There can be no doubt that improved awareness, better information and fear over legal proceedings have been key to helping protect today’s workforce from the risk of hearing damage. Before the introduction of legislative frameworks such as the Control of Noise at Work Regulations, little attention was heeded by some employers to either limiting the cause of excessive noise levels or providing adequate protection against noise induced hearing loss.

Throughout much of the twentieth century, working in excessive noisy conditions was considered ‘part of the job’, and the attitude of ‘you soon get used to it’ would prevail. Even when provided by employers, some men would fail to wear ear defenders properly, e.g. an incomplete air seal between the hearing pad and the skin – or at all! Common reasons given are not being able to hear their colleagues speaking or machinery malfunctioning. Inevitably, years of exposure to high levels of excessive noise eventually led to many workers succumbing to irreversible industrial deafness, which they only became aware of much later in life.

However, even today, studies show that as much as half of the workforce who do wear hearing protection receive only 50 per cent protection because, either they are still not being worn continuously while exposed to noise or the ear set simply does not fit properly. Properly fitted earplugs or muffs reduce noise by 15 to 30 dB of sound. As a general rule, earplugs are better protection against low frequency noise, e.g. a hydraulic jackhammer, and earmuffs are better protection against high frequency noise, e.g. airplane taking off

A hearing defender can provide an average of 30 dB noise reduction if worn continuously during an 8-hour workday. Even if removed for just one hour while exposed to noise, protection would reduce to only an average of 9dB of protection during 8 hours. It is vital to remember that a 10-times increase in noise energy occurs for each 10 dB increase in sound. Thus, without protection during just one hour, the worker is exposed to 1,000 times more sound energy than if ear protection had been worn. In addition, noise exposure is cumulative. So, noise experienced outside of the workplace must be counted in the total exposure during any one day, which can exceed the safe daily limit, i.e. 85dB over 8 hours.

Wearing both earplugs and muffs provides an additional layer of protection of up to 10 to 15 dB or more against a risk of hearing loss than either type of defence used alone. Although recommended when having to work in environments when the noise exceeds 105 dB, once again it should be remembered that at 106 dB only 3.75 min exposure is the actual time limit allowed. Substitutes like cotton wool or tissue only reduce noise by around 7dB and are strongly advised against.