The Grindleford Criteria and the future of acoustic shock claims

A recent High Court decision dealing with acoustic shock in Bevan v Ministry of Defence [2025] EWHC 1145 (KB) has outlined the criteria that should be used for causation in such cases.

The Claimant claimed damages against the Ministry of Defence (MoD) for a hearing injury allegedly caused by negligent exposure to dangerous noise whilst the Claimant was driving and testing military vehicles from 2017 to 2020. The Claimant valued the claim at over £530,000.00.

The MoD admitted breach of duty but disputed causation and quantum. The medical experts, Mr Parker, instructed by the Defendant and Professor Wright instructed by the Claimant gave evidence at trial.

The claim started as a noise induced hearing loss (NIHL) claim but by the time it reached trial it was clear that it was in fact one for acoustic shock. Acoustic shock is recognised as a clinical entity distinct from NIHL and acoustic trauma. The Court accepted that the Claimant did not suffer from NIHL as there was no notching or bulging in his audiograms and that he did not suffer from acoustic trauma as there was no exposure to a sufficiently loud noise.

Going on to consider acoustic trauma the Court determined that when considering whether someone has acoustic trauma or not it is the Grindleford Criteria as set out by Parker, W. A. E., Parker, V. L., Parker, G., & Parker, A. J in Acoustic shock: an update review. The Journal of Laryngology & Otology 2020 which should be used. This was an updated version of a 2014 paper by the same authors on acoustic shock produced following the decision in Royal Opera House Covent Garden Foundation v Goldscheider [2019] EWCA Civ 711.

The Grindleford Criteria

G1 - There must be a defined acoustic incident (which need not be negligent)
G2 - Ear symptoms should start straight away or shortly afterwards
G3 - Ear symptoms should be outside physiological or startle responses
G4 - Ear symptoms should be experienced in or arise from the exposed ear(s)
There may be significant psychological overlay or relationship to illness behaviour

In this case the Court agreed with Mr Parker that only G3 was met. The G1 criteria was not met as there was no defined incident and exposure was repetitive and broadly predictable. The G2 criteria therefore automatically failed as there was no specific event to which to match the timing of symptoms. In any event the Court found that symptoms of tinnitus came on months after exposure ended. The G4 criteria was also not met on the basis that the tinnitus was bilateral, despite exposure being on the right side only.

On that basis a diagnosis of acoustic shock could not be found. The Court said that the Claimant's tinnitus and any hearing loss was not caused by exposure to noise and the claim was dismissed.

While the MoD was able to avoid payment of a significant sum of damages in this claim the longer-term result of the Court’s decision is that the Grindleford Criteria are likely to become the accepted criteria to be met in future acoustic shock claims. The criteria will provide some certainty when analysing such claims in the future.

What this means for you

The decision gives some welcome clarity and there is now clear court approval of the criteria that should be followed when diagnosing acoustic shock. Going forward handlers of such claims need to give careful analysis of the factual basis for the claim and crucially whether there is any contemporaneous reporting of symptoms. At joint statement stage it means that experts should be directed to give full consideration of each limb of the criteria and to fully outline whether they agree or disagree whether each of the criteria are met. The decision in this case leaves no doubt that a diagnosis should not be derived by retrospectively linking symptoms to a condition, but rather by applying the correct diagnostic criteria in a forward-looking and structured manner.

Clyde & Co are specialists in dealing with Disease claims, and we closely monitor developments around related topics. For more on this subject, you can read all of our previous articles here, and if you have any questions about this topic you can contact Michael Cairns, Brennig Francis or any of our Occupational Disease and Legacy Claims team.