751 - 03/11 - Occupational noise induced hearing loss - Worldwide
During the course of our pre-employment medical examinations we have observed that a larger subset of seafarers, specifically those working in engine rooms have abnormal audiometric results. Typically they display signs of mild to moderate high frequency hearing loss. It is therefore a logical inference that seafarers working in engine rooms have a higher propensity to encounter hearing disabilities. This is especially true if they don't use precautionary measures such as ear plugs or ear defenders.
Noise-induced hearing loss (NIHL) is caused by high levels of ambient noise (typically above 85 dBA). The negative effects of such high levels of noise depend upon individual physiology but also the intensity and the duration of exposure.
Audiometric testing is the only diagnostic evaluation relevant to diagnosis of noise-induced hearing loss (NIHL). It is performed by means of an audiometric testing machine within a sound proof booth providing an accurate measure of the damage.
The following features are essential for a robust hearing conservation program:
- Criteria for Audiometry test: A baseline Audiometry test should be performed within 6 months of exposure for all seafarers. The test should ideally be performed when the seafarer has not been exposed to hazardous noise for at least 14 hours.
- Seafarers exposed to higher noise levels should receive annual training. This would educate the crew about effects of loud noises on hearing, the purpose of audiometric testing and protective devices available to mitigate it’s damaging effects.
- As exposure to loud noises such as in engine rooms is unavoidable, wearing hearing protection is HIGHLY advised. Devices for hearing protection including earplugs or earmuffs which are both low cost and highly available.
