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.
[Illustration: FIG. 36 (Tyndall). Illustrates how the vibrations of a
tuning-fork are registered on a blackened (smoked) glass. In order
that the movements of the fork shall be traced in the form of regular
curves, the surface must be kept moving at a definite regular rate.]
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.
[Illustration: FIG. 37 (Tyndall). Meant to illustrate vibrations. The
impulse communicated by the ball pushed from the hand to all the
intervening ones causes only the last to actually move bodily.]
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.
[Illustration: FIG. 38 (Bosworth). Intended to illustrate the optical
principles involved and the practical method of carrying out
laryngoscopic examination. The dotted lines show the paths of the
light-rays.]
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.
[Illustration: FIG. 39. This illustration is meant to show more
especially the relative position of observer and observed. The
observer, on the right, is wearing the head-mirror, while two
throat-mirrors seem to be in position--in reality, the same mirror in
two different positions. One is placed so as to reflect the picture of
the nasal chambers, especially their hinder portion. The walls of the
nose, etc., may for the purposes of this illustration be considered
transparent, so that the scroll (turbinated) bones, etc., come into
view. The tongue is protruded. The light, not seen in this figure, is
usually placed on the left of the subject, as in Fig. 38.]
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.
[Illustration: FIG. 40 (Grünwald). If this be compared with the next
illustration (FIG. 41), some of the differences between the larynx of
the male and that of the female may be noted. The vocal bands in FIG.
40, being those of a male, are heavier and wider. They are more
covered by the epiglottis than in the other case--that of a female
(FIG. 41). The false vocal bands are well seen in both cases, and by
their redness (dark in the figures) contrast with the whiteness of the
true vocal bands. In both illustrations the bands are in the
inspiration position.]
[Illustration: FIG. 41 (Grünwald). Laryngoscopic picture of the female
larynx--to be contrasted with that of a male, shown in FIG. 40.]
[Illustration: FIG. 42 (Grünwald). In this case, owing to the subject
having a cold, it is with difficulty that the true can be
distinguished from the false vocal bands, so reddened (dark, in the
figure) were the former, with corresponding changes in the character
of the voice. This view was obtained as the subject was phonating, so
that the vocal bands are approximated somewhat closely.]
[Illustration: FIG. 43 (Grünwald). Shows the larynx as it may be seen
only by the use of the laryngoscope. The above is an example of the
appearance of the vocal bands during a deep inspiration, and in this
subject, as in those illustrated by FIGS. 40, 41, the circumstances
were so favorable that the observer could see even the trachea, the
rings of which are indicated in the picture. The reader will bear in
mind that in this and all laryngoscopic pictures, while right remains
right, front becomes back, and back front, so that the back of the
larynx appears toward the observer--_i.e._, is lowest on the page.]
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.