THE PREVALENCE OF NOISE- INDUCED TINNITUS AMONG WORKERS IN SYRIA, AND ITS RELATED FACTORS

Elie Alazzam*, Louei Darjazini Nahas, Aliaa Bakr, Mouhammad Trabulsi and Rama Alsawah

ABSTRACT

Objectives: This cross- sectional study aimed to investigate the prevalence of noise-induced tinnitus and its relationship with other related factors. Methods: The study group was composed of 111 workers exposed to noise. Each ear was treated as a separate sample giving a sample size of 222. Workers were evaluated by filling in a form, clinical examination and undergoing a pure-tone audiometry. Noise levels in work place were also measured. Results: 28.8% of our sample complained of tinnitus, while 22.5% complained of hearing loss. Of those with tinnitus, only 21% complained of an associated hearing loss. Mean thresholds were higher in workers with tinnitus, and the highest difference between the mean thresholds was on the frequencies 4000 Hz and 6000 Hz. Mean age of workers with tinnitus was 31.1 years old, compared with 39.8 years old for those without. Other factors, showed no significant differences. Conclusion: The prevalence of tinnitus among workers exposed to noise was higher than that of hearing loss. Workers with noise induced tinnitus have higher thresholds on audiograms, especially on the 4000Hz and 6000Hz, which are also the frequencies on which noise- induced hearing loss begins, hence demonstrating a relationship between the two. The tinnitus complaint may be a prodromal symptom to hearing loss. Tinnitus was also to found to be higher in younger ages. Finally, no correlation was found between tinnitus and noise levels, and between tinnitus and lifetime cumulative exposure to noise.

Keywords: Noise-induced tinnitus, noise-induced hearing loss.