[Comparative study between the level of discomfort and the acoustic reflex in workers].

BACKGROUND Comparative study between the level of discomfort and the acoustic reflex in workers. AIM To observe the hearing behavior, through the assessment of the contraction activity of the stapedius muscle and the level of discomfort, of individuals who are and are not exposed to occupational noise, with the aim of identifying the influence of noise in the behavior of the contraction of the stapedius muscle and in the sensibility of hearing. METHOD This study was developed at the Serviço Social da Indústria - SESI - Ce. A hundred and three adults with normal hearing, male and female, with ages varying from 18 to 45 years were divided in three groups: G1 with 41 adults exposed to noise and who used AIPE; G2 with 32 adults exposed to noise and who did not use AIPE; G3 with 30 adults who were not exposed to noise. Participants were submitted to audiologic evaluation, including the analysis of the acoustic reflex level (ARL) and discomfort level (DL) at the frequencies of 500 HZ, 1000Hz, 2000Hz, 3000Hz, 4000Hz and WN. For the statistical analysis the tests of Mann Whitney, Wilcoxon and Kruskal, with significance levels of 5%, were used. RESULTS No statistically significant difference was identified for the ARL between the three groups, with mean values ranging from 93 to 103dBHL; the ARL was significantly smaller than the DL, with the mean values of DL varying from 111 to 119 dBHL for G1, from 113 to 120dBHL for G2 and from 106 to 114dBHL for G3; the DL is higher in individuals of G1 followed by individuals of G2 and G3. CONCLUSION The exposure to noise does not determine changes in the behavior of the ARL; the DL rises with the exposure to occupational noise; the DL is higher than the ARL in 10 to 25dB.