Our study population (n = 307) were male smokers working
in these noisy areas. Female workers were not included in
this study because of the low noise exposure (almost all
women were office workers). After direct interview by an
occupational medicine specialist, and considering exclusion
criteria (history of ototoxic drug consumption, diabetes
mellitus, hyperlipidemia, hypothyroidism, severe or frequent
ear infection, chronic middle ear pathology or major ear
operations, head injury, exposure to non-occupational noise,
such as amplified music, participation in war, and hunting,
noise exposure in previous job/jobs, unilateral or conductive
hearing loss or any kind of hearing loss with a known etiology
except for noise exposure), 55 persons were excluded from the
study [Table 1] and 252 male smokers who worked in noisy
workplaces comprised the target population (ex-smokers, i.e.
those who had quitted smoking were also excluded). Also
there were 453 male non-smoker workers in these noisy parts
(83 workers were excluded by applying the exclusion criteria).