Informativeness of the threshold adaptation and fatigue for assessment of the auditory health risk

The management and control of modern automated productions evidence the elevated role of the auditory system as one of the distant sensor communication systems. The present study informs about the auditory adaptation and fatigue at the end of the working shift of 385 operators at control boards in "Kremikovtzi" State Company. The results of the monitoring of the dynamic changes show significant changes, expressed in aggravation of the auditory fatigue manifestation by moderate to significant disturbance of the adaptation-recovery processes. The analysis established a significant positive correlation between the changes in auditory fatigue and the duration of service. The frequencies of the speech range are preserved for a long time. The elevated auditory fatigue is observed in the injured hearing band 4,000 Hz, followed by 6,000 Hz and continuous dissemination to the middle frequencies of the speech band-2,000 and 1,000 Hz. The results of the study of the adaptation-recovery processes are characterised by statistically significant reliability, single direction and reproducibility and can be applied as informative criteria for assessment of the auditory health risk.