Health surveillance of employees exposed to noise. Causes of hearing loss from noise would occur at higher frequencies first. The frequency of 4000 Hz or 6000, then spread to the lower frequencies. Assessment Hearing To prevent deafness from noise. Should be considered along with other factors. That can cause hearing loss, including age, susceptibility to hearing loss. Poisoning by drugs or chemicals Inflammation in the ear Obstruction of the ear canal The shock to the ears accident Employees of Tinnitus noise can permanently keep hearing back. In cases where there is a temporary increase in the level of hearing. Can be treated by separate staff from the noisy environment. The hearing was restored to normal. Those with permanent hearing loss should be changed to work without exposure to loud noise to prevent hearing loss greater.