What causes hearing loss
Causes
Hearing loss has many causes, and they behave differently
Some causes are temporary and some are permanent. Some affect one ear and some affect both. Knowing which one is involved is what determines everything that follows — which is why a hearing test looks at the ear as well as measuring it.
Ageing
Health New Zealand describes ageing as the most common cause of gradual hearing loss in adults. It usually affects both ears, and typically affects high-pitched sounds first.
That pattern explains a lot of what people report. Because the high pitches carry the detail in speech rather than the volume, conversation can become hard to follow before it becomes hard to hear.
Noise
Exposure to loud sound over a long period is a well-established cause. Health New Zealand offers a practical rule of thumb: if a sound is loud enough that you have to shout to be heard by someone standing a metre away, it is too loud.
In New Zealand, workplace noise is regulated, and WorkSafe publishes guidance on exposure and control. Loud hobbies count too — machinery, shooting, motorsport and amplified music all sit in the same territory.
Wax and fluid
Both are conductive causes: they interrupt sound on its way in, while the inner ear carries on working normally underneath.
A build-up of wax in the ear canal is extremely common and is one of the first things checked. Fluid behind the eardrum is also common, particularly in children.
These matter because they can change — which is why nobody should assume a blocked-sounding ear is permanent.
Illness, medicines and injury
A range of conditions can affect hearing, including infections of the ear and some illnesses affecting the body more generally. The New Zealand Audiological Society also publishes information on the relationship between diabetes and hearing.
Some medicines can affect hearing or balance. If you have been prescribed something and notice a change in your hearing or new ringing in your ears, that is worth raising with whoever prescribed it rather than waiting.
Head injury and sudden pressure changes can also be involved.
Present from birth, or inherited
Some hearing loss is present at birth or develops in childhood, and some runs in families. In New Zealand, newborn hearing screening is offered so that hearing differences can be identified early.
See hearing loss in children for how this works.
Sometimes no cause is found
Health New Zealand is explicit that sometimes we do not know why hearing loss happens. That can be unsatisfying, but it does not prevent anything — the measurement still shows where your hearing sits, and the options still follow from that rather than from the cause.
Which causes can change?
A rough guide, not a substitute for having your own ears looked at.
| Cause | Type | Can it change? |
|---|---|---|
| Wax in the ear canal | Conductive | Often — it can be removed |
| Fluid behind the eardrum | Conductive | Often — it may clear or be treated |
| Ear infection | Conductive | Usually treatable; see a healthcare provider |
| Age-related inner ear change | Sensorineural | Generally permanent |
| Long-term noise exposure | Sensorineural | Generally permanent |
| Present from birth or inherited | Varies | Depends entirely on the cause |
Common questions about causes
Can loud music cause permanent hearing loss?
Exposure to loud sound over time is a recognised cause of permanent hearing loss, and amplified music sits in the same category as machinery and other loud environments. The practical test Health New Zealand suggests is simple: if you have to shout to be heard by someone a metre away, it is too loud.
Does earwax really affect hearing?
It can, when there is enough of it to block the canal. It is a conductive cause, so the inner ear may be working perfectly well behind it. It is also one of the easiest things to check, which is why anyone looks in your ear before drawing conclusions.
Is hearing loss hereditary?
Some hearing loss runs in families and some is present from birth. Many other causes have nothing to do with family history at all. If hearing loss is common in your family, that is useful information to mention when you have your hearing tested.
Can medicines affect my hearing?
Some medicines can affect hearing or balance. If you notice a change in your hearing, or new ringing in your ears, after starting a medicine, raise it with whoever prescribed it rather than stopping on your own.
Why can no cause be found sometimes?
Health New Zealand notes plainly that sometimes we do not know why hearing loss happens. Hearing is a long chain from the outer ear to the brain, and not every change in it leaves something visible or testable.
If you want your own hearing checked
Book a hearing appointment
This page is general information. A hearing test measures your own hearing and is the only way to know where yours sits.
Sources
- Health New Zealand — Hearing loss in adults
- NZAS — What causes hearing loss?
- NZAS — Noise and hearing protection
- WorkSafe New Zealand — Noise
- World Health Organization — Deafness and hearing loss — fact sheet
This page is general information, not a diagnosis or individual advice.
Hearing with Heart
Audiology & Ear Hygiene
Unit 34, The Acres,
Halswell, Christchurch 8025,
New Zealand