Respiration and the Voice : Part 1

Hygienic Physiology: with Special Reference to the Use of Alcoholic Drinks and Narcotics
by Joel Dorman Steele, Ph.D.

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"The smooth soft air with pulse-like waves Flows murmuring through its hidden caves, Whose streams of brightening purple rush, Fired with a new and livelier blush; While all their burden of decay The ebbing current steals away."

The Organs of Respiration and the Voice are the larynx, the trachea, and the lungs.

Description of the Organs of the Voice. - l. The Larynx. - In the neck, is a prominence sometimes called Adam's apple. It is the front of the larynx. This is a small triangular, cartilaginous box, placed just below the root of the tongue, and at the top of the windpipe. The opening into it from the throat is called the glottis; and the cover, the epiglottis. The latter is a spoon-shaped lid, which opens when we breathe, but, by a nice arrangement, shuts when we try to swallow, and so lets our food slip over it into the esophagus the tube leading from the pharynx to the stomach.

If we laugh or talk when we swallow, our food is apt to "go the wrong way," i. e., little particles pass into the larynx, and the tickling sensation which they produce forces us to cough in order to expel the intruders.

2. The Vocal Cords. - On each side of the glottis are the so- called vocal cords. They are not really cords, but merely elastic membranes projecting from the sides of the box across the opening. When not in use, they spread apart and leave a V-shaped orifice, through which the air passes to and from the lungs. If the cords are tightened, the edges approach sometimes within 1/100 of an inch of each other, and, being thrown into vibration, cause corresponding vibrations in the current of air. Therefore sound is produced in the same manner as by the vibrations of the tongues of an accordion, or the strings of a violin, only in this case the strings are scarcely an inch long.

Different Tones of the Voice. - The higher tones of the voice are produced when the cords are short, tight, and closely in contact; the lower, by the opposite conditions. Loudness is regulated by the quantity of air and force of expulsion. A falsetto voice is thought to be the result of a peculiarity in the pharynx at the back part of the nose; it is more probably produced by some muscular maneuver not yet fully understood. When boys are about fourteen years of age, the larynx enlarges, and the cords grow proportionately longer and coarser; hence, the voice becomes deeper, or, as we say, "changes." The peculiar harshness of the voice at this time seems to be due to a congestion of the mucous membrane of the cords. The change may occur very suddenly, the voice breaking in a single night.

Speech is voice modulated by the lips, tongue, palate, and teeth. Speech and voice are commonly associated, but speech may exist without the voice, for when we whisper we articulate the words, although there is no vocalization, i. e., no action of the larynx.

Formation of Vocal Sounds. - The method of modulating voice into speech may be seen by producing the pure vowel sounds a, e, etc., from one expiration, the mouth being kept open while the form of the aperture is changed for each vowel by the tongue and the lips. H is only an explosion, or forcible throwing of a vowel sound from the mouth.

The consonants, or short sounds, may also be made without interrupting the current of air, by various modifications of the vocal organs. In sounding singly any one of the letters, we can detect its peculiar requirements. Therefore m and n can be made only by blocking the air in the mouth and sending it through the nose; l lets the air escape at the sides of the tongue; r needs a vibratory movement of the tongue; b and p stop the breath at the lips; k and g (hard), at the back of the palate. Consonants like b and d are abrupt, or, like l and s, continuous. Those made by the lips are termed labials; those by pressing the tongue against the teeth, dentals; those by the tongue, lingual.

The child gains speech slowly, first learning to pronounce the vowel a, the consonants b, m, and p, and then their unions - ba, ma, pa.

Description of the Organs of Respiration. - Beneath the larynx is the windpipe, or trachea, so called because of its roughness. It is strengthened by C-shaped cartilages with the openings behind, where they are attached to the esophagus. At the lower end, the trachea divides into two branches, called the right and left bronchi. These subdivide in the small bronchial tubes, which ramify through the lungs like the branches of a tree, the tiny twigs of which at last end in clusters of cells so small that there are six hundred million in all. This cellular structure renders the lungs exceedingly soft, elastic, and sponge-like.

The stiff, cartilaginous rings, so noticeable in the rough surface of the trachea and the bronchi, disappear as we reach the smaller bronchial tubes, so that while the former are kept constantly open for the free admission of air, the latter are provided with elastic fibers by which they may be almost closed.

Wrapping of the Lungs. - The lungs are invested with a double covering - the pleura - one layer being attached to the lungs and the other to the walls of the chest. It secretes a fluid which lubricates it, so that the layers glide upon each other with perfect ease. The lungs are lined with mucous membrane, exceedingly delicate and sensitive to the presence of anything except pure air. We have all noticed this when we have breathed any thing offensive.

The Cilia. - Along the air passages are minute filaments, which are in constant motion, like a field of grain stirred by a gentle breeze. They serve to fan the air in the lungs, and produce an outward current, which is useful in catching dust and fine particles swept inward with the breath.