See the Voice Disorders evidence map for pertinent scientific evidence, expert opinion, and client/caregiver perspective.
The scope of this page focuses on voice disorders of organic (i.e., structural and neurogenic) and functional origin. Psychogenic voice disorders are also discussed.
Portal pages on head and neck cancer, resonance disorders, aerodigestive disorders affecting voice, and transgender voice will be developed in the future.
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 (Aronson & Bless, 2009; Boone, McFarlane, Von Berg, & Zraik, 2010; Lee, Stemple, Glaze, & Kelchner, 2004). 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 (American Speech-Language-Hearing Association [ASHA], 1993; Colton & Casper, 1996; Stemple, Glaze, & Klaben, 2010; Verdolini & Ramig, 2001).
A number of different systems are used for classifying voice disorders. For the purposes of this document, voice disorders are categorized as follows:
- 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)
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 (Stemple, Glaze, & Klaben, 2010). 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.
Voice disorders are not mutually exclusive, and overlap is common. For example, the etiology of nodules is functional, as they result from behavioral voice misuse. The voice misuse results in repeated trauma to the vocal folds, which may then lead to structural (organic) changes to the vocal fold tissue.
Speech-language pathologists (SLPs) may also be involved in the assessment and treatment of disorders that affect the voice mechanism (i.e., the aerodigestive tract) but are not classified as voice disorders. An example is paradoxical vocal fold movement (PVFM), a condition in which there is intermittent adduction of the vocal folds that interferes with breathing. When PVFM is suspected, SLPs are often consulted to help identify abnormal laryngeal and respiratory function and to teach various techniques (e.g., vocal exercises, relaxation techniques, quick-release breathing techniques, and proper breath management) to improve laryngeal and respiratory control (Mathers-Schmidt, 2001; Patel, Venediktov, Schooling, & Wang, 2015; Traister, Fajt, & Petrov, 2016). An ASHA Practice Portal page on aerodigestive disorders affecting voice will be developed in the future.