Prolonged exposure to excessive noise can result in hearing impairment. Many employees are required to work in very noisy environments, which puts them at risk of industrial hearing loss (also known as occupational deafness or noise-induced hearing loss).
The introduction of acts to control noise levels in the workplace has seen the prevalence of industrial hearing loss fall, yet it still affects 14,000 people in the UK and 10,000,000 people in the US.
What causes industrial hearing loss?
Persistent sounds of 80 dB or more or sounds reaching a peak of 135 dB can cause industrial hearing loss. Such noise levels are created by mass-produced hand-held power tools such as drills, grinders, and nail guns. Industrial machines and processes can be associated with significantly greater noise.
In many professions, loud noise is an inevitable consequence of the nature of the work being carried out. For example construction, engineering, factory production, mining, textile manufacturing, iron/steel works, heavy fabrication, motor vehicle production, ship building.
Employees in such industries are regularly exposed to consistently high noise levels that, without adequate ear protection, can damage the structures of the ear and reduce the ability to hear.
What are the symptoms of industrial hearing loss?
The symptoms of industrial hearing loss build up gradually over time and are often dismissed as part of the aging process. They include temporary or permanent lack of hearing in one or both ears, difficulty hearing conversations or the TV/radio, and constant noise from within the ear(s) (typically ringing, buzzing, hissing, roaring or ticking) that impairs concentration and the ability to follow conversations (tinnitus).
Industrial hearing loss includes varying degrees of hearing impairment (which may be temporary or permanent), tinnitus (ringing in the ears), and acoustic trauma (ear damage caused by a sudden loud noise, e.g., feedback through headset, or a series of loud noises, e.g., gun fire).
Can industrial hearing loss be treated?
Hearing loss is extremely difficult to treat. However, if the signs are picked up early further hearing damage can be avoided.
There is no known cure for tinnitus. Sufferers must rely on long-term treatments such as the use of ‘de-tinnitising’ amplifiers to override the sounds of tinnitus or sound therapy classes to help retrain how the ear processes sounds.
Prevention of industrial hearing loss
It is possible to prevent industrial hearing loss by taking measures to reduce noise levels and ensuring that adequate ear protection is used effectively if noise cannot be reduced to a safe level.
It is the responsibility of the employer to protect the hearing of their employees and policies and guidelines have been developed to help them meet this. Employers are required to ensure that their workers are informed about the dangers of working in an environment where noise levels are high, to provide appropriate ear protection and enforce correct usage of the protective devices they issue.
The use of ear protection should be enforced if noise levels consistently exceed 80 dB or if sounds reach a peak of 135 dB. Average noise levels in the working environment must not exceed 87 dB (taking hearing protection into account).
Case studies of industrial hearing loss
Boat repairer
Charles had been exposed daily to the loud noises of hydraulic impacts from various machines during 10 years as a labourer in a factory that made and repaired boat motors. The high noise levels had become so commonplace to Charles that they no longer bothered him and he did not wear ear protection on a regular basis.
When Charles noticed that he was having difficulty hearing what people said to him more often and could not hear certain sounds, he sought medical advice. Charles was diagnosed with tinnitus and permanent hearing loss in both ears. Shocked by the extent of the damage Charles made sure that he always wore ear protection at work. He also began researching how to claim for compensation from his employer for neglecting to ensure his safety at work.
Iron worker
Whilst at work at a smelting works, Frank was surrounded by continuous extreme noise every working day for 35 years. Frank described the noise as being so excessive that he could not hear himself think. However, over time he became accustomed to the noise, not realising that it was causing lasting damage to his hearing.
Frank started to miss more and more of normal conversations, especially if there was background noise, and was suffering from ringing sounds in both his ears. Frank was diagnosed as having severe noise-induced hearing loss and tinnitus in both ears.
Following a claim for negligence, he received compensation from his employer for not protecting him from the noisy work environment.
Steel fitter
Malcolm had spent most of his working life as a fitter. He explained that there had always been very loud noise across the site “Noise was transmitted from the machines used to roll the steel. There were two furnaces, underground hydraulics and a roughing mill”.
He was not provided with any ear protection for the first 20 years he worked as a fitter, and wearing ear protection was not made compulsory for another five years after that. Malcolm began to struggle hearing everything that was being said to him and suffered hissing in his right ear.
The symptoms worsened over the years and Malcolm was diagnosed with industrial hearing loss and tinnitus. By the time of the diagnosis, it was too late to save his hearing, but his compensation payment helped him to buy quality equipment to help him hear better.
Further information on Industrial hearing loss
- http://www.cdc.gov/niosh/topics/noise/stats.html
- http://www.hse.gov.uk/STATISTICS/causdis/deafness/index.htm
- http://www.soundadvice.info/thewholestory/san1.htm#symptoms
- http://www.industrialdeafness.org.uk/symptoms-of-industrial-deafness
- http://www.industrialdeafnesswatch.co.uk/real-life-stories