Anatomy & Physiology

Question 1

Whats considered Level 1 of the vocal tract?

Answer 1

is the vocal cord level. This is where ‘creak’, ’creaking’ ‘air added to the voice’, and ‘hammer vibrato’ are produced.

Question 2

Whats considered Level 2 of the vocal tract?

Answer 2

is the level of the ventricular (false) folds. This is where ‘distortion’ is produced.

Question 3

Whats considered Level 3 of the vocal tract?

Answer 3

is the level of the arytenoid cartilages/cuneiform, epiglottis and aryepiglottic folds. This is where ‘arytenoid rattle’, ‘saliva rattle’ and ‘growl’ are produced.

Question 4

Whats considered Level 4 of the vocal tract?

Answer 4

is the level of the piriform fossa and posterior pharyngeal wall of the hypopharynx.

Question 5

Whats considered Level 5 of the vocal tract?

Answer 5

is the level of the soft palate, uvula, back wall of the throat (oropharynx) and the back of the tongue. This is where the ‘uvula rattle’ and ‘back tongue rattle’ are produced.

Question 6

Whats considered Level 6 of the vocal tract?

Answer 6

is the rest of the vocal tract (oral and nasal cavity). This is where the vowels and sound colour are produced. ‘Grunt’, ‘Scream’, ‘Vocal breaks’ and ‘Laryngeal vibrato’ are produced in a combination of various levels.

Question 7

We gave the various parts in the vocal tract levels in order to identify and specify on which levels the various changes take place. The levels also make it easier to communicate where the changes take places.

Answer 7

Question 8

Describe vocal cords

Answer 8

Some describe the vocal cord as consisting of two parts: 1) the membranous part anteriorly which is the part that vibrates and produces sound; 2) the cartilaginous or respiratory part posteriorly which is simply the mmucous membrane over the medial surface of the arytenoid cartilage.

Question 9

Describe false cords

Answer 9

Also known as false cord or ventricular band. They are placed just above each vocal fold separated by a little crevice known as the ventricle. The false folds consist of outer lining of mucous membrane which encloses a band of fibrous tissue known as the quadrangular membrane. The false folds also contain fat and some muscle, the upper fibres throarytenoid muscle that insert into the epiglottis rather than the arytenoid cartilage sometimes known as the thyroepiglotticus.

Question 10

Describe Arytenoid cartilages

Answer 10

These are paired pyramidal shaped cartilages that are attached to the sloping superior border of the posterior lamina of the cricoid cartilage via the cricoarytenoid joint by a complex of muscles and ligaments. The positioning of the arytenoid cartilages play an important role in regulating pitch as well as the opening and closing of the vocal folds. Each cartilage has an apex, a base, an anterolateral surface, a vocal process and lateral muscular process. The corniculate cartilage is attached to the apex. The base forms the upper surface of the cricoarytenoid joint. The vocal ligament is attached to the anterior vocal process while the quadrangular membrane is attached to the roughened anterolateral aspect. The posterior cricoarytenoid muscle, thyroarytenoid muscle and lateral cricoarytenoid muscles are attached to the muscular process. The interarytenoid muscle inserts into the posterior surface of the arytenoid cartilage which is triangular, smooth and concave.

Question 11

Describe Cuneiform cartilages?

Answer 11

A piece of cartilage shaped like an ice cream cone placed in the posterior part of the aryepiglottic fold. They appear yellowy-white or cream coloured on endoscopic examination of the larynx. They are often mistaken for the arytenoid cartilages (they sit just in front of them). They probably help provide stiffness and control of the shape of the epiglottic funnel.

Question 12

Describe Epiglottis

Answer 12

Flap of fibrocartilage that covers the entrance to the larynx helping prevent food and drink entering the trachea. It is one of nine cartilages that make up the larynx. The free upper part is broad and rounded. The lower, narrow part is attached to the angle formed by the two laminæ of the thyroid cartilage, a short distance below the superior thyroid notch, by the thyroepiglottic ligament. The lower part of its anterior surface is connected to the upper border of the body of the hyoid bone by an elastic ligamentous band, the hyoepiglottic ligament. The bulging posterior part of the inferior part of the epiglottis is known as the petiole. the epiglottis is normally pointed upward when breathing, speaking or singing rises during swallowing with the elevation of the hyoid bone moving to a more horizontal position and pointing backwards.

Question 13

Describe the aryepiglottic folds

Answer 13

The aryepiglottic fold is a fold of mucosa forming the lateral border of the laryngeal inlet. It stretches from the apex of the arytenoid cartilage to the epiglottis. The corniculate cartilage and cuneiform cartilages lie under the surface of the free edge posteriorly stiffen and helping shape the upper rim of the epiglottic funnelknown as the laryngeal inlet. The fold contains the thin sheets of muscles: the aryepiglotticus and thethyroepiglotticus. The aryepiglottic fold forms the lateral border of the larynx separating it from the piriform fossa of the hypopharynx.

Question 14

Describe the the piriform sinus

Answer 14

Also known as the piriform sinus (and sometimes wrongly spelt “pyriform”).The two piriform fossae (sinuses) are pear-shaped recesses on either side of the laryngeal inlet with the wider part anteriorly. Each has a medial wall formed by the aryepiglottic fold and an outer wall by the inner part of the thyroid cartilage and thyrohyoid membrane. There function is to provide channels for food to pass down during swallowing and the space within the fossa acts as a resonating chamber during speech and singing.

Question 15

Describe the posterior pharyngeal wall

Answer 15

This is part of the hyopharynx. It forms the back wall of the throat from the level of the hyoid bone to the postcricoid region. It’s muscular walls are formed by the middle constrictor muscles which are attached anteriorly to the hyoid bone and stylohoid ligament and the thyrohyoid inferior constrictors which are attached anteriorly to the thyroid cartilage and cricoid cartilages forming a sling around the laryngopharynx.

Question 16

Describe the hyopharynx

Answer 16

The hyopharynx is the funnel-shaped part of the throat on either side of the larynx stretching between the hyoid bone and joining the upper oesophagus at the level of the cricoid cartilage. It consists of three parts (subsites): the two piriform fossae, the posterior pharyngeal wall and the postcricoid region. Air passes through the upper part into the larynx and food also passes through the area into the oesophagus. Sound waves produced by the larynx resonate in this area to produce a dark sound colour. It is more open in the Neutral and Curbing and completely closed off in Edge.

Question 17

Describe the soft palate

Answer 17

(or Velum palatinum) The fleshy movable part of the back of the roof of the mouth that closes off the nasopharynx during swallowing and speech. The central back part that hangs down is known as the uvula.

Question 18

Describe the oropharynx

Answer 18

The oropharynx is part of the pharynx behind the oral cavity. It extends from the level of the soft palate to the level of the hyoid bone.

Question 19

Describe the nasopharynx

Answer 19

the region between the soft palate and the back of the nasal cavities

Question 20

What 3 parts does the pharynx consist of?

Answer 20

1. nasopharynx the region between the soft palate and the back of the nasal cavities
2. oropharynx the region between the soft palate and the hyoid bone
3. hypopharynx, the region between the hyoid bone and the vocal folds.

Question 21

Name the three important functions that the throat performs

Answer 21

1. swallowing
2. forming an air passage between the nose, mouth and larynx
3. shaping of the vocal tract for voice.

Question 22

Explain the Swallowing function

Answer 22

During swallowing it is of course important that food does not enter the windpipe. Once food has been chewed in the mouth the bolus is pushed backwards by the tongue into the back of the throat (oropharynx). To prevent the food bolus going into the nose the soft palate rises and the superior constrictor muscle contracts sealing off the nasopharynx. Together with the middle and inferior constrictor muscles it also helps propel the food bolus towards the oesophagus. The vocal folds and false cords close tightly together and the whole larynx rises upwards. The epiglottis tilts backwards forming a lid over the larynx preventing food going into the windpipe and helping direct it into the oesophagus. At the same time the upper oesophageal sphincter relaxes allowing the bolus to move from the pharynx into the oesophagus where a series of contractions propel it downwards into the stomach. Once the food has been swallowed the upper oesophageal sphincter closes off the top of the gullet so that food cannot be regurgitated back into the mouth. If you speak and eat at the same time food can easily go down the wrong way!

Question 23

Explain the Air Passage function

Answer 23

Air can be breathed in through the nose or mouth. When passing through the nose the air is filtered from particles such as dust and pollen and also humidified and warmed. It also allows breathing while chewing food. However when large amounts of air are required such as during exercise it is necessary to breath through the mouth. We change between nose and mouth breathing subconsciously at rest or when talking. Mouth breathing tends to dry out the vocal cords a little more but it is sometimes necessary to get enough air in rapidly before singing the next phrase.

Question 24

Explain shaping the vocal tract function

Answer 24

The voice is produced by the interaction of the sound produced by vibration of the vocal folds with the acoustic resonance of the vocal tract. Shaping the vocal tract by moving the lips, positioning the tonguein the mouth and oropharynx , moving the larynx up and down alters the vowel sounds and allows consonant sounds to be made for speech and singing. Lowering the larynx generally produces a darker sound colour while raising it causes a lighter sound colour. There are named constrictor muscles (superior, middle and inferior constrictor muscles) but there are many other ‘constrictor muscles’ in the neck such as the extrinsic laryngeal muscles which also help in the constriction and laryngeal positioning because of there attachment to the jawbone, base of the skull, sternum and collar bone. The intrinsic laryngeal muscles are the muscles within the larynx which open and close the vocal cords and alter the shape of the vocal folds so that the pitch, loudness and vocal mode can be changed.

Question 25

Explain the constrictor muscles

Answer 25

The ‘constrictor muscles’ that shape the vocal tract are very useful and also protect the vocal folds if a singer is exposed to great strain. The throat constricts if, for example, we lift something heavy or become emotional or frightened. Constriction of the throat is quite practical when we lift something heavy, because it prevents a strain on the vocal folds, but it is very impractical to constrict uncontrolled around the voice when we sing as the vocal folds must have room to stretch. Thus, we talk about uncontrolled constriction of the throat being the singer’s main enemy, not constriction or the constrictor muscles themselves. It is not difficult for the vocal folds to stretch or slacken, but it becomes difficult if the movement is obstructed. An obstruction is any uncontrolled constriction that prevents the vocal folds from stretching, thereby making it difficult to reach higher notes. A singer will try even harder to reach the note, often worsening the uncontrolled constriction. Eventually the vocal folds will not stretch at all. The singer may conclude, ‘I have a low voice, I am unable to reach the high notes’ but this is not the case! The reason why the high notes fail is not a lack of vocal ability to reach high notes but uncontrolled constriction around the vocal folds, robbing them of the space required for them to work, which is to stretch in order to reach the high notes. The ‘constrictor muscles’ of the throat contribute to this uncontrolled constriction.

Question 26

Explain how to avoid uncontrolled constriction

Answer 26

Singing requires physical strength but this can also cause uncontrolled constriction of the throat. We must therefore, by correct technique, trick the constrictor muscles in the throat into not constricting uncontrolledly even when we sing technically difficult and physically demanding material. This is often called keeping an ‘open throat’. To be precise, it is not possible to ‘open’ the throat, it is only possible to avoid constricting it. When the uncontrolled constriction is gone the stretching of the vocal folds is unhindered, the pitch is secure, and wear or fatigue of the vocal folds is avoided. Basically, singing techniques are about avoiding uncontrolled constriction, and this is obtained by using support, amongst other things. With efficient, solid support we can use lots of physical strength without uncontrolled constriction in the throat. A skilled singer knows the feeling of uncontrolled constriction and is able to avoid it in all situations.

Question 27

The anatomy of the Larynx

Answer 27

The larynx consists of numerous parts. The thyroid cartilage, positioned around the front of the vocal folds, serves to protect them and creates the pointed structure you can feel in the front of your neck (the ‘Adam’s apple’). Inside this pointed structure, the vocal folds are attached together at the front. They are positioned above and across the windpipe. At the back, the two vocal folds are each attached to anarytenoid cartilage. The arytenoid cartilages sit on the rim of the cricoid cartilage which is the top of the windpipe. It is, in fact, the arytenoid cartilages that move from side to side, opening the vocal folds when we breathe, or closing them when we speak or sing. The arytenoid cartilages are also able to tilt up or down, thereby altering the length of the vocal folds. When the vocal folds are stretched and lengthened the pitch is raised. Above the vocal folds are the false folds (ventricular folds).They consist of ligaments, muscles and glands. Outside this is a cover of mucous membrane like the rest of the inside of the body. This mucous membrane is not as flexible as that of the true vocal folds. The epiglottis is attached to the back of the thyroid cartilage at the angle just below the notch (superior thyroid notch) and above the vocal folds. When we swallow, food slides down over the tongue and the epiglottis tilts backwards. This helps prevent food passing into the trachea (windpipe) which would cause us to choke. Once the food has passed through, the epiglottis returns to its original position, standing up from the thyroid cartilage. The hyoid bone is positioned at the very top, attached to the thyroid cartilage (the hyoid bone is not shown on the figure above).

Question 28

What is sound?

Answer 28

Sound is vibration or pulsation of air. The faster these pulsations are, the higher the pitch. Pitch is defined by the number of pulsations per second, also known as Hertz (Hz). It is the vocal folds and their mucous membranes that create the pulsations with which we speak or sing. The note A4 is equal to 440 Hz, so to sing A4 the mucous membranes of the vocal folds must vibrate 440 times every second you sing this note!

Question 29

Explain the vibrations of the vocal fold and volume

Answer 29

Each vocal fold consists of a vocal ligament which is lined by a moveable mucous membrane. This membrane creates sound through its rapid opening and closing movements (vibratory cycle), creating vibrations in the air or sound waves. The larger the vibrations of the air, the more powerful the volume.

Question 30

Explain the vibratory cycles in detail

Answer 30

The vocal folds form a narrowing of the air passage (a). When the air stream passes through this narrowing, a partial vacuum is created, thus bringing together the membranes of the vocal folds (b-d). (The same effect occurs when a bus passes you at great speed, you can get sucked in behind it). The movement where the membranes close is called the ‘closed phase’ (e-i). The closed phase begins with a suction movement at the bottom edge of the vocal folds and moves upwards in a rolling motion. In the closed phase the flow of exhaled air is momentarily stopped which creates an increase in pressure beneath the vocal folds. The upwards rolling motion ends with the vocal folds separating when the pressure is released (j). Now the cords have completed one pulsation/vibration orvibratory cycle and are ready for the next one. This repeated interruption of the air stream by the mucous membranes coming together creates a series of pulsations known as a ‘sound wave’. For the note A4 the mucous membrane vibrates at 440 pulsations per second, and this requires a very stable speed of the airflow. By increasing the airflow, thevacuum strengthens and the mucous membranes go into bigger movements – this creates bigger volume. If a singer at a certain point exhales so strongly that it is forcing the membranes apart, it will consequently impair the refined vibration, so to obtain a note the singer has to bring the cords together by uncontrolled constriction. Now the singer gets into problems. The uncontrolled constriction limits the movement of the cords which thereby limits the volume. This is what is called ‘forcing’ the voice and causes much damage. Consequently there is a limit to how fast the air should be let out while singing. Above this limit the voice does not work efficiently. Even at very powerful volumes the speed of the air stream should not be so fast that it no longer feels like you are holding back the air. This is why correct singing and speaking always has the sensation of holding back the air. This control of the exhalation is achieved by using support. To keep the speed of the air within the range where the vocal folds can move freely is a balancing act and requires support energy. This is even more applicable when you reach the extreme ranges of voice and volume. On very powerful tones the danger of ‘forcing’ is great. On very quiet tones it is often more difficult to avoid uncontrolled constriction, and here even a minor change in the speed of the air may interrupt the small vibrations. So the work of supporting powerful and quiet tones is both physically and technically demanding. It is not enough for the singer to be technically skilled, s/he should also be in excellent physical shape and have great stamina.

Question 31

Explain uncontrolled constriction

Answer 31

The work of the vocal folds is a very refined process and it does not take much to spoil these delicate, rapid movements. The aim for singers is to give their vocal folds the best possible working conditions, by controlling the outflow of air and preventing uncontrolled constriction in the throat. A solid support technique is vital otherwise the membranes of the vocal folds grow weary from the constant pressure of out-flowing air. A consequence of this might be tired, swollen vocal folds vibrating irregularly. It is very strenuous for the muscles of the vocal folds to keep them together while there is constant pressure from out-flowing air. This could lead to uncontrolled constriction around the vocal folds. This uncontrolled constriction might lead to straining or incorrect use of the vocal modes which eventually causes hoarseness and an inability to reach a desired pitch.

Question 32

Explain the regulation of the pitch

Answer 32

When we produce high and low notes the vocal folds are tightened and relaxed by the thyroid cartilageand the cricoid cartilage approaching each other, and the movements of the arytenoid cartilages and a number of muscles. When the vocal folds are stretched they vibrate more rapidly and produce a higher note. On low notes the vocal folds are relaxed, become short, and vibrate more slowly. This is how pitch is regulated.

Question 33

Explain the movements of the larynx

Answer 33

The position of the larynx varies depending on whether you are producing high or low notes. If you want free and unhindered notes you MUST allow the larynx to rise on the high notes and to lower on the low notes. The larynx will always to some extend be raised on high notes and lowered on lower notes. If a singer maintains the larynx in a much too low position, high notes become unreachable. In order to reach the notes you want, it is essential NOT to fix the position of the larynx but to let it reach the right position for the pitch. Then later you can raise or lower the larynx a little within the right position for the pitch, in order to colour the sound lighter or darker.

Question 34

Summarize the vocal process

Answer 34

The vocal folds are positioned inside the larynx above the windpipe. When we inhale the cords separate, but when we sing or speak they are pulled together. Sound is vibration of the air. It is the vocal folds and their mucous membranes which make these vibrations; the faster the vibrations, the higher the note. For example at the note A4 our vocal folds and their mucous membranes are vibrating 440 times every second! The vocal folds stretch on high notes and relax on low notes. The larynx rises on high notes and lowers on low notes.