number of vibrations which the ligaments are capable of producing, or in other words, according to their dimensions and their tension. This difference is easily seen by comparing the voicebox of a soprano with that of a ba.s.s, because there the proportions are so manifestly smaller in the one than in the other. There are similar distinctions between soprano and contralto on the one hand, and between tenor and ba.s.s on the other, but they are not so striking. Neither can they, for various reasons, be demonstrated with the laryngoscope; but they exist nevertheless.

It is true that the vocal ligaments of a soprano are sometimes longer than those of a contralto, just as the ligaments of a tenor are occasionally longer than those of a ba.s.s. But I maintain that the longer ligaments of sopranos and tenors are correspondingly thinner, and that their tension is greater, owing to the ring-shield or stretching muscles being more powerful than their opponents--the shield-pyramid muscles.

Where this is the case the ligaments are more slanting than they would be otherwise, and the consequence of this is that less power of blast is required to make them speak. With this mechanism the higher registers are very readily united with the lower ones, and the voices so produced are of a light and flexible kind. Where, on the contrary, the vocal ligaments of contraltos and ba.s.ses are comparatively short, they are also thick in proportion, and the shield-pyramid muscles are more powerful than the opposing ring-shield muscles, so that there is less tension. I shall be asked how I can prove this tension theory, and my reply is this: The diameter of the vocal ligaments depends in a large measure on the magnitude of the shield-pyramid muscles. If, therefore, the ligaments are exceptionally thick, the muscles just named must of necessity be very powerful, and can easily resist the pulling of the ring-shield muscles. If, on the contrary, the ligaments are exceptionally thin, it is equally certain that the shield-pyramid muscles are weak in proportion, and then the stretching muscles can easily overcome their resistance.

I may add that I came to the above conclusions about the various cla.s.ses of voices years ago, when commencing the study of this subject. Not only have I never since seen any reason to alter my views--although I have not failed to notice and carefully examine the theories of others denying my doctrine--but I am more than ever convinced that my explanations are correct. I have now the gratification of seeing my theory confirmed by so great an authority as Dr. Merkel, of Leipzig, who most elaborately explains the subject in his latest work on the larynx, to which I have already alluded in these pages.

Besides the factors enumerated above, there are, no doubt, others which are also of consequence in determining the particular kind of voice to be produced by this vocal apparatus or by that; as, for instance, the windpipe, or the resonator, or both. The capacity of the chest--nay, the structure of the whole body, may have a more or less direct influence upon it. But there are absolutely no statistics to proceed upon, and in the absence of these it is vain to indulge in any speculations on the subject.

MOVEMENTS OF THE VOICEBOX, OR LARYNX, WHICH CAN BE SEEN OR FELT.

The voicebox in a man is situated almost exactly in the middle of the throat; in woman its position is, for reasons partly explained on page 64, considerably higher. It moves downwards in inspiration, and upwards in expiration; and the more vigorously we breathe, the more marked are these movements. In the act of swallowing the voicebox rises quickly, and in yawning it goes down so completely that the whole windpipe may vanish into the chest, and even the part of the ring cartilage may disappear.

When singing in what is called chest-voice the voicebox rises gradually with each higher tone. Changing the mode of tone production, and singing--say an octave higher--in falsetto, the voicebox makes quite a leap upwards, and then again rises gradually with each higher tone, just as in chest-voice, but in a lesser degree. The voicebox, however, does not stand so high for the lowest falsetto as for the highest chest tones.

It is possible, of course, to limit these movements to a minimum, but a teacher who insists upon his pupils keeping their voice-boxes perfectly still commits a serious mistake, because it is always injurious to do violence to nature. It is one thing to keep the voicebox steady, thereby facilitating the working of some of those muscles which act immediately upon the vocal ligaments; it is quite another thing, as will be seen below, to attempt to prevent movements which have to serve a great purpose.

In _whispering_, the voicebox occupies a different position in the throat for each vowel. I invite the reader to try the following curious experiment. Let him take the larynx gently between the thumb and the first finger, and then _whisper_ OO (as in "food,") OH, AH, A (as in "name,") and E (as in "bee"). He will find that the voicebox rises with every succeeding vowel until at last it has completely slipped away from between the finger and thumb. Each one of these _whispered_ vowels has, as first ascertained by Helmholtz, its exact pitch, whether uttered by a little child or by an old man, and the effect of the rising of the voicebox is to shorten the resonator, whereby the raising of the pitch is produced.

I stated on page 41 that the vocal ligaments were capable of being stretched by the ring-shield muscles, and that the pitch of the tones produced by their vibrations depended mainly on their tension. As we are now taking note of such movements of the voicebox as may be either seen or felt in the throat, we will take the opportunity of trying whether my statement can be verified. Let the reader, therefore, do as follows:--(1) Place the finger on the shield cartilage, and press it vigorously backward. (2) Sing loudly any high tone that is well within your compa.s.s. Hold this tone steadily, and _be quite sure you do not alter its pitch_. (3) Now suddenly remove your finger, continuing to sing as before. What is the result? Your tone is raised by a third, or even more, according to the amount of pressure you exercised on the shield. And how did this result come about? In this way: By pressing the shield backwards you elongated the ring-shield muscles, thereby counteracting their stretching influence, and at the same time slackening the vocal ligaments. The tone you sang while doing this was, we will say C'. By releasing the shield you enabled the ring-shield muscles to contract again, thereby putting the vocal ligaments on the stretch as they were at first. That changed your C' to E', or higher still. Have I proved my a.s.sertion?

Now one more test, if you please. I pointed out to you on page 34 an opening between the shield and the ring. You will see it on plate V, No.

10. Please sing a low tone; place your finger gently on the shield, and move it downwards. You will soon discover a little hollow which corresponds with the opening I just mentioned, and into which you can easily put part of the tip of your finger. Now sing up the scale, and take care to keep the tip of your finger in the hollow. Remember that in singing up the scale your voicebox will rise, which movement you must follow, or you will lose the place. If you do this carefully, you will find that the hollow gets smaller and smaller by degrees until at last it closes entirely, and you can no longer find a trace of it. Now sing down again, keeping your finger on the same spot. You will soon notice the hollow again, and it will continue to get larger and larger until you arrive at the bottom of your scale.

This, of course, is but another way of showing the mechanism by which the pitch of your tones is raised or lowered, and we have proved the same thing by our preceding experiment. But I asked you to try this chiefly because it will enable you to put a check upon my statements with regard to the registers of the voice, a subject which I propose to discuss in another chapter.

THE LARYNGOSCOPE, AND HOW TO USE IT.

The Laryngoscope in its simplest form is a thin circular mirror, about three-quarters of an inch in diameter, set in a metal frame, and fastened at an angle of 120 to a piece of wire from three to four inches long, which is put into a small wooden handle not much thicker than a pencil, and about the same length as the wire. By help of the laryngoscope we can either see our own larynx or that of another person.

The easiest experiment is upon the larynx of some one else. In this case, the person to be operated upon sits facing the sun, the head slightly bent backwards, and the mouth wide open. If he has not sufficient control over his tongue to prevent it from arching up, he must gently hold its protruding tip with a pocket handkerchief between his thumb and forefinger. The mirror is now slightly warmed to prevent its becoming dimmed by the moisture of the breath, and then, holding it like a pen, the operator introduces it into the throat so that it touches the uvula. This must be done lightly yet firmly, care being taken not to bring the mirror into contact with the base of the tongue.

The rays of the sun falling upon the mirror are reflected downwards into the voicebox, the image of which is clearly visible in the mirror. In making observations upon oneself, a second mirror in the shape of an ordinary hand looking-gla.s.s is necessary to reproduce the image in the small mirror. This is the way in which the renowned professor of singing, Senor Manuel Garcia, made those famous "Observations on the Human Voice," communicated to the Royal Society by Dr. Sharpey, on May the 24th, 1855. Similar attempts had been made before; for instance, in 1827 by Babington, in 1838 by Baumes, in 1840 by Liston, and in 1844 by Warden and Avery. But they had all ended in failure, an occasional glimpse of some parts of the voicebox being the only result obtained.

Garcia, however, brilliantly succeeded where all his predecessors had failed, and was the first not only to see the vocal ligaments, but to see them in the act of singing, and to see them so clearly as to be able to give an account of their minutest movements. The instrument has since been greatly improved, and the process of investigation has become a science. Medical men all over the world have laid hold of it, and suffering humanity is daily benefited by it. But Garcia is the man who produced the first results, and to him, therefore, is due the credit of being practically the inventor of the laryngoscope.

It is almost incredible, but it is true, that this splendid invention was received coldly and with distrust in this country, and had it not been for Dr. Johann N. Czermak, Professor of Physiology at the University of Pesth, the matter would, in all probability, have been forgotten. But this gentleman recognized the value of Garcia's invention, and he at once went enthusiastically to work, and pushed on vigorously in the way which Garcia had opened for him. He constructed an apparatus which enabled him, by making use of artificial light, to work without interruption and without waiting for the sun to shine. He then made his first attempts on himself in order to become acquainted with the conditions which have to be fulfilled by the observer as well as by the person to be operated upon. In this way he soon became a master of the new process, which he immediately brought under the notice of the profession by giving lectures and demonstrations in the chief towns of Europe.

More than twenty years have pa.s.sed since then, and the laryngoscope has, during that time, been made excellent use of, not only for the alleviation of suffering, and the cure of disease, but also for its original purpose--_i.e._, the exploration of the mechanism of the human voice.

My own connection with the matter has arisen through my desire to sift contradictory statements made by various observers. Having read many English, German, and French books on the subject, I was in position to pick up a hint here, and to get some good advice there, and the consequence was that I was able to pursue a course which made me familiar with the use of the laryngoscope in a very short time. As my experience may be useful to others, I will briefly relate how I proceeded.

I made my first attempts upon a skull, to which I attached a plaster-of-Paris model of the voicebox, the whole being fastened to an iron stand. The instrument I used was a concave reflector on a spectacle frame. The reflector had a hole in the centre, and was capable of being moved in various directions. The next thing was the little mirror described on page 73, and lastly, a gas lamp on the principle of the well-known "Queen's" reading lamps, which can be raised or lowered at pleasure. I placed the skull to the left of the lamp, and looking with my right eye through the hole in the centre of the reflector, practised throwing the light swiftly and with certainty into the upper part of the throat. I then introduced the little spy mirror, and tried to see and to recognize the various parts of the voicebox, which, let it be remembered, present a somewhat different appearance in the looking-gla.s.s from what they do if seen without it. Then I got a friend to mark my artificial voicebox, unknown to me, in various ways, and endeavoured quickly to discover what he had done. In this way I soon acquired a considerable amount of skill in handling the instrument, and also became thoroughly familiar with the image of the voicebox in the mirror.[M]

Having thus to a large extent mastered the mechanical part of my work, I proceeded to make observations upon myself. I placed to the left of the lamp an ordinary bedroom looking-gla.s.s, in which now appeared my own face instead of the skull which hitherto occupied this place. I opened my mouth, and by the help of the reflector directed the light into the image of it in the looking-gla.s.s. I then continued in every way as I had done with the skull, with this difference, however, that I had first, as pointed out before, to warm the little spy mirror in order to prevent its becoming dimmed in the throat.

An instrument has since been designed by the late Dr. G. D. Foulis, of Glasgow, which for simplicity, general excellence, and cheapness, far surpa.s.ses the above contrivance, and which I strongly recommend to intending students of laryngoscopy. It consists of a plain stand on which is placed a gla.s.s globe filled with water, the whole being surmounted by a small square mirror. The rays from a lamp or candle, placed behind the globe, are concentrated into the open mouth of the observer, who is seated in front of it, enabling him, by the use of an ordinary throat mirror, to inspect the movements of his own vocal ligaments.

[Ill.u.s.tration]

This apparatus, as shown in the annexed drawing, including a throat mirror, and safely packed for transmission, may be had from Messrs. W.

B. Hilliard & Sons, 65, Renfield Street, Glasgow, for the very small sum of 7s. 6d.

Let not the reader who tries laryngoscopic investigations be discouraged if, at first, violent retching is the result. It does not so much arise from sensitiveness of the parts touched, as from awkwardness in introducing the mirror. If he perseveres he will soon be rewarded by a view of the pearly white vocal ligaments, and a little repeated practice upon himself will enable him also to operate upon others without causing them discomfort.

I close this chapter by again reminding amateur laryngoscopists that in the vast majority of cases where the touch of the mirror causes retching and gagging, it is due less to the sensitiveness of the person operated upon than to the want of skill on the part of the operator. He should in that case renew his experiments upon himself, and continue them until he has fully mastered the use of the instrument, as it is not fair to make others suffer for his own clumsiness.