Voice Information
CARING FOR YOUR VOICE
Human
voice provides the means for the most of our communication: It is the source
of much of out inspiration, our training, our entertainment, our enlightenment,
our encouragement, and our engagement with each other. Your voice is the extension
of your personality into the world around you. We usually think of voice as
being just the “voice box” (larynx). But actually, voice is a noun
that refers to a complex set of processes that produce our vocalizations.
The voice mechanism consists of an array of elegant structures for the following
functions: Power generation (airflow), sound generation (vocal fold vibration),
and sound resonation/shaping (articulation).
The power source we use is, of course, the air pressure provided from the
lungs. The lung tissues themselves do not provide much of the active source
of the airflow. (The lungs sacs <alveoli> do have some elasticity for
compressing air.) The power for airflow arises from the contraction of the
chest wall muscles, the passive recoil of the diaphragm, the support of the
abdominal wall muscles, and the recoil elasticity of the connective tissue
within the lungs. The major focus of power for active singing, performance
speaking, and loud, active talking develops from the short muscles (intercostals)
between the lower floating ribs. The efficient supply of airflow for the power
of voice production comes more from how the air is brought in, rather than
how the air is “forced” out. If the inhalation pattern is focused
more upper chest, the airflow support will likely be weak. If the inhalation
pattern is focused lower chest, the airflow support will likely be more robust.
The vibration that is the source of the voice is generated by aerodynamic,
myoelastic action of the vocal folds. The term “vocal cords” can
be misleading. These are not “cords,” but rather are two specialized
folds of mucosal skin overlying the two vocalis muscles inside the larynx
(voice box). When the vocal folds are brought into close approximation, the
airflow below the vocal folds begins to increase in pressure (this is a light
pressure). The increased air pressure causes the vocal folds to rapidly and
momentarily burst apart. With the air pressure then rapidly decreasing, the
myoelastic tension of the vocal folds increasing, and the rapid airflow causing
a negative air pressure at the glottis (the opening between the vocal folds),
the vocal folds return to their closed state. This sequence of the opening
and closing of the vocal folds occurs from 40-50 times per second to several
hundred times per second. The slower the vibration rate, the lower the fundamental
frequency (sort of like pitch) of the voice. The faster the vibration rate,
the higher fundamental frequency of the voice. The vocal folds are held in
a less tensed, thicker posture for lower sounds and tighter and thinner for
higher sounds. The “blips” of air that burst between the vocal folds
perturbate the air column in the throat, mouth, and nose and create sound
waves, not unlike the sound waves created within the pipes of a pipe organ.
Good voice functioning requires good control of the resonating system. The
sound that is generated at the level of the vocal folds would sound similar
to a high pitched noise, not unlike the sound created by blowing a trumpet
mouthpiece vigorously. What occurs above the level of the vocal folds in the
resonance of the voice forms each individual’s distinctive voice. Sounds
resonated primarily in the mouth have more of an open, clear tone. Sounds
resonated in the back of the mouth have more of a throaty tone and feel. Sounds
resonated in the nose have more of a nasal quality. The variations in movement
of the mandible, the tongue, the soft palate, and the lips are very important
in the production of voice. Although control can be difficult, the elevation
of the larynx can affect voice production. The voice sound must also resonate
within the chest, although that sound we do not hear. This occurs because
the air vibrates both above the vocal folds and below the vocal folds. Developing
an understanding of how the voice is produced helps in realizing how voice
problems can arise and care that should be provided.The care of the voice
focuses on the structures involved in voice production: Problems with the
breathing mechanism for power generation, problems with sound generating structures
(the vocal folds), and problems with sound resonation (the mouth, throat,
and nose).
Breathing problems are frequently incurred by avocational and professional
voice users. Active singing is an aerobic activity. As such, a singer or public
speaker, should develop healthy breathing patterns and physiological support
for the use of the voice. Problems with recurring upper and lower respiratory
illness or conditions certainly can compromise voice ability. Allergies and
asthma should certainly be addressed medically to minimize their effects on
voice production. Postural support problems can adversely affect singing or
speaking ability. With poor musculoskeletal support for breathing a performer
must recruit greater vocal effort to produce the desired voice. Accidents,
illness, and aging all play an active role in limiting voice performance by
affecting breathing patterns and capacity. Good body posture and breathing
patterns are essential to efficient, effective, and economical voice production.
Researchers have given us a considerably better understanding of the elegant
structures of the larynx. The outer shell of the larynx is composed of two
cartilages: The thyroid and the cricoid. The vocal folds attach anteriorly
to the inside of the thyroid cartilage. They attach posteriorly to the two
arytenoid cartilages, which are shaped somewhat like pyramids and move on
upper posterior rim of the cricoid cartilage. Think of the vocal fold as a
triple layered structure: A tough, flexible cover; an intermediate connecting
layer (sort of like a loose velcro attachment of the cover); and a deep layer
providing support and mass. The muscles of the larynx are arrayed in such
a fashion as to allow multiple matrices of coordination for adjusting the
length, tension, thickness, and rigidity of the vocal folds. the nerves that
supply the larynx are arranged so that there is a pacing of breathing movements
and oral movements to vocal fold movements.
There are many different types of problems that can occur with the structures
of the larynx. A familiar term is “vocal nodules.” A vocal nodule
is a little like a callous. The callous on the hand is more a build-up of
keratin and collagen cells. The nodule is a build-up of elastin cells. These
nodules stiffen the vocal folds and interfere with closure of the vocal folds.
They occur from increased collision forces during voice production. Another
structural problem of the vocal fold is vocal fold polyps. These are a little
like an abrasion blister. They are fluid filled masses that weight and restrict
the vocal folds and interfere with vocal fold closure. Airborne irritants
can contribute to their formation. Also, increased compression of the vocal
folds tends to create them. Vocal fold cysts are similar to cysts that can
occur on the skin. When these are quite small, little impact on the voice
is recognized. If they become enlarged, they adversely affect the vocal fold
on which they occur. Vocal fold hemorrhage is the acute rupture of one or
more capillaries on the surface of the vocal fold. The accumulated blood causes
the vocal fold to swell. Unless great care is taken in the early stages of
this problem, long term fibrotic thickening and scarring can seriously impair
voice production. Most incidents of acute laryngitis result from voice abuse
(extension loud yelling or screaming) or infection and inflammation of the
vocal folds. These should resolve quickly with a few days of voice rest.
Singing teachers and voice therapists have long appreciated the need to develop
control of the resonating/shaping structures to provide an environment in
which voice may be appropriately produced. The need to produce a variety of
consonants and vowels adds to the complexity of the task of voice production.
Simple uulation would provide the unimpeded resonance of voice and most likely
the purest, clearest voice, but with out the intelligibility of speech added
to song. The art of voice training seeks to solve this problem by devising
means to shape the resonating and articulating structures so as to provide
the clearest and best voice. Problems in the resonating structures can be
quite varied. An often problematic area is the soft palate and it's functioning.
With poor velopharyngeal (soft palate and throat wall muscles) closure during
phonation increased nasal resonance occurs. This can affect clarity and pleasantness
of vocal tone. On the other end of the spectrum lies decreased nasal resonance
with poor qualities noted in the voice. Mandible (lower jaw) movement and
mobility can also affect resonance. Limitations in movement can decrease the
resonating cavity size needed for louder, more intense voice production. Tongue
tension or weakness can adversely affect oral resonance and voice production.
Even minor speech articulation deficits can impact on voice production. Oral
skeletal and dental problems can also interfere with good voice resonance.
Often forgotten is that the teeth are the significant portion of the bony
support of the lower 1/3 of the face. Hence, good dental care can be part
of voice care.
For the avocational or professional voice user, whether for singing or speaking,
good training is essential. Ongoing training and practicing are the foundation
of good, long term voice functioning. Napoleon Hill, probably the first really
effective motivational speaker and sales trainer instructed his salesman and
students to practice reading aloud, with vigor, inspirational passages for
10 minutes every day. This is probably, good advice for performer.
Good
voice hygiene and care require several considerations:
*Adequate hydration is essential for vocal health. The vocal folds, the resonating
structures, and the lung tissues are all covered by mucosal membranes. They
like to be moist and warm. Good hydration aids the body in caring for these
structures.
*Avoid rigorous voice use with an upper respiratory infection or condition.
Too often, individuals try to perform with the vocal folds inflamed and in
poor physical conditions. Serious fold damage may result.
*Adequate warm-up drills should be a part of the singing and speaking regimen.
*Practice of good body posture and support helps to establish the best breathing
patterns.
*Young performers need caution in the use of the voice for performance. The
structure of the vocal folds are not mature and are not as durable as they
are for the adult mechanism.
*Develop a “front, forward” feel of the voice, as if speaking into
the “mask.”
*Use amplification when available, and as needed.
*Develop good speech articulation skills.
*When traveling, allow the voice to rest. Cars and plans are very noisy. Avoid
talking in those environments. This can cause you to speak too loudly and
intensely for lengthy periods of time.
*Limit caffeine consumption; it is a diuretic and dries out the mucosal linings
of the throat. When drinking caffeinated beverages, increase water intake
to help compensate.
*Develop a good mental image of voice production and anchor voice production
to good experiences.
Robert
B. Grider, M.S./C.C.C.
Minnesota Voice & Speech Clinic
(612) 929-1981