Correlations between certain hearing changes and vegetative balance in miners.

This study responds to the priorities of the National Health Strategy aimed at control and mitigation of the hazardous effects of the workplace factors on cardio-vascular diseases of people in active working age from the branch "Mining industry". The aim of this work is to study the vegetative balance (by analysis of heart rate variability--AHRV) and the correlations with the state of miners' hearing functions. Sixty eight miners (diggers and mate-diggers) from mining industry were studied.

Masking effect of music upon oral information processing.

The masking effect of three types of music and white masking noise upon special audiometric tests was determined in laboratory c. The stimulus-noise (S/N) ratio was found to be the most considerable factor influencing oral information processing in spite of the type of music or noise used as a masking agent. All types of music (modern, classic or modern music records in backwards order) showed no significant differences in masking being in the same way stronger maskers as white noise.

The "cost" of silence.

Changes in the organism of control desk operators caused by difficulties faced during productionally relevant speech information processing under conditions of intense occupational noise, represent the psychophysiological "cost" of noise masking. Its presence attests to difficulties in processing before deterioration of the quality of the latter while its quantitative characterisation correlates positively with the degree of the masking effect of noise and with the neuropsychic stress of this particular type of work. For this reason an attempt is made to demonstrate noise masking under laboratory conditions with it approximate quantitative evaluation at two signal/noise ratios- +15 and The statistically significant differences between the values of pulse rate, plethysmography and vocal exertion at the above ratios point to both its presence, and to the necessity to be considered when assessing the occupational burden and standardisation of noise intensity in productions associated with speech signals.

[The evaluation of indices of noise impact on humans].

Due to noise, information processing changes, rate and quality of work deteriorate. Laboratory experiments prove noise exposure to increase dyastolic blood pressure. Multiple factors of occupational environment induce significant individual variability of blood pressure, putting a little value to blood pressure changes.