New guidelines for the quantification of deafness claims have been published to address the uncertainty in calculating levels of noise induced hearing loss. Stephen Simpson takes a look at the new guidelines and considers how they will impact on deafness claims.

The original Coles, Lutman and Buffin (CLB) guidelines were published in 2000 and were used to assess whether, on a balance of probability, a person had suffered noise induced hearing loss (NIHL). The new Lutman, Coles and Buffin (LCB) guidelines 2015 have been published to provide additional guidance, and enhanced accuracy, on quantifying the level of hearing loss suffered.

The original CLB guidelines (2000)

The original guidelines applied a set of diagnostic criteria to the claimant’s audiogram following a hearing test to diagnose whether there had been any NIHL. Once diagnosed, quantification of the loss was based on a calculation of age related hearing loss that was deducted from the claimant’s actual hearing loss.

One of the problems with this approach was that the method of calculating the claimant’s NIHL relied on experts choosing a baseline which corresponded on a best fit basis with the claimant’s hearing thresholds at the ‘anchor points’. This sometimes led different experts to different conclusions as to the age associated hearing loss statistic to be used and as a result different conclusions about the level of NIHL suffered.

The new LCB guidelines (2015)

The new guidelines introduce additional calculations by way of a ‘two pass’ procedure to quantify the level of NIHL and ensure the overall variance to the established NIHL will be minimal. They recognise that the average pattern of age-associated hearing loss is an abstract notion and instead recognise a range of severity of age-associated hearing loss e.g. more age-associated hearing loss than usual at the lower frequencies and less at high frequencies. They also recognise that some people may also have additional hearing loss caused by other factors not attributed to age or noise.

It should be noted that the new guidelines focus on the level of loss seen at 4kHz. If there is no damage at 4kHz then this will significantly lower the overall level of NIHL established.

Improving the system

The new guidelines provide a more accurate and consistent method for calculating NIHL. This will reduce the need to instruct expensive experts and hopefully reduce the number of cases that proceed on quantum only.

However, the quality of the examining audiologist remains key, and care should be taken to ensure that examinations are carried out in controlled test conditions.