Here begins a multi part series on the care and maintenance of the singing voice. Today I will begin with vocal anatomy.
Probably the three most important things a singer can do to maintain a healthy voice are understanding one’s vocal anatomy, remaining hydrated and getting plenty of sleep. That said, the health of a singing voice depends on much more, including one’s body, mind and soul! Any instrument that is constantly played needs to be well maintained. Singers’ instruments are their bodies- more so than any other musicians. If you are a singer you’ve probably heard that a million times. For some strange reason, many of us (singers) forget that we are what we sing and we sing what we are! Thus care and maintenance applies to a singer just as much as any other instrumentalist.
Understanding the vocal anatomy is paramount for singers. This will not only enable singers to maintain healthy singing voices, but enable them to understand vocal technique and the function of the physiological components of their instruments.
Here is a general overview of the vocal anatomy. I have copied this information from singwise.com. Singwise is an information based resource for singers written by Kayrn O’Connor. I love this site. It is easy to understand and extremely comprehensive.
Here we go!
The mechanism of breathing can be summarized in this way:
Receiving various signals from the nervous system, the diaphragmatic muscles contract and the diaphragm moves downward. As the diaphragm depresses, it creates a vacuum in the lungs and air rushes in to fill that vacuum. During exhalation, the diaphragm relaxes and rises and lung volume decreases, creating a positive pressure difference, and air rushes out.
The (thoracic) diaphragm is a shelf of muscle and tendon that extends across the bottom of the ribcage, dividing the torso in two. Above is the thorax (chest), with the lungs and heart, below is the abdomen. It is dome-shaped, slightly higher on the right side, and curves up toward the centre. It features a boomerang-shaped central tendon – the aponeurosis – which is connected all around by muscular fibres that originate on the lumbar spine, the bottom edge of the ribcage and sternum (breastbone). The heart, which is attached to the diaphragm via its pericardium – a membrane sac that envelops the heart – moves up and down with the diaphragm.
The lungs are made of a soft, elastic, spongy tissue. Their structure is much like an inverted tree. Air enters the lungs via the trachea (the “trunk”). The trachea branches in two to form the bronchi. Each bronchus continues to branch out into bronchioles until, at the end of each bronchiole, a cluster of alveoli, which are small sacs where gas exchange of carbon dioxide and oxygen takes place, is reached. The total surface of the alveoli is very large.
As the ribcage and diaphragm move, the lungs are stretched, drawing air into the lung (inhalation), or the lungs are compressed, pushing the air out (exhalation).
The intercostal muscles are found between the ribs, and there are two kinds: The internal intercostal muscles (in the inside of the ribcage) extend from the front of the ribs, and go around the back, past the bend in the ribs. In front of the ribcage, looking from the bottom of each muscle (i.e. the top of each rib), the muscles go diagonally inward. The external intercostal muscles (on the outside of the ribcage) wrap around from the back of the rib almost to the end of the bony part of the rib in front. They go downward and outward when viewed from the back. (At the bottom of the sternum can be seen the transversus thoracis muscle). These muscles can be felt during coughing.
Having the muscles on diagonals increases the amount of work that they can do, since a longer muscle can become shorter upon contraction than can a shorter, vertical muscle, as it contracts along the full length of the muscle fibres.
The Abdominal Muscles
The deepest of the abdominal muscles, the transversus abdominis, go horizontally from front to back. They are very important in respiration, and are probably instrumental in forced exhalation.
The external obliques course downward and inward, and are the largest and strongest abdominal muscles. These muscles work posturally by contracting and may flex or twist the spine. By compressing the abdomen, these muscles create higher pressure in the abdomen and thorax (chest), essential for forced expiration. Also, by relaxing these muscles, one can allow the distention of the belly to be more free, making the action of the diaphragm more easily felt.
Sandwiched in the middle between the external obliques and the transversus abdominis are the internal obliques. Their direction is down and out, or the opposite of the external obliques. They can be used to compress the abdomen for exhalation.
Muscles of the Lower Back
While some of these muscles are primarily flexors of the lower limb (i.e., thigh and pelvis), the quadratus lumborum serves as the equivalent muscle of exhalation to the abdominal muscles found in front. The psoas major, a long muscle on the side of the lumbar region of the spine and brim of the pelvis (in front of the hip joint), connects with the muscles of the diaphragm.
In terms of respiration, the quadratus lumborum can be felt to stretch most easily when the abdominals in front are contracted and one “breathes into the lower back”, allowing the diaphragm to push the organs of the abdomen against these muscles. On contraction, they serve as muscles of exhalation. They may also hold the lowest part of the ribs in place during inhalation, allowing the diaphragm to drop down more effectively.
Support works by contracting the abdominal muscles, creating higher pressure in the abdomen and thorax, allowing the diaphragm’s relaxation (and upward rise) to be more carefully controlled. There is less control in relaxing a muscle than there is in contracting it, so support gives performers a means of controlling their sound, or phonation.
The Physics of Making Sound
(please see full article of the physics of sound here).
When air is expelled from the lungs, it rises up the trachea and runs into constriction at the larynx – where the vocal cords, now called vocal folds, are housed – causing the vocal folds to vibrate or buzz. This buzzing quality to the speech is called voice or voicing. The vocal folds “chop” the air stream up into a series of rapid “puffs” that create the sound. (It isn’t the impact of the folds coming together that makes the sound). This produces a fundamental tone frequency, (the lowest frequency in a harmonic series), accompanied by several non-harmonic overtones, (a natural resonance or vibration frequency of a sound system).
The resulting sound is modified by movements in the vocal tract, (where sound that is produced at the larynx, pharynx, and oral and nasal cavities is altered), by the volume of the airflow and by the degree of constriction of the vocal folds. (During speech the flow of air is relatively small because of constrictions of the vocal folds).
The buzz created by the vocal folds resonates (vibrates) the air column and this, in turn, causes the structures above and around the larynx to vibrate, as well.
Sound is generated in the larynx – an organ in the neck involved in the protection of the trachea and in sound production. The larynx houses the vocal folds, and that is why it is commonly referred to as the “voice box”. It is situated just below the pharynx – the part of the neck and throat situated immediately behind the mouth and nasal cavity and cranial, and above the esophagus, larynx and trachea (the “windpipe”).
The larynx is also where pitch and volume are manipulated. The strength of expiration from the lungs contributes to loudness, and is necessary for the vocal folds to produce speech.
That’s all for now. Next up the dos and don’ts of vocal health. Also, links and address of where to find more information about the voice.