Noise-induced hearing loss

Noise-induced hearing loss is one of the most prevalent, but often ignored, risks in the workplace...

According to the HSE, over one million employees in Great Britain are exposed to levels of noise which put their hearing at risk.

Noise-induced hearing loss is one of the most prevalent, but often ignored, risks in the workplace and employees must, by law, be protected.

Once noise-induced hearing loss has taken place, it is irreversible.  Clearly, prevention is the most sensible option here as 1 in 7 of the UK population are either deaf or hard of hearing. The increasing ‘claim culture' dictates that companies must comply with their legal duties as detailed in the ‘Control of Noise at Work Regulations 2005'.

Pulsar Instruments plc here provide organisations who are making efforts to control their own noise problems with some very basic guidance:

What do Health & Safety/Occupational Hygienists, Environmental Health Managers need to do?

Step 1
They need to establish whether there are any noise hazards within their workplace. This can be achieved through a combination of knowledge of work practices, making straightforward observations and taking some simple noise measurements.

Step 2
Having found out which areas may be a noise hazard, they need to identify all employees who could be at risk.

They need to evaluate how harm may occur, for instance, damage to hearing, deafness, tinnitus, impaired communication and inability to hear audible alarms. They should also consider existing hearing conditions.

Step 3

They should talk with the employees to find out their typical work routine to determine the typical exposures of those at risk.

They then have a choice of measurement methods.

Integrating Averaging Sound Level Meter:
The person carrying out these measurements should have sufficient skills to be competent for the task and use a suitable sound level meter. Ideally, it should be compliant to BS EN 61672-1:2003 Class 1 or Class 2 and from a reputable manufacturer.

Representative ‘A' weighted average noise level readings (correctly written as LAeq) are taken for each ‘task' undertaken and then, using either software, mathematical formulae or the HSE exposure calculator spreadsheet (available from, to determine an individual's exposure level.

Below, all of the exposures have a value of 80dB(A) but the duration of the respective ‘tasks' has varied greatly. The 80dB(A) exposure equates to an exposure that just puts the worker into the Lower Action Level category.

level dB(A)    Duration     Exposure Level dB(A)

        80                8 hours     80
        83                4 hours     80
        86                2 hours     80
        89                1 hour       80
        92               30 mins     80

The ‘A' frequency filter is applied by sound measurement instruments in an attempt to replicate the response of the human ear to noise so that we can accurately determine the level of risk rather than the actual true noise level itself.

Personal Noise Dosemeter:
A dosemeter can be worn on the shoulder by a worker to be monitored in order to measure the noise levels they receive throughout their working shift. This is particularly effective for workers with unpredictable shift patterns, those constantly on the move, or people working in difficult to access areas.

Often forgotten is the necessity to assess the risk from any impulsive noise (sudden very loud bangs and crashes) which is done by making a ‘C' weighted Peak measurement (LCpeak). Most modern sound level meters and dosemeters will measure both the LAeq and LCpeak simultaneously.

Having made and evaluated your measurements, a Noise Control Action Plan is required to demonstrate that you are taking the necessary steps to control the identified risks.  A corresponding set of actions then need to be implemented.

Where noise can't be reduced at source, suitable hearing protection is required which must be made available to all at risk. Arrangements must be made to provide information and training to both management and workforce with respect to the risks and how to minimise and control them.

For any levels where exposures of 85dB or above are likely, a programme of health surveillance must be introduced to monitor the hearing condition of the employees involved.

Step 4
All the above findings should be used to create a clear report. This will provide permanent evidence of the decisions you have taken to comply with the law.

  • Document findings of survey
  • Identify extent of Noise Hazard Areas
  • Details of placement of warning signs
  • Prescription of suitable hearing protection
  • Details of a Training Program
  • ‘Buy Quiet' purchasing policy
  • Company Noise Policy
  • The prioritised measures to be taken to control noise levels

Step 5
The effectiveness of a noise control programme should be regularly reviewed - especially if new equipment has been introduced. 
For those companies with workers receiving exposures of 85dB(A) or above, the health surveillance programme should highlight any workers whose hearing deteriorates due to inadequacies in the noise control programme.

Any employer or safety professional wishing to discuss the above further or who is interested in obtaining information on noise measurement relevant to their industry should contact us on Tel: +44 1723 518011 or email the team at