AN INVESTIGATION INTO AUDIOLOGICAL FINDINGS IN INDIVIDUALS EXPOSED TO NOISY ENVIRONMENTS
1KTO Karatay Üniversitesi, Sağlık Bilimleri Fakültesi Odyoloji Bölümü, Konya, Türkiye2Karamanoğlu Mehmetbey Üniversitesi, Tıp Fakültesi Fizyoloji ABD, Karaman, Türkiye
3Sağlık Bilimleri Üniversitesi, Gülhane Sağlık Bilimleri Fakültesi, Odyoloji Bölümü, Ankara, Türkiye Objective: This research aimed to evaluate hearing thresholds and noise sensitivity levels in industrial workers exposed to occupational noise and compare them with normal-hearing individuals.
Materials and Methods: A total of 80 male participants, (40 noise-exposed [NE], 40 controls), aged 18-50 years were included in this study. Pure-tone and extended high-frequency (EHF) audiometry between 125 Hz and 20 kHz were performed in both groups. The Weinstein's Noise Sensitivity Scale (WNSS) was used to assess noise sensitivity. In the NE group, the Threshold Equalizing Noise (TEN) test was used to evaluate possible cochlear dead region findings between 1 and 8 kHz.
Results: EHF thresholds were significantly higher in the NE group particularly between 1 and 18 kHz (p < 0.01), compared to the control group. Characteristic threshold elevations around 4 kHz and 16 kHz were observed in both ears. WNSS scores did not differ significantly between groups (p>0.05). While no significant correlations were observed between WNSS scores and audiological parameters in the NE group, weak significant negative correlations were identified between WNSS scores and UCL values in the control group (right ear: r=-0.409, p=0.009; left ear: r=-0.368, p=0.019). TEN findings compatible with possible cochlear dead region involvement were observed at 1000, 3000, 4000, 6000, and 8000 Hz, whereas no TEN-defined findings were identified at 2000 Hz. The highest frequency of TEN-defined findings was observed bilaterally at 4000 Hz.
Conclusion: These findings highlight the importance of including EHF audiometry and dead region assessments in the audiological evaluation of individuals working in noisy environments.
Keywords : Noise exposure, Extended high-frequency audiometer, WNSS, TEN test