Alexander A. Menshov
Vladimir V. Lipovoy
Inst. for Occupational Health, 252033, Kiev, Ukraine
Occupational hardness of hearing occurs first of all in workers with heightened sensitivity to noise. Along with the objective method for determining higher excitability of the central structures of the auditory analyzer by means of the awaked brain potentials, the heightened sensitivity to noise can be determined by a simpler method [A. Peyser, Acta Oto-laryngol. (Stockh.) 28, 443--444 (1940)]. The experimental data have shown that a higher increase in TTS is observed at a tone of 2000 Hz instead of 1000 Hz according to A. Peyser. Such a modified method was approved at 42 young weavers. After 3 min of 100-dB noise load at the tone of 2000 Hz in 13% of weavers TTS was more than 12 dB (hightened sensitivity). After work for a year under the conditions of 98--100 dBA, in the weavers with hightened sensitivity, TTS at the tone of 2000 Hz was 11.9 dB, at the tone of 1000 Hz was 9.4 dB, and at the tone of 4000 Hz was 9.6 dB. In the weavers insensitive to noise, TTS at the tone of 1000 Hz was 7.0 dB, at the tone of 2000 Hz was 7.5 dB, and at the tone of 4000 Hz was 7.8 dB. In the sensitive to noise weavers, PTS at 1000 Hz was 2.3 dB, at 2000 Hz was 4.3 dB, and at 4000 Hz was 1.7 dB. In the insensitive to noise weavers, PTS at 1000 Hz was 1.1 dB, at 2000 Hz was 1.7 dB, and at 4000 Hz was 1.3 dB. The determination of human sensitivity to industrial noise by audiometry in this modification enables one to discover workers with heightened auditory sensitivity and predict the PTS auditory level.