076 211 8828 info@iohsolutions.com

Occupational Noise Measurement and its Role in Hearing Safety

We read of miners injured by cave-ins or gas explosions and of workers who have lost a limb as a result of it having become trapped in some industrial machine. However, the most common reason for employees to claim industrial compensation today is far less dramatic although no less debilitating. In this case, it is an unseen injury and one that develops over time yet one which and occupational noise assessment could easily prevent. Known as noise-induced hearing loss or NIHL, in addition to being the most common industrial injury, it is also the most common form of deafness and, with suitable precautions, it is also 100% avoidable.

Prior to the advent of audiometry, following the Second World War, NIHL was observed among soldiers and attributed to the constant exposure to gunfire, and while a high incidence of deafness among factory workers had also been noticed, in the absence of some means to quantitate their impairment, this could not be pursued further. An occupational noise assessment, however, is able to reveal any risk of NIHL to which a worker may be exposed, while an examination of a worker by an audiologist can quantify the extent of auditory impairment if present.

It is well-established that exposure to a sound level of 85 decibels, can cause irreversible hearing loss within eight hours. Furthermore, the effect is cumulative, so a further exposure of eight hours results in additional impairment.  In terms of the Occupational Health and Safety Act, employers must determine the risk of NIHL in the workplace, and this requires an occupational noise assessment. This is designed to determine both the levels of ambient noise in relevant areas of the workplace and the extent to which each of the workers in those areas is routinely exposed to those levels. Based on these findings, it can then be determined whether further action is necessary and, if so, what form it should take.

In some cases, the results of an occupational noise assessment reveal that any risk of NIHL could be mitigated by efforts to control the level of sound in the affected areas. Since this might not always be possible, it could prove necessary for a company to supply its vulnerable employees with some form of hearing protection. Typically, this could be either earplugs or earmuffs but, in order to permit critical communication between workers and supervisors, they must be of a design that is able to exclude loud noises while not interfering with normal conversation.

As is true of most health and safety measures, an occupational noise survey offers benefits to both to the employer and his or her employees. Because the decibel scale is logarithmic, a reduction of just 3dB equates to a halving of the sound intensity, which can enable a worker to remain safe for twice as long. More significantly, it could prevent costly compensation claims from staff affected by NIHL.

That said, hearing loss is not the only potential consequence of a noisy working environment. Even at levels below the accepted safety threshold, noise can create stress, which can be both a safety hazard and a threat to productivity. These are further good reasons to contact IOH Solutions about an occupational noise assessment for your company.