Any OH practitioner who is likely to find themselves working in an environment where noise is a risk needs an understanding of how hearing loss can come about. Susanna Everton provides an overview.
High levels of noise can cause permanent irreversible hearing loss, but this can be prevented. OH nurses play a vital part in hearing conservation in the workplace and should work with OH and safety colleagues to advise and guide managers and employees in noise control measures.
It has been known for centuries that excessive noise can cause hearing damage, but it was first described as an occupational hazard in the seminal work "De Morbis Artificium" by Ramazzini, published in 1713. In this, he described copper workers who hammered metal as having "ears so injured by that perpetual din that [they] become hard of hearing and, if they grow old at this work, completely deaf" (Bell, 1966).
The first British study of occupational noise-induced hearing loss (ONIHL) was published in 1866, but it was not until the 1940s that work on hearing, testing and the relationship between work and ONIHL became more widespread.
While it is generally acknowledged that workers in heavy industrial settings are exposed to loud noises, and much research has been done on the risks of hearing damage, it is only recently that other occupational settings have been demonstrated as a cause of noise-induced hearing loss (NIHL), including call centres, pubs, restaurants and clubs. It is also becoming apparent that the noise we expose ourselves to in our ordinary lives, such as in-ear headphones with MP3 players, will probably damage our hearing permanently.
In order to understand noise damage, it is necessary to understand sound. Sound is defined as the mechanical vibration of a gaseous, liquid or solid medium through which energy is transferred away from the source by progressive waves.
It is only recently that occupational outside heavy industrial settings have been demonstrated as a cause of noise-induced hearling loss."
A vibrating object loses some of its energy to surrounding areas as sound - think of a washing machine on the spin cycle. Noise has been described