7. Voice and Its Disorders Flashcards Preview

PRAXIS > 7. Voice and Its Disorders > Flashcards

Flashcards in 7. Voice and Its Disorders Deck (72)
Loading flashcards...

Larynx (and VFs): Basic Principles

*Valve located at top of trachea
*Helps close entry into trachea so food, liquids, and particles do not enter lungs
*Houses VFs (opening bet. VFs is "glottis")
*VFs composed of layers: epithelium, the TA muscle, and lamina propria; Cover-body theory of phonation...
*Ventricular/false VFs lie above true VFs
*Aryepiglottic folds lie above ventricular folds; They separate the pharynx and laryngeal vestibule and help preserve airway
CN X: primary CN involved in laryngeal innervation (main branches: SLN and RLN)


Superior Laryngeal Nerve (SLN) and Recurrent Laryngeal Nerve (RLN)

SLN: internal branch: provides all sensory info to larynx; external branch: provides motor innervation to the cricothyroid muscle

RLN: supplies all motor innervation to interarytenoid, posterior cricoarytenoid, thyroarytenoid, and lateral cricoarytenoid muscles; Supplies all sensory info below VFs; If lesion to RLN, pt may experience diff. adducting VFs


Key Laryngeal Structures and Cartilages (9)

Hyoid bone
Thyroid cartilage
Cricoid cartilage
Arytenoid cartilage
Corniculate cartilages
Cuneiform cartilages
Intrinsic laryngeal muscles
Extrinisic laryngeal muscles


Hyoid Bone

*Larynx suspended from hyoid
*Many extrinisic laryngeal muscles are attached to hyoid



*Leaf-shaped cartilage
*Attached to hyoid
*Protects trachea by closing down inferiorly and posteriorly over laryngeal area, directing liquids and food into esophagus during swallowing


Thyroid Cartilage ("Adam's Apple")

*Largest laryngeal cartilage
*Shields other laryngeal structures from damage


Cricoid Cartilage

*Second largest laryngeal cartilage
*Completely surrounds trachea
*Linked with the paired arytenoid cartilages and the thyroid cartilage


Arytenoid Cartilages

*Positioned on the cricoid cartilage on either side of the midline
*Shaped like pyramids
*Vocal processes are the most anterior angle of the base of the arytenoids; True VFs attach at the vocal processes


Corniculate and Cuneiform Cartilages

Corniculate: Sit on apex of arytenoids; small, cone-shaped

Cuneiform: Tiny, cone-shaped cartilage pieces under mucous membrane that covers aryepiglottic folds


Intrinsic Laryngeal Muscles

*These pairs of muscles have both attachments to structures within larynx
*Primarily responsible for controlling vocalization
*With one exception (PCAs), all are adductors


Intrinsic Laryngeal Muscles (6)

Posterior cricoarytenoids (only abductors)
Lateral cricoarytenoids
Transverse arytenoids
Oblique arytenoids


Extrinsic Laryngeal Muscles

*One attachment to structure outside larynx and one within larynx
*All extrinisic laryngeal muscles attached to hyoid
*Elevate or lower position of larynx in neck; Give larynx fixed support
*Infrahyoids: "depressors"; depress laryx; impact pitch
*Suprahyoids: "elevators"; elevate larynx


Extrinisic Laryngeal Muscles: Infrahyoids (4) and Suprahyoids (6)

Infrahyoids: Thyrohyoids, Omohyoids, Sternothyroids, Sternohyoids

Suprahyoids: Digastrics, Geniohyoids, Mylohyoids, Stylohyoids


Age-Related Changes in the Larnx

*Hardening of laryngeal cartilages
*Degeneration and atrophy of intrinsic laryngeal muscles
*Degeneration of glands in laryngeal mucosa
*Degenerative changes in lamina propria
*Deterioation of cricoarytenoid joint
*Degenerative changes in conus elasticus

*These changes lead to "presbyphonia," an age-related voice disorder characterized by perceptual changes in quality, range, volume/loudness, and pitch



*Perceptual correlate of frequency; Largely based on the frequency with which the VFs vibrate; This rate is often called the fundamental frequency(habitual pitch)
*Determined by mass, tension, and elasticity of VFs
*Higher pitch results when VFs are thinner, more tense, or both; Lower pitch results when the VFs are thicker, more relaxed, or both


Pitch: Frequency Perturbation/Jitter

*Are variations in vocal frequency that are often heard in dysphonic patients
*Measured instrumentally as a pt sustains vowel; useful in early detection of vocal pathology
*Pts w/ voice probs (e.g., tremor, hoarseness) might show a large amount of jitter
*People with no laryngeal pathology can sustain a vowel with less than 1% jitter



*Perceptual correlate of intensity; Determined by intensity of sound signal; Greater intensity means greater perceived loudness
*Sound is disturbance in air particles; it takes the form of waves that more forward and backward in mediums (e.g., air, water); "Amplitude" is extent of such movements; Greater the amplitude, the louder the voice


Volume: Amplitude Perturbation/Shimmer

*Cycle-to-cycle variation of vocal intensity
*Measured instrumentally as pt sustains vowel; useful in early detection of vocal pathology
*Speaker w/ no laryngeal pathology has very small amount of variation in intensity w/ each vibratory cycle
*Pts who have difficulty with regularity of VF vibration (e.g., roughness) may show large amounts of shimmer



Perceptual correlate of complexity; Refers to the physical complexity of the laryngeal tone, which is modified by resonating cavities; Determination of vocal quality is frequently subjective


Quality Types: Hoarseness and Harshness

*Hoarseness: combo of breathiness and harshness, which results from irregualr/aperiodic VF vibrations, which also lead to variation in F0
*Harshness: rough and "gravelly;" associated with excessive muscular tension and effort; VFs adducted too tightly and air is released too abruptly


Quality Types: Strain-Struggle and Breathiness

*Strain-struggle: phonation is effortful; sounds like "squeezing" voice at glottal level; initiating and sustaining phonation is difficult; talking fatigues; experience tension when speaking

*Breathiness: results from VFs being slightly open and air escapes through glottis and adds noise to the sound produced by VFs; Often feel like running out of air; Often soft, little variation in loudness, and restricted vocal range; May be due to organic (physical) or nonorganic (functional) causes


Quality Types: Glottal/Vocal Fry

*When VFs vibrate very slowly
*Low-pitch, "crackly"
*Usu. at end of utterance when air flow rate and subglottal air pressure are low and lung volume is less
*For some pts, glottal fry may help modify vocal quality problems such as stridency
*Other patients work to eliminate vocal fry by slightly increasing subglottal aur pressure and slightly elevating their pitch level


Quality Types: Diplophonia and Stridency

*Diplophonia: "Double voice;" Occurs when one can simultaneously perceive two distinct pitches during phonation; Usu. occurs when VFs vibrate at different frequencies due to different degrees of mass or tension; Ct with unilateral polyp, for example, may sound diplophonic

*Stridency: Shrill, somewhat high pitched, and "tinny;" Often caused by hypertonicity or tension of the pharyngeal constrictors and elevation of larynx; Tense pts may sound strident


Case History: The Clinician Needs To...

*Remember: a multidisciplinary, team-oritented approach is critical through evaluation

*Obtain info re: onset, duration, causes, variability of probs (ask pt and significant others)
*Obtain info re: any associated symptoms/probs (e.g., slurred speech, diff. swallowing, excessive coughing)
*ID factors (e.g., health, environ, fam hx) that may contribute to problem
*Gather info re: prev. tx, med. intervention, or other attempts to deal with voice prob
*Obtain descriptions of daily vocal use and possible abuse or misuse patterns (ask pt and sig. others)
**For culturally and linguisitically diverse cts: obtain specific perceptions of what constitutes "typical-sounding" voice in their culture


Instrumental Evaluation (9)

*Indirect Laryngoscopy (Mirror Laryngoscopy)
*Direct Laryngoscopy
*Flexible Fiber-Optic Laryngoscopy
*Acoustic Analysis
*Electroglottography (EGG)
*Electromyography (EMG)
*Aerodynamic Measurements


Indirect Laryngoscopy
Direct Laryngoscopy
Flexible Fiber-Optic Laryngoscopy

Indirect Laryngoscopy: Mirror (+light) to view laryngeal structures during phonation (usu. "eee") and during quiet respiration

Direct Laryngoscopy: Performed by surgeon when pt under anesthesia in outpatient surgery; Laryngoscope introduced through mouth and into pharyx and positioned above VFs; Pt cannot phonate so VF function cannot be determined by surgeon can obtain a direct microscopic view of larynx; Valuable when biopsy is required due to suspicion of laryngeal cancer

Flexible Fiber-Optic Laryngoscopy: Tube inserted through nasal passage, passes over velum, and into position above larynx; Fibers transmit laryngeal image to specialist's eyepiece; Pt able to speak and sing; Specialist can obtain an excellent prolonged view of vocal mechanism and photograph rapid VF movement



*Two types: flexible (inserted nasally) and rigid (inserted orally), using a 3.6mm tube
*(Fiber-optic) light at tip of scope and structures are illuminated by the light and viewed by specialist at other end of endoscope via window lens
*Endoscope can be attached to a video camera (videoendoscopy); A stroboscopic (flashing) light source can also be used
*W/ flexible endoscope, can view velopharyngeal (VP) mechanism, including VP valving; The endoscope (aka) nasopharyngoscope) can be lowered further to view laryngeal mechanism
*B/c pt can perform a variety of phonatory tasks, endoscopy may be used to study laryngeal anatomy and physiology in detail, incl. mucosal wave


Acoustic Analysis

*Acoustic measurements can be used to evaluate effectiveness of voice therapy/vocal surgery
*"Sound Spectography:" graphic representation of a sound wave's intensity and frequency as a function of time; "Spectogram:" resulting picture that reflects resonant characteristics of vocal tract and harmonic nature of glottal sound source



*Helpful in differentiating bet. functional and organic voice probs and detecting laryngeal neoplasms (tumors)
*Can use flexible fiber-optic laryngoscope, a rigid endoscope, or both
*Strobe light permits optical illusion of slow-motion viewing of VFs during a variety of tasks; Observer perceives rapidly presented images as a complete picture of cycle-to-cycle vibration
*Microphone on pts neck to record voice, then introduces scope, switches on stroboscopic light, and asks pt to phonate
*Stroboscopic image on monitor yields info re: periodicity/regularity of VF vibrations, VF amplitude, glottal closure, presence and adequacy of mucosal wave, and possible presence of lesions or neoplasms


Electroglottography (EGG)

*Noninvasive procedure yields indirect measure of VF closure patterns
*Surface electrodes placed on both sides of thyroid cartilage, and a high-frequency electrical current is passed bet. electrodes while pt phonates
*Glottal wave form results and specialist is able to view VF vibration
*EGG can also detect breathy and abrupt glottal onset of phonation
*Disagreeance re: efficacy of EGG as a diagnostic technique; Best for cross-reference tool