Chapter VII

SOUND--THE LARYNGOSCOPE--THE LARYNX RECONSIDERED.

Before discussing our subject further it is desirable that some attention be given to a few of the fundamental principles of that department of physics termed _acoustics_, and which deals with the subject of sound. If the student has the opportunity to study this subject theoretically and practically, as it is set forth in some good work on physics, he will have no reason to regret the time spent. A deep knowledge of the laws of sound is not absolutely essential, or even highly necessary, for a sufficient understanding of the principles involved in voice-production. It is, however, all-important that a few facts and principles be thoroughly grasped.

For those who feel that they have the time for a study of acoustics, the author would especially recommend Tyndall's work on sound, in which the subject is treated with wonderful clearness and charm. What we endeavor now to bring before the reader we have found sufficient for nearly all the purposes of the voice-user.

An observer on the street, looking at a military band, notices certain movements of one member of the organization which result in what he termed the sound of the drum; but a deaf man by his side, though he sees the movements, hears nothing. This, being analyzed, means that the movements of the drummer's arm, conveyed through the drumstick to the membrane of the drum, give rise to movements in it which set up corresponding movements of the air within the drum, which again cause movements of the body of the instrument, the whole causing movements of the external air; and here the purely physical process ends. The movements other than muscular ones are not readily observed, but experiments not only prove that they exist, but demonstrate their nature, even to their exact rate of occurrence, their size, etc. These movements are termed _vibrations_, and, as has been indicated previously, they are the sole physical cause of sound. But that the latter is not due wholly to a physical origin is evident from the fact that sound for the deaf does not exist. It must, therefore, be a personal, a subjective experience, and as the sleeping, unconscious person does not necessarily hear a sound, the process is not wholly a corporeal or physiological process; it is finally an experience of the mind, the consciousness, and so is psychological as well as physiological.

The fact that sound has a physical basis in the vibrations of bodies, either solid, liquid, or gaseous, may be brought home to one in various ways. Concussion or shaking of some kind is essential to start these vibrations. The air is made up of its particles, and one being moved sets up, inevitably, movements in neighboring particles on all sides, hence vibrations travel in all directions; which explains why a sound in the street may be heard by those in every part of the street not too distant, and also in the upper rooms of the houses and below in the basements. This is an important fact for the singer or speaker to bear in mind. His purpose must be to set up vibrations that will travel with great perfection and rapidity in all directions.

The following experiments of a simple kind will serve to convince those who may not have given much attention to the subject that sound is due to movements of some object, which we term the sounding body, strictly that which starts the vibrations by its own movements or vibrations.

If a sufficiently flexible band of metal or a stiff piece of whalebone be fixed at one end in a vice, and then sharply pulled to one side and suddenly let go, a sound results. The same effect is produced when a tight cord or small rope is plucked at and then suddenly released. In each of these cases, if actual movements are not seen, a certain haze which seems to surround the object may be observed. The same can be seen when a tuning-fork is set into action by a bow, a blow, etc. In the case of the fork a graphic tracing (Fig. 36) can be readily taken on smoked paper, thus demonstrating to the eye that vibrations exist, that they occur with perfect regularity and with a frequency that can be measured.

A similar observation can be made in the case of stringed instruments. If pieces of paper be laid on the strings of a violin, and the bow then drawn across them, the bits of paper will fly off owing to the movements--_i.e._, the vibrations--of the strings.

That a force applied at one end of several objects in a line or series causes an obvious effect at the other end, can be well illustrated in a simple way. If a number of individuals stand one behind another in a line, each with his hands laid firmly on the shoulders of the one next to him, and the person at the end be pushed, the force will be conveyed through all the intermediate individuals, and cause the unsupported person at the distant end to move. So is it with the particles of which the air is composed. The movements begun in the drum set up by contact corresponding movements or vibrations in the adjacent air, which ultimately reach the hearing subject's ear, thereby affect his brain, and are accompanied by that change in consciousness which he terms "hearing." It will be observed that these events constitute a chain, and a break anywhere will prevent a sound being heard; there is then, in fact, no sound.

Sounds are characterized by _pitch_, _volume_, and _quality_.

The _pitch_ is determined by the number of vibrations that reach the ear within a certain time; the more numerous the sound-waves (vibrations) in a second, the higher the pitch.

Animals differ a good deal as to the limits of hearing. Cats hear very high-pitched sounds, as of mice, that human beings may not notice, and it is likely that insects hear sounds altogether beyond the limit of the human ear. But it is wonderful how much human beings differ among themselves in regard to this matter. It has surprised the author to find that many persons cannot hear the high-pitched note of certain birds, as the wax-wing.

The lower limit, speaking generally, is for most persons 16 vibrations, and the highest 38000 vibrations a second, according to Helmholtz, hence the entire range of the human ear would be fully 11 octaves; but the practical range of musical sounds is within 40 and 4000 vibrations a second--_i.e._, about 7 octaves--and, as is well known, even this range is beyond the appreciation of most persons, though as to this much depends on cultivation--attention to the subject extending over a considerable period of time.

The _volume_, or loudness, of a sound depends on the size of the vibrations, just as one feels a blow from a large object, other things being equal, more than from a small one. The ear drum-head is in the case of a large sound beaten, as it were, more powerfully. The singers that give us bigness of sound instead of quality belabor our ears, so to speak; they treat us as persons of mean understanding--dull intellects; the thing is essentially vulgar.

The _quality_ of a sound is determined by the form of the vibrations. A sound of good quality is to the ear what a beautiful statue or picture is to the eye. As will be explained later, the form or quality depends largely on the shape, etc., of the resonance-chambers above the vocal bands.

Much discussion has taken place from time to time as to the nature of the larynx as a musical instrument, some being inclined to regard it as most closely allied to a stringed instrument, others to a wind-instrument. It has obviously points of resemblance to both, but the most recent researches make it clearer than ever that it is neither one nor the other, strictly speaking, but that it stands in a class by itself. It is, however, helpful, in considering many questions, to bear in mind its resemblances to both wind and stringed instruments. The vocal bands are not wholly free throughout their length, like the strings of a violin, nor do they bear any great resemblance to the reed of such an instrument as the clarinet, but as in the latter the force causing the vibrations is a blast of air. We have already pointed out that the vocal bands are set into vibration solely by the _expiratory_ blast of air.

THE LARYNGOSCOPE.

The distinguished physiologist Johannes Müller demonstrated the working of the larynx by special experiments. He fixed into the windpipe a bellows, and showed, in the dead larynx, of course, that the blast from this source could cause the vocal bands to vibrate and thus produce sounds, which by varying the strength of the force, etc., were made to vary in pitch.

While such experiments indicate the essential principles of a possible voice-production, as the conditions in life were not and could not be fully met these results were rather suggestive than demonstrative of Nature's methods. These investigations served a good purpose, but they were manifestly inadequate, and this was felt by one thoughtful vocal teacher so keenly that he pondered much on the subject, in the hope of finding a method of observing the larynx during actual phonation. To this distinguished teacher, Manuel Garcia, belongs the honor of inventing the means of observing the vocal bands in action. This was accomplished in 1854, and, soon after, Garcia read an account of his observations to the Royal Society of London; and though much in this paper required correction by subsequent observations, it remains to this day the foundation of our knowledge of the action of the larynx in voice-production.

As usually employed, the laryngoscope consists of two mirrors, the head-mirror, so called because it is usually attached to the forehead by an elastic band, and the throat-mirror, which is placed in the back part of the mouth cavity. The purpose of the head-mirror is to reflect the light that reaches it from a lamp or other source of illumination into the mouth cavity so perfectly that not only the back of the mouth, etc., but the larynx itself may be well lighted up; but inasmuch as this illumination may be accomplished, under favorable circumstances, by direct sunlight, the head-mirror is, though mostly indispensable, not an absolutely essential part of the laryngoscope. There is, indeed, one advantage in the use of direct sunlight, in that the color of the parts seen remains more nearly normal. Lamplight tends, because of its yellow color, to make parts seem rather of a deeper red than they actually are; but this to the practised observer, always using the same source of illumination, is not a serious matter--his standards of comparison remain the same. Moreover, this objection does not apply equally to electric light, now so much used.

It being a fundamental law of light that the angle of reflection and the angle of incidence correspond--are, in fact, the same--it was necessary that the throat-mirror should be set at an angle to its stem, so that the light passing up by reflection from the larynx should, when striking on the surface of this plane throat-mirror, be reflected outward in a straight line to the eye, which must be in the same horizontal plane with it. This and all the other facts and principles involved can only be understood by a careful inspection of the accompanying figures, which it is hoped will make the subject plain. The throat-mirror is none other than the mouth-mirror of the dentists, and in use by them before Garcia discovered how it might be employed to throw light on the larynx, in a double sense.

The essentials, then, for a view of the interior of the larynx are: A source of illumination; a mirror to reflect the light reaching it from this source into the back of the throat and larynx; and a second mirror to reflect the light outward which is, in the first instance, reflected from below, from the interior of the larynx. The principles involved are few and simple, but their application to any particular case is not easy, and is sometimes well-nigh impossible.

The throat-mirror should be placed against that curtain suspended in the back of the mouth cavity known as the soft palate, so that it must be pushed back out of the line of view. But many persons find such a foreign object in the throat a sufficient cause of unpleasant sensations so that retching may be the result. Generally there is a tendency to raise the tongue behind in a way fatal to a view of the mirror and the picture reflected from it. These difficulties, however, can be overcome by a deft hand using the mirror brought to "blood heat" by placing it in warm water or holding it over some source of heat, as a small lamp, and directing the subject observed to breathe freely and _through the mouth_. This latter tends to quiet that unruly member, the tongue, and lead it to assume the flat position so important to an unobstructed view. It is for the same reason the author urges mouth breathing during speaking and singing. No other tends so well to put the tongue in the correct position.

The extent to which one feels the annoyance of a small mirror held gently in the throat depends really on the amount of attention directed to it, and the degree of determination with which he resolves to exercise self-control. The author has examined an entire class of students of voice-production and found only one person who did not succeed in at once giving him a view of the larynx. But it must be at once said that of all persons examined by the author during his experience as an investigator of voice-production and in special medical practice, none have been able to show their throats, the larynx included, so well as speakers and, above all, singers; which in itself indicates that speaking and singing do give control of the throat--that all its parts respond to the will of the observed person. The author must further, however, remark that he has found this control associated not so much with vocal power as with intelligent study. Intelligence tells in music a good deal more than many people have yet learned to believe; but on this point the reader will long since have learned the author's views--in fact, so deep are his convictions on this subject that he hopes he may be pardoned for frequent reference to them, in one form or another.

One anatomical fact may be so invincible that a view of the glottis cannot be obtained at all: the epiglottis may so overhang the opening to the larynx that a good view of its interior is absolutely impossible, in other cases only occasionally and under very favorable circumstances. Such cases are, however, of the rarest occurrence, while there are not a few persons in whom one may even see down the windpipe as far as its division into the two main bronchial tubes, and inflammation may thus often be traced from the vocal bands far down the mucous membrane common to the larynx, windpipe, etc.

As has been remarked previously, it is only by the use of the laryngoscope that one can see the vocal mechanism of the larynx in action, so that for investigation laryngoscopy is essential. Auto-laryngoscopy, or the use of the laryngoscope by the subject to observe his own larynx, has its special difficulties and advantages, the greatest of the latter being, perhaps, that the observer may use himself as often and as long as he will, while he would hesitate to make observations on others at great length or with frequent repetition. There are no new principles involved in auto-laryngoscopy. The observer must simply see that a good light is reflected into his own throat, and that the picture in his throat-mirror is reflected into another into which he may gaze, an ordinary small hand-glass usually sufficing.

Only rarely is the individual met who can himself so control his tongue that assistance from the observing laryngologist is unnecessary. In by far the greater number of instances the tongue, after being protruded, must be gently held by the left hand of the observer, a small napkin covering the tip of the organ. The auto-laryngologist must, of course, control his own tongue, and better if without any hand contact.

It is scarcely necessary to say that before placing the mirror in the mouth its temperature must be tested by touching it for a moment against the back of the hand.

Nearly all the facts of importance in phonation, several of which have already been referred to, or will be mentioned in the "Summary and Review" below, could only have been discovered by the use of the laryngoscope. The difference in the larynx in the two sexes and in different types of singers and speakers, though open to ordinary observation, dissection, etc., are still better brought out by the use of the instrument now under consideration.

One naturally expects any organ to be larger and heavier in the male than in the female, and to this the larynx is no exception; and individual differences are equally pronounced. There may be almost if not quite as much difference between the larynx of a barytone and of a tenor as between that of an ordinary man who is not a public voice-user and the larynx of the ordinary woman. The larynx of the contralto may in its size and general development remind one of the same organ in the male. The vocal bands of the bass singer may be to those of a soprano as are the strings of a violoncello to those of a violin--using these examples, it will be understood, merely as rough illustrations.

The change in the size of the larynx produced by even a few months' judicious practice may be astonishing. As already hinted, it is important that in bringing about this development exclusive attention should not be given, as is sometimes done, especially in the case of speakers, to the lower tones, though it is not so important for them as for singers to have an even development up to the highest range.

But again the author would urge the voice-user to aim at attaining that delicate control of muscles (neuro-muscular mechanisms, to speak more scientifically) so important for the finest vocal effects, rather than be satisfied with mere power. The vocalist and speaker must indeed be athletic specialists, but they should not aim at being like the ordinary athlete, much less mere strong men of the circus.

It is said that Madame Mara within her range of three octaves could effect 2100 changes of pitch, or 100 between each two tones of the twenty-one in her compass, which would represent a successive change in the length of the vocal bands of a small fraction, possibly not more than 1/17000 of an inch--something unapproachable in nicety in the use of any other instrument. Even if we make large deductions from the above, the performances of those who have reached the highest laryngeal control must remain marvellous, all the more when it is remembered that this control over the larynx, to be efficient for musical purposes, must be accompanied by a corresponding mastery of the art of breathing. Is it necessary to point out that such wonderful development and control can only be attained after years of steady work by the best methods?

At one period in the life of the individual changes of such importance take place in the entire nature, physical, mental, and moral, that he becomes almost a new being. This epoch is known as the period of puberty or adolescence, and may be considered that of the gravest moment during one's whole life; for then, for better or worse, great changes inevitably occur. It is incomparably the period of greatest development, and, unfortunately, there may also spring into being, with striking suddenness, physical and psychic traits which cause the greatest anxiety. In any case, the thoughtful must then regard the youth or maiden with feelings of the deepest interest, if not anxiety; and in the case of the voice-user, especially the singer, this period may come laden with the destinies of the future.

The vocal organs, especially in males, undergo very marked changes in relative proportions and actual growth. So marked is this that the boy soprano may actually become a barytone, or, unfortunately, no longer have a singing voice at all.

So far as the larynx is concerned the changes are less pronounced, usually, in the girl; nevertheless, the period is one of such change for the female that the greatest care should be exercised at this time, especially in the case of city girls. The body requires all its available resources for the growth and development which is so characteristic of this biological and psychological epoch; hence it may be ruinous for the future of the girl if at this time the same strain is put upon her as on the adult, whether in the direction of study, physical exertion, or social excitement, and of course the voice must suffer with all the rest. The farmer who would attempt to work the colt of a year or two old as he does the horse of four or five would be regarded as either grossly ignorant of his business or utterly reckless as to his own interests, if not positively cruel. Do our modern usages not show a neglect of facts of vital moment still more marked? Unfortunately, the woman all her life must live, to a greater or less extent, on a sort of periodic up-curve or down-curve of vitality; and that this fact is so generally ignored by society and educators is one of those peculiarities of our age at which, in spite of its great advancement in so many directions, a future generation must wonder.

To use the voice when the health is even slightly disordered is not without risk to the vocal organs, and it is the clear duty of every teacher of vocal culture, at all events, to allow no practice and to give no lessons that imply the actual use of the vocal organs at these times. Nor is this a great loss, rightly considered, for the intellectual side of the subject, which requires so much attention, may readily be made to take the place of the vocal for a few days.

The so-called "breaking" of the voice is largely confined to males, because the growth changes, etc., as already said, are most marked in boys. At this time, also, there is frequently an excess of blood supplied to the larynx, with possibly some degree of stagnation or congestion, which results in a thickening of the vocal bands, unequal action of muscles, etc., which must involve imperfections in the voice. In all such cases common sense and physiology alike plainly indicate that rest is desirable. All shouting, singing, etc., should be refrained from, and even ordinary speech, as much as possible, in very marked cases, especially when the individual is even slightly indisposed or weary.

In other cases the changes are so gradual and so little marked that it is not at all necessary to discontinue vocal practice, if carried out with care and under the guidance of an intelligent friend or teacher; but because of the possibility of the voice changing in quality, there is no time when the advice of an experienced and enlightened teacher or laryngologist is more necessary.

The condition present in the vocal bands and larynx generally of the boy at puberty is more or less akin to that found in fatigue, ill-health, hoarseness, etc., as well as in old age, when muscular action is very uncertain, so that in the weak larynx, as elsewhere, the old man may approach the undeveloped youth, and for much the same reason--lack of co-ordinated or harmonious control of parts.

These remarks imply, of course, that the youth has already begun studies in voice-production, and that raises another important question, viz.: When should the individual who is sufficiently endowed musically begin to sing, or study public utterance practically in some of its forms?

No faculty develops earlier than the musical, and this is a strong argument in itself for the early study of music, apart altogether from other considerations about which there is room for more difference of opinion. Should the child get his musical development through the use of his own musical instrument or another? If he shows natural ability for the use of the voice, should he be trained very early?

Against early training may be urged the facts above referred to--the liability of great changes taking place in the larynx at puberty, especially in the boy. But marked are the changes that take place in other parts of the body also, and this is not urged against exercises for general development, for the boy. It is a remarkable fact that many of the great composers sang as boys, and possibly this has had something to do with their writing music for the voice, later, when they were most of them by no means fine singers; but on this too much stress should not be laid.

The question at issue is to be sharply marked off from another--the public appearance of children as soloists, reciters, etc. In this case the question is more complicated, and cannot be settled by physiological considerations alone. Our problem is also to be kept apart from another very important question--the singing of children, or, indeed, adults, in classes, choirs, etc.

If a child shows himself a desire to sing, and especially if he has musical ability above the average and a voice that is of fair range and quality, one can scarcely see why he should not be encouraged, and placed under a wise teacher; for it is doubtful if there be any better way of developing the ear and musical nature, even if in future the child shows that he will accomplish more as an instrumentalist. Such vocal training tends to development of the larynx, and that can scarcely be wholly lost, no matter what changes puberty may bring about. At the same time, one must take care not to be too hopeful in regard to child singers. Nature gives us some surprises, and not always pleasant ones.

But as to the cultivation of the vocal organs with the view of producing a beautiful speaking voice by processes akin to those used for the singer, as the teaching of this work constantly implies, there can be no doubt. Unless the individual acquires a respect for the beautiful in the speaking voice when young, it is feared he may never get it, as the existing state of things only too clearly shows.

It is hoped that enough has been said on this subject to indicate the principles, at all events so far as physiology is concerned, on which the decisions regarding some weighty questions must be made.

The question of singing with others, as usually carried out in schools, seems to the author a very doubtful procedure, to say the least, as for those with fine throats it may prove injurious, and for those who have feeble musical endowments it does little; but of this subject and concerted singing generally again.