Causation and quantum in MOD hearing loss claims
Abbott and Ors v MOD [2026] EWHC 941 (KB)
This very lengthy judgment follows a lengthy trial of two test cases and a series of generic issues arising from claims by former members of HM Armed Forces for noise-induced hearing loss (NIHL). The litigation, known as the Hugh James Military Deafness Litigation, commenced with a claim form issued in August 2017 and expanded considerably. By the time of judgment, the total number of claims stood at 10,440. The case was managed without a formal Group Litigation Order but closely mirrored such litigation, with common case management, a Group Register, lead cases and generic issues.
In spring 2024, the Hugh James Claimants and the Defendant reached an agreement (the “Matrix”) disposing of issues of Crown immunity, combat immunity, breach of duty, contributory negligence and limitation. This left only causation and quantum in issue in return for a structured discount on damages. Six lead cases were originally selected for trial; by the time of the hearing, only two remained: Mr Christopher Lambie (chosen by the Claimants) and Mr Jack Craggs (chosen by the Defendant). The court was asked to determine a series of generic issues relevant across the entire cohort, as well as to resolve the individual claims of Mr Lambie and Mr Craggs.
The Claimants
Mr Lambie (born 2 April 1980) joined the Lincolnshire Army Cadets at approximately age 16, receiving repeated unprotected or inadequately protected exposure to weapons fire. He enlisted in the Royal Marines in September 1999 and served as a General Duties Marine and later in Intelligence roles, deploying to Northern Ireland, Iraq (Op Telic) and Afghanistan (Op Herrick). He was exposed to noise from SA80 rifles, GPMGs, mortars, vehicles and aircraft throughout his career.
His first recorded complaint of hearing difficulty was in November 2001. A 2002 audiogram noted ‘Noise induced hearing loss – deterioration since last test’. He was medically downgraded in February 2012, has relied on hearing aids since then, and was commissioned in 2014. He left the Royal Marines in September 2021 and joined PA Consulting, where he has progressed to Principal Consultant. His NIHL was agreed to be permanent and progressive.
Mr Craggs (born 31 May 1979) enlisted in the British Army in August 1998, trained as a military policeman and then completed infantry training with the 2nd Battalion Royal Green Jackets. He deployed to Kosovo and Bosnia. He was discharged in January 2002. All military audiograms from 1997 to 2001 recorded normal hearing (H1H1). He entered civilian employment and from 2008 worked as an offshore scaffolder, where strict hearing protection was required.
Subsequent medicolegal audiograms (2017, 2021, 2024) showed features consistent with noise-induced hearing loss in the left ear. Both ENT experts agreed that his tinnitus is attributable to military noise exposure; however, they disagreed fundamentally on whether any hearing loss was caused during military service.
Issues
The principal generic issues were:
● The appropriate diagnostic method for military NIHL (CLB vs rM-NIHL vs MLP(18))
● The reliability of military audiograms
● The appropriate dataset for age-associated hearing loss (ISO 7029:1984/2000 vs 2017/2024)
● Whether a baseline correction is required, and if so the extent of it
● The effect of TDH39P earphones at 6 kHz
● Sensitivity and specificity of diagnostic methods, and the role of Positive Predictive Value
● The appropriate method of quantifying NIHL
● The appropriate frequencies for assessing hearing disability (1, 2, 3 kHz vs 1, 2, 4 kHz)
● Whether NIHL can accelerate age-associated hearing loss after noise exposure ceases (latency/acceleration)
● Cochlear synaptopathy (‘hidden hearing loss’) and its medico-legal relevance
● Whether tinnitus arising after cessation of noise exposure can be attributed to it
● The de minimis threshold for actionable hearing loss
● General damages, hearing aids and loss of future earnings
Methods of assessment / Quantification
Diagnostic tools
Mr Justice Garnham noted the absence of any “gold standard” diagnostic measure for noise-induced hearing loss. The rM-NIHL method (Prof. Moore’s revised military NIHL method) was held to be the preferred diagnostic tool. The Coles, Lutman & Buffin (CLB) Guidelines (CLB method) is not generally suitable for military cases. Although all diagnostic methods are guidelines only; they require consideration of the whole clinical picture.
Sensitivity, Specificity and PPV
Little weight should be attached to either sensitivity or specificity figures, which should be treated as rough ‘ballpark’ estimates only. Positive Predictive Value (PPV) is a more useful indicator for judicial purposes, though even this is not determinative. A PPV greater than 0.5 does not, of itself, satisfy the balance of probabilities standard: statistics of prevalence alone cannot establish causation in an individual case (following Sienkiewicz v Grief [2011] 2 AC 229).
Audiograms
BSA-compliant Pure Tone Audiometry (PTA) is the gold standard audiometric testing and should be used in medico-legal cases as the best evidence whenever it is available. Military screening audiograms, while less reliable, are ordinarily suitable for screening and triage and, when forming a consistent pattern, may also be used for diagnostic and quantification purposes. They should be considered in context and as a whole. The majority of military audiograms are conducted properly and in good faith, though the court should remain alert to systemic or operational inadequacies.
Quantification. The Moore, Cox and Lowe method of quantification is to be preferred. In using that method (i) the choice of the percentile in the relevant dataset should be dictated by the clinical judgement of the medicolegal ENT surgeon based on the hearing of the individual ascertained from all the available audiometry; (ii) the conventional 1, 2, 3 kHz average should continue to serve as a baseline descriptor. However, it is entirely legitimate to consider supplementary metrics that incorporate 4 kHz, particularly where speech‑in‑noise difficulty is a prominent feature. (iii) NIHL should generally be quantified using the 4:1 binaural calculation. But where the excess loss calculation does not fully reflect the totality of the problems experienced by the Claimant, the clinician, and ultimately the Court, needs to identify and reflect the additional disability.
Latency and Acceleration
The theory that hearing loss may continue to develop after noise exposure ceases is intellectually coherent but a very long way from being proven in humans. The orthodox view – that hearing loss does not progress after exposure ceases – has not been displaced. Even if the theory were sufficiently plausible (which it is not at present), there is no mechanism by which any accelerated loss could be identified or quantified in an individual claimant.
Cochlear Synaptopathy
Cochlear synaptopathy cannot definitively be demonstrated, let alone quantified, in living humans. There is no gold standard diagnostic test. Proxy measures are imprecise and cannot disentangle noise-related from age-related synaptopathy. The evidence does not establish that synaptopathy caused any identifiable or quantifiable hearing disability in any individual claimant.
Causation/ General Damages
Tinnitus
No arbitrary cut-off point can be imposed beyond which tinnitus cannot be attributed to noise exposure. However, the closer the onset of tinnitus to the cessation of noise exposure, the more likely it is to be causally related. The greater the gap, the more intense should be the scrutiny of the individual’s circumstances and veracity.
De Minimis
A binaural hearing loss of less than 4 dB (on either a 1, 2, 3 kHz or 1, 2, 4 kHz average), without other consequences, should be regarded as de minimis. Whether noise exposure causing less than this threshold nevertheless causes appreciable damage will be determined on a case-by-case basis
General Damages
The Judicial College Guidelines are the appropriate starting point. The dB measure of NIHL is highly relevant but not determinative. The court will consider all circumstances, including age at onset, functional impact, presence of tinnitus, and the likelihood of age-related deterioration accelerating the disability.
Hearing Aids
The cost of private, high-performance rechargeable hearing aids may be recoverable. The claimant must prove an intention to obtain private rather than NHS provision. The current cost is in the region of £4,200–£5,000 per 5-year replacement cycle. Specific recommendations and ancillary equipment must be justified by the evidence in each individual case.
The Two Lead Cases
Mr Lambie – Findings
Liability was admitted subject to a 10% Matrix discount; quantification of NIHL was agreed at figures set by Mr Silva. Damages were assessed as follows:
● PSLA: £39,000 (severe NIHL without tinnitus; onset at age 21, reliant on hearing aids since age 31; falls at top of JCG 18th edition Chapter 5, section (B), (d) Partial Hearing Loss and/ or tinnitus, category (ii))
● Hearing aids: £27,350 (including cost of second Roger microphone)
● Loss of future earnings: £64,800 (Smith v Manchester award equivalent to 12 months’ composite net earnings (including pension); [LK1] Ogden Table approach was rejected as producing an obviously unrealistic result given consistent employment history and career trajectory).
In relation to loss of earnings, Mr Justice Garnham commented that
“851. It is the task of the judge on a claim such as this to carry out the appropriate individual evaluative judgement based on the evidence before the Court. In my view, where the Court has a detailed picture of the Claimant, the way his injuries have impacted on his ability to work in the past, the evidence as to his current and future prospects, and the likely impact of his disabilities on those prospects, then statistical information about the average performance of a class of persons of which he forms part may well provide a useful starting point or cross check. But it will not be common for those statistics wholly to displace judicial evaluation of the individual case.
852. In my view, Mr Lambie is disabled within the meaning of the Disability Discrimination Act 1995 but his case is far from the average, even an “adjusted” average. His case is not one where it is appropriate to apply the Ogden Tables, 8th Ed. Unlike, for example, Mr Barry, Mr Lambie has been able to pursue his chosen career throughout and will, in all probability, be able to do so until retirement. His disability has not, thus far, affected the career choices open to him or the earnings he has been able to make. His hearing loss is serious and progressive with age but, as things currently stand, he is not suffering any loss of earnings, nor will he if, as seems likely, he remains in his current employment until retirement.
853. To award a man in Mr Lambie’s position the sort of sum proposed by Mr Steinberg would, in my judgment, be unconscionable. His current net take home pay is about £60,000. Including bonus but excluding pension, the sum claimed for loss of future earning amounts to more than six times his current annual net salary. And that for a man who has not been unemployed for a single day since he was 18, who is in steady employment with a reputable employer, whose work in under no threat and in respect of which there is no evidence of any future likely threat, who is highly valued by his current employers and who wishes to stay in his current job until retirement.
854. What does require recognition, however, is first that were Mr Lambie to find himself on the open labour market, for whatever reason, then, despite his enviable employment record and the doubtless excellent references he would obtain from past employers, his NIHL would put him at a significant disadvantage in seeking alternative work. And second, the fact that his chances of achieving the two promotions that might have been available to him had he not suffered hearing loss are reduced. These are, in my view, uncertain considerations not capable of precise or even approximate calculation by a multiplicand-multiplier basis.
855. In my judgment, this is not an appropriate case for an award based either on an Odgen Table disabled reduction factor or based on a traditional multiplier/multiplicand basis. The appropriate remedy is an award of damages for loss of earning capacity, under the Smith v Manchester principle. In my view, an award equivalent to 12 months at his current earning rate would be appropriate.”
Mr Craggs – Findings
Liability was admitted subject to a 25% Matrix discount. Causation was in issue.
Hearing loss: The claim failed. Mr Craggs was found to be an unreliable witness whose evidence on hearing loss was evasive, inconsistent and contradicted by the documentary record (in particular, consistent H1H1 military audiograms and normal occupational health audiograms for many years post-service). The military audiograms were found to be broadly reliable when read as a series. The late-developing asymmetric hearing loss did not satisfy rM-NIHL on the audiometric evidence, and latency/acceleration arguments were rejected. The court was not satisfied on the balance of probabilities that hearing loss was caused during military service; idiopathic loss could not be excluded.
Tinnitus: The claim succeeded. Mr Craggs gave consistent and credible evidence about the onset of bilateral ringing tinnitus after returning from Kosovo (1999–2000). His mother corroborated this. Both ENT experts agreed tinnitus was noise-induced and attributable to military service. The tinnitus was graded as at the upper end of mild/lower end of moderate. Award: £19,000 PSLA, plus £445 for tinnitus counselling (3 sessions). No hearing aids awarded.
Comment
The judgment will bind all claimants and the defendant across the Hugh James cohort on the generic issues, and will provide important guidance for the 10,440 claims awaiting resolution, as well as other Military Noise Induced Hearing Claims outside of this particular cohort.
Outside the specific context of Military Noise Induced Hearing Claims, of wider relevance to other industrial hearing loss claims is the finding that tinnitus claims may succeed even where the linked hearing loss claim fails, provided onset is proved and attributable to noise exposure.
Of more general application to personal injury/clinical negligence claims is Mr Justice Garnham’s reminder that the Ogden Table approach to future earnings loss may be displaced where the result would be obviously unrealistic and that a Smith v Manchester award may be appropriate even for a claimant who is technically ‘disabled’.
Other points of wider relevance are
- The use of ‘expert hottubbing’ (i.e. experts being called concurrently) – albeit only for one of the sets of experts
- The production of an agreed ‘judicial primer’ from the core ENT experts that was designed as an introduction for a non-specialist Court to the relevant science in highly complex case. The two experts then spoke to that joint report and answered questions in open Court and in the presence of the parties’ counsel before the commencement of the evidence. This was held to be “an invaluable exercise, providing an essential grounding in some of the basic concepts and the relevant topics.” The primer was subsequently admitted into evidence.
- Mr Justice Garnham’s comment that in future group litigation in disease cases, particularly those with a greater number of test cases, it would be essential that adequate provision is made in the timetable not only for the consideration of each test case and each generic issue, but also for breaks to enable the parties to present the evidence properly and for the Court to analyse it as the matter proceeds. There will be cases where an issue-by-issue process, with submissions and rulings on each, might prove most advantageous.
