1. Voice Disorders (Speech/Language Impaired)
Disability Awareness Training

2. Overview
A voice disorder occurs when voice quality, pitch, and loudness differ or are inappropriate for an individual's age, gender, cultural background, or geographic location.
A voice disorder is present when an individual expresses concern about having an abnormal voice that does not meet daily needs—even if others do not perceive it as different or deviant.

3. Categorization of Voice Disorders
Organic — voice disorders that are physiological in nature and result from alterations in respiratory, laryngeal, or vocal tract mechanisms.
Structural — organic voice disorders that result from physical changes in the voice mechanism (e.g., alterations in vocal fold tissues such as edema or vocal nodules; structural changes in the larynx due to aging).
Neurogenic — organic voice disorders that result from problems with the central or peripheral nervous system innervation to the larynx that affect functioning of the vocal mechanism (e.g., vocal tremor, spasmodic dysphonia, or paralysis of vocal folds).
Functional — voice disorders that result from improper or inefficient use of the vocal mechanism when the physical structure is normal (e.g., vocal fatigue; muscle tension dysphonia or aphonia; diplophonia; ventricular phonation).

4. Voice quality can also be affected when psychological stressors lead to habitual, maladaptive aphonia or dysphonia. The resulting voice disorders are referred to as psychogenic voice disorders or psychogenic conversion aphonia/dysphonia.
These voice disorders are rare. SLPs refer individuals suspected of having a psychogenic voice disorder to other appropriate professionals (e.g., psychologist or psychiatrist) for diagnosis and may collaborate in subsequent treatment.

5. Incidence and Prevalence
Voice disorders have been estimated to be present in between 3% and 9% of the U.S. population.
The prevalence of voice disorders among treatment-seeking individuals has been shown to be affected by gender, age, and occupation.
Gender
Prevalence is higher in adult females than in adult males, with a reported ratio of 1.5:1.0.
In children, voice disorders are significantly more prevalent in males than in females.
Age
Prevalence has been reported to be higher in elderly adults, with estimates ranging from 4.8% to 29.1% in population-based studies.
In the pediatric population, the reported prevalence of a voice disorder has ranged from 1.4% to 6.0%.
Occupation
Occupational groups that appear to be most at risk for developing a voice disorder include teachers, manufacturing/factory workers, salespersons, and singers.
The estimated prevalence of reporting a current voice problem was higher in teachers (11.0%) than in nonteachers (6.2%).
Reported prevalence from teachers at a single point in time ranged from 9% to 37%. Reported lifetime prevalence (i.e., the percentage of teachers who experienced a voice disorder at some point in their lifetime) was between 50% and 80%.

6. Signs and Symptoms
roughness (perception of aberrant vocal fold vibration);
breathiness (perception of audible air escape in the sound signal or bursts of breathiness);
strained quality (perception of increased effort; tense or harsh as if talking and lifting at the same time);
strangled quality (as if talking with breath held);
abnormal pitch (too high, too low, pitch breaks, decreased pitch range);
abnormal loudness/volume (too high, too low, decreased range, unsteady volume);
abnormal resonance (hypernasal, hyponasal);
aphonia (loss of voice);
phonation breaks;
asthenia (weak voice);
gurgly/wet sounding voice;
hoarse voice (raspy, audible aperiodicity in sound);
pulsed voice (fry register, audible creaks or pulses in sound);
shrill voice (high, piercing sound, as if stifling a scream); and
tremulous voice (shaky voice; rhythmic pitch and loudness undulations)
increased vocal effort associated with speaking;
decreased vocal endurance or onset of fatigue with prolonged voice use;
variable vocal quality throughout the day or during speaking;
running out of breath quickly;
frequent coughing or throat clearing (may worsen with increased voice use); and
excessive throat or laryngeal tension/pain/tenderness.

7. Causes
Normal voice production depends on power and airflow supplied by the respiratory system; laryngeal muscle strength, balance, coordination, and stamina; and coordination among these and the pharynx, oral cavity, nasal cavity.
A disturbance in one of the three subsystems of voice production (i.e., respiratory, laryngeal, and subglottal vocal tract) or in the physiological balance among the systems may lead to a voice disturbance. Disruptions can be due to organic, functional, and/or psychogenic causes.

8. Causes Organic causes include the following:
Structural
Vocal fold abnormalities (e.g., vocal nodules, edema, glottal stenosis, recurrent respiratory papilloma).
Inflammation of the larynx (e.g., arthritis of the cricoarytenoid or cricothyroid, laryngitis, reflux)
Trauma to the larynx (e.g., from intubation, chemical exposure, or external trauma)
Neurologic
Recurrent laryngeal nerve paralysis
Adductor/abductor spasmodic dysphonia
Parkinson's disease
Multiple sclerosis
Functional causes include the following:
Phonotrauma (e.g., yelling, screaming, excessive throat-clearing)
Muscle tension dysphonia
Ventricular phonation
Vocal fatigue (e.g., due to effort or overuse)
Psychogenic causes include the following:
Chronic stress disorders
Anxiety
Depression
Conversion reaction (e.g., conversion aphonia and dysphonia)

9. Treatment Approaches can be direct and/or indirect
Direct approaches focus on manipulating the voice-producing mechanisms (e.g., phonation, respiration, and musculoskeletal function) in order to modify vocal behaviors and establishing healthy voice production.
Indirect approaches modify the cognitive, behavioral, psychological, and physical environments in which voicing occurs. Indirect approaches include the following two components:
Patient education—discussing normal physiology of voice production and the impact of voice disorders on function; providing information about the impact of vocal misuse and strategies for maintaining vocal health (vocal hygiene).
Counseling—identifying and implementing strategies such as stress management to modify psychosocial factors that negatively affect vocal health.

10. Example
This is a video clip of a 14 year old girl who has had aphonia and dysphonia for seven years from the text "Pediatric Voice Disorders" by Christopher J. Hartnick, MD, Mark E. Boseley, M.D.