The Supreme Court decision in Baker v Quantum Clothing Ltd [2011] was seen as having prevented the opening of the floodgates of industrial deafness claims.

However, insurers are reporting an increase in the number of claims they are receiving. It is unclear whether this current influx is due to the impact that the Civil Justice Reforms will have after April 2013 upon claimant solicitors and their conditional fee agreement success fees, or the consequence of the action level being dropped to 80dB(A) within the Control of Noise at Work Regulations 2005. Either way we provide some guidance upon how such claims might be defended:

  1. Question the claimant’s history of noise exposure

A claimant’s exposure to noise varies depending on the task and the machinery used. Allegations often concentrate upon a worse case scenario, when a particular noisy machine is used. However breach of duty is usually determined by calculating the average level of exposure over a working day. It is, therefore, important to apportion into a working day - breaks, travelling time, rotation upon non noisy tasks etc. Production or machine operating time records may be able to suggest exposure time was limited. Information on employee numbers and those authorised to use certain machinery may indicate that tasks were rotated, thereby reducing exposure.

  1. Use the National Physical Laboratory (NPL) tables

These tables calculate the relationship between noise exposure and the expected incidence of hearing disability. If a claimant’s hearing loss is substantially different to that expected from the tables, the claimant’s account of exposure is unreliable.

  1. Instruct a CSI acoustic engineer

A factory may have closed down or machinery sold or destroyed but all is not lost. An engineer can forensically calculate noise levels if similar machinery can be inspected at other sites or at other employer’s factories. Historic noise surveys can be used to predict what noise levels may have been.

  1. Do not be afraid to challenge the audiogram

It is rarely the case that a 4kHz notch on an audiogram is produced, which is the classic indicator of noise induced hearing loss (NIHL). Even if a notch is produced, cause for suspicion should still be explored. Audiometric testing is subject to operator error and user manipulation. The circumstances of the testing are also important to the reliability of the results:

  • Where was the test carried out?
  • Was a sound proof booth used?
  • When was the claimant last exposed to noise before the test?
  • When was the audiometer last calibrated?
  • Were TDH-39 headphones used and if so has an adjustment been made for the calibration artefact (a measurement process that assigns values to the property of an artifact relative to a reference standard)?
  1. Raise questions of the ENT surgeon

An audiogram is not conclusive proof of NIHL but simply one of the diagnostic tools used by an expert. It is a subjective assessment by the expert and depending upon the emphasis he places upon each of the criteria of the Coles Guidelines (used to assist in diagnosing NIHL for medico-legal purposes), the diagnosis may vary. It is, therefore, open to scrutiny.

Areas of disagreement between ENT experts are whether you need bilateral notching for a diagnosis of NIHL? Whether a 6kHz notch is representative of NIHL or an unreliable indicator?

Cameron Clark, Partner in our Sheffield office, shall be speaking and expanding upon these and other tips at our Occupational disease conference in Birmingham on 20 November Find out more: