THE RESONANCE-CHAMBERS.
When it is borne in mind that the vocal bands have little or nothing
to do with the quality of tones, the importance of those parts of the
vocal apparatus which determine quality, and the error of speaking of
the larynx as if it alone were the sole vocal organ, become apparent.
It may be strictly said that the vocal bands serve the purpose of
making the resonance mechanism available. What one hears may be said
to be vibrations of this resonance apparatus, and not, strictly, those
of the vocal bands, though this expression would also be correct, but
would not indicate the final link in the series of vibrations.
The tone caused by the vibration of two such small bands as the vocal
cords must, in the nature of the case, be very feeble. It becomes
important for the reader to convince himself of the importance of
resonance in sounding bodies and musical instruments.
When the stem of a tuning-fork so small that it can be scarcely heard
when in vibration, except by, the person holding it, is laid against a
solid body, as a table, its sound is at once so increased that it can
be heard in the most distant part of a large room. When the same fork
is held over an empty jar of suitable size and shape, a similar but
much, less marked increase of its tone is to be observed.
If a cord of but moderate thickness be fastened at each end to a thin
piece of wood, say a split shingle, and a little block of wood, in
imitation of the bridge of a violin, be placed under the cord so as to
render it tense, we have the essentials of a stringed instrument, the
pitch of which can be made to vary by moving the block about and thus
varying the tightness of the cord. But the sound of such an improvised
instrument, produced by drawing a bow across the cord, is ridiculously
feeble.
In the actual violin the volume of sound, as well as its quality,
depends on the size, shape, and weight of the instrument. The strings
serve the purpose of causing the body of the instrument, the air
within it, and, in consequence, the air without, between it and the
ear of the auditor, to vibrate or move in a specific manner.
Similarly, the imposing size of the grand piano is associated
inevitably with loudness, as compared with a smaller instrument. A
violoncello must produce a larger tone than a violin, though not
necessarily one more intense.
These principles of resonance apply in the case of the singer and the
speaker. The bass and barytone produce tones of larger volume (as well
as different quality) than those of the tenor, because their resonance
apparatus is different in size and shape. It is true, their vocal
bands, their wind-power, and the laryngeal muscles are different--they
are not of the same size, etc.--and, in a more remote sense, this is
the cause of the differences in the tones they produce; but the
immediate cause is to be sought in the resonance mechanism, and, above
all, in the resonance-chambers.
It is true that when one speaks or sings, the chest, windpipe, and
larynx may be felt to vibrate, but the essential vibrations are
_supra-glottic_--above the vocal bands.
These resonance-chambers are the _mouth cavity_, in the widest sense,
and the _nasal chambers_. It is highly probable that the vibrations of
the chest walls and of the bones of the head may to some degree modify
the vibrations of the air within the resonance-chambers, chiefly in
the direction of intensification; but the idea that the hollow spaces
in certain of the bones of the head have any appreciable influence on
the tones of the speaker or singer, can at best not be considered as
demonstrated, and it serves no practical purpose to take into account
this possibility.
The great facts, the facts which are so plain that they may be
demonstrated to a child, are these: that the quality of any
tone--_e.g._, a vowel--is absolutely determined by the shape of these
cavities, the mouth and nasal chambers. This subject will be treated
further when the tones, etc., of speech are considered, but inasmuch
as no one can sing, in the proper sense of the term, without the use
of vowels, at least, and as we produce different vowels with
ease, one may at once demonstrate to himself that this is done by
altering the shape of his mouth cavity, and chiefly by the agency of
the tongue and soft palate.
[Illustration: FIG. 46 (Tyndall). Representing water being poured into
the vessel A B, till the air-space is just sufficient to respond to
the vibrations of the tuning-fork. The air thus becomes a resonator of
the fork.]
[Illustration: FIG. 47 (Spalteholz). The mouth is extremely widely
opened. The soft palate is seen terminating in the uvula, and on each
side, extending from it, are the pillars of the fauces, a pair of
folds between which the tonsil is seen to lie.]
[Illustration: FIG. 48. View of the nose, etc., from behind, showing
the parts enumerated above. It is not hard to understand that any
considerable amount of swelling of the lining mucous membrane might
give rise to difficulty in breathing through the nose, and even compel
mouth-breathing.]
[Illustration: FIG. 49 (Spalteholz). Showing well the scroll
(turbinated) bones of the nose, which break up the space and make it
more cavernous. It can be seen that there is free communication
behind, between the mouth and the nasal cavities, and that if the soft
palate and the tongue approximate, the breath-stream must pass into
and through the nose, giving rise to nasality in utterance.]
A short description of a part to which many voice-users remain
strangers all their lives will now be given. These resonance-chambers
remain, for many, an apparatus used daily and absolutely essential,
yet never examined. Fortunately, a few illustrations, which should be
followed by an examination of the student's own resonance-chambers and
their various parts as they may be seen in a mirror, will remove all
difficulty in the understanding of them, and prepare for that detailed
study to be recommended in a subsequent chapter.
Passing from before backward, one meets the _lips_, the _teeth_ and
_gums_, the _hard palate_, which is a continuation of the gums; then,
suspended from the hard palate, behind, is the _soft palate_, back of
which lies the _pharynx_ (often termed "the throat"), and above it and
constituting its continuation, the _naso-pharynx_; and lying on the
floor of the mouth there is the _tongue_.
Certain of these parts, as the teeth, gums, hard palate, nasal bones,
etc., constitute fixed structures, and though they determine in no
small measure the shape of the resonance-chambers, and so to a degree
the quality of the voice, so movable are the lips, soft palate, and,
above all, the tongue, that there is the widest scope for varying the
quality and even the volume of the voice; so that it is a good thing,
practically, for every one to believe that so far as quality, at all
events, is concerned, he is the master of his own destinies.
Though we are accustomed to believe that the mouth and nose are,
though neighbors, quite separate and independent of each other, such
is not the case. Indeed, in the pre-natal condition these are not two,
but one; and in some instances they remain imperfectly separated,
owing to the failure of the hard palate to develop to the full--a
condition known as "cleft palate," and giving rise to a peculiar nasal
intonation, to be explained presently.
The _nasal chambers_ are divided into two by a vertical partition, as
one can readily demonstrate by the use of his fingers, and are still
further broken up by certain bones, the scroll-shaped or _turbinated_
bones, so that the nasal chambers are of very limited size, and much
divided up by bony outgrowths from their walls. The _vertical septum_,
while bony above, is cartilaginous and flexible below.
Without the aid of instruments and a good light the nose can be but
indifferently examined from the front, while it requires the greatest
skill on the part of a laryngologist to see it well from behind.
However, the whole difficulty can be got over by visiting a butcher
and securing a sheep's head split through from before back. In a few
moments one can learn all the essential facts, including that one of
great practical importance--viz.: that every part of the
resonance-chambers is lined by the same mucous membrane which is also
continued downward into the larynx and the gullet.
It will be thus observed that the throat and nose communicate in the
freest manner behind, and that the only way of closing off the mouth
cavity from the nasal chambers is by means of the tongue and the soft
palate working together. As in the proper use of the tongue and soft
palate lie many of the secrets of the art of the speaker and singer,
special attention must be given to these parts.
The _tongue_, which completely fills the floor of the mouth, is made
up of several muscles of different attachments, which explains why
this organ is so movable. To say that it can with the greatest ease
and rapidity be turned toward every one of the thirty-two points
marked on a mariner's compass, is but to feebly express its capacity
for movements. What we are most concerned with now is its power to
alter the shape of the mouth cavity in every part.
The _soft palate_ is suspended like a curtain from the hard palate,
behind. It is composed of muscles arranged in pairs, and is continued
into a conical tip below known as the _uvula_, and on each side into
folds, the _pillars of the fauces_, between which lie the _tonsils_,
which are in shape like very small almond nuts. When quite normal
these should not protrude much, if at all, beyond the cavity made by
the folds referred to above.
Both the tonsils and the uvula may become so enlarged as to be a
source of awkwardness or more serious evil to the voice-user. They
may, in fact, require operative interference. So serious, however, is
the decision to operate, or the reverse, for the voice-user, that the
author recommends that such operations be entrusted only to
laryngologists who have some knowledge of their influence on
voice-production.
It is of the greatest moment to observe that the quality of tones can
be made to vary in the highest degree by the joint use of the tongue
and soft palate. When in vocalizing the tongue is raised behind and
the soft palate made to approach it, or actually to meet it, the tone
assumes a more or less nasal character. The reason of this is that the
cavity of the mouth proper, or "mouth" in the narrower sense, the
forward part, is shut off from the hinder part, or the pharynx, so
that the breath is then directed upward and passes chiefly through the
nose, producing a nasal tone or twang--always a fault, and one
fearfully common in America.
When the tongue alone is raised behind, or drawn back unduly, tones
become muffled--indistinct, etc. This is also a very common fault, but
is found in England and Germany also. English speech is often hard and
guttural, German unduly guttural, if not so hard, and American
slovenly and horribly nasal.
But what may in a certain degree be disagreeable and a vocal error, is
in another a positive excellence; so, in this case, the use of the
tongue and soft palate in the proper degree and at the right moment
gives us emotional expression. This subject will, however, be
considered again later; in the meantime, the student is advised to do
a little experimenting in the use of his tongue and soft palate, with
a view of noting how the quality of tone may be thus made to vary. He
is also advised to use a hand-glass with the object of observing the
parts mentioned in this chapter, and if he can also find a friend
willing to lend his mouth for observation, so much the better.
The sooner any voice-user comes to feel that his vocal destinies lie
in his own hands, the better. "Know thyself" is as necessary an
admonition for the speaker and singer as for any other artist, but
with that must go another, "Believe in thyself"--that thou canst
produce tones of beautiful and expressive quality if thou wilt; it may
be only after much wisely directed work, but yet it is possible.
Allusion must be made to the danger of those engaged in mathematical
and physical investigations applying their conclusions in too rigid a
manner to the animal body. It was held till recently that the pitch of
a vocal tone was determined solely by the number of vibrations of the
vocal bands, as if they acted like the strings of a violin or the reed
of a clarinet, while the resonance-chambers were thought to simply
take up these vibrations and determine nothing but the quality of
tone; they were believed not to have any influence on pitch. Against
this view the author long ago demurred. To Prof. Scripture, however,
belongs the credit of demonstrating that the resonance-chambers
determine pitch also. It seems probable that the vocal bands so beat
the air within the resonance-chambers as to determine the rate of
vibration of the air of these cavities, and so the pitch of the tone
produced. These chambers not having rigid walls, one can the better
understand that the tension of these parts may not only be different
in individuals, but vary in the same person from time to time,
according to the condition of his health, etc. Herein we find another
source of explanation of variations in the voice. All these
considerations make the resonance-chambers more important than ever,
so that there is greater objection to speaking of the larynx as _the_
vocal organ than we were aware of before these investigations were
undertaken.
SUMMARY.
Without a resonator, which may be solid or hollow, the sound made by a
reed or tense string is feeble. That the mouth can act as a resonator
may be proved by holding a vibrating tuning-fork of suitable pitch
before this chamber when open.
The resonating chambers of importance are supra-glottic. Of these the
"mouth" including all as far back as the pharynx and the nasal
chambers are the principal. These two main cavities are separated from
each other by the hard palate, which is a bony floor, covered with
mucous membrane, as are all the parts of the resonance-chambers. The
hard palate extends horizontally from the gums backward, and
is continued as the soft palate. The latter is a muscular and
therefore movable curtain that divides, with varying degrees of
completeness, the mouth (in the narrower sense) from the pharynx and
naso-pharynx--_i.e._, the space back of the soft palate and the
posterior nares (back nostrils) respectively. By the elevation of the
back of the tongue and the lowering of the soft palate as when one
speaks nasally, the mouth proper is largely shut off from the nasal
chambers, so that the breath must be directed through the nose. "Cleft
palate" also connects undesirably the mouth and nasal chambers. The
tonsils lie between two folds, the pillars of the fauces, connected
with the soft palate. When normal in size the tonsils should scarcely
extend beyond these folds. The uvula is the central lower tip of the
soft palate. The nasal chambers are divided by a central bony and
cartilaginous partition, the septum nasi, but are further encroached
upon, on each side, by three scroll-like (turbinated) bones. The
tongue is composed of several muscles, which explains why its
movements may be so complicated and delicate. The mouth cavity is
bounded in front by the gums, teeth, and lips.
The form and, to some extent, possibly; the size of the
resonance-chambers determine the quality of the tone produced in
speaking and singing. The shape and size of the mouth can be made to
vary by the soft palate and lips, but chiefly by the tongue, so that
the movements of the latter, especially, cannot be too well studied.
It was formerly considered that pitch was determined solely by the
rate of vibration of the vocal bands; though the author opposed this
view as rigidly applied. Very recently Prof. Scripture, by the use of
new methods, has shown that the supra-glottic chambers cannot be
correctly likened to a resonator with rigid walls. It is held that the
vocal bands give a number of sudden shocks to the air in the
resonators, so that, in a sense, the resonance-chambers determine both
the pitch and the quality of the tone; and as the tension of the
resonators varies with both the physical and psychical condition of
the individual, variations in tone-production, more especially as to
quality, can now be the better understood. According to this view
these chambers are not properly resonators but sounding cavities.
The reader's attention is particularly drawn to the new
views of the method of action of the vocal bands, etc.,
referred to on this page. Since the above was written, such
views have become more widely known, and it is hoped that as
they are very radical they may be established by other
methods.