Voice disorders can be categorized as organic or functional. An organic voice disorder is defined as a physiological variable stemming from alterations in respiratory, laryngeal, or vocal tract mechanisms.
Within the organic category, there are subtypes (i.e. structural, neurogenic) that are characterized by deferment impairments. Structural is documented to be an organic voice disorder that results from physical changes in the vocal mechanism, such as alterations in vocal fold tissues (e.g., edema or vocal nodules) and/or structural changes in the larynx due to aging. Neurogenic is documented to be an organic voice disorder that results from problems with the central or peripheral nervous system innervation to the larynx that affect the functioning of the vocal mechanism, such as vocal tremor, spasmodic dysphonia, or vocal fold paralysis.
References
American Speech-Language-Hearing Association. (1993). Definitions of communication disorders and variations [Relevant paper].
