Noise-Induced Hearing Loss

Theresa Pitt, Aud.D., F.S.H.A.A., Audiology Services in S.E. Ireland.

Causes & Prevention of Noise-Induced Hearing Loss

Noise Induced Hearing Loss (NIHL) can generally be avoided by the use of common sense, and an increased awareness of the potentially harmful effects of noise. Damaging noise and annoying noise are not always the same thing. Noise-Induced Hearing Loss can be sudden and traumatic - for example after a bomb blast - but the vast majority of people suffer very gradual deterioration after years of exposure to sound levels of 85-90dB(A) or above. The changes can be so gradual that sufferers do not notice or believe for many years just how much they are missing - although families may be more aware of the difficulties.

Walkmans may seem particularly risky to an individual because there is no-one else to judge the loudness except the wearer - because sound is so close to the ear, it is usually louder than the wearer thinks (although, in fact, concerts seem to be the most risky setting in which to experience noise followed by night clubs). Young children may become adapted to listening at high levels without realising that there could be a risk - unless they are told about it early enough. If you feel that a sound is uncomfortable then do listen if it upsets your child too.

Some people are naturally more sensitive to loud sound; this is likely to be 'normal' if unpleasant for them; research suggests that if you have hyperacusis you may be at higher risk of developing tinnitus - so such people must be extra careful to avoid risk.

Musicians, too - not only rock musicians but orchestral musicians - may be exposed to excessive bursts of noise. Using earplugs to protect the ears should help - various types are available which can allow 'monitoring' of the music or voices around you whilst still reducing loud noise. If the sound hurts, turn it down before your ears start to ‘acclimatise’ with a ‘temporary threshold shift’ (i.e. hearing loss!).

Workplace noise may not be continuous (e.g. in tractor cabs, in bottling plants or when working with pneumatic drills, noise may come and go), but this is no less dangerous & no excuse for failure to wear ear protection if available.

New ear protectors are available which permit some conversation whilst reducing ‘noise’ quite effectively; ear protectors should be rated according to how much sound they can block out. Employers need to be aware of changes here, and general tightening of noise exposure limits through E.U. legislation, as well as remembering it as a design feature in new plants.

Hearing Screening Programmes can halt the gradual progression which occurs with noise exposure before the hearing loss reaches a problematic stage and causes real stress to the person in their everyday communication. These should be available to workers (musicians and their entourage included!) if you usually have to shout in your workplace when you want to communicate.

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