Book: Voice Production in Singing and Speaking

W >> Wesley Mills >> Voice Production in Singing and Speaking




The chest is enlarged by the muscles of inspiration, the principal 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 pass along the nerves to the
muscles; that is, the ingoing impulses pass 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 assumes 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.

[Illustration: 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.]

[Illustration: FIG. 21 (Spalteholz). A front view of FIG. 20.]

[Illustration: FIG. 22 (Spalteholz). The back or signet surface of the
cricoid or ring cartilage, to which several muscles are attached.]

[Illustration: 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.]

[Illustration: 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.
It is situated below the thyroid cartilage, with which it is connected
by a membrane, the crico-thyroid. The wider part of this signet-ring
is situated behind, where it affords attachment to large muscles. It
also furnishes a base of support for two very important structures,
the _arytenoid_ (_arutaina_, a ladle) cartilages. As the vocal bands
are attached behind to them, and as they have a large degree of
mobility, they are from a physiological point of view the most
important of all the solid structures of the larynx.

There are two pairs of small bodies, the _cartilages of Santorini_, or
_cornicula laryngis_, surmounting the arytenoids, and the _cuneiform_,
or _cartilages of Wrisberg_, situated in the folds of mucous membrane
on each side of the arytenoids; but these structures are of little
importance.

The whole of the inner surface of the larynx is lined with mucous
membrane, though that covering over the true vocal bands is very thin,
and so does not cause them to appear red like the false vocal bands,
which are merely folds of the mucous membrane. However, the true vocal
bands may become red and thickened when inflamed, because of this same
mucous membrane, which, though ordinarily not visible to the eye,
becomes so when the condition referred to is present; for inflammation
is always attended by excess in the blood supply, with a prominence of
the small blood-vessels resulting in a corresponding redness. The
same thing happens, in fact, as in inflammation of the eyes or the
nose, both of which are more open to observation. Bearing this in mind
one can readily understand why in such a condition, which is often
approached if not actually present in the case of "a cold," the voice
becomes so changed. Such vocal bands are clumsy in movement, as the
arms or any other part would be if thus swollen. The plain remedy is
rest, cessation of function--no speaking, much less attempts at
singing. Like the nose the larynx, and especially the vocal bands, may
be catarrhal, and such a condition may call for medical treatment
before the speaker or singer can do the most effective vocal work.

While the _false vocal bands_ have little or nothing to do with
phonation directly, they do serve a good purpose as protectors to the
more exalted true vocal bands. When coughing, swallowing, vomiting,
holding the breath tightly, etc., these folds of mucous membrane close
over the true bands, often completely, and thus shut up for the moment
the whole of that space between the bands known as the glottis, or
glottic chink, to which reference was made in a previous chapter as
the space through which the air finally gains access to the lungs.

The true vocal cords (which, because of having some breadth and being
rather flat, are better termed vocal bands) are composed largely of
_elastic tissue_. The reader may be familiar with this structure,
which is often to be found in the portions of the neck of the ox that
the butcher sells as soup beef. It is yellow in color, and stretching
it has furnished many a boy with amusement. It is so unmanageable when
raw that when it falls to the dog he usually bolts it, the case being
otherwise hopeless. Such elastic tissue is, however, the very material
for the construction of vocal bands, as they require to be firm yet
elastic.

[Illustration: FIG. 25 (Spalteholz). A view of the larynx from behind.
Several of the muscles are well shown, of which the two indicated
above are of the most importance. The arytenoideus proprius tends to
bring the cartilages from which it is named, and therefore the vocal
bands, toward each other; while the posterior crico-thyroid, from its
attachments and line of pull, tends to separate these and lengthen the
vocal bands.]

[Illustration: FIG. 26 (Spalteholz). Showing structures as indicated
above. The mucous membrane, that naturally covers all parts within the
vocal mechanism, has been dissected away to show the muscles.]

[Illustration: FIG. 27 (Spalteholz). Showing the parts indicated
above; and of these the crico-thyroid muscle is to be especially
observed. The oblique (especially so in the posterior part) direction
of its fibres is evident, so that when it contracts, it must pull up
the ring cartilage in front, and so tilt back its hinder portion and
with it the arytenoid cartilages, and so lengthen and tense the vocal
bands, as in the utterance of low tones.]

[Illustration: FIG. 28 (Spalteholz). A back (posterior) view of the
larynx, etc. Note how the arytenoid cartilages rest on the cricoid;
how the epiglottis overhangs, as its name implies, the glottis; and
that the posterior part of the windpipe is closed in by soft
structures, including (unstriped) muscle.]

It is important to remember the relative position of parts and to bear
in mind that most of the laryngeal structures are in pairs. To this
last statement the thyroid and cricoid cartilages and the epiglottis
are exceptions, being single.

Of the _epiglottis_, a flexible cartilage, it is necessary to say
little, as its function in voice-production, if it have any, has never
been determined. It hangs as a flexible protective lid over the
glottis, and food in being swallowed passes over and about it. It no
doubt acts to keep food and drink out of the larynx, yet in its
absence, in some cases, owing to disease, no very great difficulty was
experienced, probably because certain muscles acted more vigorously
than usual and tended to close up the glottic chink.

The following simple diagram will, it is hoped, make the relative
position of parts plain so far as the anterior (front) attachments of
parts to the thyroid cartilage are concerned. It will be understood
that the inner anterior surface is meant, and that by "middle line"
is intended the middle line of the body, the imaginary vertical
diameter passing like a plumb-line from the middle plane of the head,
let us suppose, downward just in front of the larynx.

[Illustration: FIG. 29.]

The angle made above and in front where the two wings of the thyroid
cartilage meet is termed _Adam's apple_ (_Pomum Adami_), and in some
cases, mostly males, is very prominent. Adam's apple has in itself,
however, no special significance in voice-production.

The little concavity between the false vocal bands above and the true
vocal bands below is termed the _ventricle of the larynx_. It allows
of more space for the free movements of the bands, especially those
more important in voice-production.

The vocal bands are attached behind to the projecting angle of the
base of the arytenoid cartilage, which is itself somewhat triangular
in shape, the base of the triangle being downward and resting on the
upper and posterior (back) surface of the cricoid cartilage, with
which it makes a free joint, so that it can move swivel-like in all
directions. This is most important, because through it is explained
the fact that the vocal bands may be either tensed and lengthened or
relaxed and shortened.

_The muscles act on these movable cartilages, and nearly all the
changes in the vocal bands are brought about through the alterations
in position of the arytenoid cartilages, to which they are attached
behind._

Before describing the muscles of the larynx, the reader is reminded of
the order of structures from above downward, in front, which is as
follows:

The hyoid bone.
The thyro-hyoid membrane.
The thyroid cartilage.
The crico-thyroid membrane.
The cricoid cartilage.
The trachea.

The latter is connected with the cricoid cartilage by its membrane.

All the above structures can be felt in one's own person, the more
readily if he be thin and have a long neck. The hyoid bone, or
tongue-bone, is that hard structure just above the cricoid cartilage,
and which one may easily demonstrate to be much more movable than the
larynx itself. The tongue muscles are attached to it above, and from
it, below, the larynx is suspended, as already explained.

The muscles of the larynx are best understood if the principle of
antagonistic action already referred to be remembered. Speaking
generally, the muscles are arranged _in pairs_ which have an opposite
or antagonistic action--viz.: (1) Those that open and close the
glottis; (2) those that regulate the tension, or degree of tightness,
of the vocal bands.

1. The muscles whose action tends to approximate the vocal bands--the
_adductors_--are the _arytenoid[=e]us proprius_ and the
_thyro-arytenoid[=e]us_. The former is attached to the posterior or
back surface of both arytenoid cartilages; the latter, as its name
indicates, to the anterior and inner surface of the thyroid and the
anterior lower surface or angle (_vocal process_) of the arytenoid.

The opening or widening of the glottis is effected on each side (one
muscle of the pair and its action being alone described in this
and other cases) by the antagonist of these muscles, the
_crico-arytenoid[=e]us posticus_, whose attachments are exactly as
indicated by the names--viz., to the posterior part of the two
cartilages named. When reading the description of these or other
muscles it is absolutely necessary to have a pictorial illustration or
the real object before one. The pull of this muscle is from the more
fixed point, as in all other cases; hence the force is applied in a
direction from below and outward, with the result that the
arytenoid cartilage is tilted outward, and with it the vocal band is
moved from the middle line.

[Illustration: FIG. 30 (Chapman). Diagram showing action of
crico-thyroid muscle, stretching of the vocal cords, and lengthening
of them. The dotted lines indicate the position assumed when the
muscle has contracted.]

[Illustration: FIG. 31 (Spalteholz). View of the larynx as looked at
from above. The illustration shows particularly well both the true and
the false vocal bands. The true vocal bands are placed much as they
are when a barytone is singing a very low tone. The part of the figure
lowest on the page represents the back part of the larynx.]

[Illustration: FIG. 32 (Spalteholz). A cross-section transverse to the
larynx, such as can be readily made with a strong knife.]

The _crico-thyroid_ also tends to open the glottis. Just as the
diaphragm is the most important muscle of breathing, so is the
crico-thyroid the most important in ordinary speaking and in singing
in the lower register. It is a relatively large and strong muscle with
an oblique direction in the main, though it is composed in reality of
several sets of fibres some of which are much more oblique in
direction than others (Fig. 28). As its name indicates, its points of
attachment are to the thyroid and the cricoid cartilages, but the most
fixed point (_origin_) is its point of attachment to the larger
cartilage; hence its direction of pull is from the thyroid, with the
result that the anterior part of the cricoid is drawn up, the
posterior part down, and the arytenoid cartilage, resting on the upper
part of the cricoid, backward, so that the vocal band is rendered
longer and more tense (see especially Fig. 29). It is important to
note that this is the muscle most used in singing the lower tones of
the scale, and that its action must necessarily cease, to a great
extent, when a certain point in the pitch is reached, as there is a
limit to the degree of contraction of all muscles; and, besides, the
crico-thyroid space is of very moderate size, and the cricoid
cartilage can ascend only within the limits thus determined. It thus
follows that Nature has provided in the change of mechanism for a new
register, which is nothing else than a change of mechanism with a
corresponding change of function. It will be at once apparent that the
claim that registers are an invention of men, and without foundation
in nature, is without support in anatomy and physiology. The
crico-thyroid is probably, however, of much more importance to tragic
actors and barytones than to tenors or sopranos. This, however, is no
excuse for the neglect of its development by the latter class, as
often happens, for without it the best tones of the lower register are
impossible. On the other hand, the elocutionists who prescribe for
students practices that involve the excessive use of this muscle, with
a cramped position of the vocal organs, the larynx being greatly drawn
down, with the view of producing disproportionately heavy lower tones,
must take no comfort from the above anatomical and physiological
facts. Art implies proportion, and it was one of the ambitions of all
the best actors in the golden age of histrionic art to have an "even
voice"--_i.e._, one equally good through the whole range required. The
tragic actor, elocutionist, and public speaker, and the singer,
whether soprano or bass, should neglect no muscle, though they may be
justified in developing some in excess of others, but ever with a
watchful eye on the weakest part.

2. The muscles which regulate the tension of the vocal bands are the
following:

(_a_) The _thyro-arytenoid[=e]us_ (pair), which by tilting the
arytenoid cartilages forward relaxes the tension of the vocal bands.
When they act with the adductors--_e.g._, the arytenoid[=e]us
proprius--the result must be relaxation and approximation behind,
which implies a greater or less degree of shortening, as usually
happens when a certain point in an ascending scale is reached in
persons whose methods of voice-production have not been in some way
modified, and a new register begins, which in most female voices is
marked by a more or less distinct and abrupt alteration of the quality
of the tone.

The crico-thyroids are the antagonists of the above-named muscles, and
they may act either very much alone or, to some extent, in cooeperation
with the above, to regulate or steady their action; for in movements
so complicated as those required for voice-production it is highly
probable that we are inclined to reduce our explanations of muscular
action to a simplicity that is excessive, and to appreciate but
inadequately the delicacy and complexity of the mechanism and the
processes involved. It is quite certain that in the production of the
highest tones of a tenor or soprano several muscles cooeperate, and
one, especially, seems to be of great importance in the formation of
such tones, most of all, perhaps, in high sopranos. The muscle
referred to is the thyro-arytenoid already described. It is not only
attached to the two cartilages indicated by its name, but also along
the whole of the external or outer surface of the vocal band. It will
be remembered that practically all the muscles are arranged in pairs,
one on each side of the middle line. The muscle now under
consideration, more, perhaps, than any other, is complex in its
action. Apparently a very few of its fibres may act more or less
independently of all the others at a particular moment and with a
specific and very delicate result, a very slight change in pitch.
Exactly how this is attained no one has as yet adequately explained;
but it is doubtful whether any singer who does not possess a perfect
control over this muscle can produce the highest tones of the soprano
with ease and effectiveness. It is especially the muscle of the human
birds of the higher flights.

(_b_) To these thyro-arytenoids, which for most singers and all
speakers are probably chiefly relaxing in action, must be added as
aiding in this function another pair, the _lateral crico-arytenoids_.
They are situated between the cricoid and arytenoid cartilages, and
the direction of action is obliquely from below and forward, upward,
and backward, so that the arytenoids are brought forward and also
approximated more or less, which involves relaxed tension, at least,
possibly also shortening of the vocal bands.

When a tenor or soprano singer reaches the upper tones, say about
[Illustration: e'' f'' g''], or higher, there is considerable closing
up in the larynx, much in the way in which the parts of the month are
brought together in sucking. This is termed _sphincter action_, the
mouth and the eyes being closed by such action, of which they are
the most easily observed examples. As a result of this squeezing there
is in some cases that reddening of the face and that tightness which
is often felt uncomfortably, and which is _straining_, because when
present in more than a very slight degree it is injurious, owing to
congestion or accumulation of blood in the blood-vessels, with all the
bad consequences of such a state of things. When the tightening does
not go beyond a certain point it is normal--indeed, such sphincter
action is inevitable; but it is the excess which is so common in
tenors and others who strain for undue power, and to produce tones too
high in pitch for their development or their method, which is so
disastrous to the throat and to the best art also.

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