Functional voice disorders – what are they?
Functional (malregulatory) dysphonia is characterized by a disorder of vocal sound, limitation of vocal performance, and subjective voice-related discomfort in the absence of evidence of pathological primary organic changes in the anatomical structures involved in voice production (Schwartz 2011; Wendler 1977).
In patients with functional voice disorders, laryngoscopy and stroboscopy do not reveal any organic lesions on the vocal folds. In these cases, voice changes are caused by technical (functional) limitations of voice use. In most cases, mislearned (behavioral) muscle misuse/overuse and breathing problems are major components of functional voice disorders.
As a result, the closing and vibrating behavior of the vocal folds during vocalization is disturbed.
The cause is thought to be multifactorial. Possible causes include constitutional factors (e.g., a larynx that is not naturally strong and powerful, or a limitation of the overall physical constitution) and habitual factors (conscious or unconscious habituation to an unfavorable vocal technique, an inappropriate speaking pitch, unconscious imitation of other unfavorable voice models, and voice-damaging habits such as throat clearing) or overuse of the voice by speaking too long or too loudly. A voice disorder can also occur as a result of a serious general illness due to poor general health, without a cause in the larynx.
Of course, there is always the possibility of a psychological influence on the use of the voice, which in extreme cases can lead to partial or total loss of the voice (dysphonia or aphonia). Therapeutically, in patients with functional voice disorders, we have a good chance of improving the patient’s voice because we have access to the entire arsenal of voice treatment techniques.
Functional voice disorders can be divided into “too much” and “too little”. There are forms in which there is too much tension in the vocal folds and laryngeal muscles (called hyperfunctional dysphonia) and forms in which there is too little tension (called hypofunctional dysphonia). There is often a mixed symptomatology.
