In April of this year, new guidelines for diagnosing and quantifying noise-induced hearing loss (NIHL) in medico-legal claims were published in the journal, Trends in Hearing,[i] which propose some significant amendments to the conventionally used CLB / LCB Guidelines.[ii]

We refer to the new guidelines as the ‘MLC Guidelines’, owing to authorship by Brian Moore, David Lowe and Graham Cox.

The MLC Guidelines recommend:

  • A distinction to be made between different types of noise exposure, with differing diagnostic guidelines to apply: modified CLB Guidelines for steady state noise; the Moore Guidelines (2020) for military exposure; and a new method for individuals exposed to intense tones (rather than noise), such as those arising from the use of ‘tone set equipment’.
  • A lowering of the acceptable threshold of noise exposure which could lead to NIHL.
  • The existence and extent of any NIHL to be assessed with reference to an updated database of ‘normal hearing’ – ISO 7029 (2017).
  • Assessment on the basis of the most recent of audiograms to reflect a progressive development of NIHL after noise exposure ceases – contrary to the general scientific consensus that NIHL is not progressive in this way.
  • Quantification of NIHL to be assessed across the frequencies 1,2 and 4 kHz, as opposed to the more usual 1, 2 and 3 kHz.

All of the above recommendations – if applied – would increase both the diagnostic incidence of NIHL and the severity of NIHL diagnosed.

Over the next few weeks, we will dive into the MLC Guidelines in detail, setting out and critiquing the new proposed methodologies and looking at their practical impact on claims volumes, types and quantum.

In the meantime, our NIHL claims handling tool – ABCNoise – has been updated to allow analysis of claims based upon the MLC Guidelines. If you would like training on the new MLC Guidelines, please contact This email address is being protected from spambots. You need JavaScript enabled to view it..


[i] Moore, Lowe & Cox (2022). Guidelines for Diagnosing and Quantifying Noise-Induced Hearing Loss. Trends in Hearing Volume 26: 1-21

[ii] Coles, Lutman & Buffin (2000). Guidelines on the diagnosis of noise-induced hearing loss for medicolegal purposes. Clinical Otolaryngology, 25, 264-273; Lutman, Coles & Buffin (2016). Guidelines for quantification of noise-induced hearing loss in a medicolegal context. Clinical Otolaryngology, 41, 347-357.