Health effects of noise. Ill health. Moving on from the previous article on Health Effects of Noise, it would probably be helpful to discuss the effects of stress and anxiety as well as physical Ill Health caused by noise in the workplace.
There are 3-distinct section to the human ear starting with the external ear (outer ear), the middle ear and the internal ear.
Hearing is based upon sound pressure waves being captured and funneled by the outer ear down towards the middle ear. The pressure waves then strike the drum which is positioned approximately 25mm inside the head.
Set inside the middle ear is a delicate array of 3 small bones which transfer the vibration from the drum to the inner ear (or cochlea).
The cochlea contains a fluid that in turn creates movement in a membrane causing connected hair cells to bend.
The bending of these hair cells create a tiny electrical impulse which is transmitted to the brain along the auditory nerve which the brain then scrambles into the sensation we know as sound.
There are about 30,000 or so of these hair cells, and damage to them causes irreversible hearing loss.
Ill Health Effects of Noise
Ear damage can have two classifications. Acute effects and Chronic effects.
Acute damage can be classed as temporary where some sort of regain will occur, while chronic is generally classed as irreversible.
In addition, there are 3 classifications of both acute and chronic effects.
Temporary threshold shift
This can be caused by short excessive exposure to noise and creates a disturbance within the inner ear by reducing the impulses sent to the brain. This results in a slight deafness, but is reversed when the noise subsides.
Acute acoustic trauma
This can be caused by extreme sudden noises such as gunshot or explosion. It affects the ear drum and tiny bones in the inner ear, and again usually reverses itself after a period of time. (Although sudden loud noises can also cause permanent damage).
Usually caused by an intense noise over a period of time over stimulating the tiny hair cells created a perceived ringing noise in the ear. Often it subsides over 24 hours, but it can become a lifelong debilitating condition.
There are also 3 classifications of chronic effects of hearing loss.
Permanent threshold shift
This condition is in response to the permanently unprotected or insufficiently protected loud sustained noise levels. The damage created is the irreversible reduction in nerve impulses sent to the brain which leads to the inability to hear at certain frequency levels, typically 4000hz.
Noise Induced hearing loss
Although not total deafness, the ability to hear clearly is significantly reduced due to irreversible damage to the hair cells within the cochlear.
This chronic condition is the same as the acute Tinnitus but permanent and very unpleasant, often leading to mental health instability and conditions such as depression or even suicide.
It’s also important to remember that repeated uncontrolled exposure can lead to gradual hearing loss that often goes unnoticed into older age. This is often classified as Presbycusis, or deafness in old age which could have been completely avoidable if appropriate ear protection had been worn at an earlier stage, or sufficient measures were put in place by the employer.
Anxiety caused by noise in the workplace
Further to the physical effects of hearing damage caused by noise in the workplace, we need to consider the psychological effects of persistent background noise or the type of sudden noise that’s unexpected and makes you jump, such as the screech of a chopsaw or the banging of machinery.
Being exposed to this sort of noise continually can lead to work related stress and anxiety.
Even in an office situation there may be the low drone of airconditioning or cooling fans (sometimes know as white noise) which can play a very subtle but dramatic part in affecting a person’s mental or anxious state.
Legally, the employer has a duty under the Health and Safety at Work Act 1974 and the Management of Health and Safety at Work Regulations to assess the risks of stress and anxiety caused by noise or anything else in the workplace and put into place measures that control those risks.
And last but not least
We all have a role to play in effective health and safety, and for those actively involved in promoting safe working practices it can be a rewarding, interesting and varied role.
Please visit this site often where you will find a growing number of articles, resources, advice and opinion.
Whether you are a seasoned health and safety professional, or just getting started, we value your opinions and input so please feel free to comment on any of the posts.
Due to the ever-changing nature of regulations and the law, please visit http://www.hse.gov.uk/ for the very latest information and updates.
Watch the video on the way that sound affects us