We all know that going to work can sometimes be a figurative pain in the neck but in many industries there is a real risk of harm: permanent and painful hearing loss.
Occupational hearing loss or occupational Noise Induced Hearing Loss (NIHL) has been considered a serious issue for many years now. In fact, it has been estimated that some 30 million people in America alone are exposed to hazardous noise levels in the workplace each year and that one in four of those people will develop permanent hearing loss as a result.
All too often, workers appear to take a rather laissez-faire attitude to their hearing perhaps because the damage is frequently invisible and takes place over a period of time or they are under time pressure to get the job done. But it’s your hearing and you need to take some responsibility for looking after it.
What are the risks?
The workplace hazards that can damage your hearing fall under three categories:
- Sudden traumatic exposure to noise, such as explosions
- Continuous noise sufficiently loud enough to cause permanent damage over weeks, months, and years
- Ototoxic chemicals such as solvents and heavy metals
The focus in this article will be mostly on exploring the causes of NIHL (1 & 2) and outlining ways to protect your hearing but we encourage you to protect yourself against chemical hazards in the workplace as well.
If it’s harmful why doesn’t it hurt?
Sudden traumatic noise that can cause instant, permanent hearing loss is painful and may be accompanied by obvious physical damage such as burst eardrums. However, most occupational NIHL occurs in industries such as the manufacturing sector including carpentry and engineering or amongst airline ground crews where the noise may be loud enough to cause hearing loss over time but not cause immediate pain.
With gradual NIHL, the key factor is length of exposure. The table below (courtesy of Health Canada) demonstrates this link clearly.
|Due to the noise around you:||Means the sound levels are probably:||Means you’re at significant risk of permanent hearing loss if exposed daily for:|
|someone standing a metre away has to shout to be understood||higher than 85 dBA||8 hours or more|
|someone standing 30 cm away has to shout to be understood||higher than 95 dBA||45 minutes or more|
|someone has to shout into your ear to be understood||higher than 105 dBA||5 minutes or more|
A more concrete example of just what 85 dBA sounds like would be the noise of a heavy truck at a distance of 15 m. However, there is evidence that even these time limits may not be adequate for some people and that the effects are cumulative.
You need to give serious heed to any of the following warning signs as they indicate your hearing is under stress:
- Temporary deafness after loud noise—as though sounds are being muffled
- Tinnitus—hissing sounds in the ears
Hearing loss is usually the result of damage to the delicate hair cells (stereocilia); such hearing loss is permanent, as the cells do not grow back.
How can I protect my hearing?
Health and safety laws govern noise exposure in the workplace and whether you are an employer or employee you need to familiarize yourself with these and make sure they are being adhered to. You should also:
- Wear appropriate hearing protection such as earplugs or earmuffs. It is important to ensure that you choose the right type of hearing protection with adequate noise rating. You also need to make sure that hearing protection is worn correctly, as poorly fitted earmuffs or earplugs may render them completely ineffective.
- Put barriers in place such as screens or sound walls between noisy machinery and yourself.
- Be aware that attempting to drown out factory noise by listening to loud music through earpieces is equally harmful.
- Give your ears a break after exposure to loud noise. Perhaps you can designate a quiet area in the canteen and limit your noise exposure outside of work to allow your ears to recover.
- Run an education programme in your workplace. Let people know about the hazards of noise. Role model safe hearing protection behaviour such as wearing earmuffs correctly.
Hear today, hear tomorrow
Unfortunately, the most at risk from occupational NIHL appear to be younger workers. This may be because age related hearing loss can mask the effects of NIHL in older workers. However, regardless of your age you need to take care of your hearing today if you want to avoid the pain and distress of hearing loss.
Come and visit us at House of Hearing — we can advise you on all aspects of hearing protection in the workplace.