Module 1 Speech Science Quiz + Short Answer Questions

According to Boyle's Law, if volume decreases from 52 units to 24 units, what happens to pressure? Show the applicable formula, indicate whether pressure increases or decreases, and calculate the specific factor by which pressure changes.

Boyle's Law states that: P1V1=P2V2P1​V1​=P2​V2​.  Pressure and volume are inversely related. Therefore, when volume decreases, pressure increases.The factor of change is: 52/24​=2.17.  Thus, pressure increases by a factor of approximately 2.17 (i.e., pressure becomes about 2.17 times greater than its original value).

To increase vocal pitch (fundamental frequency), indicate whether each of the following variables must increase or decrease Vocal fold length, Vocal fold tension and Vocal fold cross-sectional mass. Next, identify the muscle that lowers vocal pitch and describe the effect of its contraction on vocal fold length.

To increase pitch, the vocal folds become longer, thinner, and more tense. Vocal fold cross-sectional mass also influences pitch. Although the actual mass of the vocal folds does not change, the effective mass (the portion of the vocal folds participating in vibration) can change. Increased effective mass results in a lower pitch, whereas decreased effective mass results in a higher pitch. The thyroarytenoid (TA) muscle is activated to decrease pitch. Contraction of the TA muscle draws the thyroid and arytenoid cartilages closer together, thereby shortening the vocal folds, reducing their longitudinal tension, and lowering fundamental frequency (pitch).

Sit upright on the floor and breathe quietly. At the end of a normal expiration, close your airway (either by closing your larynx or by closing your mouth while plugging your nose). Lie back into a supine position and then reopen your airway. Repeat the activity while speaking a favorite phrase. In your own words, compare and contrast Upright versus supine positioning and Resting (tidal) breathing versus speech breathing. In your discussion, describe the respiratory mechanics involved in inhalation and exhalation, including the effects of gravity, lung volume, respiratory muscle activity, breath timing, and pressure generation.

When the airway is reopened in the supine position, inhalation may feel more effortful because gravity shifts the abdominal contents toward the thorax, elevating the diaphragm and reducing resting lung volume. In the upright position, gravity pulls the abdominal contents downward, allowing greater lung expansion and a larger resting lung volume. During both upright and supine breathing, the diaphragm remains the primary muscle of inspiration. However, body position alters the mechanical advantage of the respiratory system and the contribution of the rib cage and abdominal structures.

Compared with resting tidal breathing, speech breathing involves:

• Larger lung volume excursions.

• Rapid inspirations and prolonged, controlled expirations.

• Expirations that are linguistically driven and therefore variable in duration.

• Breath groups that are typically initiated at lung volumes above resting tidal breathing, often within the inspiratory reserve volume (IRV) range.

• Active expiratory control to maintain relatively constant subglottal pressure for speech production.

During inspiration, alveolar pressure falls below atmospheric pressure, allowing air to enter the lungs.

Describe the velopharyngeal configuration associated with production of /i/ ("ee"). How does this configuration differ from that expected during production of /ɑ/ ("ah")? Include discussion of velar height and velopharyngeal closure characteristics.

The probability of airtight closure favors high vowels (such as “ee” in peek) over low vowels (such as “a” in cat) (Moll, 1962). Whether or not airtight velopharyngeal closure is achieved, high vowels and low vowels contrast in still other ways. Compared with low vowel production, high vowel production is associated with: (a) greater velar height, (b) greater extent of velar contact with the posterior pharyngeal wall when the two surfaces are in apposition, and (c) smaller distance between the velum and the posterior pharyngeal wall when closure is not complete (Iglesias et al., 1980; Lubker, 1968; Moll, 1962). High vowel production also involves greater velopharyngeal sphincter compression (closing force) than low vowel production when velopharyngeal closure is complete (Gotto, 1977; Kuehn & Moon, 1998; Moon, Kuehn, & Huisman, 1994a; Nusbaum, Foly, & Wells, 1935).

How do we humans use our breathing and layrnx to increase loudness levels. Include what aerodynamic forces are involved, how the change in these aerodynamic forces is achieved, and what effect this has on vocal fold vibration.

The main mechanisms involved in increasing loudness are the changes made by the breathing apparatus and laryngeal apparatus. An increase in air speed through increased lung volume and muscular force leads to an increase in tracheal air pressure. Increased tracheal air pressure creates greater sound pressure levels in dB creating the increase in “loudness”. The laryngeal apparatus also helps to increase loudness by increasing pressures through intensifying lateral cricoarytenoid and arytenoid muscle contractions. This increase in laryngeal pressure help to support high tracheal air pressure. These two changes together make the vocal folds separate and return to midline faster. The reason this creates greater loudness is due to the Bernoulli effect. The Bernoulli effect states that the faster air moves across an item the lower the pressure below that item will be. In the human vocal tract, the faster air moves from our lungs out, the more negative the pressure on our vocal folds will be. This negative pressure creates a suction that pushes the vocal folds back together making them stay midline longer and with more force.

As children grow, anatomical changes occur that influence speech production. Describe the anatomical changes that affect velopharyngeal closure during speech AND those that affect pitch (fundamental frequency) throughout childhood and adolescence. Be sure to explain how growth and development contribute to the observed changes in speech production.

The nasopharyngeal tonsils (adenoids) enlarge during childhood and typically begin to atrophy after approximately 10 years of age. As the adenoids shrink, children usually adapt by modifying velopharyngeal function to maintain adequate closure during speech. However, children with insufficient velar tissue may experience difficulty achieving velopharyngeal closure as the adenoids regress. Similarly, surgical removal of the adenoids may temporarily affect velopharyngeal closure until the child adapts to the altered anatomy.

Fundamental frequency decreases throughout childhood as the larynx and vocal folds grow. At birth, average fundamental frequency is approximately 500 Hz and gradually declines to about 250 Hz by age 10. Before puberty, males and females have similar average fundamental frequencies. During adolescence, however, male fundamental frequency decreases more dramatically because of substantial laryngeal growth, increased vocal fold length and thickness, and changes in laryngeal anatomy, including a more acute thyroid cartilage angle. The lamina propria continues to mature through adolescence, contributing to development of the adult voice. As a result, adult males typically develop lower fundamental frequencies than adult females.