Voice Characteristics in Patients with Thyroid Disorders

This study investigated acoustic and perceptual characteristics of the voice of patients with thyroid gland disorders such as hypothyroidism and hyperthyroidism immediately after the diagnosis was made and six months later, after using drug therapy.

The study includes 20 female outpatients with hypothyroidism and 27 female outpatients with hyperthyroidism. The criterion for the selection of the patients was a thyroid gland disorder medical diagnosis, no history of voice disorders and absence of other possible causes of voice changes. Acoustic, perceptual and aerodynamic parameters were assessed. Acoustic analysis was performed by specific software. Experienced speech and language pathologists made perceptual voice assessment by using grade, roughness, breathiness, asthenia, and strain (GRBAS) scale.

Significant differences in patients with hypothyroidism were established on parameter amplitude perturbation, jitter and noise-to-harmonics ratio between pretreatment and posttreatment period, in which patients took drug therapy. In group of patients with hyperthyroidism significant difference was noted only on aerodynamic parameter maximum phonation time. There were a significant differences in all perceptual parameters in both groups of patients (p<0.05) in pre and posttreatment, except on grade and asthenia parameter in the group of patients with hypothyroidism and parameter grade was borderline insignificant in the group of patients with hyperthyroidism.

Voice quality is affected by thyroid disease. Thyroid gland disorders cause minor changes in acoustic voice parameters of patients with hypothyroidism and hyperthyroidism, but perceptual deviations in these patients are especially noticeable.