What is the total at rest length of the vocal folds for women? For men? 18 millimeters for women, 23 for men.
What is the average length of the vibrating portion of the vocal folds? 12-15 millimeters.
Why do we call them vocal folds instead of vocal cords? Because "fold" is a more accurate term. The vocal folds are small folds of tissue located at the top of the airway. They are not shaped like cords.
What are the vocal folds? ...small folds of tissue located at the top of the airway.
What do the vocal folds look like when viewed from above? Like a V, with the point of the V towards the front of the neck and the opening at the back. When the folds adduct, the sides of the V close together.
What is the thin layer of skin cells on the VFs called? What do these 3 terms mean? stratifies (become progressively larger toward the bottom layer) squamous (interlock like paving stones) epithelium (skin cells).
This area has another name. What is it and why is it called this? It is the cover because it is the outermost layer of the folds.
What is unique about this layer of skin (covering the VFs) as opposed to the rest of the epithelium of the vocal tract? It is the only portion that is squamous epithelium, as the rest of the airway is coated by columnar epithelium. It is also the only area that is not ciliated (not covered in microscopic hair).
What makes up the body of the vocal folds? The thyroarytenoid muscle.
What is the transitional layer called? Describe it. The lamina propria is made up of elastin and collagen fibers that varies in composition creating three distinct layers. The superficial layer (anchored to the epithelium through the basement membrane) is the smallest and most viscous layer. The intermediate layer is larger and more viscous. The vocal ligament runs through it. The deep layer of the lamina propria is the densest and most viscous (the consistency of a gummi bear).
How is the structure of the vocal folds like both the back and the palm of your hand? The cover is allowed to move freely, like the skin on the back of your hand, but the lamina propria also cussions the folds and acts as a shock absorber, like the tissue of the palm of your hand.
Describe the steps of a single cycle of vibration according to the Myoelastic-Aerodynamic Model.
1. The vocal folds are gently closed by muscular forces within the larynx.
2. Air pressure increases beneath the closed glottis.
3. Increased air pressure begins to open the glottis. Because of the ability of the cover to move independently of the body, this opening begins on the underside of the glottis.
4. The glottis continues to open, from bottom to top, until air begins to escape.
5. As the air begins to flow through the glottis, its velocity increases and its pressure decreases, as explained by the Bernoilli Effect.
6.Elasticity of the vocal fold acts somewhat like a spring, exerting a return force that begins to close the glottis; negative pressure caused by the Bernoilli effect supplies additional closing force.
7. The glottis closes again, from bottom to top.
8. As soon as the glottis is fully closed, the process begins again, repeating as many times per second as the frequency of the pitch being spoken or sung.
What is vertical phase difference? Why is this important to vocal sound? It describes the nature of the vocal fold adduction, in that it closes in portions, but never all at once. Like a wave motion. I do not know. yet.
Are aerodynamic factors sufficient to maintain vocal fold oscillation? No.
Describe the steps of VF oscillation according to the one-mass model. The glottis is initially closed by the muscles of the larynx. Subglottal air pressure increases until it overcomes the resistence of VF muscles and tissues and opens the glottis. Reduced air pressure through the glottis and elasticity of the vocal folds brings the glottis back together, reducing the flow of air. Air above the glottis continues its forward motion, leaving a space above the glottis of low air pressure. The combination of elastic recoil, the dropping pressure through the glottis, and the low pressure region above the glottis completes the cycle - closing the glottis. Asymmetry of air pressure below and above the glottis allows vocal fold oscillation to continue for as many times per second as the fundamental of the pitch spoken or sung.
Describe the improvements in understanding VF oscillation because of the 3-mass model. The three mass model takes into account the independent properties of the three masses of the vocal folds (body, cover, cover) and describes it's effect on air pressure.
What is the neurochronaxic theory? If it valid? It states that nerve impulses from the brain are responsible for the oscillation of the vocal folds, and that the role air flow plays is merely to carry the sound out of the body. It has been discredited scientifically.
Name the 5 cartilages that form the basic laryngeal framework. Thyroid, Cricoid, Arytenoids, Epiglottis.
Name and describe the membranes and ligaments found within the larynx. The thyrohyoid membrane connects the thyroid cartilage to the hyoid bone above. The cricothyroid membrane and ligament connect the cricoid cartilage to the thyroid in a similar fassion. The conus elasticus is a membrane that lines the inside of the cricoid.
Describe the aryepiglottic fold. What is its alternate name? What is its function?
The aryepiglottis encircles the epiglottis and the arytenoids, creating a kind of collar that helps close the epiglottis. It is also called the laryngeal collar and the epilarynx.
What is the purpose of the vocal ligament?
The vocal ligaments stretch from the thyroid to the arytenoids and add
strength to the vocal folds as well as preventing them from being
stretched too far.
What is the function of the aryepiglottic and the thyroepiglottic muscles for singing? They contract slightly, tipping the epiglottis back and tightening to enhance the singer's formant.
What is phonation threshold pressure (PTP)? The pressure required to overcome the resistance of glottal adduction and initiate vocal fold oscillation.
What are the 3 principle types of vocal onset? Describe how they differ in terms of the sequence of adduction and airflow. A glottal onset occurs when strong adduction precedes breath energy. An aspirate onset is breathy and soft and occurs when breath flow is started and the vocal folds are slowly adducted into the already moving air. The goal is a balanced (simultaneous) onset, where adduction and airflow begin at precisely the same instant.
What is flow phonation? Flow "mode" phonation is a balance between airflow and adductory tension.
What happens if we increase breath pressure with constant adductory tension? It gets louder, but also goes sharp and tight and breathy.
What happens is you increase glottal resistance at the same time as you increase breath pressure? Amplitude of sound waves increases.
As amplitude increases, how does this affect the glottis? What happens to help this situation?It is closed more often than open.
How do we increase vocal fold thickness, and what affect does this have on the sound? The thyroaryteniod muscle contracts and shortens and thickens the vocal folds.
What is the typical dynamic range for dramatic voices? What was maximum amplitude for these singers? 60-64 dB. max is 120 dB.
How does the dynamic range and maximum amplitude of lighter voiced singers compare? the range is the same, but the maximum amplitude is lower in lighter voices.
How do pitch and amplitude relate to each other? Higher pitches can be sung at a higher amplitude.
How is the time that the glottis remains open impacted by adduction and pressure changes? The glottis will be open for a larger portion of the time if there is more air pressure. If the adduction increases then there will be less open time.
What is the estimated times of the various phases in q quiet tone vs a louder tone? Open for 50%, transitioning for 37%, and closed for 13% in loud singing, and open for 33%, transitioning for 37% still, and closed for 30%.
What is the open quotient? The amount of time the glottis is open during each cycle.
How does the open quotient relate to amplitude? The most amplitude is found around 0.5 or 0.6.
Why is it wrong to just blow harder to get louder? Because the pitch will be affected, you will loose air, and it's dumb.
In very general terms, what must the vocal folds do to change pitch? They must oscillate at a higher frequency. Elongated for pitch to ascend, and shortened for pitch to descend.
How does the body/cover model affect pitch change? In higher pitches, only the edges of the cover may be adducting. In the low range, the entire fold tends to oscillate.
How do pitch and intensity overlap in terms of vocal fold function? Because the folds need to be long for high pitches, and thick for loud pitches.
How do the CT and TA work together to control pitch and amplitude? The CT lengthens the folds to the appropriate tension, and the TA thickens them.
Describe how variations in air pressure have different impacts on low vs. high frequencies. They have a higher impact on low pitches than on high pitches.
Describe the inferior pharyngeal constrictor muscles connection to the larynx. Describe its function. It connects to the thyroid cartilage and wraps around the esophogus and the base of the larynx. When it contracts it raises the larynx and narrows the pharynx.
What is ossification? The gradual transformation of cartilage to bone.
What is the downside of the flexibility of the thyroid cartilage in young people. Vocal instability and unpredictability.
Describe the actions of swallowing The larynx elevates sharply, the epiglottis folds over the larynx, the soft palate raises to close off the nasal passageway, the walls of the pharynx constrict and the tongue raises to guide the food down into the esophagus.
Describe the pharyngeal constrictor muscles. The superior constrictor wraps around the top of the vocal tract in the area of the nose, mouth, and jaw. The middle constrictor connects to the hyoid and the stylohyoid process. The inferior constrictor attaches the throid laminae and the cricoid cartilage. The upper two constrict to push food down. The lowest raises the larynx.
What doe gola aperta mean?open throat.
How do we open the throat? We must release the tension in the muscles of the throat. They cannot constrict open - they only close. Release!
What are the two ways in which laryngeal elevation can occur? It is lifted directly through an attachment to the thyroid or cricoid cartilages, or it is lifted indirectly through the hyoid bone.
Which structures is the hyoid connected to? The larynx, tongue, and jaw.
Besides the inferior pharyngeal constrictor, what is the other true laryngeal elevator? Describe its function. They thyrohyoid muscles. It raises the larynx and closes the space between the thyroid and hyoid.
Which muscles are indirect laryngeal elevators? digastric, stylohyoid, mylohyoid, geniohyoid, genioglossus.
If the muscles that close the jaw (masseter, temporalis, medial pterygoid) fail to release when the jaw is opened, what if the effect of the contraction of the anterior belly of the digastric? It raises the larynx as well.
Which muscles can both depress the jaw and raise the larynx? The digastric muscle for one, and some other ones too.
Which muscles are laryngeal depressors? Sternothyoid, sternohyoid, omohyoid.
What is the ideal laryngeal position for classical singing? There is disagreement on this, but the author suggests that the larynx should stay at or slightly below its natural resting position.
How does the vertical position of the larynx change as we age? Be specific. At birth it is level with C3. By age 5 it is level with C5. During puberty it lowers to C7, and lowers a little more than that as we age.
What is tracheal pull (tug)? As the diaphragm descends in inhalation, the trachea pulls down very slightly, and the larynx comes down with it
Which nerves serve the larynx? The vegus nerve! Ha!
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