Overview of the Anatomy and Physiology of the Speech Production Mechanism

Question 1

Anatomy:

Answer 1

Anatomy: Study of structures of the body and relationship of the structures

Question 2

Physiology:

Answer 2

Study of the functions of organisms and bodily structures

Question 3

Three physiological subsystems are involved in speech production

Answer 3

Respiratory: Driving force for speech via positive air pressure beneath vocal folds
Laryngeal: Vocal fold vibrate at high speeds
Articulatory/resonatory: An acoustic filter that allows certain frequencies to pass while blocking others

Question 4

The Respiratory System

Answer 4

Primary biological functions
Supply oxygen to the blood
Remove excess carbon dioxide
Also the generating source for speech production

Question 5

Lungs:

Answer 5

Pair of air-filled elastic sacs that change in size and shape and allow us to breathe

Question 6

Trachea:

Answer 6

Air moves into the lungs via the trachea and branches into bronchi

Question 7

Structures of the Respiratory System

Answer 7

Pulmonary apparatus
Lungs: Pair of air-filled elastic sacs that change in size and shape and allow us to breathe
Trachea: Air moves into the lungs via the trachea and branches into bronchi
Pulmonary airways
Chest wall (thorax)
Rib cage
Abdominal wall
Abdominal content
Diaphragm

Question 8

Muscles of the Respiratory System

Answer 8

Inspiratory muscles – generally above the diaphragm
Expiratory muscles – generally below the diaphragm
Muscles of Inspiration

Question 9

Diaphragm

Answer 9

Principle muscle of inspiration
Dome-shaped structure composed of a thin, flat, nonelastic central tendon and broad rim of muscle fibers that radiate to the edges of the central tendon
Contracts during inspiration, pulling down and forward, increasing lung volume
Numerous thoracic and neck muscles also contribute

Question 10

Muscles of Expiration

Answer 10

Most important muscles of expiration are located in the front and sides of the abdomen
Assist the diaphragm’s movement back to its relaxed, dome-shape
Other muscles may be used depending on body position, pathological state, and environmental conditions

Question 11

Resting tidal breathing

Answer 11

Breathing to sustain life
Duration of inspiration and expiration is relatively equal

Question 12

Inspiration

Answer 12

Diaphragm contracts, rib cage and lungs expand, lung volume increases and alveolar pressure drops
Causes air to rush in and equalize with atmospheric pressure

Question 13

Expiration

Answer 13

Decrease in the size of the rib cage wall, compression of the lungs, increase in pressure in the lungs, air rushes out to achieve equilibrium with atmospheric pressure
Does not require active muscle contraction
A respiratory cycle is one inhalation and one exhalation

Question 14

Speech breathing

Answer 14

Contraction of diaphragm leads to rapid, forceful inspirations
Inspirations are much shorter than expirations
The amount of air inspired is greater than during resting tidal breathing
Inspiratory and expiratory muscles are both activated during speech

Question 15

Lifespan Issues of the Respiratory System

Answer 15

Resting tidal breathing rate decreases from birth to adulthood
More alveoli
Maximum lung capacity is reached in early adulthood
Constant until middle age
Respiratory function is affected by exercise, health, and smoking

Question 16

Larynx

Answer 16

Air valve composed of cartilages, muscles, and other tissue
Main sound generator for speech
Sits on top of the trachea and opens into the pharynx
Appears to be suspended from the hyoid bone, the point of attachment for laryngeal and tongue muscles

Question 17

The Laryngeal System

Answer 17

Primary biological function of the larynx
Prevent foreign objects from entering the trachea and lungs
Larynx can impound air for forceful expulsion of foreign objects threatening lower airways
Structures of the Laryngeal System

Question 18

Thyroid cartilage

Answer 18

Largest laryngeal cartilage
Forms the front and sides of the laryngeal skeleton and protects the inner components of the larynx

Question 19

Thyroid prominence

Answer 19

“Adam’s apple”; just below the thyroid notch

Question 20

Vocal folds

Answer 20

Attached at the front near the midline of the thyroid cartilage and at the back to the arytenoid cartilages via the vocal ligament
Abduct during respiration and adduct during phonation

Question 21

Glottis

Answer 21

The space between the vocal folds

Question 22

Thyroarytenoid muscle

Answer 22

Bulk of each vocal fold
Contraction shortens and thickens the vocal folds

Question 23

Cricoarytenoid muscle

Answer 23

Stiffens and lengthens the vocal folds, increases pitch

Question 24

Lateral cricoarytenoid and arytenoid muscles

Answer 24

Contraction results in vocal fold adduction

Question 25

Posterior cricoarytenoid muscle

Answer 25

Primary muscle of vocal fold abduction

Question 26

Lifespan Issues of the Laryngeal System

Answer 26

Larynx is small and high in the neck in newborns Reaches final position between 10 and 20 years of age Laryngeal cartilages increase in size and become less pliable Vocal folds increase in length differentially for males and females 29 mm for males; 21 mm for females Female laryngeal cartilage never completely ossifies Vocal folds atrophy and lose elasticity with age Men notice increase in pitch with advancing age Women experience decreased pitch with the contribution of hormone-related changes

Question 27

The Articulatory/Resonating System

Answer 27

Composed of Oral cavity Nasal cavity Pharyngeal cavity Vocal tract is a resonant acoustic tube Shapes sound energy produced by respiratory and laryngeal systems into speech sounds

Question 28

Mandible articulates with the temporal bone by the

Answer 28

Mandible articulates with the temporal bone by the temporomandibular joint

Question 29

Structures of the Articulatory/Resonating System

Answer 29

22 bones in the facial skeleton and cranium Mandible articulates with the temporal bone by the temporomandibular joint Teeth Tongue

Question 30

Teeth

Answer 30

Adults have 32 teeth within alveolar processes of the mandible and maxilla Hard palate is composed of the horizontal bones of the maxilla

Question 31

Tongue

Answer 31

Muscular hydrostat Structural support through contraction of muscles and has a soft skeleton of connective tissue

Question 32

Velum

Answer 32

Also called the soft palate Located in the pharynx Uvula: Termination of the velum Velopharyngeal closure Contact of the velum with the lateral and posterior pharyngeal walls

Question 33

Velar elevation

Answer 33

Necessary to prevent air or food escaping through the nose Necessary to build up air pressure for production of pressure sounds Air that escapes through the nose during speech results in a nasal quality

Question 34

Lifespan Issues of the Articulatory/Resonating System

Answer 34

Bones of the skull reach adult size by about age 8 Newborns have 45 separate skull bones that fuse into 22 at adulthood Lower facial bones reach adult size at about 18 years Dentition emerges at about 6 months and is complete around 3 years Secondary dentition is complete around 18 years A newborn’s tongue occupies most of the oral cavity Tongue reaches adult size by about 16 years of age By 2 months of age, infants can inconsistently close the velopharynx for syllable productions Consistent between 6 mos and 3 yrs Aging has minimal impact on velopharyngeal function for speech Length and volume of oral cavity increases Influences the overall resonant characteristics Lowers the frequencies at which the vocal tract naturally resonates

Question 35

Fundamental frequency

Answer 35

Fundamental frequency: Number of cycles of vocal fold vibration per second

Question 36

Harmonics

Answer 36

Harmonics: Whole number multiples of the fundamental frequency Movement of the tongue, lips, and larynx change the shape of the vocal tract and modify sound

Question 37

The Speech Production Process

Answer 37

Begins with phonation Air pressure builds up beneath adducted vocal folds (alveolar pressure) Air pressure from below displaces the lower edges of each vocal fold laterally Followed by lateral displacement of the upper edges Elastic properties results in vocal folds colliding Fundamental frequency: Number of cycles of vocal fold vibration per second Harmonics: Whole number multiples of the fundamental frequency Movement of the tongue, lips, and larynx change the shape of the vocal tract and modify sound

Question 38

Anterior view of the vocal folds

Answer 38

Anterior view of the vocal folds during one cycle of vibration. Air from the lungs creates pressure beneath the vocal folds (1, 2, and 3). This pressure causes the vocal folds to separate (4). The natural elastic restoring forces of the vocal folds and the time delay with respect to the upper and lower portions of the vocal folds causes the vocal folds to begin to close (5 and 6). The vocal folds close the glottis to end the cycle, and the next cycle begins (7).