Noise-Induced Hearing Loss (NIHL): A Guide for Serving Personnel and Veterans

For members of the Armed Forces, that exposure can be very different from ordinary workplace noise. It can include repeated weapons fire, artillery, explosions, aircraft, helicopters, armoured vehicles, machinery, engines and other intense military sound.

Some people notice a problem immediately. For others, hearing difficulty becomes obvious only gradually — sometimes years later, when existing noise damage combines with hearing changes associated with ageing.

This guide explains what NIHL is, how noise damages hearing, the symptoms people commonly notice, how military NIHL is investigated and what a hearing test can — and cannot — establish.

The short version

• NIHL is hearing damage caused by excessive noise.
• It usually affects the inner ear and is a form of sensorineural hearing loss.
• Permanent NIHL cannot currently be reversed.
• Damage can result from repeated exposure over time or very intense impulsive noise.
• Weapons fire, explosions, aircraft, helicopters, armoured vehicles and machinery can all create potentially hazardous military noise.
• Tinnitus can occur alongside NIHL, but tinnitus and hearing loss are not the same condition.
• NIHL often affects higher frequencies first, but there is no single audiogram shape that proves military NIHL.
• A traditional 4 kHz "noise notch" can be relevant, but its absence does not automatically exclude military NIHL.
• Historic military audiograms can be useful evidence when considered as part of a series.
• Age-related hearing loss and NIHL can exist in the same person.
• Current evidence does not establish that the original noise injury itself continues progressing after the harmful noise exposure has ended.
• A proper assessment considers the audiogram alongside the person's history, noise exposure, symptoms and possible alternative causes.

What is noise-induced hearing loss?

Sound reaches the inner ear through a chain of structures beginning with the outer and middle ear.

Inside the inner ear is the cochlea. It contains specialised sensory cells, commonly referred to as hair cells, that help convert sound vibrations into electrical signals. Those signals are carried through the auditory system and interpreted by the brain as sound.

Excessive noise can damage these delicate structures.

If that damage becomes permanent, the result may be noise-induced hearing loss.

NIHL is therefore generally a form of sensorineural hearing loss — hearing loss arising from damage within the inner ear or associated auditory structures, rather than a simple blockage preventing sound from reaching the inner ear.

Is noise-induced hearing loss permanent?

Permanent NIHL is irreversible.

Damaged cochlear hair cells do not simply regenerate once the person leaves the noisy environment.

That does not mean nothing can be done.

Hearing aids, assistive listening equipment, communication strategies and appropriate audiological care can substantially improve how some people manage their hearing loss.

But these measures manage the consequences of hearing damage; they do not restore damaged inner-ear structures to their original condition.

Can loud noise cause temporary hearing loss?

Yes.

After exposure to loud noise, someone may temporarily notice:

• muffled hearing;
• dulled sound;
• ringing or buzzing;
• a feeling that hearing is less sharp than usual.

Hearing may then appear to recover.

This is sometimes described as a temporary threshold shift.

Temporary recovery should not be taken to mean the noise was safe. UK health and safety guidance treats temporary deafness or muffled hearing after noise exposure as a warning that continued exposure may result in permanent damage.

Repeated or sufficiently severe exposure can produce a permanent threshold shift instead.

Does NIHL happen gradually or suddenly?

Both patterns can occur, although they should not always be treated as medically identical.

Repeated noise exposure

Someone exposed repeatedly to excessive noise over months or years may develop gradual permanent hearing damage.

The person may not notice the change while it is happening.

Very intense sound

A single extremely loud event can also injure hearing.

Military examples include:

• explosions;
• blast;
• weapons fire at close range; and
• other intense impulse noise.

A sudden injury from a particular high-intensity sound is often discussed as acute acoustic trauma.

We explain that separately because a one-off acoustic injury can raise different medical questions from hearing loss associated with cumulative exposure over many years.

Why is military noise different?

Military service can involve both continuous noise and impulse noise.

The Ministry of Defence has itself described two broad military hearing hazards:

• sustained noise associated with sources such as machinery, helicopters and armoured vehicles; and
• high-intensity impulse noise from weapons, explosive devices and other percussive sounds.

Modern MOD noise policy also specifically treats weapons firing and explosions as examples of peak-noise hazards.

This matters because a soldier, sailor, airman or Marine may have had a very different exposure history from somebody who spent their career beside one industrial machine operating at a relatively stable noise level.

A military hearing assessment therefore needs to consider what the person actually did.

Examples of military noise exposure

Potential military sources include:

Weapons

• rifles;
• machine guns;
• pistols;
• heavy weapons;
• live-fire exercises;
• repeated range exposure.

Explosions and blast

• explosive devices;
• demolitions;
• grenades;
• mortars;
• artillery;
• operational blast exposure.

Vehicles

• tanks;
• tracked armoured vehicles;
• personnel carriers;
• engineering vehicles;
• high-noise vehicle interiors.

Aviation

• fast jets;
• helicopters;
• transport aircraft;
• aircraft ground operations;
• flight-line work.

Ships and engineering environments

• engine rooms;
• machinery spaces;
• generators;
• mechanical and engineering equipment.

The fact that a source is capable of producing harmful noise does not prove that it caused hearing loss in a particular person. The intensity, duration, frequency and pattern of exposure all matter.

What are the symptoms of NIHL?

People do not all experience hearing loss in the same way.

Possible signs include:

• difficulty following conversation;
• needing people to repeat themselves;
• struggling to hear speech when several people are talking;
• difficulty understanding speech in restaurants, pubs or other noisy places;
• turning the television or radio louder;
• difficulty hearing certain higher-pitched sounds;
• feeling that people are mumbling;
• hearing a voice but not clearly understanding the words;
• relying more heavily on lip-reading or visual cues;
• difficulty locating where sounds are coming from;
• tinnitus.

A person can also have measurable hearing loss without appreciating how much their hearing has changed.

Why can I hear someone speaking but not understand the words?

Hearing is not simply a question of whether sound is loud enough.

Some forms of hearing loss affect certain frequencies more than others. Important speech information may therefore become less distinct even though the voice itself remains audible.

This can produce a common complaint:

"I can hear people talking, but I can't make out what they're saying."

Background noise can make this much worse.

NICE specifically recognises that people can have listening difficulties — including problems hearing in noisy environments — that are not fully obvious from the audiogram alone.

That is one reason a proper hearing assessment involves more than simply reading a number from a chart.

Does NIHL cause tinnitus?

Noise exposure can be associated with both hearing loss and tinnitus.

Tinnitus means hearing a sound that does not come from an external sound source. It may be described as:

• ringing;
• buzzing;
• humming;
• hissing;
• whistling;
• another persistent or intermittent sound.

Tinnitus can occur with NIHL, but the two terms are not interchangeable.

A person may have hearing loss without troublesome tinnitus.

A person may also report tinnitus even when conventional hearing testing does not demonstrate the type or degree of hearing loss someone might expect.

For that reason, tinnitus requires its own assessment rather than being treated simply as another name for deafness.

Is military NIHL always in both ears?

No.

Many noise-exposure patterns may produce broadly bilateral hearing loss, but symmetry cannot simply be assumed.

Military exposure may sometimes be uneven.

The position of a weapon, the person's role, the direction of a noise source, vehicle or aircraft position, hearing protection and other circumstances can potentially produce different exposure between the ears.

Significant asymmetry can also have causes unrelated to noise exposure and may require further clinical investigation.

An asymmetric audiogram should therefore be interpreted medically rather than being treated automatically as either proof of or evidence against military NIHL.

What does NIHL look like on an audiogram?

There is no single audiogram shape that proves NIHL.

Noise damage commonly affects higher frequencies, and traditional descriptions of occupational NIHL often refer to an audiometric notch, particularly around 4 kHz.

But military NIHL is more complicated than:

notch = NIHL

or

no notch = no NIHL.

The High Court examined this issue in detail in [Abbott v Ministry of Defence [2026] EWHC 941 (KB)](/cases/abbott-v-mod-2026/).

The Court ultimately preferred the rM-NIHL diagnostic method for military NIHL and concluded that the older CLB guidelines are not generally suitable for military cases.

That is important because military exposure can involve high-intensity impulsive sound and audiometric patterns that do not fit neatly into the traditional industrial-noise model.

An audiogram therefore needs to be interpreted in the context of the person's full history.

What is a 4 kHz notch?

An audiogram tests hearing across a range of sound frequencies.

A "notch" describes a pattern where hearing thresholds become poorer over part of the higher-frequency range and then improve again at a still higher frequency.

The classic occupational-noise discussion often focuses on a notch around 4 kHz.

A notch can be relevant evidence of noise exposure.

It is not a diagnostic stamp.

Its presence does not prove that the MOD caused somebody's hearing loss, and its absence does not automatically rule military NIHL out.

The interpretation becomes particularly important in military cases because the type of noise involved may differ materially from ordinary civilian industrial exposure.

Our guide to how to read a military audiogram explains frequencies, decibels, thresholds and notches in more detail.

What is rM-NIHL?

rM-NIHL is a diagnostic method developed specifically for assessing military noise-induced hearing loss.

In Abbott, the High Court concluded that rM-NIHL was the diagnostic method to be preferred for military NIHL.

That does not make it an online eligibility test.

Medical diagnosis still requires clinical judgement and consideration of the whole evidence.

Our guide to what rM-NIHL is explains the method, its limitations by age and sex, and the 2026 research proposing a different method for men aged 61–80.

Are old military hearing tests useful?

Potentially, yes.

Many serving personnel undergo screening audiometry as part of hearing surveillance. The result may be recorded against a PULHHEEMS hearing grade, which describes hearing acuity rather than diagnosing anything.

Military screening audiograms were not generally produced for litigation. Their purpose is principally health surveillance and identification of personnel who may require further assessment.

That does not make them worthless evidence.

Abbott concluded that military audiograms can be used where they form part of a consistent pattern and are assessed as part of proper clinical judgement.

A modern diagnostic audiogram conducted to appropriate standards will generally be stronger evidence of current hearing ability, but historic tests can help show what happened over time.

Useful records might include:

• entry or enlistment audiograms;
• periodic service hearing tests;
• hearing-conservation records;
• medical referrals;
• discharge audiograms;
• civilian occupational hearing tests after service;
• later NHS or private audiograms.

Ideally, the tests are considered as a series, not by selecting one result in isolation.

What if my military hearing tests were normal?

A historic test described as "normal" should be considered carefully rather than treated as a complete answer by itself.

Questions may include:

• which frequencies were tested;
• whether the test conditions were appropriate;
• whether there are several tests showing a consistent pattern;
• when the test occurred relative to the alleged harmful exposure;
• what later tests show;
• whether the person was still being exposed to noise;
• what the complete medical history shows.

Conversely, somebody should not assume that a later abnormal audiogram proves earlier military noise caused the loss.

Both conclusions require evidence.

Can hearing loss appear years after leaving the Armed Forces?

This question needs careful wording.

A veteran may notice hearing problems long after the harmful military noise ended.

That does not necessarily mean the original noise injury suddenly developed years later.

Existing damage can become more noticeable when:

• communication demands change;
• the person enters a different working environment;
• their hearing is tested properly for the first time;
• age-related hearing changes develop as well.

The distinction is important.

Does NIHL keep getting worse after noise exposure ends?

The current legal and medical position adopted in Abbott is that the theory of continuing progression after noise exposure ends is scientifically plausible but has not been established in humans.

The Court concluded that the orthodox view has not been displaced: the original noise-induced injury itself is not proven to continue progressing after the harmful exposure ceases.

However, a person's overall hearing can still worsen.

Someone may have permanent noise damage and later develop additional age-associated hearing loss or another hearing condition.

So:

"My hearing is worse now than when I left"

does not necessarily mean:

"The military noise injury has continued damaging my ears every year since discharge."

Those are different propositions.

NIHL and age-related hearing loss

Age-related hearing loss is often called presbycusis.

It is extremely important not to treat NIHL and ageing as mutually exclusive.

A person can have both.

HSE specifically notes that people may only appreciate how impaired their hearing has become when earlier noise damage combines with hearing loss associated with ageing.

For an individual veteran, the medical question may therefore be how much of the present hearing loss is attributable to:

• noise;
• age;
• another medical condition;
• later occupational or recreational exposure;
• or a combination of factors.

There is no reliable rule that allows a website to calculate that simply from a person's age.

What else can cause hearing loss?

Not every hearing problem in a veteran is military NIHL.

Possible causes of hearing difficulty include:

• age-associated hearing loss;
• earwax;
• ear infection;
• perforated eardrum;
• middle-ear disease;
• Ménière's disease;
• certain medicines;
• head or ear injury;
• other neurological or medical conditions;
• later occupational noise;
• recreational noise exposure.

Some are temporary or treatable.

Others are permanent.

That is why self-diagnosing NIHL from symptoms alone is unsafe.

What is sensorineural hearing loss?

Sensorineural hearing loss arises from damage affecting the inner ear or associated auditory pathways.

Noise damage is one possible cause.

Ageing is another.

Sensorineural hearing loss differs from conductive hearing loss, where sound is being prevented from travelling normally through the outer or middle ear — for example because of certain ear conditions or obstruction.

Someone can also have mixed hearing loss, involving both sensorineural and conductive components.

A hearing assessment helps distinguish between these possibilities.

How is suspected NIHL assessed?

There is no single test that answers every question.

An assessment may include:

Medical and hearing history

This can cover:

• when hearing difficulty was first noticed;
• whether one or both ears are affected;
• tinnitus;
• previous ear disease;
• medication;
• head or ear injuries;
• military noise;
• civilian occupational noise;
• recreational noise;
• hearing protection;
• family history.

Examination of the ears

This can help identify issues such as wax, infection or other visible problems that may affect hearing.

Pure-tone audiometry

This measures the quietest sounds a person can detect across different frequencies.

The results are plotted on an audiogram.

Other audiological tests

Depending on the circumstances, an audiologist or doctor may use other tests to investigate middle-ear function, speech understanding or another suspected condition.

For suspected military NIHL, the clinician may also need to review historic audiograms and the pattern of service exposure.

Does an audiogram prove what caused hearing loss?

No.

An audiogram measures hearing thresholds.

It does not contain a label saying:

"MOD caused this."

It may display features that support or weaken a particular diagnosis, but causation involves the complete clinical picture.

That can include:

• the pattern and degree of hearing loss;
• military noise history;
• timing;
• historic audiograms;
• later audiograms;
• age;
• other noise exposure;
• medical history;
• tinnitus;
• alternative diagnoses.

This distinction matters particularly in compensation claims.

Can family members notice hearing loss before the person does?

Yes.

Hearing changes can develop gradually, and someone may adapt without consciously recognising the extent of the problem.

Family members or colleagues may notice things such as:

• repeatedly being asked to speak up;
• the television becoming louder;
• missed parts of conversations;
• difficulty in groups;
• misunderstanding words;
• greater reliance on seeing the speaker's face.

These observations do not diagnose NIHL, but they can help describe how hearing difficulty has affected everyday life.

Can NIHL be cured?

There is currently no treatment that reverses established permanent NIHL.

Management may include:

• hearing aids;
• communication strategies;
• assistive listening devices;
• workplace adjustments;
• tinnitus support where relevant;
• ongoing audiology care.

NICE recommends discussing an individual's communication needs as well as the audiogram itself when planning hearing-loss management.

Do hearing aids help NIHL?

They can help many people.

A hearing aid does not restore normal biological hearing. It processes and amplifies sound to make useful information easier to hear.

How much benefit someone receives can depend on:

• the type and degree of hearing loss;
• frequencies affected;
• the listening environment;
• hearing-aid fitting;
• the technology being used;
• the individual's needs.

The appropriate hearing solution should therefore be based on an audiological assessment rather than simply buying the most expensive device available.

When should I get my hearing tested?

If you think your hearing is gradually getting worse, NHS guidance recommends seeing a GP or arranging an appropriate hearing assessment.

A free NHS hearing test may be available following referral.

You do not need to be considering a compensation claim before having your hearing investigated.

Your health comes first.

When is hearing loss urgent?

Do not assume sudden hearing loss is NIHL or wait for a claims assessment.

Does wearing hearing protection mean military noise could not have caused NIHL?

Not necessarily.

Hearing protection is important and can substantially reduce exposure when it is appropriate, correctly fitted and consistently worn.

But the existence of issued ear protection does not by itself establish:

• what level of noise reached the ear;
• whether the equipment was suitable for the task;
• whether it fitted correctly;
• whether it was worn at every relevant moment;
• whether communications or operational requirements affected its use;
• whether harmful exposure had already occurred.

Equally, a person should not assume that simply remembering occasions without hearing protection proves that military service caused their present hearing loss.

The actual exposure and medical evidence matter.

Does having NIHL mean I have a compensation claim?

No.

A medical diagnosis and a legal claim are different questions.

Someone can have NIHL without having a viable civil claim against the Ministry of Defence.

A civil military hearing-loss claim can involve additional issues such as:

• when the relevant exposure occurred;
• whether the MOD owed and breached the relevant duty;
• Crown immunity;
• combat immunity where applicable;
• limitation;
• causation;
• contributory negligence;
• later noise exposure;
• the degree of injury and loss.

There are also separate no-fault routes such as the Armed Forces Compensation Scheme and War Pension Scheme.

Those schemes have their own eligibility rules and are not the same as suing the MOD in a civil claim.

Does Abbott mean everybody with military NIHL can claim?

No.

Abbott v Ministry of Defence [2026] EWHC 941 (KB) resolved important generic medical and evidential questions arising in military hearing litigation.

It did not decide that every veteran exposed to military noise has NIHL, nor that every veteran diagnosed with NIHL has a viable civil claim.

Individual causation and eligibility still depend on individual evidence.

Read our full Abbott v Ministry of Defence (2026) guide for the findings and their limitations.

Frequently asked questions