However we do know that the damage is caused to the sensitive cells in the cochlea. For reasons which are not entirely clear some of the cells part of the way along the sensory organ in the cochlea are more sensitive than others. The effects of hearing loss In another web page you can investigate the effects of age and length of exposure on hearing loss, provided your resources include a soundcard and speakers as well as supporting software. The first symptom of noise-induced hearing loss is usually difficulty hearing a conversation against a noisy background. The sufferer comes to dislike parties where everyone is apparently chattering away happily, yet he or she hears just a jumble of noise.
Consonants seem to be lost first.
Often he or she will mention intermittent high-pitched ringing in the ears, though this is rarely sufficient to be more than an irritant. By the time these symptoms have become sufficient to prompt medical consultation, the damage as measured by audiometry will be severe and, even with cessation of noise exposure, progressive. When hearing is reduced at 3kHz and below, conversation is significantly interfered with. As well as steps to protect workers from noise, many companies now carry out regular audiometry. The most reasonable way to protect the ears is to generate less noise in the first place, by better design of machinery and equipment.