Vocal loading test: An investigation into its acoustic consequences and the effects of vocal training in theachers with dysphonia

Ewa Niebudek-Bogusz, Piotr Kotylo, Mariola Sliwinska-Kowalska

Introduction : Voice analysis related to vocal loading test makes it possible to objectively evaluate occupational dysphonia and its treatment results.
Materials and Methods: Forty-six female teachers with functional voice disorders had laryngological/phoniatric examination with videostroboscopy and were asked to complete the Voice Handicap Index (VHI) questionnaire. They had also acoustic analysis performed before and after the vocal loading test. Thirty subjects received vocal training (group I) and the remaining 16 did not (group II). In group I, the examination protocol was repeated just after the training was over, and in group II, at 3th month after the initial examination. Results: After voice therapy VHI in group I revealed improved results (p<0.000), compared to the initial examination. The acoustic parameters also improved particularly in group I: Jitter: p="0.001," Shimmer: p< 0.000 and NHR: p< 0.000. Furtheremore an acoustic analysis performed in the initial examination after the vocal-loading test showed an increased rate of abnormal frequency perturbation parameters in the total study population (Jitter p="0.002," RAP p= 0.04, PPQ p= 0.01) compared to the outcomes before the vocal loading. After the training the vocal loading test did not reveal such effect on acoustic parameters in the study group I, contrary to group II.
Conclusions: The recorded impairments of voice acoustic parameters related to vocal loading provide further evidence for dysphonia. The voice acoustic analysis performed before and after the vocal loading test can be a significant contribution to objective voice examinations and a helpful tool for evaluating the treatment of occupational dysphonia.

Keywords: voice acoustic analysis, vocal loading test,dysphonia, teachers, vocal training

Ewa Niebudek-Bogusz, Piotr Kotylo, Mariola Sliwinska-Kowalska
Department of Audiology and Phoniatrics,
Nofer Institute of Occupational Medicine, Lodz, Poland
ul.Teresy 8, 91-348 Lodz, tel+42 6314545 , fax +42 6314519,
ebogusz@imp.lodz.pl