Ch. 7: Voice & Its Disorders Flashcards
Larynx
The biological valve located at the top of the trachea. It helps close the entry into the trachea so food, liquids, and other particles do not enter the lungs. Connects superiorly to the oral cavity and vocal tract and inferiorly to the lungs and trachea. Builds air pressure below it to assist in the performance of biological functions such as getting rid of bodily waste, coughing, heavy lifting, and child bearing. Houses the VF.
Vocal Folds
Vibrate to produce voice. Adduct or abduct. Have a layered structure that is composed of the epithelium, the thyroarytenoid (TA) muscle, and the lamina propria.
Glottis
Opening between the VF.
Cover-Body Theory of Phonation
According to this theory, the epithelium, the superficial layer of the lamina propria, and much of the intermediate layer of the lamina propria vibrate as a “cover” on a relatively stationary “body.” The body is composed of the remained of the intermediate layer, the deep layer, and the TA muscle.
Ventricular/False VF
Lie above the “true” VF. They do not usually vibrate during normal phonation and are only using during activities such as lifting and coughing.
Aryepiglottic Folds
Lie above the ventricular folds. They separate the pharynx and laryngeal vestibule and help preserve the airway.
Laryngeal Innervation
- CN VII (facial): Innervates the posterior belly of the digastric muscle of the VF.
- CN X (vagus: Primary CN involves in laryngeal innervation. Primary branches are SLN and RLN.
Superior Laryngeal Nerve (SLN)
Has internal and external branches. The internal branch provides all sensory information to the larynx, and the external branch supplies motor innervation solely to the cricothyroid muscle.
Recurrent Laryngeal Nerve (RLN)
Supplies all motor innervation to the interarytenoid, posterior cricoarytenoids, thyroarytenoid, and lateral cricoarytenoid muscles. It supplies all sensory information below the VF. If there is a lesion here, the patient may experience (among other problems) difficult adducting the VF.
Hyoid Bone
Bone that the larynx is suspended from. Many extrinsic laryngeal muscles are attached to this bone.
Epiglottis
A leaf-shaped cartilage that is attached to the hyoid bone. Protects the trachea by closing down inferiorly and posteriorly over the laryngeal area, directing liquids and food into the esophagus during swallow.
Thyroid Cartilage
The largest of all the laryngeal cartilages. Sometimes called the Adam’s apple and is particularly prominent in men. Shields other laryngeal structures from damage. Composed of two lamina, or plates of cartilage, that are joined at midline and form an angle.
Cricoid Cartilage
The second-largest laryngeal cartilage. Sometimes called the uppermost tracheal ring (however, it is quite different from the other tracheal rings). Completely surrounds the trachea. It is linked with the paired arytenoid cartilages and the thyroid cartilage.
Arytenoid Cartilages
Cartilages positioned on the supraposterior surface of the cricoid cartilage on either side of the midline. Shaped like pyramids. The vocal processes are the most anterior angle of the base of the arytenoids. The true VF attach at the vocal processes.
Corniculate Cartilages
Cartilages that sit on the apex of the arytenoids and are small and cone-shaped. They play a minor role in vocalization.
Cuneiform Cartilages
Tiny, cone-shaped cartilage pieces under the mucous membrane that covers the aryepiglottic folds. They play a very minor role in the phonatory functions of the larynx.
Intrinsic Laryngeal Muscles
These pairs of muscles have both of their attachments to structures within the larynx. With one exception, all are adductors. Primarily responsible for controlling vocalization. Include:
- Thyroarytenoids
- Cricothyroids
- Posterior cricoarytenoids (the only abductors)
- Lateral cricoarytenoids
- Transverse arytenoids
- Oblique arytenoids
Extrinsic Laryngeal Muscles
These muscles have one attachment to a structure outside the larynx and one attachment to a structure within the larynx. All extrinsic laryngeal muscles are attached to the hyoid bone. These muscles elevate or lower the position of the larynx in the neck. They give the larynx fixed support. Includes the infrahyoid muscles: - Thyrohyoids - Omohyoids - Sternothyroids - Sternohyoids Includes the suprahyoid muscles: - Digastrics - Geniohyoids - Mylohyoids - Stylohyoids - Genioglossus - Hyoglossus
Infrahyoid Muscles
Extrinsic laryngeal muscles that lie below the hyoid bone. Their primary function is to depress the larynx. They are sometimes called the depressors. They have a strong impact upon vocal pitch. Includes: (remember the acronym TOSS)
- Thyrohyoids
- Omohyoids
- Sternothyroids
- Sternohyoids
Suprahyoid Laryngeal Muscles
Extrinsic laryngeal muscles that lie above the hyoid bone. Their primary function is to elevate the larynx. They are sometimes called elevators. Includes:
- Digastrics
- Geniohyoids
- Mylohyoids
- Stylohyoids
- Genioglossus
- Hyoglossus
Mean Fundamental Frequency (MFF)
Mean fundamental frequency. Tends to decrease with age. MFF 19 y/o female → 217 Hz MFF 19 y/o male → 117 Hz MFF adult male → 100 – 150 Hz MFF adult female → 180 – 250 Hz MFF 70 – 94 y/o female → 201 Hz MFF 70 – 89 y/o male → 132 – 146 Hz
Maximum Phonation Time (MPT)
Refers to a client’s ability to sustain “ah.” Usually, the client is asked to breathe deeply and “say ah for as long as you can.” MPT 3 – 4 y/o → 7.5 – 8.95 MPT 5 – 12 y/o → 14.97 – 17.74 MPT 18 – 39 y/o → 20.9 – 24.6 MPT 66 – 93 y/o → 14.2 – 18.1
Vocal Changes Resulting from Puberty
Grils’ voices may lower by 3 – 4 semitones. Boys’ voices may lower as much as an octave. Boys may show pitch breaks, huskiness, and hoarseness as their pitch lowers due to laryngeal growth.
Average Fundamental Frequency
Men → 125 Hz
Women → 225 Hz
Presbyphonia
Age-related voice disorder characterized by perceptual changes in quality, range, loudness, and pitch in older speakers’ voices.
Age-Related Vocal Changes
- Hardening of the laryngeal cartilages
- Degeneration and atrophy of the intrinsic laryngeal muscles
- Degeneration of glands in the laryngeal mucosa
- Degenerative changes in the lamina propria
- Deterioration of the cricoarytenoids joint
- Degenerative changes in the conus elasticus
Pitch
The perceptual correlate of frequency. Largely based on the frequency with which the VF vibrate. Determined by mass, tension, and elasticity of the VF. Higher pitch results when the VF are thinner, more tense, or both. Lower pitch results when the VF are thicker, more relaxed, or both.
Fundamental Frequency
Rate at which the VF vibrate. Generally considered a person’s pitch.
Jitter/Frequency Perturbation
Refers to variations in vocal frequency that are often heard in dysphonic patients. Can be measured instrumentally as a patient sustains a vowel. May occur in patients with voice problems such as tremor or hoarseness. People with no laryngeal pathology are able to sustain a vowel with less than 1% of this.
Volume
The perceptual correlate of intensity. Determined by the intensity of the sound signal. The more intense the sound signal, the greater its perceived loudness.
Amplitude
The extent of movement of air particles in response to a disturbance.
Shimmer/Amplitude Perturbation
Refers to the cycle-to-cyle variation of vocal intensity. It can be measured instrumentally as a patient sustains a vowel. A speaker with no laryngeal pathology should have a very small amount of variation of intensity with each vibratory cycle. Some experts believe that more than 1 dB of variation across cycles makes a patient sound dysphonic. Patients who have difficulties with regularity of VF vibration (e.g., roughness) might show large amounts of this.
Voice Quality
The perceptual correlate of complexity. Refers to the physical complexity of the laryngeal tone, which is modified by the resonating cavities. Frequently subjective.
Hoarseness
In this type of vocal quality, the voice shows a combination of breathiness and harshness, which results from irregular VF vibrations. In such cases, the fundamental frequency of the speaker varies randomly due to aperiodic vibration. Often sounds breathy, low-pitched, and husky. There may also be pitch breaks and excessive throat clearing.
Harshness
In this type of vocal quality, the voice is described as rough, unpleasant, and “gravelly” sounding. It is associated with excessive muscular tension and effort. The VF are adducted too tightly, and the air is then released too abruptly.
Strain-Strangle
In this type of vocal quality, the phonation is effortful, and the patient sounds as if she is “squeezing” the voice at the glottal level. Initiating and sustaining phonation are both difficult. Talking fatigues patients and they experience much tension when they speak.
Breathiness
In this type of vocal quality, the VF are slightly open (or not firmly approximated) during phonation. Air escapes through the glottis and adds noise to the sound produced by the VF. May be due to organic (physical) or nonorganic (nonphysical or functional) causes. Patients often complain that they feel like they are running out of air. This kind of voice is often soft, with little variation in loudness. Patients frequently show restricted vocal range.
Glottal Fry/Vocal Fry
Vocal quality that is heard when the VF vibrate very slowly. The resultant sound occurs in slow but discrete bursts and is of extremely low pitch. The voice sounds “crackly.” May be the vibratory cycle we use near the bottom of our normal pitch rate. Typically, it is produced near the end of a long phrase or sentence when air flow rate and subglottal air pressure are both low and lung volume is less.
Diplophonia
Means “double voice.” Occurs when one can simultaneously perceive two distinct pitches during phonation. Usually occurs when the VF vibrate at different frequencies due to differing degrees of mass or tension. E.g., might occur in a client with a unilateral polyp.
Stridency
This vocal quality sounds shrill, unpleasant, somewhat high pitched, and “tinny.” Often caused by hypertonicity or tension of the pharyngeal constrictors and elevation of the larynx.
Indirect Laryngoscopy (Mirror Laryngoscopy)
In this instrumental evaluation, the specialist uses a bright light source and a small, round, 21-25 mm mirror, angled on a long, slender handle, to lift the velum and press gently against the patient’s posterior pharyngeal wall area. The specialist maneuvers the mirror to view the laryngeal structures during phonation (usually the patient’s production of “eeeee”) and during quiet respiration.
Direct Laryngoscopy
This procedure is performed by a surgeon when a patient is under general anesthesia in outpatient surgery. The laryngoscope is introduced through the mouth into the pharynx and positioned above the VF. The patient cannot phonate, thus vocal function cannot be determined. However, the surgeon can obtain a direct microscopic view of the larynx. Valuable when a biopsy is required due to the suspicion of laryngeal cancer.
Flexible Fiber-Optic Laryngoscopy
This procedure utilizes a thin, flexible tube containing a lens and fiber-optic ight bundles. The specialist inserts the tube through the patient’s nasal passage, passes it over the velum, and maneuvers it into position above the larynx. The fibers transmit the laryngeal image to the specialist’s eyepiece. The patient is able to speak and sing. The specialist can obtain an excellent, prolonged view of the vocal mechanism and photograph rapid VF movement.
Endoscopy
Type of imaging study where a scope with a light at the tip is introduced orally or nasally. The light is fiber optic and comes from an external light source. The structures are illuminated by the light and viewed by the specialist at the other end of the endoscope through a window lens. Can be attached to a video camera. May be used to study laryngeal anatomy and physiology in detail, including the mucosal wave.
Sound Spectrography
The graphic representation of a sound wave’s intensity and frequency as a function of time. Very useful for quantitative analysis of speech.
Spectrogram
Picture resulting from sound spectrography. Reflects the resonant characteristics of the vocal tract and the harmonic nature of the glottal sound source.
Videostroboscopy
Imaging study that can be helpful in differentiating between functional and organic voice problems. It can also be used to detect laryngeal neoplasms (tumors). Uses a pulsing strobe light on an endoscope that permits the optical illusion of slow-motion viewing of the VF during a variety of tasks. The image yields information about the periodicity or regularity of VF vibrations, VF amplitude (horizontal excursion), glottal closure, presence and adequacy of the mucosal wave, and the possible presence of lesions or neoplasms.
Electroglottography (EGG)
Noninvasive procedure that yields an indirect measure of VF closure patterns. Surface electrodes are placed on both sides of the thyroid cartilage, and a high-frequency electric current is passed between the electrodes while the patient phonates. The laryngeal and neck tissue conducts the current. A glottal wave form results, and the specialist is able to observe VF vibration. Can also detect breathy and abrupt glottal onset of phonation. Cross-validate this tool with another measure. Researchers debate its efficacy as a diagnostic technique.
Elecromyography (EMG)
This invasive procedure directly measures laryngeal function to study the pattern of electrical activity of the VF and to view muscle activity patterns. The specialist inserts needle electrodes into the patient’s peripheral laryngeal muscles. The resulting electrical signals are judges as either normal or indicative of pathology. When the specialist interprets the electric signals she is looking for:
- Reduced or increased speech of muscle activation
- Extraneous bursts of muscle activity
- Onset or termination of muscle activity
Useful when attempting to determine VF pathology, especially that caused by neurological and neuromuscular diseases. Also useful in verifying excessive muscle activity prior to the injection of Botox for patients with spasmodic dysphonia.
Aerodynamic Measurements
Refer to the airflows, air volumes, and average air pressures produced as part of the peripheral mechanics of the respiratory, laryngeal, and supralaryngeal airways. Used to evaluate dysphonia, monitor voice changes and treatment progress, and differentiate between laryngeal and respiratory problems. Specific measures can be made of the following: - Tidal volume - Vital capacity - Total lung capacity Various instruments may be used to obtain these measures, such as: - Wet spirometers - Dry spirometers - Manometric devices - Plethysmographs
Tidal Volume
Amount of air inhaled and exhaled during a normal breathing cycle.
Vital Capacity
The volume of air that the patient can exhale after a maximal inhalation.
