Kovalchuk T.A., Savushyna I.V.
SI “Ukrainian Institute of Industrial Medicine”, Kryvyi Rih
Introduction. Functional dysphonia are among the common diseases in spoken voice professions. Vegetative dysfunction shows the functional insufficiency of the diencephalic area, resulting in changes in timbre and normal mode of vibration of the vocal folds. The instability of the vegetative balance is considered as a starting mechanism, contributing to development and formation of voice disorders.
Purpose of the study – determination of the risk of functional dysphonia and adaptive capabilities of a voice load in spoken voice professions.
Materials and methods. The adaptation potential was assessed by Bayevsky index, the stress coefficient, the universal cardiorespiratory indicator, duration of an individual minute.
Results of research and their discussion. The main factor of changes in the color and tone of the vocal folds is a voice load, when the correlation coefficient (r) with the vocal load experience is significantly high (r=0,82, p<0.05, the coefficient of determination is r2=67,2 %). The higher chances in the tone of the vocal folds are when the value of the AP (adaptation potential) is 2,1–3,2 relative units, i.e. when there is an adaptation tension (odds ratio OR=60,9±0,4; χ2=345,8 p<0,001, bond strength – medium). In the case when there are no functional changes in the vocal folds, the connection of the adaptation potential with the tone is almost absent. An increase of the adaptation potential above the norm by 0,1 relative units leads to an increase of the risk of damaging vocal folds by 0,27 (27,0 %).
The duration of an IM (individual minute) was 33,2±2,0 seconds on the average in 61,5±3,5 % of cases; changes in vocal folds were noted, and in those that had an individual minute with a duration of 61,4±2,8 seconds – only in 30,8±2,8 %. That is, psycho-emotional stress, related to occupational activity, causes the increase of the risk of occurrence of tension in the vocal folds twice. The etiological part of such psycho-emotional stress makes 49,8 %.
The stress level above 1,12 relative units caused the increase of the number of cases of circulatory disorders in the vocal folds by 50 %, tonus by 24,8 %. The greatest chances of changes in the tone of the vocal folds where when the value of the UCI (universal cardiorespiratory indicator) made 3,5–4,5 relative units, i.e. when there was available the adaptation tension and subcompensation was developed (odds ratio OR=1,72±0,04; χ2=41,8, p<0,3; the bond strength was medium).
Conclusions. The adaptive potential affects significantly the quality of blood circulation in the vocal folds with tendency to increasing and depends on the work experience, and on the voice load. The psychoemotional stress, associated with the professional activity, increases twice the risk of changes in the vocal folds. The greatest chances of changes in the tone of the vocal folds were at the value of the universal cardiorespiratory indicator 3,5–4,5 cu.
Key words: workers of spoken voice professions, functional dysphonia, occupational pathology of the vocal folds, adaptation potential, psycho-emotional stress
ORCID ID of authors and their contribution to preparation and writing the paper:
Kovalchuk T.A. (ORCID ID 0000-0002-2580-3032) - introduction, formulation of purposes and tasks of the study, conclusion.
Savushina I.V. (ORCID ID 0000-0003-1341-3624) – conduction of the studies, statistical processing of the received materials, writing a section according to the results of the study.