BRIEF OUTLINE OF THE ANATOMY OF THE VOCAL ORGANS
In giving a brief survey of the anatomy of the vocal apparatus
we will avoid as much as possible scientific terms, exhibiting
in simple form only what is indispensable for singers to know
about the physiological functions of those organs which
represent the essential factors of voice production.
The mechanism of the human voice consists of three elements: the
moving power, or breathing apparatus; the producing power, or
laryngeal apparatus; and the resonating power, or resonating
apparatus.
These three elements are organized as follows:
1. The moving power consists of the lungs, the respiratory
muscles, the bronchial tubes, and the trachea.
2. The producing power, the larynx, its muscles, cartilages, and
vocal cords.
3. The resonating power, the pharynx, the mouth, and the
chambers of resonance.
The author includes among the chamber of resonance all the
body’s cavities.
The _lungs_ are two bellows of spongy tissue which contain a
large number of little cavities filled with air (the air we
inhale). To these cavities are joined numerous small tubes,
called bronchial tubes, which run into the lungs carrying the
air and becoming gradually larger in size and fewer in number.
Toward their exit from the lungs the bronchial tubes are reduced
to two—the large bronchiae, and finally to one—the trachea (Fig.
1).
[Illustration:
FIG. 1.—THE LUNGS
]
In the second figure the lungs are contained in a cage (the
chest) which is formed by the ribs and the intercostal muscles,
attached between the ribs. Under the lower border of the lungs,
adherent to the spinal column and to the lower six ribs, lies a
large and strong muscle called the diaphragm. Its function, very
important, though very much exaggerated by some improperly
called physiological schools of singing, is a coördinate
movement of contraction and relaxation, which, in connection
with the movement of the other muscles of respiration,
establishes the mechanism of breathing by enlarging and reducing
the chest and lungs to their normal position.
[Illustration:
FIG. 2.—THE CHEST
]
The _larynx_, the second element of the vocal apparatus,
represents the sound box of the vocal organs (Fig. 3) and
embraces its cartilages and muscles, and, most important, the
two elastic bands called the vocal cords.
The cartilages of the larynx, situated above the trachea, are
the following: the cricoid and thyroid, the arytenoids and
epiglottis (Fig. 4), and the two smaller cartilages (Santorini
and Wrisberg) which are of minor importance. All of these
cartilages are joined by ligaments and muscles, which move the
larynx, and adapt the vocal cords to the different adjustments
for producing the relative sounds.
[Illustration:
FIG. 3.—THE LARYNX
]
[Illustration:
FIG. 4.—THE VOCAL CORDS
]
The vocal cords (Fig. 4) are two elastic bands, inside of the
larynx, kept in tension during their vibratory function by the
cartilages and the muscles, so that they can be put in vibration
by the blast of air pushed by the lungs and produce the sound.
The fissure between the vocal cords is called the glottis. The
vocal cords, in a position of rest, are relaxed and wide open,
thus leaving a larger space for the passage of the air, which is
called the glottis.
In the upper part of the larynx there exists a very important
cartilage called the epiglottis (Fig. 5). The epiglottis is
flexible and is situated between the base of the tongue and the
opening of the larynx. Its function is doubly important, since
it acts as a protective lid to the glottis, by closing the
larynx in swallowing, so that food and drink may pass over it
without exposing the breathing apparatus to any danger; and in
singing it lends free passage to the sounds, from the vocal
cords to the mouth and chambers of resonance, by holding itself
in an erect position, so as to leave the larynx wide open. The
epiglottis is attached to the base of the tongue and their
relationship is very important, as together they play one of the
most essential rôles in the mechanism of voice production, to
which, unfortunately, not enough consideration has thus far been
given.
[Illustration:
FIG. 5.—THE EPIGLOTTIS
]
The third element, _the resonating power_, consists of the
pharynx, the mouth, and the chambers of resonance.
The pharynx (Fig. 6) extends from the opening of the larynx to
the opening of the posterior nasal cavities, and includes also
the uvula, which represents the boundary between the pharynx and
the mouth. The upper part of the pharynx is called the
nasopharynx and is an important factor for the resonance of the
voice. The uvula is attached to the soft palate and is prominent
in the mechanism of the voice, because it has the faculty of
controlling the opening and the closing of the posterior nasal
fossae. By this function the nasal resonance can be improved or
checked.
[Illustration:
FIG. 6.—THE PHARYNX
]
The mouth (Fig. 7), the very important organ of voice
production, is the cavity which contains the tongue—the
invaluable factor in speaking and singing—the palate, and the
lips. Above the palate are the chambers of resonance, which
consist of the so-called masque, made up of all the cavities,
frontal sinuses, antrum, etc., of the upper maxillary and
frontal bones.
[Illustration:
FIG. 7.—THE MOUTH
]
All of these organs above described are parts of one single
apparatus, which is formed by a long tube going from the mouth
to the lungs, called the vocal apparatus. This apparatus has the
mission of producing and carrying the breath from the lungs to
the vocal cords, which puts them into vibration and produces the
sounds. From the vocal cords the sounds are carried, by the
breath, to the mouth, where they are transformed into voice, and
to the resonance chambers, where they get their full resonance.
The resonating power, however, is not represented by the
resonance chambers alone, but by all the cavities of the entire
body, according to the author’s view, which will be more fully
discussed in a later chapter devoted to resonance.
In order to enable the reader to obtain a full view of the
entire vocal apparatus, the author has condensed in the
accompanying illustration (Fig. 8) all the organs that take part
in the formation of the voice. The most important of them are
specially indicated.
The illustration is a transverse section of the vocal apparatus.
Familiarity with it is of great help in the study of the
mechanism of voice production. Therefore we recommend to the
reader a thorough examination of it, starting from the bottom
and working up. Held by the convexity of the diaphragm are the
lungs. From them originate the small bronchial tubes, which
gradually become the two large bronchial tubes which, in their
exit from the lungs, converge into the trachea. At the top of
the trachea is the larynx, which contains the vocal cords. At
the opening of the larynx stands the epiglottis, which is
attached to the base of the tongue. Then follows the pharynx,
the uvula, the mouth, the palate, and the resonance chambers.
[Illustration:
FIG. 8.—TRANSVERSE SECTION OF THE VOCAL APPARATUS
]
The task of demonstrating the important functions of these
organs belongs to physiology, which, by means of its natural
rules, can give the very correct exhibition of the mechanism of
the voice. This preliminary knowledge of the vocal apparatus and
of the fundamental laws of acoustics prepares the ground for the
development of our principles, in reference to voice production,
the aim of which is centered, according to our conception, on
closely following the dictates of nature.