Functional voice disorders (FVD) are caused by insufficient or improper use of the larynx and diaphragm without any identifiable physical structural abnormality or neurological dysfunction.These disorders often have a noticeable adverse impact on social and occupational function.
Although there is a vast amount of literature relating to the topic, there is no consensus regarding foundational concepts or methodology of evaluation of voice disorders, as very few authors have rigorously investigated the most effective vocal assessment or video laryngoscopic examination techniques required to produce a consistent and definitive diagnosis of FVD.
The most common FVDs are vocal fatigue, muscle tension dysphonia or aphonia, diplophonia, and ventricular phonation.
Vocal fatigue is caused by overuse of the voice and resultant tiring of the laryngeal musculature.
Muscle tension dysphonia or aphonia is caused by hypertonicity of the laryngeal musculature, which in turn limits the vocal folds' ability to abduct and adduct with coordination and rapidity.
Diplophonia is the phenomenon in which two separate fundamental frequencies are being produced during phonation, which may result from waves of different phases passing through the vocal fold mucosal surface or from different oscillatory frequencies occurring in the left and right vocal folds.
Functional Voice disorder
Functional voice disorders (FVD) are caused by insufficient or improper use of the larynx and diaphragm without any identifiable physical structural abnormality or neurological dysfunction.These disorders often have a noticeable adverse impact on social and occupational function.
Although there is a vast amount of literature relating to the topic, there is no consensus regarding foundational concepts or methodology of evaluation of voice disorders, as very few authors have rigorously investigated the most effective vocal assessment or video laryngoscopic examination techniques required to produce a consistent and definitive diagnosis of FVD.
The most common FVDs are vocal fatigue, muscle tension dysphonia or aphonia, diplophonia, and ventricular phonation.
Vocal fatigue is caused by overuse of the voice and resultant tiring of the laryngeal musculature.
Muscle tension dysphonia or aphonia is caused by hypertonicity of the laryngeal musculature, which in turn limits the vocal folds' ability to abduct and adduct with coordination and rapidity.
Diplophonia is the phenomenon in which two separate fundamental frequencies are being produced during phonation, which may result from waves of different phases passing through the vocal fold mucosal surface or from different oscillatory frequencies occurring in the left and right vocal folds.